import {
  Alert,
  ActivityIndicator,
  Linking,
  Platform,
  ScrollView,
  Switch,
  Text,
  TouchableOpacity,
  View,
} from 'react-native';
import { useRef, useState } from 'react';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { useRouter } from 'expo-router';
import { Ionicons } from '@expo/vector-icons';
import { MenuView, type MenuAction } from '@react-native-menu/menu';
import { TrueSheet } from '@lodev09/react-native-true-sheet';
import { useTranslation } from 'react-i18next';
import { LanguageIcon } from '../components/icons/LanguageIcon';
import { useColors } from '../lib/theme';
import { useAuthStore } from '../stores/auth';
import { useAppLockStore } from '../stores/appLock';
import { useThemeStore, type ThemeMode } from '../stores/theme';
import { useLanguageStore, type AppLanguage } from '../stores/language';
import { useUserPlan } from '../hooks/useUserPlan';
import { useMe, invalidateMe, type Plan } from '../hooks/useMe';
import { apiFetch } from '../lib/api';
import { AppHeader } from '../components/AppHeader';

// ─── Subscription Sheet ────────────────────────────────────────────────────

type SubscriptionSheetProps = {
  plan: 'free' | 'pro' | 'legend';
  colors: import('../lib/theme').ColorScheme;
  t: (key: string) => string;
};

const PLAN_ACCENT: Record<string, string> = {
  free: '#737373',
  pro: '#007AFF',
  legend: '#f59e0b',
};

function SubscriptionSheet({ plan, colors, t }: SubscriptionSheetProps) {
  const accentColor = PLAN_ACCENT[plan] ?? '#737373';
  const planLabel =
    plan === 'legend'
      ? t('settings.subscription_plan_legend')
      : plan === 'pro'
        ? t('settings.subscription_plan_pro')
        : t('settings.subscription_plan_free');

  return (
    <View
      style={{
        paddingHorizontal: 20,
        paddingTop: 8,
        paddingBottom: 32,
        backgroundColor: colors.surface,
      }}
    >
      <View style={{ flexDirection: 'row', alignItems: 'center', gap: 10, marginBottom: 16 }}>
        <Ionicons name="star-outline" size={22} color={accentColor} />
        <Text
          style={{
            fontSize: 22,
            color: colors.text,
            fontFamily: 'Nunito_700Bold',
            flex: 1,
          }}
        >
          {t('settings.subscription_sheet_title')}
        </Text>
        <View
          style={{
            paddingHorizontal: 10,
            paddingVertical: 4,
            borderRadius: 20,
            backgroundColor: accentColor + '22',
          }}
        >
          <Text
            style={{
              fontSize: 12,
              fontFamily: 'Nunito_700Bold',
              color: accentColor,
              textTransform: 'uppercase',
              letterSpacing: 0.5,
            }}
          >
            {planLabel}
          </Text>
        </View>
      </View>

      <Text
        style={{
          fontSize: 14,
          color: colors.textMuted,
          fontFamily: 'Nunito_400Regular',
          lineHeight: 20,
          marginBottom: 24,
        }}
      >
        {t('settings.subscription_sheet_body')}
      </Text>

      <TouchableOpacity
        onPress={() => {
          // TODO: für iOS-Submission ggf. zu nicht-tippbarem Text degradieren
          // (Apple Guideline 3.1.1: externe Abo-Links können Review-Ablehnung triggern,
          // wenn sie als Kauf-Umgehung gewertet werden. Standalone-URL ohne Preis-Info
          // sollte ok sein, ist aber ungeprüft — bei Submission erneut prüfen.)
          Linking.openURL('https://rebreak.org/account');
        }}
        activeOpacity={0.8}
        style={{
          backgroundColor: accentColor,
          borderRadius: 14,
          paddingVertical: 14,
          alignItems: 'center',
        }}
      >
        <Text
          style={{
            fontSize: 16,
            color: '#ffffff',
            fontFamily: 'Nunito_700Bold',
          }}
        >
          {t('settings.subscription_sheet_cta')}
        </Text>
      </TouchableOpacity>
    </View>
  );
}

