/**
 * accounting-view.js
 *
 * Phase 1: Accounts Overview, Register, Reports
 * Phase 2 Lieferung 2: Expenses-Section + Auto-Sync-on-First-Open-of-Day
 */

import '../utils/api.js';
import { formatDate } from '../utils/helpers.js';
import { openExpenseModal } from '../modals/expense-modal.js';
import { openRefundModal } from '../modals/refund-modal.js';

// ────────────────────────────────────────────────────────────────────
// State (modul-lokal)
// ────────────────────────────────────────────────────────────────────

let allAccounts = [];
let registerAccountId = null;
let registerStartDate = null;
let registerEndDate = null;
let registerLoadSeq = 0;

let plStartDate = null;
let plEndDate = null;
let plAccountingMethod = 'Accrual';

let bsAsOfDate = null;
let bsAccountingMethod = 'Accrual';

let tsMonth = null; // 'YYYY-MM' — selected month for tax summary
let tsAccountingMethod = 'Accrual';

let crStartDate = null;
let crEndDate = null;

let stPeriods = [];
let stEditingPeriodId = null;  // current period in detail dialog, null = new
let stAccounts = [];           // cached account list for pickers

let expStartDate = null;
let expEndDate = null;
let expOnlyMine = false;

// Auto-Sync nur einmal pro View-Mount
let autoSyncDoneThisOpen = false;

// ────────────────────────────────────────────────────────────────────
// Helpers
// ────────────────────────────────────────────────────────────────────

function fmtMoney(n) {
    if (n == null || isNaN(n)) return '';
    return n.toLocaleString('en-US', {
        style: 'currency', currency: 'USD',
        minimumFractionDigits: 2, maximumFractionDigits: 2
    });
}

function todayISO() { return new Date().toISOString().split('T')[0]; }
function firstOfMonthISO(year, month) {
    const d = year != null ? new Date(year, month, 1) : new Date();
    return year != null ? d.toISOString().split('T')[0] : new Date(d.getFullYear(), d.getMonth(), 1).toISOString().split('T')[0];
}
function lastOfMonthISO(year, month) {
    const d = year != null ? new Date(year, month + 1, 0) : new Date();
    return year != null ? d.toISOString().split('T')[0] : new Date(d.getFullYear(), d.getMonth() + 1, 0).toISOString().split('T')[0];
}
function prevMonthISO() {
    const d = new Date();
    const m = d.getMonth() === 0 ? 11 : d.getMonth() - 1;
    const y = d.getMonth() === 0 ? d.getFullYear() - 1 : d.getFullYear();
    return `${y}-${String(m + 1).padStart(2, '0')}`;
}
function firstOfYearISO() {
    const d = new Date();
    return new Date(d.getFullYear(), 0, 1).toISOString().split('T')[0];
}

function escapeHtml(s) {
    if (s == null) return '';
    return String(s)
        .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;').replace(/'/g, '&#39;');
}

function showError(slotId, message) {
    const el = document.getElementById(slotId);
    if (!el) return;
    el.innerHTML = `
        <div class="p-4 bg-red-50 border border-red-200 rounded-lg">
            <p class="font-semibold text-red-800">QBO Error</p>
            <p class="text-sm text-red-600 mt-1">${escapeHtml(message)}</p>
        </div>`;
}

function showLoading(slotId, message = 'Loading…') {
    const el = document.getElementById(slotId);
    if (!el) return;
    el.innerHTML = `
        <div class="flex items-center gap-3 p-4 text-gray-500">
            <svg class="animate-spin h-5 w-5 text-blue-600" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24">
                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"></path>
            </svg>
            <span>${escapeHtml(message)}</span>
        </div>`;
}
function makeCollapsible(headerText, contentId, startCollapsed = false) {
    return `
        <div class="flex items-center gap-2 cursor-pointer select-none mb-2" 
             onclick="window.accountingView.toggleSection('${contentId}', this)">
            <svg class="w-4 h-4 text-gray-500 transition-transform ${startCollapsed ? '' : 'rotate-90'}" 
                 fill="none" viewBox="0 0 24 24" stroke="currentColor">
                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" />
            </svg>
            <h3 class="text-base font-semibold text-gray-800">${escapeHtml(headerText)}</h3>
        </div>`;
}

export function toggleSection(contentId, headerEl) {
    const content = document.getElementById(contentId);
    if (!content) return;
    const isHidden = content.classList.toggle('hidden');
    const arrow = headerEl.querySelector('svg');
    if (arrow) arrow.classList.toggle('rotate-90', !isHidden);
}
// ────────────────────────────────────────────────────────────────────
// Toolbar
// ────────────────────────────────────────────────────────────────────

export function injectToolbar() {
    const c = document.getElementById('accounting-toolbar');
    if (!c) return;
    c.innerHTML = `
        <div class="flex items-center gap-3 mb-4 p-4 bg-white rounded-lg shadow-sm border border-gray-200">
            <h2 class="text-lg font-semibold text-gray-800">Accounting</h2>
            <span class="text-sm text-gray-400">read-only registers · expense entry</span>
            <div class="ml-auto flex items-center gap-2">
                <span id="accounting-sync-status" class="text-xs text-gray-500"></span>
                <button onclick="window.accountingView.manualSync()"
                    class="px-3 py-1.5 bg-gray-100 hover:bg-gray-200 text-gray-700 rounded-md text-sm font-medium border border-gray-300">
                    🔄 Sync from QBO
                </button>
                <button onclick="window.accountingView.refreshAll()"
                    class="px-3 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">
                    ↻ Refresh
                </button>
            </div>
        </div>`;
}

// ────────────────────────────────────────────────────────────────────
// Auto-Sync beim ersten Öffnen des Tages
// ────────────────────────────────────────────────────────────────────

async function maybeAutoSyncCaches() {
    if (autoSyncDoneThisOpen) return;
    autoSyncDoneThisOpen = true;

    try {
        const status = await window.API.accounting.getSyncStatus();
        const accStale = status.accounts && status.accounts.staleToday;
        const venStale = status.vendors  && status.vendors.staleToday;

        if (!accStale && !venStale) {
            updateSyncStatusBadge(status);
            return;
        }

        const syncBadge = document.getElementById('accounting-sync-status');
        if (syncBadge) syncBadge.textContent = '🔄 Syncing caches…';

        const tasks = [];
        if (accStale) tasks.push(window.API.accounting.syncAccounts());
        if (venStale) tasks.push(window.API.accounting.syncVendors());
        await Promise.all(tasks);

        const newStatus = await window.API.accounting.getSyncStatus();
        updateSyncStatusBadge(newStatus);
        console.log('✅ Auto-synced QBO caches (first open of day)');
    } catch (err) {
        console.warn('Auto-sync failed:', err.message);
        const syncBadge = document.getElementById('accounting-sync-status');
        if (syncBadge) syncBadge.textContent = '⚠️ Sync failed';
    }
}

export async function manualSync() {
    const syncBadge = document.getElementById('accounting-sync-status');
    if (syncBadge) syncBadge.textContent = '🔄 Syncing…';
    try {
        await Promise.all([
            window.API.accounting.syncAccounts(),
            window.API.accounting.syncVendors()
        ]);
        const status = await window.API.accounting.getSyncStatus();
        updateSyncStatusBadge(status);
    } catch (err) {
        if (syncBadge) syncBadge.textContent = '⚠️ Sync failed';
        alert('Sync failed: ' + err.message);
    }
}

function updateSyncStatusBadge(status) {
    const el = document.getElementById('accounting-sync-status');
    if (!el) return;
    const a = status.accounts;
    const v = status.vendors;
    if (a?.last_synced_at && v?.last_synced_at) {
        const aTime = new Date(a.last_synced_at).toLocaleTimeString('en-US', { hour: '2-digit', minute: '2-digit' });
        el.innerHTML = `Synced @ ${aTime} · ${a.last_sync_count} accts · ${v.last_sync_count} vendors`;
    } else {
        el.textContent = 'Not yet synced';
    }
}

