/**
 * MemoryViewer — 记忆浏览器
 *
 * 列出所有记忆（episodic/semantic/working），支持搜索、删除。
 * Agent 完成任务后自动刷新（监听 agentStatus: thinking|executing -> idle）。
 */

import { useState, useEffect, useRef, useCallback } from 'react';
import {
  Box,
  Typography,
  Stack,
  Accordion,
  AccordionSummary,
  AccordionDetails,
  IconButton,
  TextField,
  Chip,
  Alert,
  InputAdornment,
} from '@mui/material';
import { Brain, Search, Trash2, ChevronDown } from 'lucide-react';
import { useAgentStore } from '@renderer/stores/agent-store';
import { useUIStore } from '@renderer/stores/ui-store';
import { formatTime, truncate } from '@renderer/lib/formatters';
// v0.7.3 P4-3: 文案出层（字典含注册副作用，须在 t() 使用前 import）
import { t } from '@renderer/lib/i18n';
import '@renderer/lib/i18n-strings';

// ===== 类型 =====

type MemoryType = 'episodic' | 'semantic' | 'working';

interface MemoryItem {
  id: string;
  type: MemoryType;
  content: string;
  summary?: string;
  importance?: number;
  createdAt?: number;
  created_at?: number;
}

interface SearchResult {
  id: string;
  type: MemoryType;
  content: string;
  summary?: string;
  importance: number;
  relevanceScore: number;
  createdAt: number;
}

// ===== 常量 =====

const MEMORY_TYPES: MemoryType[] = ['episodic', 'semantic', 'working'];

// v0.7.3 P4-3: 类型标签渲染时求值（i18next 字典注册是异步的，模块顶层固化会拿到 key 本体）
const MEMORY_TYPE_LABEL_KEYS: Record<MemoryType, string> = {
  episodic: 'memory.type.episodic',
  semantic: 'memory.type.semantic',
  working: 'memory.type.working',
};
const memoryTypeLabel = (type: MemoryType): string => t(MEMORY_TYPE_LABEL_KEYS[type]);

const MEMORY_TYPE_COLORS: Record<MemoryType, string> = {
  episodic: '#22d3ee',
  semantic: '#a855f7',
  working: '#fbbf24',
};

function importanceColor(score: number): string {
  if (score >= 0.8) return '#ef4444';
  if (score >= 0.5) return '#f59e0b';
  return '#64748b';
}

function getCreatedAt(item: MemoryItem): number {
  return item.createdAt ?? item.created_at ?? 0;
}

function getId(item: MemoryItem): string {
  return item.id;
}

// ===== 主组件 =====

export function MemoryViewer(): React.JSX.Element {
  const [memories, setMemories] = useState<Record<MemoryType, MemoryItem[]>>({
    episodic: [],
    semantic: [],
    working: [],
  });
  const [searchQuery, setSearchQuery] = useState('');
  const [searchResults, setSearchResults] = useState<SearchResult[] | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [searching, setSearching] = useState(false);
  // v0.6.4 修复（折叠交互根治）：单值 `MemoryType | 'all'` 无法同时表达
  // "全展开"与"收起其一"——初始 'all' 时点击任一类型想收起，onChange(false) 会把
  // 状态设回 'all'，首次点击视觉无效、二次点击却收起其它组。改为显式集合模型，
  // 每个类型的展开态互不干扰，初始仍为全展开（保持原体验）。
  const [expandedTypes, setExpandedTypes] = useState<Set<MemoryType>>(
    () => new Set<MemoryType>(MEMORY_TYPES),
  );

