/**
 * Memory-Browser — Liste mit Suche + Filter, Tap oeffnet MemoryDetailModal.
 *
 * Eingesetzt von:
 *  - SettingsScreen → Sektion "Gedächtnis" (kompletter Editor)
 *  - Inbox-Modal (Notizen-Button neben Lupe) — kann aber auch Bubbles
 *    aus dem Chat als zusaetzlichen Filter zeigen
 */

import React, { useEffect, useState, useCallback } from 'react';
import {
  ActivityIndicator,
  FlatList,
  StyleSheet,
  Text,
  TextInput,
  TouchableOpacity,
  View,
  Alert,
  Modal,
} from 'react-native';

import brainApi, { Memory } from '../services/brainApi';
import MemoryDetailModal from './MemoryDetailModal';

const TYPE_LABELS: Record<string, string> = {
  identity: 'Identität', rule: 'Regeln', preference: 'Präferenzen',
  tool: 'Tools', skill: 'Skills', fact: 'Fakten',
  conversation: 'Konversation', reminder: 'Reminder',
};
const TYPE_OPTIONS = ['', 'identity', 'rule', 'preference', 'tool', 'skill', 'fact', 'conversation', 'reminder'];

interface Props {
  /** Wenn gesetzt: nur diese IDs anzeigen (z.B. Inbox-Modal mit Chat-Bubbles-Filter). */
  restrictToIds?: string[];
  /** Headline ueber der Liste. */
  title?: string;
  /** Style-Erweiterung fuer den Container. */
  flatStyle?: boolean;
  /** Wenn gesetzt: kein eigenes DetailModal mounten — Parent kuemmert sich. */
  onOpenMemory?: (id: string) => void;
}

export const MemoryBrowser: React.FC<Props> = ({ restrictToIds, title, flatStyle, onOpenMemory }) => {
  const [items, setItems] = useState<Memory[]>([]);
  const [filtered, setFiltered] = useState<Memory[]>([]);
  const [loading, setLoading] = useState(false);
  const [err, setErr] = useState<string | null>(null);
  const [q, setQ] = useState('');
  const [typeFilter, setTypeFilter] = useState('');
  const [pinnedFilter, setPinnedFilter] = useState<'all' | 'pinned' | 'cold'>('all');
  const [showTypeMenu, setShowTypeMenu] = useState(false);
  const [openId, setOpenId] = useState<string | null>(null);

  const load = useCallback(() => {
    setLoading(true); setErr(null);
    brainApi.listMemories({ limit: 500 })
      .then(setItems)
      .catch(e => setErr(String(e?.message || e)))
      .finally(() => setLoading(false));
  }, []);

  useEffect(() => { load(); }, [load]);

  // Filter clientseitig — bei kleiner DB (<1000) easy
  useEffect(() => {
    let out = items;
    if (restrictToIds && restrictToIds.length) {
      const set = new Set(restrictToIds);
      out = out.filter(m => set.has(m.id));
    }
    if (typeFilter) out = out.filter(m => m.type === typeFilter);
    if (pinnedFilter === 'pinned') out = out.filter(m => m.pinned);
    else if (pinnedFilter === 'cold') out = out.filter(m => !m.pinned);
    if (q.trim()) {
      const needle = q.toLowerCase();
      out = out.filter(m =>
        (m.title || '').toLowerCase().includes(needle) ||
        (m.content || '').toLowerCase().includes(needle) ||
        (m.category || '').toLowerCase().includes(needle) ||
        (m.tags || []).some(t => t.toLowerCase().includes(needle))
      );
    }
    setFiltered(out);
  }, [items, q, typeFilter, pinnedFilter, restrictToIds]);

  const [showNewMemoryDialog, setShowNewMemoryDialog] = useState(false);
  const [newMemoryTitle, setNewMemoryTitle] = useState('');

  const onAddNew = () => {
    setNewMemoryTitle('');
    setShowNewMemoryDialog(true);
  };

  const confirmAddNew = async () => {
    const t = newMemoryTitle.trim();
    if (!t) { setShowNewMemoryDialog(false); return; }
    setShowNewMemoryDialog(false);
    try {
      const m = await brainApi.saveMemory({
        type: 'fact', title: t,
        content: '(noch leer — bitte editieren)',
      });
      load();
      if (onOpenMemory) onOpenMemory(m.id);
      else setOpenId(m.id);
    } catch (e: any) {
      Alert.alert('Fehler', String(e?.message || e));
    }
  };