// ────────────────────────────────────────────────────────────────────
// Accounts Overview
// ────────────────────────────────────────────────────────────────────

export async function loadAccountsOverview() {
    const slot = 'accounting-accounts';
    showLoading(slot, 'Loading accounts from QBO…');

    try {
        const accounts = await window.API.accounting.getAccounts(null, true);
        if (accounts.error) return showError(slot, accounts.error);

        allAccounts = accounts;
        const cards = accounts.filter(a => a.accountType === 'Bank' || a.accountType === 'Credit Card');

        const el = document.getElementById(slot);
        if (!cards.length) {
            el.innerHTML = `<div class="p-4 bg-gray-50 border border-gray-200 rounded-lg text-gray-600">No bank or credit card accounts found.</div>`;
        } else {
            el.innerHTML = `<div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">${cards.map(renderAccountCard).join('')}</div>`;
        }

        populateRegisterAccountDropdown(cards);
    } catch (err) {
        console.error('Accounts load failed:', err);
        showError(slot, err.message || 'Failed to load accounts');
    }
}

function renderAccountCard(a) {
    const isBank = a.accountType === 'Bank';
    const accent = isBank ? 'border-blue-200 bg-blue-50' : 'border-purple-200 bg-purple-50';
    const label  = isBank ? 'Bank' : 'Credit Card';
    const labelColor = isBank ? 'text-blue-700' : 'text-purple-700';
    const balText = a.currentBalance != null ? fmtMoney(a.currentBalance) : '—';
    return `
        <div class="rounded-lg border ${accent} p-4 cursor-pointer hover:shadow-md transition"
             onclick="window.accountingView.selectRegisterAccount('${a.id}')">
            <div class="flex items-center justify-between mb-1">
                <span class="text-xs font-semibold uppercase tracking-wide ${labelColor}">${label}</span>
                <span class="text-xs text-gray-400">#${a.id}</span>
            </div>
            <div class="text-base font-semibold text-gray-900 mb-2">${escapeHtml(a.name)}</div>
            <div class="text-2xl font-bold text-gray-900">${balText}</div>
            ${a.accountSubType ? `<div class="text-xs text-gray-500 mt-1">${escapeHtml(a.accountSubType)}</div>` : ''}
        </div>`;
}

// ────────────────────────────────────────────────────────────────────
// Register
// ────────────────────────────────────────────────────────────────────

function populateRegisterAccountDropdown(bankCardAccounts) {
    const sel = document.getElementById('reg-account');
    if (!sel) return;
    const current = registerAccountId || sel.value;
    sel.innerHTML = `<option value="">— Select account —</option>` +
        bankCardAccounts.map(a => `<option value="${a.id}">${escapeHtml(a.name)} (${a.accountType})</option>`).join('');
    if (current && bankCardAccounts.find(a => a.id === current)) sel.value = current;
}

export function injectRegisterControls() {
    const c = document.getElementById('accounting-register-controls');
    if (!c) return;
    if (!registerStartDate) registerStartDate = firstOfMonthISO();
    if (!registerEndDate)   registerEndDate   = todayISO();

    c.innerHTML = `
        ${makeCollapsible('Register', 'register-section-body')}
        <div id="register-section-body">
            <div class="flex flex-wrap items-end gap-3 mb-3 p-4 bg-white rounded-lg shadow-sm border border-gray-200">
                <div>
                    <label class="block text-xs font-medium text-gray-700 mb-1">Account</label>
                    <select id="reg-account" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm w-72">
                        <option value="">— Loading accounts —</option>
                    </select>
                </div>
                <div>
                    <label class="block text-xs font-medium text-gray-700 mb-1">Start Date</label>
                    <input type="date" id="reg-start" value="${registerStartDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                </div>
                <div>
                    <label class="block text-xs font-medium text-gray-700 mb-1">End Date</label>
                    <input type="date" id="reg-end" value="${registerEndDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                </div>
                <button onclick="window.accountingView.loadRegister()"
                        class="px-4 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">
                    Load Register
                </button>
            </div>
            <div id="accounting-register-table"></div>
        </div>`;
}

export function selectRegisterAccount(accountId) {
    registerAccountId = accountId;
    const sel = document.getElementById('reg-account');
    if (sel) sel.value = accountId;
    loadRegister();
}

export async function loadRegister() {
    const sel   = document.getElementById('reg-account');
    const start = document.getElementById('reg-start');
    const end   = document.getElementById('reg-end');

    if (!sel || !sel.value) {
        const slot = document.getElementById('accounting-register-table');
        if (slot) slot.innerHTML = `<p class="text-sm text-gray-500 px-4 py-3">Select an account to view the register.</p>`;
        return;
    }

    registerAccountId = sel.value;
    registerStartDate = start.value;
    registerEndDate   = end.value;

    const slot = 'accounting-register-table';
    showLoading(slot, 'Loading register from QBO…');
    const mySeq = ++registerLoadSeq;

    try {
        const result = await window.API.accounting.getRegister(registerAccountId, registerStartDate, registerEndDate);
        if (mySeq !== registerLoadSeq) return;
        if (result.error) return showError(slot, result.error);
        renderRegisterTable(result);
    } catch (err) {
        if (mySeq !== registerLoadSeq) return;
        console.error('Register load failed:', err);
        showError(slot, err.message || 'Failed to load register');
    }
}

function renderRegisterTable(result) {
    const el = document.getElementById('accounting-register-table');
    if (!el) return;

    let rows = (result.rows || []).slice().sort((a, b) => (b.date || '').localeCompare(a.date || ''));
    const meta = result.meta || {};

    if (!rows.length) {
        el.innerHTML = `<div class="p-4 bg-gray-50 border border-gray-200 rounded-lg text-gray-600">No transactions in selected range.</div>`;
        return;
    }

    const tbody = rows.map(renderRegisterRow).join('');
    el.innerHTML = `
        <div class="bg-white rounded-lg shadow-sm border border-gray-200 overflow-hidden">
            <div class="px-4 py-2 border-b bg-gray-50 flex items-center justify-between">
                <div class="text-xs text-gray-500">
                    ${escapeHtml(meta.reportName || 'Transaction List')}
                    ${meta.startPeriod ? '— ' + escapeHtml(meta.startPeriod) : ''}
                    ${meta.endPeriod ? ' to ' + escapeHtml(meta.endPeriod) : ''}
                </div>
                <div class="text-sm font-semibold text-gray-700">
                    ${rows.length} ${rows.length === 1 ? 'transaction' : 'transactions'}
                </div>
            </div>
            <div class="overflow-x-auto">
                <table class="min-w-full text-sm">
                    <thead class="bg-gray-50">
                        <tr>
                            <th class="px-3 py-2 text-left font-medium text-gray-700">Date</th>
                            <th class="px-3 py-2 text-left font-medium text-gray-700">Type</th>
                            <th class="px-3 py-2 text-left font-medium text-gray-700">No.</th>
                            <th class="px-3 py-2 text-left font-medium text-gray-700">Payee</th>
                            <th class="px-3 py-2 text-left font-medium text-gray-700">Split / Category</th>
                            <th class="px-3 py-2 text-left font-medium text-gray-700">Memo</th>
                            <th class="px-3 py-2 text-right font-medium text-gray-700">Amount</th>
                        </tr>
                    </thead>
                    <tbody>${tbody}</tbody>
                </table>
            </div>
        </div>`;
}

function renderRegisterRow(r) {
    const isSplit = r.splitAccount === '-Split-';
    const splitContent = isSplit ? renderSplitCell(r) : escapeHtml(r.splitAccount || '');
    return `
        <tr class="border-t hover:bg-gray-50 align-top">
            <td class="px-3 py-2 text-sm whitespace-nowrap">${escapeHtml(r.date || '')}</td>
            <td class="px-3 py-2 text-sm">${escapeHtml(r.type || '')}</td>
            <td class="px-3 py-2 text-sm">${escapeHtml(r.docNum || '')}</td>
            <td class="px-3 py-2 text-sm">${escapeHtml(r.payee || '')}</td>
            <td class="px-3 py-2 text-sm text-gray-600">${splitContent}</td>
            <td class="px-3 py-2 text-sm text-gray-500">${escapeHtml(r.memo || '')}</td>
            <td class="px-3 py-2 text-sm text-right whitespace-nowrap ${r.amount < 0 ? 'text-red-600' : 'text-gray-900'}">
                ${r.amount != null ? fmtMoney(r.amount) : ''}
            </td>
        </tr>`;
}

