/**
 * Baner jednorazowej migracji na nowo podpisane APK.
 *
 * Dlaczego w ogóle: klucz podpisujący stare buildy przepadł, a Android pozwala nadpisać
 * aplikację tylko buildem z tym samym podpisem. Nowa wersja wymaga więc odinstalowania
 * starej, co czyści SecureStore razem z `goon.device_id`, czyli kodem synchronizacji.
 * Dane (ulubione, zapisane wyszukiwania, ukryte, postęp) zostają na serwerze pod tym id,
 * ale bez kodu nie ma jak ich odzyskać. Dlatego kod jest w banerze na wierzchu, a nie
 * schowany w ustawieniach: liczy się, żeby user skopiował go PRZED odinstalowaniem.
 *
 * Zwinięty pasek siedzi nad listą scen (nie w ListHeaderComponent, tam znikałby przy
 * wyszukiwaniu i odjeżdżał przy scrollu). Rozwija się w modal z krokami.
 */
import React from 'react';
import { Linking, Modal, Pressable, ScrollView, StyleSheet, Text, View } from 'react-native';
import * as Clipboard from 'expo-clipboard';

import { MIGRATION_NOTICE, needsManualMigration } from '../migrationNotice';
import {
  dismissMigrationNotice,
  getDeviceId,
  isMigrationNoticeHidden,
  snoozeMigrationNotice,
} from '../storage';
import { theme } from '../theme';

export function MigrationBanner() {
  const [show, setShow] = React.useState(false);
  const [open, setOpen] = React.useState(false);
  const [deviceId, setDeviceId] = React.useState('');
  const [copied, setCopied] = React.useState(false);

  React.useEffect(() => {
    // Warunek na runtime, nie tylko na kanał OTA: ten sam bundle bywa publikowany na 1.2,
    // a tam baner byłby szkodliwy (kazałby migrować z wersji, na którą user właśnie przeszedł).
    if (!needsManualMigration()) return;
    let cancelled = false;
    (async () => {
      try {
        const [hidden, id] = await Promise.all([isMigrationNoticeHidden(), getDeviceId()]);
        if (cancelled || hidden) return;
        setDeviceId(id);
        setShow(true);
      } catch {
        // brak SecureStore → nie ma czym migrować, nie strasz banerem
      }
    })();
    return () => {
      cancelled = true;
    };
  }, []);

  const copy = React.useCallback(async () => {
    await Clipboard.setStringAsync(deviceId);
    setCopied(true);
  }, [deviceId]);

  const later = React.useCallback(() => {
    setOpen(false);
    setShow(false);
    snoozeMigrationNotice().catch(() => {});
  }, []);

  const done = React.useCallback(() => {
    setOpen(false);
    setShow(false);
    dismissMigrationNotice().catch(() => {});
  }, []);

  if (!show) return null;

  return (
    <>
      <Pressable style={styles.bar} onPress={() => setOpen(true)}>
        <View style={{ flex: 1 }}>
          <Text style={styles.barTitle}>Update {MIGRATION_NOTICE.version} needs a manual install</Text>
          <Text style={styles.barHint}>
            Copy your sync code first, or your favourites do not come across. Tap for the steps.
          </Text>
        </View>
        <Text style={styles.barChevron}>›</Text>
      </Pressable>

      <Modal visible={open} transparent animationType="fade" onRequestClose={later}>
        <View style={styles.backdrop}>
          <View style={styles.card}>
            <Text style={styles.title}>Update {MIGRATION_NOTICE.version}</Text>
            <ScrollView style={styles.scroll} contentContainerStyle={{ paddingBottom: 4 }}>
              <Text style={styles.lead}>
                The new build is signed with a different key, so Android will not install it
                over the current app. Uninstall first, install the download second. That wipes
                what is stored on the phone, so copy your sync code before you start.
              </Text>

              <Text style={styles.step}>1. Copy your sync code</Text>
              <Pressable style={styles.codeRow} onPress={copy}>
                <Text style={styles.code} numberOfLines={1}>
                  {deviceId || '…'}
                </Text>
                <Text style={styles.copyBtn}>{copied ? 'Copied' : 'Copy'}</Text>
              </Pressable>
              <Text style={styles.note}>
                Paste it somewhere safe. Without it your favourites, saved searches, hidden
                list and watch progress cannot be found again.
              </Text>

