import MaterialIcons from '@expo/vector-icons/MaterialIcons';
import { useRouter } from 'expo-router';
import { ApiError, type Track } from '@pipu/core';
import type { ComponentProps, ReactNode } from 'react';
import { useState, useSyncExternalStore } from 'react';
import { useTranslation } from 'react-i18next';
import {
  ActivityIndicator,
  Image,
  Modal,
  Pressable,
  StyleSheet,
  Text,
  TextInput,
  View,
  type StyleProp,
  type TextInputProps,
  type ViewStyle,
} from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';

import { useSessionCtx } from '../lib/session';
import { downloads, sizedCover } from '../offline/downloads';
import { absolute } from '../player/controller';
import { radius, useColors, type Colors } from '../theme';

export type IconName = ComponentProps<typeof MaterialIcons>['name'];

export function Icon({ name, size = 22, color }: { name: IconName; size?: number; color?: string }) {
  const colors = useColors();
  return <MaterialIcons name={name} size={size} color={color ?? colors.text2} />;
}

export function Screen({ children, scroll = false, style }: { children: ReactNode; scroll?: boolean; style?: StyleProp<ViewStyle> }) {
  const s = useStyles();
  void scroll;
  return (
    <SafeAreaView style={[s.screen, style]} edges={['top', 'left', 'right']}>
      {children}
    </SafeAreaView>
  );
}

export function H1({ children }: { children: ReactNode }) {
  const s = useStyles();
  return <Text style={s.h1}>{children}</Text>;
}

export function Muted({ children, style }: { children: ReactNode; style?: StyleProp<ViewStyle> }) {
  const s = useStyles();
  return <Text style={[s.muted, style as object]}>{children}</Text>;
}

export function Field({
  label,
  error,
  hint,
  secure,
  ...rest
}: TextInputProps & { label: string; error?: string; hint?: string; secure?: boolean }) {
  const s = useStyles();
  const colors = useColors();
  const { t } = useTranslation();
  const [shown, setShown] = useState(false);
  return (
    <View style={{ gap: 6 }}>
      <Text style={s.label}>{label}</Text>
      <View>
        <TextInput
          placeholderTextColor={colors.text3}
          autoCapitalize="none"
          autoCorrect={false}
          secureTextEntry={secure && !shown}
          accessibilityLabel={label}
          style={[s.input, error ? { borderColor: colors.danger } : null, secure ? { paddingRight: 48 } : null]}
          {...rest}
        />
        {secure && (
          <Pressable
            onPress={() => setShown((v) => !v)}
            style={s.reveal}
            accessibilityRole="button"
            accessibilityLabel={shown ? t('form.hide_password') : t('form.show_password')}
          >
            <Icon name={shown ? 'visibility-off' : 'visibility'} size={20} color={colors.text3} />
          </Pressable>
        )}
      </View>
      {(error ?? hint) && <Text style={{ color: error ? colors.danger : colors.text3, fontSize: 12 }}>{error ?? hint}</Text>}
    </View>
  );
}

export function Button({
  title,
  onPress,
  variant = 'primary',
  busy,
  disabled,
  icon,
}: {
  title: string;
  onPress: () => void;
  variant?: 'primary' | 'secondary' | 'ghost' | 'danger';
  busy?: boolean;
  disabled?: boolean;
  icon?: IconName;
}) {
  const s = useStyles();
  const colors = useColors();
  const bg = { primary: colors['accent-fill'], secondary: colors.surface3, ghost: 'transparent', danger: colors['danger-soft'] }[variant];
  const fg = { primary: '#fff', secondary: colors.text, ghost: colors.text2, danger: colors.danger }[variant];
  return (
    <Pressable
      onPress={onPress}
      disabled={disabled || busy}
      accessibilityRole="button"
      accessibilityState={{ disabled: disabled || busy, busy }}
      style={({ pressed }) => [s.button, { backgroundColor: bg, opacity: disabled ? 0.5 : pressed ? 0.75 : 1 }]}
    >
      {busy ? <ActivityIndicator color={fg} /> : icon ? <Icon name={icon} size={20} color={fg} /> : null}
      <Text style={{ color: fg, fontWeight: '600', fontSize: 15 }}>{title}</Text>
    </Pressable>
  );
}

export function ErrorBox({ children }: { children?: ReactNode }) {
  const s = useStyles();
  const colors = useColors();
  if (!children) return null;
  return (
    <View style={s.error} accessibilityRole="alert">
      <Text style={{ color: colors.danger, fontWeight: '500' }}>{children}</Text>
    </View>
  );
}