function renderSplitCell(r) {
    if (!r.splits || !r.splits.length) {
        const type = (r.type || '').toLowerCase();
        if (type.includes('tax payment')) {
            return `<span class="text-gray-500 italic" title="Sales Tax remittance — see Memo for period">-Split- (Sales Tax)</span>`;
        }
        if (type.includes('paycheck') || type.includes('payroll')) {
            return `<span class="text-gray-500 italic" title="Payroll transaction">-Split- (Payroll)</span>`;
        }
        return `<span class="text-gray-500 italic">-Split-</span>`;
    }
    const lines = r.splits.map(s => `
        <div class="flex justify-between gap-3 text-xs">
            <span class="text-gray-700">${escapeHtml(s.account || '?')}</span>
            <span class="text-gray-600 whitespace-nowrap">${s.amount != null ? fmtMoney(s.amount) : ''}</span>
        </div>`).join('');
    return `<div class="space-y-0.5">${lines}</div>`;
}

// ────────────────────────────────────────────────────────────────────
// Reports
// ────────────────────────────────────────────────────────────────────

export function injectReportsControls() {
    const c = document.getElementById('accounting-reports');
    if (!c) return;
    if (!plStartDate) plStartDate = firstOfYearISO();
    if (!plEndDate)   plEndDate   = todayISO();
    if (!bsAsOfDate)  bsAsOfDate  = todayISO();
    if (!tsMonth)     tsMonth     = prevMonthISO();
    if (!crStartDate) crStartDate = firstOfYearISO();
    if (!crEndDate)   crEndDate   = todayISO();

    c.innerHTML = `
        ${makeCollapsible('Reports', 'reports-section-body')}
        <div id="reports-section-body">
            <div class="grid grid-cols-1 lg:grid-cols-2 gap-4">
                <div class="bg-white rounded-lg shadow-sm border border-gray-200">
                    <div class="px-4 py-3 border-b bg-gray-50"><h3 class="font-semibold text-gray-800">Profit &amp; Loss</h3></div>
                    <div class="p-4">
                        <div class="flex flex-wrap items-end gap-3 mb-3">
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">Start</label>
                                <input type="date" id="pl-start" value="${plStartDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm"></div>
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">End</label>
                                <input type="date" id="pl-end" value="${plEndDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm"></div>
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">Method</label>
                                <select id="pl-method" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                                    <option value="Accrual" ${plAccountingMethod === 'Accrual' ? 'selected' : ''}>Accrual</option>
                                    <option value="Cash" ${plAccountingMethod === 'Cash' ? 'selected' : ''}>Cash</option>
                                </select></div>
                            <button onclick="window.accountingView.loadProfitLoss()" class="px-3 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">Run</button>
                        </div>
                        <div id="pl-result"></div>
                    </div>
                </div>
                <div class="bg-white rounded-lg shadow-sm border border-gray-200">
                    <div class="px-4 py-3 border-b bg-gray-50"><h3 class="font-semibold text-gray-800">Balance Sheet</h3></div>
                    <div class="p-4">
                        <div class="flex flex-wrap items-end gap-3 mb-3">
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">As of</label>
                                <input type="date" id="bs-asof" value="${bsAsOfDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm"></div>
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">Method</label>
                                <select id="bs-method" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                                    <option value="Accrual" ${bsAccountingMethod === 'Accrual' ? 'selected' : ''}>Accrual</option>
                                    <option value="Cash" ${bsAccountingMethod === 'Cash' ? 'selected' : ''}>Cash</option>
                                </select></div>
                            <button onclick="window.accountingView.loadBalanceSheet()" class="px-3 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">Run</button>
                        </div>
                        <div id="bs-result"></div>
                    </div>
                </div>
                <div class="bg-white rounded-lg shadow-sm border border-gray-200">
                    <div class="px-4 py-3 border-b bg-gray-50"><h3 class="font-semibold text-gray-800">Sales Tax (QBO)</h3></div>
                    <div class="p-4">
                        <div class="flex flex-wrap items-end gap-3 mb-3">
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">Month</label>
                                <input type="month" id="ts-month" value="${tsMonth}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm"></div>
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">Method</label>
                                <select id="ts-method" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                                    <option value="Accrual" ${tsAccountingMethod === 'Accrual' ? 'selected' : ''}>Accrual</option>
                                    <option value="Cash" ${tsAccountingMethod === 'Cash' ? 'selected' : ''}>Cash</option>
                                </select></div>
                            <button onclick="window.accountingView.loadTaxSummary()" class="px-3 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">Run</button>
                        </div>
                        <div id="ts-result"></div>
                    </div>
                </div>
                <div class="bg-white rounded-lg shadow-sm border border-gray-200">
                    <div class="px-4 py-3 border-b bg-gray-50"><h3 class="font-semibold text-gray-800">Customer Revenue</h3></div>
                    <div class="p-4">
                        <div class="flex flex-wrap items-end gap-3 mb-3">
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">Start</label>
                                <input type="date" id="cr-start" value="${crStartDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm"></div>
                            <div><label class="block text-xs font-medium text-gray-700 mb-1">End</label>
                                <input type="date" id="cr-end" value="${crEndDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm"></div>
                            <button onclick="window.accountingView.loadCustomerRevenue()" class="px-3 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">Run</button>
                            <button onclick="window.accountingView.exportCustomerRevenuePdf()" class="px-3 py-1.5 bg-gray-100 hover:bg-gray-200 text-gray-700 rounded-md text-sm font-medium border border-gray-300">📄 Export PDF</button>
                            <label class="flex items-center gap-1 pt-5 text-xs text-gray-600 cursor-pointer">
                                <input type="checkbox" id="cr-anonymize" class="h-4 w-4 text-blue-600 border-gray-300 rounded">
                                Anonymize
                            </label>
                        </div>
                        <div id="cr-result"></div>
                    </div>
                </div>
            </div>
        </div>`;
}

export async function loadProfitLoss() {
    plStartDate = document.getElementById('pl-start').value;
    plEndDate   = document.getElementById('pl-end').value;
    plAccountingMethod = document.getElementById('pl-method').value;
    showLoading('pl-result', 'Loading P&L from QBO…');
    try {
        const data = await window.API.accounting.getProfitAndLoss(plStartDate, plEndDate, plAccountingMethod);
        if (data.error) return showError('pl-result', data.error);
        document.getElementById('pl-result').innerHTML = renderQboReport(data);
    } catch (err) { showError('pl-result', err.message || 'Failed to load P&L'); }
}

export async function loadBalanceSheet() {
    bsAsOfDate = document.getElementById('bs-asof').value;
    bsAccountingMethod = document.getElementById('bs-method').value;
    showLoading('bs-result', 'Loading Balance Sheet from QBO…');
    try {
        const data = await window.API.accounting.getBalanceSheet(bsAsOfDate, bsAccountingMethod);
        if (data.error) return showError('bs-result', data.error);
        document.getElementById('bs-result').innerHTML = renderQboReport(data);
    } catch (err) { showError('bs-result', err.message || 'Failed to load Balance Sheet'); }
}

export async function loadTaxSummary() {
    tsMonth = document.getElementById('ts-month').value;
    tsAccountingMethod = document.getElementById('ts-method').value;
    if (!tsMonth) return showError('ts-result', 'Please select a month.');
    const [y, m] = tsMonth.split('-').map(Number);
    const startDate = firstOfMonthISO(y, m - 1);
    const endDate = lastOfMonthISO(y, m - 1);
    showLoading('ts-result', 'Loading Sales Tax Liability from QBO…');
    try {
        const data = await window.API.accounting.getTaxSummary(startDate, endDate, tsAccountingMethod);
        if (data.error) return showError('ts-result', data.error);
        document.getElementById('ts-result').innerHTML = renderQboReport(data);
    } catch (err) { showError('ts-result', err.message || 'Failed to load Tax Summary'); }
}