// ─── Settings Screen ───────────────────────────────────────────────────────

type PickerOption<T extends string> = { value: T; label: string };

type SectionRow = {
  /** Ionicons-name ODER eigenes SVG-Component (für custom icons wie LanguageIcon) */
  icon: React.ComponentProps<typeof Ionicons>['name'] | React.ComponentType<{ size?: number; color?: string }>;
  label: string;
  sublabel: string;
  soon?: boolean;
  destructive?: boolean;
  value?: string;
  onPress?: () => void;
  /** Wenn gesetzt, wrappt UIMenu (anchored Pull-Down) statt onPress-trigger */
  menu?: {
    title: string;
    actions: MenuAction[];
    onSelect: (id: string) => void;
  };
  /** Wenn gesetzt, rendert ein native UISwitch am End-Anchor statt Chevron/Value */
  toggle?: {
    value: boolean;
    onValueChange: (next: boolean) => void;
    disabled?: boolean;
  };
};

type Section = {
  key: string;
  title: string;
  rows: SectionRow[];
};

export default function SettingsScreen() {
  const router = useRouter();
  const insets = useSafeAreaInsets();
  const { t } = useTranslation();
  const { signOut } = useAuthStore();
  const appLockEnabled = useAppLockStore((s) => s.enabled);
  const appLockAvailable = useAppLockStore((s) => s.available);
  const setAppLockEnabled = useAppLockStore((s) => s.setEnabled);
  const appLockAuthenticate = useAppLockStore((s) => s.authenticate);
  const { mode: themeMode, setMode: setThemeMode } = useThemeStore();
  const { language, setLanguage } = useLanguageStore();
  const { plan } = useUserPlan();
  const colors = useColors();

  // Lyra Voice: hardcoded ElevenLabs voice IDs (expandable by user later)
  // Backend endpoint PATCH /api/profile/me/demographics does NOT accept lyraVoiceId.
  // A dedicated PATCH /api/profile/me/lyra-voice endpoint is needed from backend-agent.
  // For now: picker is wired to local state only, changes are NOT persisted.
  const [selectedVoice, setSelectedVoice] = useState('EXAVITQu4vr4xnSDxMaL');

  const { me } = useMe();

  // TrueSheet ref for Lyra-Voice picker (UISheetPresentationController bottom-sheet)
  const voiceSheetRef = useRef<TrueSheet>(null);
  const subscriptionSheetRef = useRef<TrueSheet>(null);
  const planSheetRef = useRef<TrueSheet>(null);

  async function handleToggleAppLock(next: boolean) {
    if (next) {
      // Erst verifizieren, dass Face ID / Touch ID / Passcode klappt — sonst nicht aktivieren.
      // (Switch ist controlled über appLockEnabled → springt von selbst zurück wenn wir nicht persistieren.)
      const ok = await appLockAuthenticate(t('applock.prompt'));
      if (!ok) return;
      await setAppLockEnabled(true);
    } else {
      await setAppLockEnabled(false);
    }
  }

  async function handleSignOut() {
    Alert.alert(t('auth.signOut'), '', [
      { text: t('common.cancel'), style: 'cancel' },
      {
        text: t('auth.signOut'),
        style: 'cancel',
        onPress: async () => {
          await signOut();
          router.replace('/');
        },
      },
    ]);
  }

  const themeOptions: PickerOption<ThemeMode>[] = [
    { value: 'system', label: t('settings.theme_system') },
    { value: 'light', label: t('settings.theme_light') },
    { value: 'dark', label: t('settings.theme_dark') },
  ];

  const themeLabel =
    themeMode === 'system'
      ? t('settings.theme_system')
      : themeMode === 'light'
        ? t('settings.theme_light')
        : t('settings.theme_dark');

  const langOptions: PickerOption<AppLanguage>[] = [
    { value: 'de', label: t('settings.language_de') },
    { value: 'en', label: t('settings.language_en') },
  ];

  const voiceOptions: PickerOption<string>[] = [
    { value: 'EXAVITQu4vr4xnSDxMaL', label: t('settings.lyra_voice_sarah') },
    { value: 'ThT5KcBeYPX3keUQqHPh', label: t('settings.lyra_voice_aria') },
    { value: 'XB0fDUnXU5powFXDhCwa', label: t('settings.lyra_voice_charlotte') },
    { value: 'Xb7hH8MSUJpSbSDYk0k2', label: t('settings.lyra_voice_alice') },
    { value: 'pqHfZKP75CvOlQylNhV4', label: t('settings.lyra_voice_bill') },
  ];

