import { useMemo, useState } from 'react';
import { Pressable, ScrollView, StyleSheet, Text, TextInput, View } from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { SearchIcon } from '../../src/components/Icons';
import { LetterRow } from '../../src/components/LetterRow';
import { archiveFilters, filterLetters, letters, type ArchiveFilter } from '../../src/data/letters';
import { colors, font, radius, shadow, space } from '../../src/theme';

/** Archive, design option 3b: search, filter chips, letters grouped by month. */
export default function Archive() {
  const insets = useSafeAreaInsets();
  const [filter, setFilter] = useState<ArchiveFilter>('Alle');
  const [query, setQuery] = useState('');

  const groups = useMemo(() => {
    const needle = query.trim().toLowerCase();
    const matches = filterLetters(filter).filter(
      (l) =>
        !needle ||
        l.sender.toLowerCase().includes(needle) ||
        l.summary.toLowerCase().includes(needle),
    );

    const out: { month: string; items: typeof letters }[] = [];
    for (const letter of matches) {
      const last = out[out.length - 1];
      if (last && last.month === letter.month) last.items.push(letter);
      else out.push({ month: letter.month, items: [letter] });
    }
    return out;
  }, [filter, query]);

  return (
    <View style={styles.screen}>
      <ScrollView
        contentContainerStyle={{ paddingTop: insets.top + 22, paddingBottom: 24 }}
        showsVerticalScrollIndicator={false}
        keyboardShouldPersistTaps="handled"
      >
        <View style={styles.header}>
          <Text style={styles.title}>Dein Archiv</Text>
          <Text style={styles.subtitle}>{letters.length} Briefe – alles sicher an einem Ort</Text>
        </View>

        <View style={styles.search}>
          <SearchIcon />
          <TextInput
            style={styles.searchInput}
            value={query}
            onChangeText={setQuery}
            placeholder="Suchen, z. B. „Jobcenter“"
            placeholderTextColor={colors.slateLight}
            returnKeyType="search"
          />
        </View>

        <ScrollView
          horizontal
          showsHorizontalScrollIndicator={false}
          contentContainerStyle={styles.chips}
        >
          {archiveFilters.map((name) => {
            const active = name === filter;
            return (
              <Pressable
                key={name}
                onPress={() => setFilter(name)}
                style={[styles.chip, active ? styles.chipActive : styles.chipIdle]}
                accessibilityRole="button"
                accessibilityState={{ selected: active }}
              >
                <Text style={active ? styles.chipLabelActive : styles.chipLabel}>{name}</Text>
              </Pressable>
            );
          })}
        </ScrollView>

        <View style={styles.body}>
          {groups.length === 0 ? (
            <Text style={styles.empty}>Keine Briefe gefunden.</Text>
          ) : (
            groups.map((group) => (
              <View key={group.month}>
                <Text style={styles.month}>{group.month}</Text>
                <View style={styles.list}>
                  {group.items.map((letter) => (
                    <LetterRow key={letter.id} letter={letter} variant="archive" />
                  ))}
                </View>
              </View>
            ))
          )}
        </View>
      </ScrollView>
    </View>
  );
}

const styles = StyleSheet.create({
  screen: { flex: 1, backgroundColor: colors.canvas },

  header: { paddingHorizontal: space.gutter },
  title: { fontFamily: font.display, fontSize: 26, letterSpacing: -0.5, color: colors.ink },
  subtitle: { fontFamily: font.semibold, fontSize: 14, color: colors.slate, marginTop: 2 },

  search: {
    marginHorizontal: space.gutter,
    marginTop: 16,
    backgroundColor: colors.surface,
    borderRadius: radius.lg,
    paddingVertical: 13,
    paddingHorizontal: 16,
    flexDirection: 'row',
    alignItems: 'center',
    gap: 10,
    ...shadow.card,
  },
  searchInput: { flex: 1, fontFamily: font.semibold, fontSize: 14, color: colors.ink, padding: 0 },

  chips: { gap: 8, paddingHorizontal: space.gutter, marginTop: 12 },
  chip: { borderRadius: radius.pill, paddingVertical: 8, paddingHorizontal: 16 },
  chipActive: { backgroundColor: colors.blue },
  chipIdle: {
    backgroundColor: colors.surface,
    shadowColor: '#22304F',
    shadowOpacity: 0.06,
    shadowRadius: 4,
    shadowOffset: { width: 0, height: 1 },
    elevation: 1,
  },
  chipLabel: { fontFamily: font.bold, fontSize: 12.5, color: colors.inkMuted },
  chipLabelActive: { fontFamily: font.extrabold, fontSize: 12.5, color: colors.onBlue },

  body: { paddingHorizontal: space.gutter, marginTop: 20, gap: 18 },
  month: { fontFamily: font.extrabold, fontSize: 12, color: colors.slate, letterSpacing: 0.8 },
  list: { gap: 9, marginTop: 10 },
  empty: { fontFamily: font.semibold, fontSize: 14, color: colors.slate },
});