export async function loadCustomerRevenue() {
    crStartDate = document.getElementById('cr-start').value;
    crEndDate   = document.getElementById('cr-end').value;
    const anonymize = document.getElementById('cr-anonymize')?.checked || false;
    if (!crStartDate || !crEndDate) return showError('cr-result', 'Please select both start and end dates.');
    showLoading('cr-result', 'Loading customer revenue...');
    const maskName = (name) => anonymize ? name.charAt(0) : name;
    try {
        const data = await window.API.accounting.getCustomerRevenue(crStartDate, crEndDate);
        if (data.error) return showError('cr-result', data.error);
        if (!data.length) {
            document.getElementById('cr-result').innerHTML = '<p class="text-sm text-gray-500">No invoices found in this period.</p>';
            return;
        }
        const grandTotal = parseFloat(data[0].grand_total) || 0;
        const totalInvoices = data.reduce((s, r) => s + parseInt(r.invoice_count), 0);
        let rowsHtml = '';
        let rank = 0;
        for (const r of data) {
            rank++;
            const rev = parseFloat(r.total_revenue) || 0;
            const pct = grandTotal > 0 ? ((rev / grandTotal) * 100).toFixed(1) : '0.0';
            rowsHtml += `<tr class="border-t hover:bg-gray-50">
                <td class="px-3 py-2 text-sm font-medium">${rank}. ${escapeHtml(maskName(r.customer_name))}</td>
                <td class="px-3 py-2 text-sm text-center">${r.invoice_count}</td>
                <td class="px-3 py-2 text-sm text-right">${fmtMoney(rev)}</td>
                <td class="px-3 py-2 text-sm text-right text-gray-500">${pct}%</td>
            </tr>`;
        }
        rowsHtml += `<tr class="border-t bg-gray-50 font-semibold">
            <td class="px-3 py-2 text-sm">TOTAL (${data.length} customers)</td>
            <td class="px-3 py-2 text-sm text-center">${totalInvoices}</td>
            <td class="px-3 py-2 text-sm text-right">${fmtMoney(grandTotal)}</td>
            <td class="px-3 py-2 text-sm text-right">100.0%</td>
        </tr>`;

        document.getElementById('cr-result').innerHTML = `
            <div class="overflow-x-auto border border-gray-200 rounded">
                <table class="min-w-full text-sm">
                    <thead class="bg-gray-50">
                        <tr>
                            <th class="px-3 py-2 text-left font-medium text-gray-700">Customer</th>
                            <th class="px-3 py-2 text-center font-medium text-gray-700">Invoices</th>
                            <th class="px-3 py-2 text-right font-medium text-gray-700">Revenue (net)</th>
                            <th class="px-3 py-2 text-right font-medium text-gray-700">% of Total</th>
                        </tr>
                    </thead>
                    <tbody>${rowsHtml}</tbody>
                </table>
            </div>`;
    } catch (err) { showError('cr-result', err.message || 'Failed to load revenue report'); }
}

export function exportCustomerRevenuePdf() {
    const startEl = document.getElementById('cr-start');
    const endEl   = document.getElementById('cr-end');
    const anonymize = document.getElementById('cr-anonymize')?.checked || false;
    if (!startEl?.value || !endEl?.value) return alert('Please select start and end dates first.');
    let url = `/api/accounting/reports/customer-revenue/pdf?startDate=${startEl.value}&endDate=${endEl.value}`;
    if (anonymize) url += '&anonymize=true';
    window.open(url, '_blank');
}

function renderQboReport(report) {
    if (!report || !report.Header) return `<p class="text-sm text-gray-500">No report data.</p>`;
    const cols = (report.Columns && report.Columns.Column) || [];
    const headerRow = cols.map(c => `<th class="px-3 py-2 text-right font-medium text-gray-700 first:text-left">${escapeHtml(c.ColTitle || '')}</th>`).join('');
    const body = report.Rows && report.Rows.Row ? renderReportRows(report.Rows.Row, 0) : '';
    return `
        <div class="text-xs text-gray-500 mb-2">
            ${escapeHtml(report.Header.ReportName || '')}
            ${report.Header.StartPeriod ? '· ' + escapeHtml(report.Header.StartPeriod) + ' – ' + escapeHtml(report.Header.EndPeriod) : ''}
            ${report.Header.ReportBasis ? '· ' + escapeHtml(report.Header.ReportBasis) : ''}
        </div>
        <div class="overflow-x-auto border border-gray-200 rounded">
            <table class="min-w-full text-sm">
                <thead class="bg-gray-50 border-b"><tr>${headerRow}</tr></thead>
                <tbody>${body}</tbody>
            </table>
        </div>`;
}

function renderReportRows(rows, depth) {
    if (!rows) return '';
    const arr = Array.isArray(rows) ? rows : [rows];
    let html = '';
    for (const row of arr) {
        const isSection = row.type === 'Section' || row.Rows || row.Summary;
        const indent = depth * 16;
        if (row.Header && row.Header.ColData) {
            const cells = row.Header.ColData.map((c, i) =>
                i === 0
                    ? `<td class="px-3 py-1.5 font-semibold text-gray-800" style="padding-left:${12 + indent}px">${escapeHtml(c.value || '')}</td>`
                    : `<td class="px-3 py-1.5 text-right text-gray-500"></td>`
            ).join('');
            html += `<tr class="bg-gray-50">${cells}</tr>`;
        }
        if (isSection && row.Rows && row.Rows.Row) html += renderReportRows(row.Rows.Row, depth + 1);
        if (row.Summary && row.Summary.ColData) {
            const cells = row.Summary.ColData.map((c, i) =>
                i === 0
                    ? `<td class="px-3 py-1.5 font-semibold text-gray-700 border-t" style="padding-left:${12 + indent}px">${escapeHtml(c.value || '')}</td>`
                    : `<td class="px-3 py-1.5 text-right font-semibold text-gray-900 border-t">${escapeHtml(c.value || '')}</td>`
            ).join('');
            html += `<tr>${cells}</tr>`;
        }
        if (!isSection && row.ColData) {
            const cells = row.ColData.map((c, i) =>
                i === 0
                    ? `<td class="px-3 py-1.5" style="padding-left:${12 + indent}px">${escapeHtml(c.value || '')}</td>`
                    : `<td class="px-3 py-1.5 text-right">${escapeHtml(c.value || '')}</td>`
            ).join('');
            html += `<tr>${cells}</tr>`;
        }
    }
    return html;
}

// ════════════════════════════════════════════════════════════════════
// Phase 2 Lieferung 2 — Expenses Section
// ════════════════════════════════════════════════════════════════════

export function injectExpensesSection() {
    const c = document.getElementById('accounting-expenses');
    if (!c) return;
    if (!expStartDate) expStartDate = firstOfMonthISO();
    if (!expEndDate)   expEndDate   = todayISO();

    c.innerHTML = `
        ${makeCollapsible('Expenses', 'expenses-section-body')}
        <div id="expenses-section-body">
            <div class="bg-white rounded-lg shadow-sm border border-gray-200 overflow-hidden">
                <div class="px-4 py-3 border-b bg-gray-50 flex flex-wrap items-end gap-3">
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">Start</label>
                        <input type="date" id="exp-start" value="${expStartDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                    </div>
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">End</label>
                        <input type="date" id="exp-end" value="${expEndDate}" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                    </div>
                    <div class="flex items-center gap-2 pt-5">
                        <input type="checkbox" id="exp-only-mine" ${expOnlyMine ? 'checked' : ''}
                            class="h-4 w-4 text-blue-600 border-gray-300 rounded">
                        <label for="exp-only-mine" class="text-sm text-gray-700" title="Only show expenses created from this app">Only mine</label>
                    </div>
                    <button onclick="window.accountingView.loadExpenses()"
                            class="px-3 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">
                        Load
                    </button>
                    <div class="ml-auto flex gap-2">
                        <button onclick="window.accountingView.openNewRefund()"
                                class="px-4 py-1.5 bg-amber-600 text-white rounded-md text-sm font-semibold hover:bg-amber-700">
                            ↩️ Record Refund
                        </button>
                        <button onclick="window.accountingView.openNewExpense()"
                                class="px-4 py-1.5 bg-green-600 text-white rounded-md text-sm font-semibold hover:bg-green-700">
                            + New Expense
                        </button>
                    </div>
                </div>
                <div id="accounting-expenses-table"></div>
            </div>
        </div>`;
}