/** Текст ошибки API: перевод errors:<code>. */
export function useErrorText(): (err: unknown) => string {
  const { t, i18n } = useTranslation();
  const tr = t as unknown as (k: string, o?: Record<string, unknown>) => string;
  return (err) => {
    const code = err instanceof ApiError ? err.code : 'common.internal';
    const key = `errors:${code}`;
    return i18n.exists(key) ? tr(key, err instanceof ApiError ? err.params : {}) : tr('errors:common.internal');
  };
}

export function Cover({
  album,
  size,
  round,
}: {
  album: { id: string; cover_url?: string | null; cover_colors?: string[] };
  size: number;
  round?: boolean;
}) {
  const colors = useColors();
  const { server } = useSessionCtx();
  const remote = server ? absolute(server, album.cover_url) : undefined;
  const px = size * 2 <= 64 ? 64 : size * 2 <= 300 ? 300 : 1200;
  // У скачанных альбомов обложка 300 px лежит на устройстве — работает и без сети.
  const local = useSyncExternalStore(downloads.subscribe, () => (px <= 300 ? downloads.localAlbumCover(album.id) : undefined));
  const uri = local ?? (remote ? sizedCover(remote, px) : undefined);
  const bg = album.cover_colors?.[0] ?? colors.surface3;
  return (
    <View style={{ width: size, height: size, borderRadius: round ? size / 2 : 8, backgroundColor: bg, overflow: 'hidden', alignItems: 'center', justifyContent: 'center' }}>
      {uri ? (
        <Image source={{ uri }} style={{ width: size, height: size }} />
      ) : (
        <Icon name={round ? 'person' : 'album'} size={size * 0.45} color="rgba(255,255,255,0.8)" />
      )}
    </View>
  );
}

export function formatDuration(ms: number): string {
  const sec = Math.max(0, Math.round(ms / 1000));
  return `${Math.floor(sec / 60)}:${String(sec % 60).padStart(2, '0')}`;
}

export function TrackRow({
  track,
  current,
  onPress,
  onLike,
  numbered,
  meta,
  trailing,
}: {
  track: Track;
  current?: boolean;
  onPress: () => void;
  onLike?: () => void;
  numbered?: number;
  meta?: string;
  trailing?: ReactNode;
}) {
  const s = useStyles();
  const colors = useColors();
  const { t } = useTranslation();
  const liked = track.reaction === 'like';
  const router = useRouter();
  const saved = useSyncExternalStore(downloads.subscribe, () => downloads.isDownloaded(track.id));
  return (
    <Pressable
      onPress={onPress}
      disabled={!track.available}
      accessibilityRole="button"
      accessibilityLabel={`${track.title}, ${track.artists.map((a) => a.name).join(', ')}`}
      style={({ pressed }) => [s.row, current && { backgroundColor: colors['accent-soft'] }, pressed && { backgroundColor: colors.hover }, !track.available && { opacity: 0.4 }]}
    >
      {numbered !== undefined ? (
        <Text style={s.num}>{numbered}</Text>
      ) : (
        <Cover album={track.album} size={44} />
      )}
      <View style={{ flex: 1, minWidth: 0 }}>
        <Text numberOfLines={1} style={[s.rowTitle, current && { color: colors.accent2 }]}>
          {track.title}
        </Text>
        <Text numberOfLines={1} style={s.rowSub}>
          {track.artists.map((a) => a.name).join(', ')}
          {meta ? ` · ${meta}` : ''}
        </Text>
      </View>
      {onLike && (
        <Pressable
          onPress={onLike}
          hitSlop={10}
          accessibilityRole="button"
          accessibilityLabel={t(liked ? 'player.unlike' : 'player.like')}
        >
          <Icon name={liked ? 'favorite' : 'favorite-border'} size={20} color={liked ? colors.accent2 : colors.text3} />
        </Pressable>
      )}
      {trailing}
      <Pressable accessibilityRole="button" accessibilityLabel={t('playlists.add')} style={{ padding: 8 }}
        onPress={(e) => { e.stopPropagation(); router.push({ pathname: '/playlists', params: { track: track.id } }); }}>
        <Icon name="playlist-add" size={22} />
      </Pressable>
      {saved && !trailing && <Icon name="download-done" size={16} color={colors.accent2} />}
      <Text style={s.duration}>{formatDuration(track.duration_ms)}</Text>
    </Pressable>
  );
}