  const selectedVoiceName =
    voiceOptions.find((v) => v.value === selectedVoice)?.label ?? t('settings.lyra_voice_sarah');

  const sections: Section[] = [
    // Profile-Section entfernt — Profile-Edits sind in /profile-Page direkt
    {
      key: 'security',
      title: t('settings.section_security'),
      rows: [
        {
          icon: 'lock-closed-outline',
          label: t('settings.app_lock'),
          sublabel: !appLockAvailable
            ? t('settings.app_lock_unavailable')
            : Platform.OS === 'ios'
              ? t('settings.app_lock_desc')
              : t('settings.app_lock_desc_android'),
          toggle: {
            value: appLockEnabled,
            onValueChange: handleToggleAppLock,
            disabled: !appLockAvailable,
          },
        },
      ],
    },
    {
      key: 'theme',
      title: t('settings.section_theme'),
      rows: [
        {
          icon: 'color-palette-outline',
          label: t('settings.theme'),
          sublabel: t('settings.theme_desc'),
          value: themeLabel,
          menu: {
            title: t('settings.theme'),
            // Bewusst KEINE `image`-Props (SF-Symbols) — sonst rendert UIMenu mit
            // Icon-Slot reserviert und das Menu wird breiter/höher als bei Sprache.
            actions: themeOptions.map((opt) => ({
              id: opt.value,
              title: opt.label,
              state: opt.value === themeMode ? 'on' : 'off',
            })),
            onSelect: (id) => setThemeMode(id as ThemeMode),
          },
        },
        {
          icon: LanguageIcon,
          label: t('settings.language'),
          sublabel: t('settings.language_desc'),
          value: language === 'de' ? t('settings.language_de') : t('settings.language_en'),
          menu: {
            title: t('settings.language'),
            actions: langOptions.map((opt) => ({
              id: opt.value,
              title: opt.label,
              state: opt.value === language ? 'on' : 'off',
            })),
            onSelect: (id) => setLanguage(id as AppLanguage),
          },
        },
      ],
    },
    {
      key: 'notifications',
      title: t('settings.section_notifications'),
      rows: [
        {
          icon: 'notifications-outline',
          label: t('settings.notifications_push'),
          sublabel: t('settings.notifications_push_desc'),
          soon: true,
        },
        {
          icon: 'flame-outline',
          label: t('settings.notifications_streak'),
          sublabel: t('settings.notifications_streak_desc'),
          soon: true,
        },
      ],
    },
    {
      key: 'devices',
      title: t('settings.section_devices'),
      rows: [
        {
          icon: 'phone-portrait-outline',
          label: t('settings.devices'),
          sublabel: t('settings.devices_desc'),
          onPress: () => router.push('/devices'),
        },
        {
          icon: 'star-outline',
          label: t('settings.subscription'),
          sublabel: t('settings.subscription_desc'),
          value:
            plan === 'legend'
              ? t('settings.subscription_plan_legend')
              : plan === 'pro'
                ? t('settings.subscription_plan_pro')
                : t('settings.subscription_plan_free'),
          onPress: () => subscriptionSheetRef.current?.present(),
        },
      ],
    },
    {
      key: 'lyra',
      title: t('settings.section_lyra'),
      rows: [
        {
          icon: 'mic-outline',
          label: t('settings.lyra_voice'),
          sublabel:
            plan === 'legend'
              ? t('settings.lyra_voice_desc')
              : t('settings.lyra_voice_only_legend'),
          value: plan === 'legend' ? selectedVoiceName : undefined,
          // Voice picker is wired but changes are local-only until
          // PATCH /api/profile/me/lyra-voice endpoint is added by backend-agent.
          onPress:
            plan === 'legend' ? () => voiceSheetRef.current?.present() : undefined,
          soon: plan !== 'legend',
        },
      ],
    },
    {
      key: 'account',
      title: t('settings.danger_section'),
      rows: [
        {
          icon: 'log-out-outline',
          label: t('settings.sign_out'),
          sublabel: '',
          onPress: handleSignOut,
        },
        {
          icon: 'trash-outline',
          label: t('settings.delete_account'),
          sublabel: t('settings.delete_desc'),
          destructive: true,
          soon: true,
        },
      ],
    },
  ];