  // Agent 完成时自动刷新：监听 agentStatus 从 thinking/executing -> idle
  const agentStatus = useAgentStore((s) => s.agentStatus);
  const prevStatus = useRef(agentStatus);
  // v0.3.6: 监听 memoryVersion 变化（SettingsModal 清理记忆后自增），触发重新加载
  const memoryVersion = useUIStore((s) => s.memoryVersion);
  // M-53 修复: 竞态保护 ref，防止多次 loadMemories 调用乱序完成导致旧数据覆盖
  const loadReqIdRef = useRef(0);
  // 审计补充修复: handleSearch 使用独立 ref，避免与 loadMemories 共用导致 searching 状态卡死
  // 原问题：handleSearch 与 loadMemories 共用 loadReqIdRef，当 agent 完成触发 loadMemories 时
  // 会 ++ref，使 handleSearch 的 finally 检查失败，setSearching(false) 不执行，UI 永久显示"搜索中..."
  const searchReqIdRef = useRef(0);

  const loadMemories = useCallback(async () => {
    if (!window.metona?.memory?.listAll) return;
    const reqId = ++loadReqIdRef.current;
    try {
      setError(null);
      const res = await window.metona.memory.listAll();
      // 竞态保护：若已被新请求取代或组件已卸载，放弃本次结果
      if (loadReqIdRef.current !== reqId) return;
      if (!res.success) {
        setError(res.error ?? t('memory.loadFailed'));
        return;
      }
      const data = res.data ?? {};
      setMemories({
        episodic: (data.episodic as MemoryItem[] | undefined) ?? [],
        semantic: (data.semantic as MemoryItem[] | undefined) ?? [],
        working: (data.working as MemoryItem[] | undefined) ?? [],
      });
    } catch (err) {
      if (loadReqIdRef.current !== reqId) return;
      setError((err as Error).message ?? t('memory.loadFailed'));
    }
  }, []);

  // 初次挂载加载
  useEffect(() => {
    loadMemories();
    // cleanup: 使当前请求失效（防止卸载后 setState）
    return () => {
      loadReqIdRef.current++;
    };
  }, [loadMemories]);

  // Agent 完成自动刷新
  useEffect(() => {
    const prev = prevStatus.current;
    prevStatus.current = agentStatus;
    if ((prev === 'thinking' || prev === 'executing') && agentStatus === 'idle') {
      loadMemories();
    }
  }, [agentStatus, loadMemories]);

  // v0.3.6: SettingsModal 清理记忆后 memoryVersion 自增，触发重新加载
  // 之前清理后需重启应用 MemoryViewer 才会刷新（与 clearSessions 同样的 bug）
  useEffect(() => {
    if (memoryVersion > 0) {
      loadMemories();
    }
  }, [memoryVersion, loadMemories]);

  const handleSearch = async () => {
    const q = searchQuery.trim();
    if (!q || !window.metona?.memory?.search) return;
    setSearching(true);
    setError(null);
    // 审计补充修复: 使用独立 searchReqIdRef，不再与 loadMemories 共用
    const reqId = ++searchReqIdRef.current;
    try {
      const results = await window.metona.memory.search(q, { topK: 20 });
      // 竞态保护：若已被新搜索请求取代或组件已卸载，放弃本次结果
      if (searchReqIdRef.current !== reqId) return;
      setSearchResults(results);
    } catch (err) {
      if (searchReqIdRef.current !== reqId) return;
      setError((err as Error).message ?? t('memory.loadFailed'));
      setSearchResults([]);
    } finally {
      // 审计补充修复: 无条件清理 searching 状态，避免被 loadMemories 取代时卡死
      // searching 仅对当前搜索有意义，请求被取代后应停止 spinner
      setSearching(false);
    }
  };

  const handleClearSearch = () => {
    setSearchQuery('');
    setSearchResults(null);
  };

  const handleDelete = async (type: MemoryType, id: string) => {
    if (!window.metona?.memory?.delete) return;
    try {
      const res = await window.metona.memory.delete(type, id);
      if (!res.success) {
        // 用户主动操作失败应用 toast（与项目惯例一致），不污染加载/搜索的 Alert
        import('@metona-team/metona-toast')
          .then((mod) => mod.default.error(res.error ?? t('memory.deleteFailed')))
          .catch(() => {});
        return;
      }
      await loadMemories();
    } catch (err) {
      import('@metona-team/metona-toast')
        .then((mod) => mod.default.error((err as Error).message ?? t('memory.deleteFailed')))
        .catch(() => {});
    }
  };

  const totalCount = memories.episodic.length + memories.semantic.length + memories.working.length;

