import {
  View, Text, TextInput, TouchableOpacity,
  KeyboardAvoidingView, Platform, ActivityIndicator, StyleSheet,
} from 'react-native'
import { useState } from 'react'
import { useRouter } from 'expo-router'
import { SafeAreaView } from 'react-native-safe-area-context'
import { Ionicons } from '@expo/vector-icons'
import { authClient } from '@/lib/auth-client'
import { useAuthStore } from '@/store/auth.store'
import { getApiBaseUrl } from '@/lib/api-url'
import { getOrgSlug } from '@/lib/org-config'

export default function LoginScreen() {
  const router = useRouter()
  const setSession = useAuthStore((s) => s.setSession)
  const [email, setEmail] = useState('')
  const [password, setPassword] = useState('')
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState('')

  const canSubmit = email.trim().length > 0 && password.length > 0 && !loading

  async function handleLogin() {
    if (!canSubmit) return
    setLoading(true)
    setError('')

    const result = await authClient.signIn.email({
      email: email.trim().toLowerCase(),
      password,
    })

    if (result.error) {
      setError(result.error.message ?? 'E-Mail oder Passwort falsch.')
      setLoading(false)
      return
    }

    const token = (result.data as any)?.session?.token
    const rawUser = (result.data as any)?.user
    const user = rawUser
      ? {
          id: rawUser.id,
          email: rawUser.email,
          name: rawUser.name,
          mustChangePassword: rawUser.mustChangePassword ?? false,
        }
      : null
    await setSession(user ? { user } : null, token)

    // Retroaktive Org-Bindung: idempotent, schlägt still fehl wenn bereits verknüpft
    const orgSlug = getOrgSlug()
    const emailClean = email.trim().toLowerCase()
    const nameForSignup = user?.name?.trim() || emailClean.split('@')[0]
    fetch(`${getApiBaseUrl()}/api/registrierung/${orgSlug}/signup`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ name: nameForSignup, email: emailClean }),
    }).catch(() => {/* ignore */})

    setLoading(false)
    router.replace('/(app)/home' as never)
  }

  return (
    <SafeAreaView style={styles.safeArea}>
      <KeyboardAvoidingView
        behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
        style={styles.keyboardView}
      >
        <View style={styles.content}>
          <View style={styles.logoSection}>
            <View style={styles.logoBox}>
              <Text style={styles.logoLetter}>I</Text>
            </View>
            <Text style={styles.appName}>InnungsApp</Text>
            <Text style={styles.tagline}>Ihre Kreishandwerkerschaft digital</Text>
          </View>

          <View style={styles.form}>
            <Text style={styles.inputLabel}>Email-Adresse</Text>
            <View style={styles.inputWrap}>
              <Ionicons name="mail-outline" size={18} color="#94A3B8" />
              <TextInput
                style={styles.input}
                placeholder="beispiel@handwerk.de"
                placeholderTextColor="#94A3B8"
                keyboardType="email-address"
                autoCapitalize="none"
                autoCorrect={false}
                value={email}
                onChangeText={setEmail}
                returnKeyType="next"
              />
            </View>

            <Text style={[styles.inputLabel, { marginTop: 4 }]}>Passwort</Text>
            <View style={styles.inputWrap}>
              <Ionicons name="lock-closed-outline" size={18} color="#94A3B8" />
              <TextInput
                style={styles.input}
                placeholder="••••••••"
                placeholderTextColor="#94A3B8"
                secureTextEntry
                value={password}
                onChangeText={setPassword}
                onSubmitEditing={handleLogin}
                returnKeyType="go"
              />
            </View>

            {error ? (
              <View style={styles.errorBox}>
                <Text style={styles.errorText}>{error}</Text>
              </View>
            ) : null}

            <TouchableOpacity
              onPress={handleLogin}
              disabled={!canSubmit}
              style={[styles.submitBtn, !canSubmit && styles.submitBtnDisabled]}
              activeOpacity={0.85}
            >
              {loading ? (
                <ActivityIndicator color="#FFFFFF" />
              ) : (
                <View style={styles.submitContent}>
                  <Text style={styles.submitLabel}>Anmelden</Text>
                  <Ionicons name="arrow-forward" size={16} color="#FFFFFF" />
                </View>
              )}
            </TouchableOpacity>
          </View>

          <TouchableOpacity onPress={() => router.push('/(auth)/registrierung' as never)}>
            <Text style={styles.hint}>
              Noch kein Konto?{' '}
              <Text style={styles.registerLink}>Jetzt registrieren</Text>
            </Text>
          </TouchableOpacity>
        </View>
      </KeyboardAvoidingView>
    </SafeAreaView>
  )
}

const styles = StyleSheet.create({
  safeArea: { flex: 1, backgroundColor: '#FFFFFF' },
  keyboardView: { flex: 1 },
  content: { flex: 1, justifyContent: 'center', paddingHorizontal: 24 },
  logoSection: { alignItems: 'center', marginBottom: 40 },
  logoBox: {
    width: 64, height: 64, backgroundColor: '#003B7E',
    borderRadius: 18, alignItems: 'center', justifyContent: 'center', marginBottom: 16,
  },
  logoLetter: { color: '#FFFFFF', fontSize: 30, fontWeight: '900' },
  appName: { fontSize: 30, fontWeight: '800', color: '#0F172A', letterSpacing: -0.6, marginBottom: 4 },
  tagline: { fontSize: 14, color: '#64748B', textAlign: 'center' },
  form: { gap: 8 },
  inputLabel: { fontSize: 14, fontWeight: '700', color: '#334155' },
  inputWrap: {
    flexDirection: 'row', alignItems: 'center',
    backgroundColor: '#F8FAFC', borderRadius: 14,
    borderWidth: 1, borderColor: '#E2E8F0',
    paddingHorizontal: 12, gap: 8,
  },
  input: { flex: 1, paddingVertical: 13, color: '#0F172A', fontSize: 15 },
  errorBox: {
    backgroundColor: '#FEF2F2', borderWidth: 1,
    borderColor: '#FECACA', borderRadius: 12,
    paddingHorizontal: 14, paddingVertical: 10,
  },
  errorText: { color: '#B91C1C', fontSize: 13 },
  submitBtn: {
    backgroundColor: '#003B7E', borderRadius: 14,
    paddingVertical: 14, alignItems: 'center', marginTop: 8,
  },
  submitBtnDisabled: { backgroundColor: '#CBD5E1' },
  submitContent: { flexDirection: 'row', alignItems: 'center', gap: 6 },
  submitLabel: { color: '#FFFFFF', fontWeight: '700', fontSize: 15 },
  hint: { marginTop: 24, textAlign: 'center', color: '#64748B', fontSize: 13, lineHeight: 18 },
  registerLink: { color: '#003B7E', fontWeight: '700' },
})