/** Нижний лист: затемнение, заголовок, содержимое; закрывается кнопкой «назад» и тапом по фону. */
export function Sheet({ visible, title, onClose, children }: { visible: boolean; title: string; onClose: () => void; children: ReactNode }) {
  const colors = useColors();
  const { t } = useTranslation();
  return (
    <Modal transparent animationType="slide" visible={visible} onRequestClose={onClose}>
      <Pressable style={{ flex: 1, backgroundColor: colors.overlay }} onPress={onClose} accessibilityLabel={title} />
      <SafeAreaView edges={['bottom']} style={{ backgroundColor: colors.surface, borderTopLeftRadius: radius.lg, borderTopRightRadius: radius.lg }}>
        <View style={{ padding: 20, gap: 16 }}>
          <View style={{ flexDirection: 'row', alignItems: 'center', justifyContent: 'space-between' }}>
            <Text style={{ color: colors.text, fontSize: 18, fontWeight: '700' }} accessibilityRole="header">
              {title}
            </Text>
            <Pressable onPress={onClose} hitSlop={10} accessibilityRole="button" accessibilityLabel={t('form.close')}>
              <Icon name="close" color={colors.text2} />
            </Pressable>
          </View>
          {children}
        </View>
      </SafeAreaView>
    </Modal>
  );
}

export function Segmented<T extends string>({
  value,
  options,
  onChange,
}: {
  value: T;
  options: { value: T; label: string }[];
  onChange: (v: T) => void;
}) {
  const s = useStyles();
  const colors = useColors();
  return (
    <View style={s.segmented} accessibilityRole="tablist">
      {options.map((o) => (
        <Pressable
          key={o.value}
          onPress={() => onChange(o.value)}
          accessibilityRole="tab"
          accessibilityState={{ selected: value === o.value }}
          style={[s.segment, value === o.value && { backgroundColor: colors['accent-fill'] }]}
        >
          <Text style={{ color: value === o.value ? '#fff' : colors.text2, fontWeight: '600', fontSize: 13 }}>{o.label}</Text>
        </Pressable>
      ))}
    </View>
  );
}

const styles = new Map<Colors, ReturnType<typeof makeStyles>>();

/** Стили кита под активную тему (создаются один раз на тему). */
function useStyles() {
  const colors = useColors();
  let st = styles.get(colors);
  if (!st) styles.set(colors, (st = makeStyles(colors)));
  return st;
}

const makeStyles = (colors: Colors) =>
  StyleSheet.create({
    screen: { flex: 1, backgroundColor: colors.bg },
    h1: { color: colors.text, fontSize: 26, fontWeight: '700', letterSpacing: -0.3 },
    muted: { color: colors.text2, lineHeight: 21 },
    label: { color: colors.text2, fontSize: 13, fontWeight: '600' },
    input: {
      height: 48,
      paddingHorizontal: 14,
      borderRadius: radius.md,
      backgroundColor: colors.surface2,
      borderWidth: 1,
      borderColor: colors.line2,
      color: colors.text,
      fontSize: 15,
    },
    reveal: { position: 'absolute', right: 6, top: 6, width: 36, height: 36, alignItems: 'center', justifyContent: 'center' },
    button: { height: 48, borderRadius: radius.md, flexDirection: 'row', gap: 8, alignItems: 'center', justifyContent: 'center', paddingHorizontal: 18 },
    error: { padding: 12, borderRadius: 10, backgroundColor: colors['danger-soft'] },
    row: { flexDirection: 'row', alignItems: 'center', gap: 12, paddingHorizontal: 16, paddingVertical: 8, minHeight: 60 },
    num: { width: 44, textAlign: 'center', color: colors.text3, fontVariant: ['tabular-nums'] },
    rowTitle: { color: colors.text, fontSize: 15, fontWeight: '500' },
    rowSub: { color: colors.text2, fontSize: 13, marginTop: 2 },
    duration: { color: colors.text3, fontSize: 12, fontVariant: ['tabular-nums'] },
    segmented: { flexDirection: 'row', gap: 2, padding: 3, borderRadius: 10, backgroundColor: colors.surface2, alignSelf: 'flex-start' },
    segment: { paddingHorizontal: 14, height: 32, borderRadius: 8, alignItems: 'center', justifyContent: 'center' },
  });