  if (__DEV__) {
    sections.push({
      key: 'debug',
      title: t('settings.section_debug'),
      rows: [
        {
          icon: 'bug-outline',
          label: t('settings.debug_llm'),
          sublabel: t('settings.debug_llm_desc'),
          soon: true,
        },
        {
          icon: 'volume-high-outline',
          label: t('settings.debug_tts'),
          sublabel: t('settings.debug_tts_desc'),
          soon: true,
        },
        {
          icon: 'star-outline',
          label: t('settings.debug_plan'),
          sublabel: t('settings.debug_plan_desc'),
          value: me?.plan ?? '…',
          onPress: () => planSheetRef.current?.present(),
        },
      ],
    });
  }

  return (
    <View style={{ flex: 1, backgroundColor: colors.groupedBg }}>
      <AppHeader showBack title={t('settings.title')} />

      <ScrollView
        style={{ flex: 1 }}
        contentContainerStyle={{
          paddingHorizontal: 16,
          paddingTop: 16,
          paddingBottom: insets.bottom + 40,
        }}
        showsVerticalScrollIndicator={false}
      >
        {sections.map((section) => (
          <View key={section.key} style={{ marginBottom: 24 }}>
            <Text
              style={{
                fontSize: 11,
                color: colors.textMuted,
                fontFamily: 'Nunito_600SemiBold',
                textTransform: 'uppercase',
                letterSpacing: 1,
                marginBottom: 8,
                marginLeft: 4,
              }}
            >
              {section.title}
            </Text>
            <View
              style={{
                backgroundColor: colors.card,
                borderRadius: 14,
                overflow: 'hidden',
                shadowColor: '#000',
                shadowOffset: { width: 0, height: 1 },
                shadowOpacity: 0.04,
                shadowRadius: 3,
                elevation: 1,
              }}
            >
              {section.rows.map((row, i) => {
                // Visual content of the row (icon + label + sublabel)
                const iconColor = row.destructive ? colors.error : colors.textMuted;
                const IconComponent = typeof row.icon === 'string' ? null : row.icon;
                const rowLeft = (
                  <>
                    {IconComponent ? (
                      <IconComponent size={18} color={iconColor} />
                    ) : (
                      <Ionicons
                        name={row.icon as React.ComponentProps<typeof Ionicons>['name']}
                        size={18}
                        color={iconColor}
                      />
                    )}
                    <View style={{ flex: 1 }}>
                      <Text
                        numberOfLines={1}
                        style={{
                          fontSize: 15,
                          color: row.destructive ? colors.error : colors.text,
                          fontFamily: 'Nunito_600SemiBold',
                        }}
                      >
                        {row.label}
                      </Text>
                      {row.sublabel ? (
                        <Text
                          numberOfLines={1}
                          style={{
                            fontSize: 12,
                            color: colors.textMuted,
                            fontFamily: 'Nunito_400Regular',
                            marginTop: 2,
                          }}
                        >
                          {row.sublabel}
                        </Text>
                      ) : null}
                    </View>
                  </>
                );

                const containerStyle = {
                  flexDirection: 'row' as const,
                  alignItems: 'center' as const,
                  gap: 12,
                  paddingHorizontal: 14,
                  paddingVertical: 12,
                  minHeight: 56,
                  borderBottomWidth: i < section.rows.length - 1 ? 1 : 0,
                  borderBottomColor: colors.border,
                  opacity: row.soon ? 0.5 : 1,
                };

                // Row mit Toggle: native UISwitch am End-Anchor, Label-Bereich nicht tappable
                if (row.toggle) {
                  return (
                    <View key={row.label} style={containerStyle}>
                      {rowLeft}
                      <Switch
                        value={row.toggle.value}
                        onValueChange={row.toggle.onValueChange}
                        disabled={row.toggle.disabled}
                        trackColor={{ false: colors.border, true: '#6366f1' }}
                      />
                    </View>
                  );
                }

