// email-modal.js — ES Module
// Modal to review and send invoice emails via AWS SES
// With Stripe Payment Link integration

import { showSpinner, hideSpinner, formatDate  } from '../utils/helpers.js';

let currentInvoice = null;
let quillInstance = null;

// ============================================================
// DOM & Render
// ============================================================

function ensureModalElement() {
    let modal = document.getElementById('email-modal');
    if (!modal) {
        modal = document.createElement('div');
        modal.id = 'email-modal';
        modal.className = 'modal fixed inset-0 bg-black bg-opacity-50 z-50 justify-center items-start pt-10 overflow-y-auto hidden';
        document.body.appendChild(modal);
    }
}

function renderModalContent() {
    const modal = document.getElementById('email-modal');
    if (!modal) return;

    const defaultEmail = currentInvoice.email || '';
    const existingStripeUrl = currentInvoice.stripe_payment_link_url || '';
    const stripeStatus = currentInvoice.stripe_payment_status || '';

    // Status indicator for existing link
    let stripeBadgeHtml = '';
    if (existingStripeUrl && stripeStatus === 'paid') {
        stripeBadgeHtml = '<span class="ml-2 inline-block px-2 py-0.5 text-xs font-semibold rounded-full bg-green-100 text-green-800">Paid</span>';
    } else if (existingStripeUrl && stripeStatus === 'processing') {
        stripeBadgeHtml = '<span class="ml-2 inline-block px-2 py-0.5 text-xs font-semibold rounded-full bg-yellow-100 text-yellow-800">Processing</span>';
    } else if (existingStripeUrl) {
        stripeBadgeHtml = '<span class="ml-2 inline-block px-2 py-0.5 text-xs font-semibold rounded-full bg-purple-100 text-purple-800">Active</span>';
    }

    modal.innerHTML = `
        <div class="bg-white rounded-lg shadow-2xl w-full max-w-3xl mx-auto p-8">
            <div class="flex justify-between items-center mb-6">
                <h2 class="text-2xl font-bold text-gray-800">📤 Send Invoice #${currentInvoice.invoice_number || currentInvoice.id}</h2>
                <button onclick="window.emailModal.close()" class="text-gray-400 hover:text-gray-600">
                    <svg class="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12" />
                    </svg>
                </button>
            </div>

            <form id="email-send-form" class="space-y-5">
                <div class="grid grid-cols-2 gap-4">
                    <div>
                        <label class="block text-sm font-medium text-gray-700 mb-1">Recipient Email *</label>
                        <input type="email" id="email-recipient" value="${defaultEmail}" required
                               class="w-full px-3 py-2 border border-gray-300 rounded-md focus:ring-blue-500 focus:border-blue-500">
                        <p class="text-xs text-gray-400 mt-1">You can override this for testing.</p>
                    </div>
                    <div>
                        <label class="block text-sm font-medium text-gray-700 mb-1">
                            Stripe Payment Link${stripeBadgeHtml}
                        </label>
                        <div class="flex gap-2">
                            <input type="url" id="email-stripe-link" value="${existingStripeUrl}" readonly
                                   placeholder="Click Generate to create link..."
                                   class="flex-1 px-3 py-2 border border-gray-300 rounded-md bg-gray-50 text-sm text-gray-600 focus:ring-purple-500 focus:border-purple-500">
                            <button type="button" id="stripe-generate-btn" onclick="window.emailModal.generateStripeLink()"
                                    class="px-4 py-2 bg-purple-600 text-white rounded-md hover:bg-purple-700 text-sm font-semibold whitespace-nowrap">
                                ${existingStripeUrl ? '♻️ Regenerate' : '💳 Generate'}
                            </button>
                        </div>
                        <p class="text-xs text-gray-400 mt-1" id="stripe-link-info">
                            ${existingStripeUrl 
                                ? 'Link exists. Regenerate will create a new link for the current balance.' 
                                : 'Generates a Stripe Payment Link for Card and ACH payments.'}
                        </p>
                    </div>
                </div>

                <div>
                    <label class="block text-sm font-medium text-gray-700 mb-1">Message Body</label>
                    <div id="email-message-editor" class="border border-gray-300 rounded-md bg-white h-48 overflow-y-auto"></div>
                </div>