  const renderItem = ({ item }: { item: Memory }) => {
    const attCount = (item.attachments || []).length;
    return (
      <TouchableOpacity style={s.row} onPress={() => onOpenMemory ? onOpenMemory(item.id) : setOpenId(item.id)}>
        <View style={{flex:1}}>
          <Text style={s.rowTitle} numberOfLines={1}>
            {item.pinned ? '📌 ' : ''}{item.title || '(ohne Titel)'}
            {attCount > 0 ? <Text style={s.attBadge}>{`  📎${attCount}`}</Text> : null}
          </Text>
          <Text style={s.rowMeta} numberOfLines={1}>
            {TYPE_LABELS[item.type] || item.type}
            {item.category ? ` · [${item.category}]` : ''}
          </Text>
          <Text style={s.rowPreview} numberOfLines={2}>{item.content}</Text>
        </View>
      </TouchableOpacity>
    );
  };

  return (
    <View style={[s.container, flatStyle && {padding:0,backgroundColor:'transparent'}]}>
      {title ? <Text style={s.heading}>{title}</Text> : null}

      <View style={s.searchRow}>
        <TextInput
          style={s.search}
          value={q}
          onChangeText={setQ}
          placeholder="Suche in Titel, Inhalt, Tags…"
          placeholderTextColor="#555570"
        />
        <TouchableOpacity style={s.iconBtn} onPress={load}>
          <Text style={{color:'#0096FF'}}>↻</Text>
        </TouchableOpacity>
      </View>
      <View style={s.filterRow}>
        <TouchableOpacity style={s.filterBtn} onPress={() => setShowTypeMenu(true)}>
          <Text style={s.filterText}>{typeFilter ? (TYPE_LABELS[typeFilter] || typeFilter) : 'Alle Typen'} ▾</Text>
        </TouchableOpacity>
        <TouchableOpacity style={s.filterBtn} onPress={() => {
          setPinnedFilter(pinnedFilter === 'all' ? 'pinned' : pinnedFilter === 'pinned' ? 'cold' : 'all');
        }}>
          <Text style={s.filterText}>
            {pinnedFilter === 'pinned' ? '📌 Nur Pinned' : pinnedFilter === 'cold' ? 'Nur Cold' : 'Alle'}
          </Text>
        </TouchableOpacity>
        <TouchableOpacity style={[s.filterBtn,{backgroundColor:'#0096FF'}]} onPress={onAddNew}>
          <Text style={[s.filterText,{color:'#fff'}]}>+ Neu</Text>
        </TouchableOpacity>
      </View>

      {err ? <Text style={s.err}>{err}</Text> : null}

      {loading && items.length === 0 ? (
        <ActivityIndicator color="#0096FF" style={{marginTop:20}} />
      ) : (
        <FlatList
          data={filtered}
          keyExtractor={m => m.id}
          renderItem={renderItem}
          // nestedScrollEnabled: notwendig damit die FlatList auf Android
          // scrollt wenn sie in einer aeusseren ScrollView haengt (Settings-
          // Screen ist ScrollView). Ohne das frisst der aeussere ScrollView
          // alle Gesten und die innere Liste ist tot.
          nestedScrollEnabled={true}
          keyboardShouldPersistTaps="handled"
          ListEmptyComponent={
            <Text style={{color:'#555570',textAlign:'center',padding:20,fontStyle:'italic'}}>
              {items.length === 0 ? '(keine Memories in der DB)' : '(keine Treffer für diese Filter)'}
            </Text>
          }
          contentContainerStyle={{paddingBottom:20}}
        />
      )}

      <Text style={s.footer}>
        {filtered.length}/{items.length} Memories
      </Text>

      {/* Type-Filter-Auswahl */}
      <Modal visible={showTypeMenu} transparent animationType="fade" onRequestClose={() => setShowTypeMenu(false)}>
        <TouchableOpacity style={s.menuBack} activeOpacity={1} onPress={() => setShowTypeMenu(false)}>
          <View style={s.menuBox}>
            {TYPE_OPTIONS.map(t => (
              <TouchableOpacity
                key={t || 'all'}
                style={s.menuItem}
                onPress={() => { setTypeFilter(t); setShowTypeMenu(false); }}
              >
                <Text style={s.menuItemText}>
                  {t ? (TYPE_LABELS[t] || t) : 'Alle Typen'}
                </Text>
              </TouchableOpacity>
            ))}
          </View>
        </TouchableOpacity>
      </Modal>

