import {
  Alert,
  Platform,
  Pressable,
  ScrollView,
  Text,
  View,
} from 'react-native';
import { useState } from 'react';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { useRouter } from 'expo-router';
import { Ionicons } from '@expo/vector-icons';
import { useNativeActionSheet } from '../lib/useNativeActionSheet';
import { useTranslation } from 'react-i18next';
import { colors } from '../lib/theme';
import { useAuthStore } from '../stores/auth';
import { useThemeStore, type ThemeMode } from '../stores/theme';
import { useLanguageStore, type AppLanguage } from '../stores/language';
import { useUserPlan } from '../hooks/useUserPlan';
import { AppHeader } from '../components/AppHeader';

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

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

type SectionRow = {
  icon: React.ComponentProps<typeof Ionicons>['name'];
  label: string;
  sublabel: string;
  soon?: boolean;
  destructive?: boolean;
  value?: string;
  onPress?: () => void;
};

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 { mode: themeMode, setMode: setThemeMode } = useThemeStore();
  const { language, setLanguage } = useLanguageStore();
  const { plan } = useUserPlan();
  const { showActionSheetWithOptions } = useNativeActionSheet();

  // 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');

  function pickFromOptions<T extends string>(
    title: string,
    options: PickerOption<T>[],
    onPick: (value: T) => void,
  ) {
    const labels = options.map((o) => o.label);
    showActionSheetWithOptions(
      {
        title,
        options: [...labels, t('common.cancel')],
        cancelButtonIndex: labels.length,
      },
      (idx) => {
        if (idx === undefined || idx === labels.length) return;
        onPick(options[idx].value);
      },
    );
  }

  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: 'theme',
      title: t('settings.section_theme'),
      rows: [
        {
          icon: 'color-palette-outline',
          label: t('settings.theme'),
          sublabel: t('settings.theme_desc'),
          value: themeLabel,
          onPress: () =>
            pickFromOptions<ThemeMode>(t('settings.theme'), themeOptions, (v) =>
              setThemeMode(v),
            ),
        },
        {
          icon: 'language-outline',
          label: t('settings.language'),
          sublabel: t('settings.language_desc'),
          value: language === 'de' ? t('settings.language_de') : t('settings.language_en'),
          onPress: () =>
            pickFromOptions<AppLanguage>(t('settings.language'), langOptions, (v) =>
              setLanguage(v),
            ),
        },
      ],
    },
    {
      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'),
          soon: true,
        },
        {
          icon: 'star-outline',
          label: t('settings.subscription'),
          sublabel: t('settings.subscription_desc'),
          soon: true,
        },
      ],
    },
    {
      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'
              ? () =>
                  pickFromOptions<string>(
                    t('settings.lyra_voice'),
                    voiceOptions,
                    (v) => setSelectedVoice(v),
                  )
              : 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,
        },
      ],
    });
  }

  return (
    <View style={{ flex: 1, backgroundColor: '#fafafa' }}>
      <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: '#a3a3a3',
                fontFamily: 'Nunito_600SemiBold',
                textTransform: 'uppercase',
                letterSpacing: 1,
                marginBottom: 8,
                marginLeft: 4,
              }}
            >
              {section.title}
            </Text>
            <View
              style={{
                backgroundColor: '#ffffff',
                borderRadius: 14,
                overflow: 'hidden',
                shadowColor: '#000',
                shadowOffset: { width: 0, height: 1 },
                shadowOpacity: 0.04,
                shadowRadius: 3,
                elevation: 1,
              }}
            >
              {section.rows.map((row, i) => (
                <Pressable
                  key={row.label}
                  onPress={row.soon ? undefined : row.onPress}
                  disabled={row.soon}
                  style={({ pressed }) => ({
                    opacity: row.soon ? 0.5 : pressed ? 0.7 : 1,
                  })}
                >
                  <View
                    style={{
                      flexDirection: 'row',
                      alignItems: 'center',
                      gap: 12,
                      paddingHorizontal: 14,
                      paddingVertical: 12,
                      minHeight: 56,
                      borderBottomWidth: i < section.rows.length - 1 ? 1 : 0,
                      borderBottomColor: 'rgba(0,0,0,0.04)',
                    }}
                  >
                    <Ionicons
                      name={row.icon}
                      size={18}
                      color={row.destructive ? colors.error : colors.textMuted}
                    />
                    <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>
                    {row.soon ? (
                      <Text
                        style={{
                          fontSize: 10,
                          color: '#a3a3a3',
                          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="#d4d4d8"
                      />
                    )}
                  </View>
                </Pressable>
              ))}
            </View>
          </View>
        ))}

        <Text
          style={{
            textAlign: 'center',
            fontSize: 11,
            color: '#a3a3a3',
            fontFamily: 'Nunito_400Regular',
            marginTop: 6,
            opacity: 0.7,
          }}
        >
          {t('settings.skeleton_footer')}
        </Text>
        <Text
          style={{
            textAlign: 'center',
            fontSize: 10,
            color: '#a3a3a3',
            fontFamily: 'Nunito_400Regular',
            marginTop: 4,
            opacity: 0.5,
          }}
        >
          {Platform.OS}
        </Text>
      </ScrollView>
    </View>
  );
}