export async function loadExpenses() {
    const startEl = document.getElementById('exp-start');
    const endEl   = document.getElementById('exp-end');
    const onlyEl  = document.getElementById('exp-only-mine');
    expStartDate = startEl.value;
    expEndDate   = endEl.value;
    expOnlyMine  = onlyEl.checked;

    const slot = 'accounting-expenses-table';
    showLoading(slot, 'Loading expenses from QBO…');

    try {
        const list = await window.API.accounting.listExpenses(expStartDate, expEndDate, expOnlyMine);
        if (list.error) return showError(slot, list.error);
        renderExpensesTable(list);
    } catch (err) {
        showError(slot, err.message || 'Failed to load expenses');
    }
}

function renderExpensesTable(expenses) {
    const el = document.getElementById('accounting-expenses-table');
    if (!el) return;

    if (!expenses.length) {
        el.innerHTML = `<div class="p-4 text-gray-500 text-sm">No expenses in selected range${expOnlyMine ? ' (created from this app)' : ''}.</div>`;
        return;
    }

    const sorted = expenses.slice().sort((a, b) => (b.txnDate || '').localeCompare(a.txnDate || ''));
    const tbody = sorted.map(e => {
        const splitsHtml = e.lines && e.lines.length > 1
            ? `<details><summary class="cursor-pointer text-blue-600 text-xs">${e.lines.length} lines</summary>
                  <div class="mt-1 space-y-0.5">
                      ${e.lines.map(l => `
                          <div class="flex justify-between gap-3 text-xs">
                              <span class="text-gray-700">${escapeHtml(l.accountName || '?')}</span>
                              <span class="text-gray-600 whitespace-nowrap">${l.amount != null ? fmtMoney(l.amount) : ''}</span>
                          </div>`).join('')}
                  </div>
               </details>`
            : escapeHtml(e.lines[0]?.accountName || '');

        const editBtn = expOnlyMine
            ? `<button onclick='window.accountingView.editExpense(${JSON.stringify(JSON.stringify(e))})'
                       class="text-blue-600 hover:text-blue-800 text-xs font-medium">Edit</button>`
            : `<span class="text-gray-300 text-xs" title="Only expenses created from this app can be edited">—</span>`;

        return `
            <tr class="border-t hover:bg-gray-50 align-top">
                <td class="px-3 py-2 text-sm whitespace-nowrap">${escapeHtml(e.txnDate || '')}</td>
                <td class="px-3 py-2 text-sm">${escapeHtml(e.vendorName || '')}</td>
                <td class="px-3 py-2 text-sm">${escapeHtml(e.accountName || '')}</td>
                <td class="px-3 py-2 text-sm text-gray-600">${splitsHtml}</td>
                <td class="px-3 py-2 text-sm">${escapeHtml(e.refNo || '')}</td>
                <td class="px-3 py-2 text-sm text-gray-500">${escapeHtml(e.memo || '')}</td>
                <td class="px-3 py-2 text-sm text-right whitespace-nowrap text-red-600">${fmtMoney(e.totalAmt)}</td>
                <td class="px-3 py-2 text-sm text-center">${editBtn}</td>
            </tr>`;
    }).join('');

    el.innerHTML = `
        <div class="overflow-x-auto">
            <table class="min-w-full text-sm">
                <thead class="bg-gray-50">
                    <tr>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Date</th>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Vendor</th>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Payment Account</th>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Category</th>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Ref</th>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Memo</th>
                        <th class="px-3 py-2 text-right font-medium text-gray-700">Amount</th>
                        <th class="px-3 py-2 text-center font-medium text-gray-700">Action</th>
                    </tr>
                </thead>
                <tbody>${tbody}</tbody>
            </table>
            <div class="px-3 py-2 text-xs text-gray-500 border-t bg-gray-50">${sorted.length} expense${sorted.length === 1 ? '' : 's'}</div>
        </div>`;
}

// ────────────────────────────────────────────────────────────────────
// Sales Tax Periods
// ────────────────────────────────────────────────────────────────────

export function injectSalesTaxSection() {
    const c = document.getElementById('accounting-sales-tax');
    if (!c) return;
    c.innerHTML = `
        ${makeCollapsible('Sales Tax', 'sales-tax-section-body')}
        <div id="sales-tax-section-body">
            <div class="bg-white rounded-lg shadow-sm border border-gray-200 overflow-hidden">
                <div class="px-4 py-3 border-b bg-gray-50 flex flex-wrap items-center gap-3">
                    <h3 class="font-semibold text-gray-800 text-sm">Period Overview</h3>
                    <div class="ml-auto flex gap-2">
                        <button onclick="window.accountingView.openNewTaxPeriod()"
                                class="px-3 py-1.5 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700">
                            + New Period
                        </button>
                    </div>
                </div>
                <div id="sales-tax-periods-table"></div>
            </div>
            <div id="sales-tax-detail" class="mt-4 hidden"></div>
        </div>`;
}

export async function loadTaxPeriods() {
    try {
        stPeriods = await window.API.accounting.getTaxPeriods() || [];
    } catch (e) {
        stPeriods = [];
        console.error('Failed to load tax periods:', e.message);
    }
    renderTaxPeriodsTable();
}

function renderTaxPeriodsTable() {
    const el = document.getElementById('sales-tax-periods-table');
    if (!el) return;

    if (!stPeriods.length) {
        el.innerHTML = `<div class="p-4 text-gray-500 text-sm">No sales tax periods recorded yet. Click "+ New Period" to get started.</div>`;
        return;
    }

    const rows = stPeriods.map(p => {
        const pStatus = p.status || (p.qbo_journal_entry_id ? 'booked' : 'open');
        let statusHtml, statusColor;
        if (pStatus === 'booked')      { statusHtml = 'Booked';   statusColor = 'bg-green-100 text-green-800'; }
        else if (pStatus === 'external') { statusHtml = 'External'; statusColor = 'bg-blue-100 text-blue-800'; }
        else                            { statusHtml = 'Open';     statusColor = 'bg-yellow-100 text-yellow-800'; }

        const monthLabel = new Date(p.period_start).toLocaleDateString('en-US', { year: 'numeric', month: 'long' });
        const adj = parseFloat(p.adjustment_amount) || 0;
        const adjStr = adj !== 0 ? (adj > 0 ? `−$${adj.toFixed(2)}` : `+$${Math.abs(adj).toFixed(2)}`) : '—';
        const netPaid = parseFloat(p.net_paid) || parseFloat(p.tax_collected) || 0;
        const paidOn = pStatus === 'external' ? 'Paid in QBO' : (p.booked_at ? formatDate(p.booked_at) : '—');

        return `
            <tr class="border-t hover:bg-gray-50">
                <td class="px-3 py-2 text-sm font-medium text-gray-800">${monthLabel}</td>
                <td class="px-3 py-2 text-sm">
                    <span class="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-semibold ${statusColor}">${statusHtml}</span>
                </td>
                <td class="px-3 py-2 text-sm text-right">${fmtMoney(parseFloat(p.tax_collected) || 0)}</td>
                <td class="px-3 py-2 text-sm text-right">${adjStr}</td>
                <td class="px-3 py-2 text-sm text-right font-semibold">${fmtMoney(netPaid)}</td>
                <td class="px-3 py-2 text-sm text-gray-500">${paidOn}</td>
                <td class="px-3 py-2 text-sm text-center">
                    <button onclick="window.accountingView.openTaxPeriod(${p.id})"
                            class="text-blue-600 hover:text-blue-800 text-xs font-medium">View summary</button>
                </td>
            </tr>`;
    }).join('');