  // 搜索结果视图
  if (searchResults !== null) {
    return (
      <Box
        sx={{ flex: 1, display: 'flex', flexDirection: 'column', overflow: 'hidden', minHeight: 0 }}
      >
        <Stack direction="row" spacing={1} sx={{ mb: 1.5, flexShrink: 0, alignItems: 'center' }}>
          <Brain size={14} style={{ color: '#a855f7' }} />
          <Typography
            variant="caption"
            sx={{
              fontWeight: 600,
              textTransform: 'uppercase',
              letterSpacing: 1,
              color: 'text.secondary',
            }}
          >
            {t('memory.search.title')}
          </Typography>
          <Typography variant="caption" sx={{ ml: 'auto', color: 'text.disabled', fontSize: 10 }}>
            {t('memory.results', { count: searchResults.length })}
          </Typography>
        </Stack>

        <TextField
          size="small"
          fullWidth
          value={searchQuery}
          onChange={(e) => setSearchQuery(e.target.value)}
          onKeyDown={(e) => {
            if (e.key === 'Enter') handleSearch();
          }}
          placeholder={t('memory.search.placeholder')}
          sx={{
            mb: 1.5,
            flexShrink: 0,
            '& .MuiOutlinedInput-root': { fontSize: 11, height: 30, borderRadius: 1.5 },
          }}
          slotProps={{
            input: {
              startAdornment: (
                <InputAdornment position="start">
                  <Search size={12} style={{ color: '#8b8fa7' }} />
                </InputAdornment>
              ),
              endAdornment: searchQuery ? (
                <InputAdornment
                  position="end"
                  sx={{ cursor: 'pointer' }}
                  onClick={handleClearSearch}
                >
                  <Typography variant="caption" sx={{ fontSize: 10, color: 'text.secondary' }}>
                    {t('memory.search.clear')}
                  </Typography>
                </InputAdornment>
              ) : null,
            },
          }}
        />

        {error && (
          <Alert severity="error" sx={{ mb: 1, py: 0.5, fontSize: 11, flexShrink: 0 }}>
            {error}
          </Alert>
        )}

        <Box
          sx={{
            flex: 1,
            overflowY: 'auto',
            display: 'flex',
            flexDirection: 'column',
            gap: 0.5,
            minHeight: 0,
          }}
        >
          {searching ? (
            <Typography
              variant="caption"
              sx={{ textAlign: 'center', py: 2, color: 'text.disabled' }}
            >
              {t('memory.searching')}
            </Typography>
          ) : searchResults.length === 0 ? (
            <Typography
              variant="caption"
              sx={{ textAlign: 'center', py: 2, color: 'text.disabled' }}
            >
              {t('memory.search.empty')}
            </Typography>
          ) : (
            searchResults.map((r) => (
              <MemorySearchItem key={`${r.type}-${r.id}`} item={r} onDelete={handleDelete} />
            ))
          )}
        </Box>
      </Box>
    );
  }

  // 全量列表视图
  return (
    <Box
      sx={{ flex: 1, display: 'flex', flexDirection: 'column', overflow: 'hidden', minHeight: 0 }}
    >
      <Stack direction="row" spacing={1} sx={{ mb: 1.5, flexShrink: 0, alignItems: 'center' }}>
        <Brain size={14} style={{ color: '#a855f7' }} />
        <Typography
          variant="caption"
          sx={{
            fontWeight: 600,
            textTransform: 'uppercase',
            letterSpacing: 1,
            color: 'text.secondary',
          }}
        >
          {t('memory.list.title')}
        </Typography>
        <Typography variant="caption" sx={{ ml: 'auto', color: 'text.disabled', fontSize: 10 }}>
          {t('memory.total', { count: totalCount })}
        </Typography>
      </Stack>