                <div class="bg-blue-50 border border-blue-200 p-4 rounded-md flex items-center gap-3">
                    <span class="text-2xl">📎</span>
                    <div class="text-sm text-blue-800">
                        <strong>Invoice_${currentInvoice.invoice_number || currentInvoice.id}.pdf</strong> will be generated and attached automatically.
                    </div>
                </div>

                <div class="flex justify-end space-x-3 pt-4">
                    <button type="button" onclick="window.emailModal.close()"
                            class="px-6 py-2 bg-gray-200 text-gray-700 rounded-md hover:bg-gray-300">Cancel</button>
                    <button type="submit" id="email-submit-btn"
                            class="px-6 py-2 bg-blue-600 text-white rounded-md hover:bg-blue-700 font-semibold">
                        Send via AWS SES
                    </button>
                </div>
            </form>
        </div>`;

    // Initialize Quill
    const editorDiv = document.getElementById('email-message-editor');
    quillInstance = new Quill(editorDiv, {
        theme: 'snow',
        modules: {
            toolbar: [
                ['bold', 'italic', 'underline'], 
                [{ 'list': 'ordered'}, { 'list': 'bullet' }], 
                ['clean']
            ]
        }
    });

    // Variablen für den Text aufbereiten
    const invoiceNum = currentInvoice.invoice_number || currentInvoice.id;
    const totalDue = parseFloat(currentInvoice.balance ?? currentInvoice.total).toFixed(2);
    const customerName = currentInvoice.customer_name || 'Valued Customer';

    // Datum formatieren
    let dueDateStr = 'Upon Receipt';
    if (currentInvoice.due_date) {
        const d = new Date(currentInvoice.due_date);
        dueDateStr = d.toLocaleDateString('en-US', { timeZone: 'UTC' }); 
    }
    
    // Dynamischer Text für die Fälligkeit
    let paymentText = '';
    if (currentInvoice.terms && currentInvoice.terms.toLowerCase().includes('receipt')) {
        paymentText = 'Our terms are Net 30.';
    } else if (dueDateStr !== 'Upon Receipt') {
        paymentText = `payable by <strong>${dueDateStr}</strong>.`;
    } else {
        paymentText = 'Our terms are Net 30.';
    }
    
    // Detect overdue: unpaid + older than 30 days
    const invoiceDateParsed = currentInvoice.invoice_date 
        ? new Date(currentInvoice.invoice_date.split('T')[0]) 
        : null;
    const daysSinceInvoice = invoiceDateParsed 
        ? Math.floor((new Date() - invoiceDateParsed) / 86400000) 
        : 0;
    const isOverdue = !currentInvoice.paid_date && daysSinceInvoice > 30;

    let defaultHtml = '';

    if (isOverdue) {
        // Reminder / Overdue template
        defaultHtml = `
            <p>Dear ${customerName},</p>
            <p>We hope this message finds you well. Our records indicate that invoice <strong>#${invoiceNum}</strong> in the amount of <strong>$${totalDue}</strong>, dated ${formatDate(currentInvoice.invoice_date)}, remains unpaid.</p>
            <p>This invoice is now <strong>${daysSinceInvoice} days past the invoice date</strong>. We kindly request prompt payment at your earliest convenience.</p>
            <p>For your convenience, you can pay securely online using the payment link included below. We accept both Credit Card and ACH bank transfer.</p>
            <p>If payment has already been sent, please disregard this notice. Should you have any questions or need to discuss payment arrangements, please do not hesitate to reply to this email.</p>
            <p>Thank you for your attention to this matter. We value your business and look forward to continuing our partnership.</p>
            <p>Best regards,</p>
            <p><strong>Claudia Knuth</strong></p>
            <p>Bay Area Affiliates, Inc.</p>
            <p>accounting@bayarea-cc.com</p>
        `;
    } else {
        // Standard template
        defaultHtml = `
            <p>Dear ${customerName},</p>
            <p>Attached is invoice <strong>#${invoiceNum}</strong> for service performed at your location. The total amount due is <strong>$${totalDue}</strong>, ${paymentText}</p>
            <p>Please pay at your earliest convenience. We appreciate your continued business.</p>
            <p>If you have any questions about the invoice, feel free to reply to this email.</p>
            <p>Best regards,</p>
            <p><strong>Claudia Knuth</strong></p>
            <p>Bay Area Affiliates, Inc.</p>
            <p>accounting@bayarea-cc.com</p>
        `;
    }

    quillInstance.root.innerHTML = defaultHtml;