    el.innerHTML = `
        <div class="overflow-x-auto">
            <table class="min-w-full text-sm">
                <thead class="bg-gray-50">
                    <tr>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Period</th>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Status</th>
                        <th class="px-3 py-2 text-right font-medium text-gray-700">Tax Amount</th>
                        <th class="px-3 py-2 text-right font-medium text-gray-700">Adjustment</th>
                        <th class="px-3 py-2 text-right font-medium text-gray-700">Net Due</th>
                        <th class="px-3 py-2 text-left font-medium text-gray-700">Paid On</th>
                        <th class="px-3 py-2 text-center font-medium text-gray-700">Actions</th>
                    </tr>
                </thead>
                <tbody>${rows}</tbody>
            </table>
            <div class="px-3 py-2 text-xs text-gray-500 border-t bg-gray-50">${stPeriods.length} period${stPeriods.length === 1 ? '' : 's'}</div>
        </div>`;
}

export async function openNewTaxPeriod() {
    const [y, m] = prevMonthISO().split('-').map(Number);
    const startDate = firstOfMonthISO(y, m - 1);
    const endDate = lastOfMonthISO(y, m - 1);
    await openTaxPeriodDetail(startDate, endDate, null);
}

export async function openTaxPeriod(periodId) {
    const period = stPeriods.find(p => p.id === periodId);
    if (!period) return alert('Period not found.');
    await openTaxPeriodDetail(period.period_start, period.period_end, period);
}

async function openTaxPeriodDetail(startDate, endDate, existingPeriod) {
    const detailEl = document.getElementById('sales-tax-detail');
    if (!detailEl) return;

    stEditingPeriodId = existingPeriod ? existingPeriod.id : null;

    showLoading('sales-tax-detail', 'Loading tax summary from QBO…');
    let taxData;
    try {
        taxData = await window.API.accounting.getTaxSummary(startDate, endDate, 'Accrual');
    } catch (e) {
        showError('sales-tax-detail', e.message || 'Failed to load tax summary');
        return;
    }

    if (!stAccounts.length) {
        try {
            const accts = await window.API.accounting.getAccounts() || [];
            stAccounts = Array.isArray(accts) ? accts : [];
        } catch (e) { stAccounts = []; }
    }

    const reportHtml = taxData?.Rows ? renderQboReport(taxData) : `<p class="text-sm text-gray-500">No tax data for this period.</p>`;

    const parsed = parseTaxDataFromReport(taxData);
    stCurrentTaxData = { ...parsed, startDate, endDate };
    const taxCollected = parsed.taxCollected;
    const totalSales = parsed.totalSales;
    const nontaxable = parsed.nontaxableSales;
    const taxable = parsed.taxableSales;
    const adjustments = existingPeriod?.adjustment_amount != null ? parseFloat(existingPeriod.adjustment_amount) || 0 : 0;
    const adjReason = existingPeriod?.adjustment_reason || '';
    const netPaid = taxCollected - adjustments;
    const periodStatus = existingPeriod?.status || (existingPeriod?.qbo_journal_entry_id ? 'booked' : 'open');
    const isOpen = periodStatus === 'open';
    const isEditable = isOpen;

    const bankOpts = stAccounts
        .filter(a => a.accountType === 'Bank' || a.accountType === 'Credit Card')
        .map(a => `<option value="${a.id}" ${a.id === existingPeriod?.bank_account_id ? 'selected' : ''}>${escapeHtml(a.name)} (${a.accountType})</option>`).join('');
    const liabilityOpts = stAccounts
        .filter(a => a.accountType === 'Other Current Liability')
        .map(a => `<option value="${a.id}" ${a.id === existingPeriod?.sales_tax_payable_id ? 'selected' : ''}>${escapeHtml(a.name)}</option>`).join('');
    const adjustOpts = stAccounts
        .filter(a => a.accountType === 'Income' || a.accountType === 'Expense' || a.classification === 'Revenue' || a.classification === 'Expense')
        .map(a => {
            const sel = a.id === existingPeriod?.adjustment_account_id ? 'selected' : '';
            const name = (a.fullyQualifiedName || a.name || '');
            const isDiscount = name.toLowerCase().includes('discount');
            return `<option value="${a.id}" ${sel} data-hint="${isDiscount ? 'discount' : ''}">${escapeHtml(name)}${isDiscount ? ' ★' : ''}</option>`;
        }).join('');

    const today = todayISO();
    const [y, m] = startDate.split('-').map(Number);
    const monthLabel = new Date(y, m - 1).toLocaleDateString('en-US', { year: 'numeric', month: 'long' });

    detailEl.innerHTML = `
        <div class="bg-white rounded-lg shadow-sm border border-gray-200 p-4">
            <div class="flex items-center justify-between mb-3">
                <h3 class="font-semibold text-gray-800">${monthLabel} — Sales Tax Detail</h3>
                <button onclick="window.accountingView.closeTaxPeriodDetail()"
                        class="px-2 py-1 text-gray-400 hover:text-gray-600 text-lg leading-none">&times;</button>
            </div>
            ${reportHtml}

            <div class="mt-4 border-t pt-4">
                <div class="flex items-center gap-4 text-sm mb-3" id="st-summary-bar">
                    <span><strong>Tax Collected:</strong> ${fmtMoney(taxCollected)}</span>
                    <span id="st-adj-display" class="${adjustments !== 0 ? 'text-red-600' : ''}"><strong>Adjustment:</strong> ${adjustments > 0 ? `−${fmtMoney(adjustments)}` : adjustments < 0 ? `+$${Math.abs(adjustments).toFixed(2)}` : '—'}</span>
                    <span id="st-net-due" class="text-lg font-bold text-gray-900"><strong>Net Due:</strong> ${fmtMoney(netPaid)}</span>
                </div>

                <div class="grid grid-cols-1 md:grid-cols-3 gap-3 mb-3">
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">Adjustment Amount</label>
                        <input type="number" step="0.01" id="st-adjustment" value="${adjustments !== 0 ? adjustments : ''}" placeholder="e.g. 6.15 (discount)" ${isEditable ? '' : 'disabled'}
                               oninput="window.accountingView.updateTaxPreview()"
                               class="w-full px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                        <p class="text-xs text-gray-400 mt-0.5">Positive = discount (reduces net due)</p>
                    </div>
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">Reason</label>
                        <input type="text" id="st-adjustment-reason" value="${escapeHtml(adjReason)}" placeholder="e.g. Timely filing discount" ${isEditable ? '' : 'disabled'}
                               class="w-full px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                    </div>
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">Adjustment Account</label>
                        <select id="st-adjustment-account" class="w-full px-3 py-1.5 border border-gray-300 rounded-md text-sm" ${isEditable ? '' : 'disabled'}>
                            <option value="">— Select income account —</option>
                            ${adjustOpts}
                        </select>
                    </div>
                </div>

                <div class="grid grid-cols-1 md:grid-cols-3 gap-3 mb-3">
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">Bank Account (payment source)</label>
                        <select id="st-bank-account" class="w-full px-3 py-1.5 border border-gray-300 rounded-md text-sm" ${isEditable ? '' : 'disabled'}>
                            <option value="">— Select bank account —</option>
                            ${bankOpts}
                        </select>
                    </div>
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">Sales Tax Payable Account</label>
                        <select id="st-payable-account" class="w-full px-3 py-1.5 border border-gray-300 rounded-md text-sm" ${isEditable ? '' : 'disabled'}>
                            <option value="">— Select liability account —</option>
                            ${liabilityOpts}
                        </select>
                    </div>
                    <div>
                        <label class="block text-xs font-medium text-gray-700 mb-1">Payment Date</label>
                        <input type="date" id="st-payment-date" value="${today}" ${isEditable ? '' : 'disabled'}
                               class="w-full px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                    </div>
                </div>