      {/* Eigenes DetailModal nur wenn der Parent kein Callback uebergibt
          (vermeidet Modal-in-Modal-Stacking auf Android). */}
      {!onOpenMemory && (
        <MemoryDetailModal
          memoryId={openId}
          visible={!!openId}
          onClose={() => { setOpenId(null); load(); }}
          onDeleted={() => { setOpenId(null); load(); }}
        />
      )}

      {/* "Neue Memory"-Dialog (Alert.prompt ist iOS-only, daher eigenes Modal) */}
      <Modal visible={showNewMemoryDialog} transparent animationType="fade" onRequestClose={() => setShowNewMemoryDialog(false)}>
        <View style={s.menuBack}>
          <View style={[s.menuBox, {padding:16, minWidth:280}]}>
            <Text style={{color:'#FFD60A', fontWeight:'bold', fontSize:14, marginBottom:10}}>Neue Memory anlegen</Text>
            <Text style={{color:'#8888AA', fontSize:11, marginBottom:6}}>Titel:</Text>
            <TextInput
              value={newMemoryTitle}
              onChangeText={setNewMemoryTitle}
              autoFocus
              placeholder="z.B. Stefans Auto"
              placeholderTextColor="#555570"
              style={{backgroundColor:'#1E1E2E', color:'#E0E0F0', padding:8, borderRadius:4, fontSize:13, marginBottom:12}}
            />
            <View style={{flexDirection:'row', gap:8, justifyContent:'flex-end'}}>
              <TouchableOpacity onPress={() => setShowNewMemoryDialog(false)} style={{padding:8}}>
                <Text style={{color:'#8888AA'}}>Abbrechen</Text>
              </TouchableOpacity>
              <TouchableOpacity onPress={confirmAddNew} style={{backgroundColor:'#0096FF', paddingHorizontal:14, paddingVertical:8, borderRadius:4}}>
                <Text style={{color:'#fff', fontWeight:'600'}}>Anlegen</Text>
              </TouchableOpacity>
            </View>
          </View>
        </View>
      </Modal>
    </View>
  );
};

const s = StyleSheet.create({
  container: { flex:1, padding:8, backgroundColor:'#0D0D1A' },
  heading: { color:'#0096FF', fontWeight:'bold', fontSize:14, marginBottom:8 },
  searchRow: { flexDirection:'row', gap:6, marginBottom:6 },
  search: { flex:1, backgroundColor:'#1E1E2E', color:'#E0E0F0', padding:8, borderRadius:6, fontSize:13 },
  iconBtn: { paddingHorizontal:12, justifyContent:'center', backgroundColor:'#1E1E2E', borderRadius:6 },
  filterRow: { flexDirection:'row', gap:6, marginBottom:8 },
  filterBtn: { backgroundColor:'#1E1E2E', paddingHorizontal:10, paddingVertical:6, borderRadius:6 },
  filterText: { color:'#E0E0F0', fontSize:12 },
  err: { color:'#FF6B6B', fontSize:12, marginVertical:6 },
  row: { backgroundColor:'#1E1E2E', padding:10, borderRadius:6, marginBottom:6 },
  rowTitle: { color:'#E0E0F0', fontWeight:'600', fontSize:13 },
  attBadge: { color:'#34C759', fontWeight:'normal', fontSize:11 },
  rowMeta: { color:'#8888AA', fontSize:11, marginTop:2 },
  rowPreview: { color:'#666680', fontSize:11, marginTop:4 },
  footer: { color:'#555570', fontSize:10, textAlign:'center', paddingVertical:6 },
  menuBack: { flex:1, backgroundColor:'rgba(0,0,0,0.7)', justifyContent:'center', alignItems:'center' },
  menuBox: { backgroundColor:'#0D0D1A', borderRadius:8, paddingVertical:4, minWidth:200 },
  menuItem: { paddingVertical:10, paddingHorizontal:14 },
  menuItemText: { color:'#E0E0F0', fontSize:13 },
});

export default MemoryBrowser;