              <Text style={styles.step}>2. Download the new version</Text>
              <Pressable
                style={styles.dlBtn}
                onPress={() => Linking.openURL(MIGRATION_NOTICE.downloadUrl).catch(() => {})}
              >
                <Text style={styles.dlText}>Open {MIGRATION_NOTICE.downloadUrl.replace(/^https?:\/\//, '').replace(/\/$/, '')}</Text>
              </Pressable>

              <Text style={styles.step}>3. Uninstall Goon, then open the file</Text>
              <Text style={styles.note}>
                Long-press the app icon, Uninstall. Then open the .apk from your notifications
                or Downloads.
              </Text>

              <Text style={styles.step}>4. Paste the code back</Text>
              <Text style={styles.note}>
                Settings, Backup &amp; sync, Restore: paste the code, tap Import.
              </Text>

              <Text style={styles.sorry}>
                A one-off, sorry. Signing keys cannot be recovered, so this once it has to be
                done by hand. Later updates install themselves again.
              </Text>
            </ScrollView>

            <Pressable style={styles.primaryBtn} onPress={done}>
              <Text style={styles.primaryText}>Done, do not show again</Text>
            </Pressable>
            <Pressable style={styles.secondaryBtn} onPress={later}>
              <Text style={styles.secondaryText}>Remind me tomorrow</Text>
            </Pressable>
          </View>
        </View>
      </Modal>
    </>
  );
}

const styles = StyleSheet.create({
  bar: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 10,
    marginHorizontal: 12,
    marginBottom: 10,
    paddingVertical: 10,
    paddingHorizontal: 12,
    borderRadius: 12,
    borderWidth: 1,
    borderColor: theme.accentText,
    backgroundColor: theme.bgElevated,
  },
  barTitle: { color: theme.fg, fontSize: 14, fontWeight: '700' },
  barHint: { color: theme.muted, fontSize: 12, marginTop: 2, lineHeight: 16 },
  barChevron: { color: theme.accentText, fontSize: 22, fontWeight: '700' },

  backdrop: {
    flex: 1,
    backgroundColor: 'rgba(0,0,0,0.7)',
    alignItems: 'center',
    justifyContent: 'center',
    padding: 24,
  },
  card: {
    width: '100%',
    maxHeight: '85%',
    backgroundColor: theme.bgElevated,
    borderRadius: 16,
    borderColor: theme.border,
    borderWidth: 1,
    padding: 20,
  },
  title: { color: theme.fg, fontSize: 20, fontWeight: '800', marginBottom: 12 },
  scroll: { flexGrow: 0 },
  lead: { color: theme.fg, fontSize: 14, lineHeight: 20, marginBottom: 16 },
  step: {
    color: theme.accentText,
    fontSize: 12,
    fontWeight: '800',
    textTransform: 'uppercase',
    letterSpacing: 0.5,
    marginTop: 8,
    marginBottom: 8,
  },
  codeRow: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 10,
    backgroundColor: theme.card,
    borderRadius: 10,
    borderWidth: 1,
    borderColor: theme.border,
    paddingVertical: 10,
    paddingHorizontal: 12,
  },
  code: { color: theme.fg, fontSize: 13, flex: 1 },
  copyBtn: { color: theme.accentText, fontSize: 13, fontWeight: '800' },
  note: { color: theme.muted, fontSize: 13, lineHeight: 19, marginTop: 8 },
  dlBtn: {
    backgroundColor: theme.card,
    borderRadius: 10,
    borderWidth: 1,
    borderColor: theme.accentText,
    paddingVertical: 12,
    alignItems: 'center',
  },
  dlText: { color: theme.fg, fontSize: 14, fontWeight: '700' },
  sorry: { color: theme.mutedDim, fontSize: 12, lineHeight: 18, marginTop: 18 },

  primaryBtn: {
    marginTop: 14,
    backgroundColor: theme.accent,
    borderRadius: 10,
    paddingVertical: 12,
    alignItems: 'center',
  },
  primaryText: { color: theme.fg, fontSize: 15, fontWeight: '700' },
  secondaryBtn: { marginTop: 8, paddingVertical: 10, alignItems: 'center' },
  secondaryText: { color: theme.muted, fontSize: 14, fontWeight: '600' },
});