                ${isEditable ? `
                <div class="flex items-center justify-between border-t pt-3 mt-1">
                    <div id="st-je-lines">
                        <p class="text-sm"><strong>Journal Entry lines:</strong></p>
                        <p class="text-xs text-gray-500 font-mono">Debit Sales Tax Payable: ${fmtMoney(taxCollected)}</p>
                        ${adjustments > 0 ? `<p class="text-xs text-gray-500 font-mono">Credit Discount: ${fmtMoney(adjustments)}</p>` : ''}
                        ${adjustments < 0 ? `<p class="text-xs text-gray-500 font-mono">Debit Penalty: ${fmtMoney(Math.abs(adjustments))}</p>` : ''}
                        <p class="text-xs text-gray-500 font-mono" id="st-je-bank">Credit Bank: ${fmtMoney(netPaid)}</p>
                    </div>
                    <div class="flex gap-2">
                        <button onclick="window.accountingView.saveTaxPeriodDraft()"
                                class="px-3 py-1.5 bg-gray-100 hover:bg-gray-200 text-gray-700 rounded-md text-sm font-medium border border-gray-300">
                            💾 Save Draft
                        </button>
                        <button onclick="window.accountingView.markTaxPaidExternal()"
                                class="px-3 py-1.5 bg-blue-100 hover:bg-blue-200 text-blue-800 rounded-md text-sm font-medium border border-blue-300">
                            📋 Mark as already paid (external)
                        </button>
                        <button onclick="window.accountingView.recordTaxPayment()"
                                class="px-4 py-2 bg-green-600 text-white rounded-md text-sm font-semibold hover:bg-green-700">
                            ✅ Record Payment in QBO
                        </button>
                    </div>
                </div>
                ` : periodStatus === 'booked' ? `
                <div class="border-t pt-3 mt-1">
                    <p class="text-sm text-green-700 font-semibold">✅ Booked — Journal Entry #${escapeHtml(existingPeriod.qbo_journal_entry_id)} on ${formatDate(existingPeriod.booked_at)}</p>
                </div>
                ` : `
                <div class="border-t pt-3 mt-1">
                    <p class="text-sm text-blue-700 font-semibold">📋 Marked as paid externally on ${formatDate(existingPeriod.booked_at)}</p>
                </div>
                `}
            </div>
        </div>`;

    detailEl.classList.remove('hidden');
    detailEl.scrollIntoView({ behavior: 'smooth' });
}

export function closeTaxPeriodDetail() {
    const el = document.getElementById('sales-tax-detail');
    if (el) el.classList.add('hidden');
    stEditingPeriodId = null;
}

export function updateTaxPreview() {
    if (!stCurrentTaxData) return;
    const adjInput = document.getElementById('st-adjustment');
    const adj = parseFloat(adjInput?.value) || 0;
    const taxCollected = stCurrentTaxData.taxCollected;
    const netPaid = taxCollected - adj;

    const adjDisplay = document.getElementById('st-adj-display');
    if (adjDisplay) {
        adjDisplay.className = adj !== 0 ? 'text-red-600' : '';
        adjDisplay.innerHTML = adj > 0
            ? `<strong>Adjustment:</strong> −${fmtMoney(adj)}`
            : adj < 0
                ? `<strong>Adjustment:</strong> +$${Math.abs(adj).toFixed(2)}`
                : `<strong>Adjustment:</strong> —`;
    }

    const netDue = document.getElementById('st-net-due');
    if (netDue) {
        netDue.innerHTML = `<strong>Net Due:</strong> ${fmtMoney(netPaid)}`;
    }

    const jeLines = document.getElementById('st-je-lines');
    if (jeLines) {
        jeLines.innerHTML = `
            <p class="text-sm"><strong>Journal Entry lines:</strong></p>
            <p class="text-xs text-gray-500 font-mono">Debit Sales Tax Payable: ${fmtMoney(taxCollected)}</p>
            ${adj > 0 ? `<p class="text-xs text-gray-500 font-mono">Credit Discount: ${fmtMoney(adj)}</p>` : ''}
            ${adj < 0 ? `<p class="text-xs text-gray-500 font-mono">Debit Penalty: ${fmtMoney(Math.abs(adj))}</p>` : ''}
            <p class="text-xs text-gray-500 font-mono">Credit Bank: ${fmtMoney(netPaid)}</p>`;
    }
}

export async function saveTaxPeriodDraft() {
    const adjAmount = parseFloat(document.getElementById('st-adjustment').value) || 0;
    const adjReason = document.getElementById('st-adjustment-reason').value.trim();
    const adjAccountEl = document.getElementById('st-adjustment-account');
    const adjAccountId = adjAccountEl.value;
    const adjAccountName = adjAccountId ? adjAccountEl.options[adjAccountEl.selectedIndex]?.text : '';

    const bankEl = document.getElementById('st-bank-account');
    const bankId = bankEl.value;
    const bankName = bankId ? bankEl.options[bankEl.selectedIndex]?.text : '';

    const payableEl = document.getElementById('st-payable-account');
    const payableId = payableEl.value;
    const payableName = payableId ? payableEl.options[payableEl.selectedIndex]?.text : '';

    if (!stCurrentTaxData) return alert('No tax data loaded.');

    try {
        const period = await window.API.accounting.upsertTaxPeriod({
            period_start: stCurrentTaxData.startDate,
            period_end: stCurrentTaxData.endDate,
            total_sales: stCurrentTaxData.totalSales,
            nontaxable_sales: stCurrentTaxData.nontaxableSales,
            taxable_sales: stCurrentTaxData.taxableSales,
            tax_collected: stCurrentTaxData.taxCollected,
            adjustment_amount: adjAmount,
            adjustment_reason: adjReason || null,
            adjustment_account_id: adjAccountId || null,
            adjustment_account_name: adjAccountName || null,
            net_paid: stCurrentTaxData.taxCollected - adjAmount,
            bank_account_id: bankId || null,
            bank_account_name: bankName || null,
            sales_tax_payable_id: payableId || null,
            sales_tax_payable_name: payableName || null
        });
        await loadTaxPeriods();
        if (period?.period_start) {
            await openTaxPeriodDetail(period.period_start, period.period_end, period);
        }
    } catch (e) {
        alert('Failed to save: ' + e.message);
    }
}

export async function recordTaxPayment() {
    const adjAmount = parseFloat(document.getElementById('st-adjustment').value) || 0;
    const adjReason = document.getElementById('st-adjustment-reason').value.trim();
    const adjAccountEl = document.getElementById('st-adjustment-account');
    const adjAccountId = adjAccountEl.value;
    const adjAccountName = adjAccountId ? adjAccountEl.options[adjAccountEl.selectedIndex]?.text : '';

    const bankEl = document.getElementById('st-bank-account');
    const bankId = bankEl.value;
    const bankName = bankId ? bankEl.options[bankEl.selectedIndex]?.text : '';

    const payableEl = document.getElementById('st-payable-account');
    const payableId = payableEl.value;
    const payableName = payableId ? payableEl.options[payableEl.selectedIndex]?.text : '';

    const txnDate = document.getElementById('st-payment-date').value;
    if (!txnDate) return alert('Please select a payment date.');

    if (!stCurrentTaxData) return alert('No tax data loaded.');

    const taxCollected = stCurrentTaxData.taxCollected;
    const netPaid = taxCollected - adjAmount;

    if (!payableId) return alert('Please select the Sales Tax Payable account.');
    if (!bankId) return alert('Please select a bank account.');

    const preview = `Journal Entry on ${txnDate}:\n\n` +
        `Debit Sales Tax Payable: $${taxCollected.toFixed(2)}\n` +
        (adjAmount > 0 ? `Credit Discount: $${adjAmount.toFixed(2)} (${adjReason || 'Adjustment'})\n` : '') +
        (adjAmount < 0 ? `Debit Penalty: $${Math.abs(adjAmount).toFixed(2)} (${adjReason || 'Adjustment'})\n` : '') +
        `Credit Bank: $${netPaid.toFixed(2)}\n\n` +
        (adjAmount > 0 ? `Debits (${taxCollected.toFixed(2)}) = Credits (${adjAmount.toFixed(2)} + ${netPaid.toFixed(2)} = ${(adjAmount + netPaid).toFixed(2)})` : 
         adjAmount < 0 ? `Debits (${taxCollected.toFixed(2)} + ${Math.abs(adjAmount).toFixed(2)} = ${(taxCollected + Math.abs(adjAmount)).toFixed(2)}) = Credits (${netPaid.toFixed(2)})` :
         `Debits = Credits = ${taxCollected.toFixed(2)}`) + 
        '\n\nRecord this in QBO?';