    // Bind Submit Handler
    document.getElementById('email-send-form').addEventListener('submit', submitEmail);
}

// ============================================================
// Stripe Payment Link Generation
// ============================================================

async function generateStripeLink() {
    const btn = document.getElementById('stripe-generate-btn');
    const input = document.getElementById('email-stripe-link');
    const info = document.getElementById('stripe-link-info');

    const originalBtnText = btn.innerHTML;
    btn.innerHTML = '⏳ Creating...';
    btn.disabled = true;

    try {
        const response = await fetch(`/api/invoices/${currentInvoice.id}/create-payment-link`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' }
        });

        const result = await response.json();

        if (response.ok) {
            input.value = result.paymentLinkUrl;
            currentInvoice.stripe_payment_link_url = result.paymentLinkUrl;
            currentInvoice.stripe_payment_link_id = result.paymentLinkId;
            currentInvoice.stripe_payment_status = 'pending';

            btn.innerHTML = '♻️ Regenerate';
            info.innerHTML = `✅ Payment link created for <strong>$${result.amount.toFixed(2)}</strong>. Will be included in the email.`;
            info.classList.remove('text-gray-400');
            info.classList.add('text-green-600');
        } else {
            info.textContent = `❌ ${result.error}`;
            info.classList.remove('text-gray-400');
            info.classList.add('text-red-500');
        }
    } catch (e) {
        console.error('Stripe link generation error:', e);
        info.textContent = '❌ Network error creating payment link.';
        info.classList.remove('text-gray-400');
        info.classList.add('text-red-500');
    } finally {
        btn.disabled = false;
        if (btn.innerHTML === '⏳ Creating...') {
            btn.innerHTML = originalBtnText;
        }
    }
}

// ============================================================
// Logic & API
// ============================================================

export async function openEmailModal(invoiceId) {
    ensureModalElement();
    
    if (typeof showSpinner === 'function') showSpinner('Loading invoice data...');

    try {
        const res = await fetch(`/api/invoices/${invoiceId}`);
        const data = await res.json();
        
        if (!data.invoice) throw new Error('Invoice not found');
        currentInvoice = data.invoice;

        renderModalContent();
        
        document.getElementById('email-modal').classList.remove('hidden');
        document.getElementById('email-modal').classList.add('flex');

    } catch (e) {
        console.error('Error loading invoice for email:', e);
        alert('Could not load invoice details.');
    } finally {
        if (typeof hideSpinner === 'function') hideSpinner();
    }
}

export function closeEmailModal() {
    const modal = document.getElementById('email-modal');
    if (modal) {
        modal.classList.add('hidden');
        modal.classList.remove('flex');
    }
    currentInvoice = null;
    quillInstance = null;
}

async function submitEmail(e) {
    e.preventDefault();

    const recipientEmail = document.getElementById('email-recipient').value.trim();
    const customText = quillInstance.root.innerHTML;

    if (!recipientEmail) {
        alert('Please enter a recipient email.');
        return;
    }

    const submitBtn = document.getElementById('email-submit-btn');
    submitBtn.innerHTML = '⏳ Sending...';
    submitBtn.disabled = true;

    if (typeof showSpinner === 'function') showSpinner('Generating PDF and sending email...');

    try {
        const response = await fetch(`/api/invoices/${currentInvoice.id}/send-email`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({
                recipientEmail,
                customText
            })
        });

        const result = await response.json();

        if (response.ok) {
            alert('✅ Invoice sent successfully!');
            closeEmailModal();
            if (window.invoiceView) window.invoiceView.loadInvoices();
        } else {
            alert(`❌ Error: ${result.error}`);
        }
    } catch (e) {
        console.error('Send email error:', e);
        alert('Network error while sending email.');
    } finally {
        submitBtn.innerHTML = 'Send via AWS SES';
        submitBtn.disabled = false;
        if (typeof hideSpinner === 'function') hideSpinner();
    }
}

// ============================================================
// Expose
// ============================================================
window.emailModal = {
    open: openEmailModal,
    close: closeEmailModal,
    generateStripeLink
};