                // Row mit Menu: Label-Bereich nicht tappable, MenuView nur am End-Anchor
                if (row.menu) {
                  return (
                    <View key={row.label} style={containerStyle}>
                      {rowLeft}
                      <MenuView
                        title={row.menu.title}
                        actions={row.menu.actions}
                        onPressAction={({ nativeEvent: { event } }) =>
                          row.menu!.onSelect(event)
                        }
                        shouldOpenOnLongPress={false}
                      >
                        <TouchableOpacity
                          hitSlop={8}
                          activeOpacity={0.6}
                        >
                          <View
                            style={{
                              flexDirection: 'row',
                              alignItems: 'center',
                              gap: 4,
                              paddingHorizontal: 8,
                              paddingVertical: 6,
                              borderRadius: 8,
                              backgroundColor: colors.surfaceElevated,
                            }}
                          >
                            {row.value ? (
                              <Text
                                style={{
                                  fontSize: 13,
                                  color: colors.textMuted,
                                  fontFamily: 'Nunito_400Regular',
                                }}
                                numberOfLines={1}
                              >
                                {row.value}
                              </Text>
                            ) : null}
                            <Ionicons
                              name="chevron-forward"
                              size={14}
                              color={colors.textMuted}
                            />
                          </View>
                        </TouchableOpacity>
                      </MenuView>
                    </View>
                  );
                }

                return (
                  <TouchableOpacity
                    key={row.label}
                    onPress={row.soon ? undefined : row.onPress}
                    disabled={row.soon}
                    activeOpacity={0.7}
                    style={{ opacity: row.soon ? 0.5 : 1 }}
                  >
                    <View style={containerStyle}>
                      {rowLeft}
                      {row.soon ? (
                        <Text
                          style={{
                            fontSize: 10,
                            color: colors.textMuted,
                            fontFamily: 'Nunito_600SemiBold',
                            textTransform: 'uppercase',
                            letterSpacing: 0.5,
                          }}
                        >
                          {t('settings.soon_badge')}
                        </Text>
                      ) : row.value ? (
                        <Text
                          style={{
                            fontSize: 13,
                            color: colors.textMuted,
                            fontFamily: 'Nunito_400Regular',
                            marginLeft: 4,
                          }}
                          numberOfLines={1}
                        >
                          {row.value}
                        </Text>
                      ) : (
                        <Ionicons
                          name="chevron-forward"
                          size={16}
                          color={colors.border}
                        />
                      )}
                    </View>
                  </TouchableOpacity>
                );
              })}
            </View>
          </View>
        ))}

        <Text
          style={{
            textAlign: 'center',
            fontSize: 11,
            color: colors.textMuted,
            fontFamily: 'Nunito_400Regular',
            marginTop: 6,
            opacity: 0.7,
          }}
        >
          {t('settings.skeleton_footer')}
        </Text>
        <Text
          style={{
            textAlign: 'center',
            fontSize: 10,
            color: colors.textMuted,
            fontFamily: 'Nunito_400Regular',
            marginTop: 4,
            opacity: 0.5,
          }}
        >
          {Platform.OS}
        </Text>
      </ScrollView>

      <TrueSheet
        ref={subscriptionSheetRef}
        detents={['auto']}
        cornerRadius={20}
        grabber
        backgroundColor={colors.surface}
      >
        <SubscriptionSheet plan={plan} colors={colors} t={t} />
      </TrueSheet>

      {__DEV__ && (
        <TrueSheet
          ref={planSheetRef}
          detents={['auto']}
          cornerRadius={20}
          grabber
          backgroundColor={colors.surface}
        >
          <PlanPickerSheetContent
            currentPlan={me?.plan ?? 'free'}
            colors={colors}
            t={t}
            onDone={() => planSheetRef.current?.dismiss()}
          />
        </TrueSheet>
      )}