    if (!confirm(preview)) return;

    let periodId = stEditingPeriodId;
    try {
        const period = await window.API.accounting.upsertTaxPeriod({
            period_start: stCurrentTaxData.startDate,
            period_end: stCurrentTaxData.endDate,
            total_sales: stCurrentTaxData.totalSales,
            nontaxable_sales: stCurrentTaxData.nontaxableSales,
            taxable_sales: stCurrentTaxData.taxableSales,
            tax_collected: stCurrentTaxData.taxCollected,
            adjustment_amount: adjAmount,
            adjustment_reason: adjReason || null,
            adjustment_account_id: adjAccountId || null,
            adjustment_account_name: adjAccountName || null,
            net_paid: netPaid,
            bank_account_id: bankId || null,
            bank_account_name: bankName || null,
            sales_tax_payable_id: payableId || null,
            sales_tax_payable_name: payableName || null
        });
        periodId = period.id;
    } catch (e) {
        return alert('Failed to save period before payment: ' + e.message);
    }

    if (typeof showSpinner === 'function') showSpinner('Recording tax payment in QBO…');
    try {
        const result = await window.API.accounting.recordTaxPayment(periodId, {
            txnDate,
            taxCollected,
            adjustmentAmount: adjAmount,
            netPaid,
            salesTaxPayableId: payableId,
            salesTaxPayableName: payableName,
            adjustmentAccountId: adjAccountId || null,
            adjustmentAccountName: adjAccountName || null,
            adjustmentReason: adjReason || null,
            bankAccountId: bankId,
            bankAccountName: bankName
        });
        if (result.error) return alert('Failed: ' + result.error);
        await loadTaxPeriods();
        const updated = stPeriods.find(p => p.id === periodId);
        if (updated) {
            await openTaxPeriodDetail(updated.period_start, updated.period_end, updated);
        }
    } catch (e) {
        alert('QBO payment failed: ' + e.message);
    } finally {
        if (typeof hideSpinner === 'function') hideSpinner();
    }
}

export async function markTaxPaidExternal() {
    if (!stEditingPeriodId) return alert('Please save the period first (Save Draft).');

    const adjAmount = parseFloat(document.getElementById('st-adjustment').value) || 0;
    const adjReason = document.getElementById('st-adjustment-reason').value.trim();
    const adjAccountEl = document.getElementById('st-adjustment-account');
    const adjAccountId = adjAccountEl.value;
    const adjAccountName = adjAccountId ? adjAccountEl.options[adjAccountEl.selectedIndex]?.text : '';

    const bankEl = document.getElementById('st-bank-account');
    const bankId = bankEl.value;
    const bankName = bankId ? bankEl.options[bankEl.selectedIndex]?.text : '';

    const payableEl = document.getElementById('st-payable-account');
    const payableId = payableEl.value;
    const payableName = payableId ? payableEl.options[payableEl.selectedIndex]?.text : '';

    if (!confirm(`Mark this period as already paid in QBO (external)?\n\nNo Journal Entry will be created — this only records the status in the app.\n\nTax Collected: $${stCurrentTaxData.taxCollected.toFixed(2)}\nAdjustment: $${adjAmount.toFixed(2)}\nNet Due: $${(stCurrentTaxData.taxCollected - adjAmount).toFixed(2)}`)) return;

    if (!stCurrentTaxData) return alert('No tax data loaded.');

    try {
        await window.API.accounting.upsertTaxPeriod({
            period_start: stCurrentTaxData.startDate,
            period_end: stCurrentTaxData.endDate,
            total_sales: stCurrentTaxData.totalSales,
            nontaxable_sales: stCurrentTaxData.nontaxableSales,
            taxable_sales: stCurrentTaxData.taxableSales,
            tax_collected: stCurrentTaxData.taxCollected,
            adjustment_amount: adjAmount,
            adjustment_reason: adjReason || null,
            adjustment_account_id: adjAccountId || null,
            adjustment_account_name: adjAccountName || null,
            net_paid: stCurrentTaxData.taxCollected - adjAmount,
            bank_account_id: bankId || null,
            bank_account_name: bankName || null,
            sales_tax_payable_id: payableId || null,
            sales_tax_payable_name: payableName || null,
            status: 'open'
        });
    } catch (e) {
        return alert('Failed to save period: ' + e.message);
    }

    try {
        const result = await window.API.accounting.markTaxPaidExternal(stEditingPeriodId);
        await loadTaxPeriods();
        const updated = stPeriods.find(p => p.id === stEditingPeriodId);
        if (updated) {
            await openTaxPeriodDetail(updated.period_start, updated.period_end, updated);
        }
    } catch (e) {
        alert('Failed: ' + e.message);
    }
}

function parseTaxDataFromReport(taxData) {
    if (!taxData?.Rows?.Row) return { totalSales: 0, nontaxableSales: 0, taxableSales: 0, taxCollected: 0 };
    const rows = Array.isArray(taxData.Rows.Row) ? taxData.Rows.Row : [];
    for (const row of rows) {
        if (row.type === 'Section' && row.Header?.ColData?.[0]?.value?.toLowerCase().includes('grand total')) {
            const cd = row.Summary?.ColData || [];
            return {
                totalSales: parseFloat(cd[1]?.value || '0') || 0,
                nontaxableSales: parseFloat(cd[2]?.value || '0') || 0,
                taxableSales: parseFloat(cd[3]?.value || '0') || 0,
                taxCollected: parseFloat(cd[4]?.value || '0') || 0
            };
        }
    }
    return { totalSales: 0, nontaxableSales: 0, taxableSales: 0, taxCollected: 0 };
}

let stCurrentTaxData = null; // parsed data for the open detail dialog

export async function openNewExpense() {
    await openExpenseModal({
        onSaved: () => loadExpenses()
    });
}

// ────────────────────────────────────────────────────────────────────
// Init / Public Entry Points
// ────────────────────────────────────────────────────────────────────

export function renderAccountingView() {
    autoSyncDoneThisOpen = false;
    injectToolbar();
    injectRegisterControls();
    injectReportsControls();
    injectExpensesSection();
    injectSalesTaxSection();
    loadTaxPeriods();

    maybeAutoSyncCaches().then(() => {
        loadAccountsOverview();
    });
}

export function refreshAll() {
    loadAccountsOverview();
    if (registerAccountId) loadRegister();
}
export async function editExpense(expenseJson) {
    let expense;
    try {
        expense = typeof expenseJson === 'string' ? JSON.parse(expenseJson) : expenseJson;
    } catch (e) {
        alert('Could not open expense for editing.');
        return;
    }
    await openExpenseModal({
        expense,
        onSaved: () => loadExpenses()
    });
}
export async function openNewRefund() {
    await openRefundModal({
        onSaved: (result) => {
            alert(`✅ Refund recorded: ${fmtMoney(result.totalAmt)} from ${result.vendorName}\nDeposit #${result.id} — booked to ${result.categoryName}`);
            loadExpenses();
        }
    });
}
window.accountingView = {
    renderAccountingView,
    refreshAll,
    manualSync,
    loadAccountsOverview,
    loadRegister,
    loadProfitLoss,
    loadBalanceSheet,
    loadTaxSummary,
    loadExpenses,
    openNewExpense,
    openNewRefund,
    editExpense,
    selectRegisterAccount,
    toggleSection,
    injectSalesTaxSection,
    loadTaxPeriods,
    openNewTaxPeriod,
    openTaxPeriod,
    closeTaxPeriodDetail,
    updateTaxPreview,
    saveTaxPeriodDraft,
    recordTaxPayment,
    markTaxPaidExternal,
    loadCustomerRevenue,
    exportCustomerRevenuePdf
};