import {
  View, Text, TextInput, TouchableOpacity,
  KeyboardAvoidingView, Platform, ActivityIndicator, StyleSheet, ScrollView,
} 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 RegistrierungScreen() {
  const router = useRouter()
  const setSession = useAuthStore((s) => s.setSession)
  const [name, setName] = useState('')
  const [email, setEmail] = useState('')
  const [password, setPassword] = useState('')
  const [passwordConfirm, setPasswordConfirm] = useState('')
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState('')

  const canSubmit =
    name.trim().length > 0 &&
    email.trim().length > 0 &&
    password.length >= 8 &&
    password === passwordConfirm &&
    !loading

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

    const orgSlug = getOrgSlug()

    // Step 1: Create better-auth account
    const signUpResult = await authClient.signUp.email({
      name: name.trim(),
      email: email.trim().toLowerCase(),
      password,
    })

    if (signUpResult.error) {
      setError(signUpResult.error.message ?? 'Registrierung fehlgeschlagen.')
      setLoading(false)
      return
    }

    // Step 2: Create Member record linked to org
    try {
      const apiUrl = getApiBaseUrl()
      const res = await fetch(`${apiUrl}/api/registrierung/${orgSlug}/signup`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          name: name.trim(),
          email: email.trim().toLowerCase(),
        }),
      })
      if (!res.ok) {
        console.warn('Member-Datensatz konnte nicht angelegt werden:', await res.text())
      }
    } catch (e) {
      console.warn('Member-API nicht erreichbar:', e)
    }

    // Step 3: Sign in to get session
    const signInResult = await authClient.signIn.email({
      email: email.trim().toLowerCase(),
      password,
    })

    if (signInResult.error) {
      setError('Konto erstellt, aber Anmeldung fehlgeschlagen. Bitte einloggen.')
      setLoading(false)
      router.replace('/(auth)/login' as never)
      return
    }

    const token = (signInResult.data as any)?.session?.token
    const user = (signInResult.data as any)?.user
    await setSession(user ? { user } : null, token)

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

  return (
    <SafeAreaView style={styles.safeArea}>
      <KeyboardAvoidingView
        behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
        style={styles.keyboardView}
      >
        <ScrollView contentContainerStyle={styles.scrollContent} keyboardShouldPersistTaps="handled">
          <View style={styles.content}>
            <TouchableOpacity onPress={() => router.back()} style={styles.backBtn}>
              <Ionicons name="arrow-back" size={20} color="#334155" />
            </TouchableOpacity>

            <View style={styles.logoSection}>
              <View style={styles.logoBox}>
                <Text style={styles.logoLetter}>I</Text>
              </View>
              <Text style={styles.title}>Konto erstellen</Text>
              <Text style={styles.subtitle}>Registrieren Sie sich für Ihre Innung</Text>
            </View>

            <View style={styles.form}>
              <Text style={styles.inputLabel}>Name</Text>
              <View style={styles.inputWrap}>
                <Ionicons name="person-outline" size={18} color="#94A3B8" />
                <TextInput
                  style={styles.input}
                  placeholder="Vor- und Nachname"
                  placeholderTextColor="#94A3B8"
                  autoCapitalize="words"
                  autoCorrect={false}
                  value={name}
                  onChangeText={setName}
                  returnKeyType="next"
                />
              </View>

              <Text style={[styles.inputLabel, { marginTop: 4 }]}>E-Mail-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="Mindestens 8 Zeichen"
                  placeholderTextColor="#94A3B8"
                  secureTextEntry
                  value={password}
                  onChangeText={setPassword}
                  returnKeyType="next"
                />
              </View>

              <Text style={[styles.inputLabel, { marginTop: 4 }]}>Passwort bestätigen</Text>
              <View style={[styles.inputWrap, passwordConfirm.length > 0 && password !== passwordConfirm && styles.inputError]}>
                <Ionicons name="lock-closed-outline" size={18} color="#94A3B8" />
                <TextInput
                  style={styles.input}
                  placeholder="Passwort wiederholen"
                  placeholderTextColor="#94A3B8"
                  secureTextEntry
                  value={passwordConfirm}
                  onChangeText={setPasswordConfirm}
                  onSubmitEditing={handleRegister}
                  returnKeyType="go"
                />
              </View>

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

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

            <TouchableOpacity onPress={() => router.replace('/(auth)/login' as never)}>
              <Text style={styles.loginLink}>
                Bereits registriert?{' '}
                <Text style={styles.loginLinkBold}>Jetzt anmelden</Text>
              </Text>
            </TouchableOpacity>
          </View>
        </ScrollView>
      </KeyboardAvoidingView>
    </SafeAreaView>
  )
}

const styles = StyleSheet.create({
  safeArea: { flex: 1, backgroundColor: '#FFFFFF' },
  keyboardView: { flex: 1 },
  scrollContent: { flexGrow: 1 },
  content: { flex: 1, paddingHorizontal: 24, paddingTop: 16, paddingBottom: 32 },
  backBtn: {
    width: 40, height: 40,
    borderRadius: 12,
    backgroundColor: '#F8FAFC',
    borderWidth: 1, borderColor: '#E2E8F0',
    alignItems: 'center', justifyContent: 'center',
    marginBottom: 24,
  },
  logoSection: { alignItems: 'center', marginBottom: 32 },
  logoBox: {
    width: 64, height: 64, backgroundColor: '#003B7E',
    borderRadius: 18, alignItems: 'center', justifyContent: 'center', marginBottom: 16,
  },
  logoLetter: { color: '#FFFFFF', fontSize: 30, fontWeight: '900' },
  title: { fontSize: 26, fontWeight: '800', color: '#0F172A', letterSpacing: -0.5, marginBottom: 4 },
  subtitle: { fontSize: 14, color: '#64748B', textAlign: 'center' },
  form: { gap: 8, marginBottom: 24 },
  inputLabel: { fontSize: 14, fontWeight: '700', color: '#334155' },
  inputWrap: {
    flexDirection: 'row', alignItems: 'center',
    backgroundColor: '#F8FAFC', borderRadius: 14,
    borderWidth: 1, borderColor: '#E2E8F0',
    paddingHorizontal: 12, gap: 8,
  },
  inputError: { borderColor: '#FECACA' },
  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 },
  loginLink: { textAlign: 'center', color: '#64748B', fontSize: 14 },
  loginLinkBold: { color: '#003B7E', fontWeight: '700' },
})