      <TrueSheet
        ref={voiceSheetRef}
        detents={['auto', 1]}
        cornerRadius={20}
        grabber
        backgroundColor={colors.surface}
      >
        <View style={{ paddingHorizontal: 20, paddingTop: 8, paddingBottom: 24, backgroundColor: colors.surface }}>
          <Text
            style={{
              fontSize: 22,
              color: colors.text,
              fontFamily: 'Nunito_700Bold',
              marginBottom: 8,
            }}
          >
            {t('settings.lyra_voice')}
          </Text>
          <Text
            style={{
              fontSize: 13,
              color: colors.textMuted,
              fontFamily: 'Nunito_400Regular',
              marginBottom: 20,
              lineHeight: 18,
            }}
          >
            {t('settings.lyra_voice_desc')}
          </Text>
          {voiceOptions.map((opt, idx) => {
            const isSelected = opt.value === selectedVoice;
            return (
              <TouchableOpacity
                key={opt.value}
                onPress={() => {
                  setSelectedVoice(opt.value);
                  voiceSheetRef.current?.dismiss();
                }}
                activeOpacity={0.6}
              >
                <View
                  style={{
                    flexDirection: 'row',
                    alignItems: 'center',
                    justifyContent: 'space-between',
                    paddingVertical: 16,
                    borderBottomWidth: idx < voiceOptions.length - 1 ? 1 : 0,
                    borderBottomColor: colors.border,
                  }}
                >
                  <Text
                    style={{
                      fontSize: 16,
                      color: colors.text,
                      fontFamily: isSelected ? 'Nunito_700Bold' : 'Nunito_400Regular',
                    }}
                  >
                    {opt.label}
                  </Text>
                  {isSelected ? (
                    <Ionicons name="checkmark" size={20} color={colors.brandOrange} />
                  ) : null}
                </View>
              </TouchableOpacity>
            );
          })}
        </View>
      </TrueSheet>
    </View>
  );
}

// ─── Plan-Override Sheet (DEV only) ───────────────────────────────────────

const DEV_PLANS: Plan[] = ['free', 'pro', 'legend'];

const DEV_PLAN_ACCENT: Record<Plan, string> = {
  free: '#737373',
  pro: '#007AFF',
  legend: '#f59e0b',
};

function PlanPickerSheetContent({
  currentPlan,
  colors,
  t,
  onDone,
}: {
  currentPlan: Plan;
  colors: import('../lib/theme').ColorScheme;
  t: (key: string) => string;
  onDone: () => void;
}) {
  const [loading, setLoading] = useState(false);

  async function pick(plan: Plan) {
    if (plan === currentPlan || loading) return;
    setLoading(true);
    try {
      await apiFetch('/api/dev/set-plan', { method: 'POST', body: { plan } });
      invalidateMe();
      onDone();
    } catch (e: unknown) {
      Alert.alert(t('common.error'), e instanceof Error ? e.message : String(e));
    } finally {
      setLoading(false);
    }
  }

  return (
    <View style={{ paddingHorizontal: 20, paddingTop: 8, paddingBottom: 32, backgroundColor: colors.surface }}>
      <Text style={{ fontSize: 16, fontFamily: 'Nunito_700Bold', color: colors.text, marginBottom: 4 }}>
        {t('settings.debug_plan')}
      </Text>
      <Text style={{ fontSize: 12, fontFamily: 'Nunito_400Regular', color: colors.textMuted, marginBottom: 20, lineHeight: 17 }}>
        {t('settings.debug_plan_desc')}
      </Text>
      {DEV_PLANS.map((plan, idx) => {
        const isActive = plan === currentPlan;
        const accent = DEV_PLAN_ACCENT[plan];
        return (
          <TouchableOpacity
            key={plan}
            onPress={() => pick(plan)}
            disabled={loading || isActive}
            activeOpacity={0.6}
          >
            <View
              style={{
                flexDirection: 'row',
                alignItems: 'center',
                justifyContent: 'space-between',
                paddingVertical: 16,
                borderBottomWidth: idx < DEV_PLANS.length - 1 ? 1 : 0,
                borderBottomColor: colors.border,
                opacity: loading && !isActive ? 0.5 : 1,
              }}
            >
              <View style={{ flexDirection: 'row', alignItems: 'center', gap: 10 }}>
                <View style={{ width: 10, height: 10, borderRadius: 5, backgroundColor: accent }} />
                <Text
                  style={{
                    fontSize: 16,
                    color: colors.text,
                    fontFamily: isActive ? 'Nunito_700Bold' : 'Nunito_400Regular',
                    textTransform: 'capitalize',
                  }}
                >
                  {plan}
                </Text>
              </View>
              {isActive ? (
                loading ? (
                  <ActivityIndicator size="small" color={accent} />
                ) : (
                  <Ionicons name="checkmark" size={20} color={accent} />
                )
              ) : null}
            </View>
          </TouchableOpacity>
        );
      })}
    </View>
  );
}