      <TextField
        size="small"
        fullWidth
        value={searchQuery}
        onChange={(e) => setSearchQuery(e.target.value)}
        onKeyDown={(e) => {
          if (e.key === 'Enter') handleSearch();
        }}
        placeholder={t('memory.search.placeholder')}
        sx={{
          mb: 1.5,
          flexShrink: 0,
          '& .MuiOutlinedInput-root': { fontSize: 11, height: 30, borderRadius: 1.5 },
        }}
        slotProps={{
          input: {
            startAdornment: (
              <InputAdornment position="start">
                <Search size={12} style={{ color: '#8b8fa7' }} />
              </InputAdornment>
            ),
          },
        }}
      />

      {error && (
        <Alert severity="error" sx={{ mb: 1, py: 0.5, fontSize: 11, flexShrink: 0 }}>
          {error}
        </Alert>
      )}

      <Box sx={{ flex: 1, overflowY: 'auto', minHeight: 0 }}>
        {totalCount === 0 ? (
          <Typography
            variant="caption"
            sx={{ textAlign: 'center', py: 4, display: 'block', color: 'text.disabled' }}
          >
            暂无记忆数据
          </Typography>
        ) : (
          MEMORY_TYPES.map((type) => {
            const items = memories[type];
            if (items.length === 0) return null;
            return (
              <Accordion
                key={type}
                expanded={expandedTypes.has(type)}
                onChange={(_, isExpanded) =>
                  setExpandedTypes((prev) => {
                    const next = new Set(prev);
                    if (isExpanded) {
                      next.add(type);
                    } else {
                      next.delete(type);
                    }
                    return next;
                  })
                }
                elevation={0}
                sx={{
                  '&:before': { display: 'none' },
                  '& .MuiAccordionSummary-root': { minHeight: 32, px: 0 },
                  '& .MuiAccordionSummary-content': { my: 0, mx: 0 },
                  '& .MuiAccordionDetails-root': { px: 0, py: 0 },
                }}
              >
                <AccordionSummary expandIcon={<ChevronDown size={14} />}>
                  <Stack direction="row" spacing={1} sx={{ alignItems: 'center', width: '100%' }}>
                    <Box
                      sx={{
                        width: 6,
                        height: 6,
                        borderRadius: '50%',
                        bgcolor: MEMORY_TYPE_COLORS[type],
                        flexShrink: 0,
                      }}
                    />
                    <Typography
                      variant="caption"
                      sx={{ fontWeight: 600, fontSize: 11, color: 'text.primary' }}
                    >
                      {memoryTypeLabel(type)}
                    </Typography>
                    <Chip
                      label={items.length}
                      size="small"
                      sx={{
                        ml: 'auto',
                        mr: 0.5,
                        height: 16,
                        fontSize: 10,
                        bgcolor: 'action.hover',
                        color: 'text.secondary',
                        '& .MuiChip-label': { px: 0.5 },
                      }}
                    />
                  </Stack>
                </AccordionSummary>
                <AccordionDetails>
                  <Stack spacing={0.5}>
                    {items.map((item) => (
                      <MemoryItemRow key={getId(item)} item={item} onDelete={handleDelete} />
                    ))}
                  </Stack>
                </AccordionDetails>
              </Accordion>
            );
          })
        )}
      </Box>
    </Box>
  );
}

// ===== 子组件 =====

function MemoryItemRow({
  item,
  onDelete,
}: {
  item: MemoryItem;
  onDelete: (type: MemoryType, id: string) => void;
}): React.JSX.Element {
  const type = item.type;
  const createdAt = getCreatedAt(item);

  return (
    <Box
      sx={{
        px: 1,
        py: 0.75,
        borderRadius: 1,
        bgcolor: 'background.default',
        border: '1px solid',
        borderColor: 'divider',
        '&:hover .delete-btn': { opacity: 1 },
      }}
    >
      <Stack direction="row" spacing={0.5} sx={{ mb: 0.25, alignItems: 'center' }}>
        <Chip
          label={memoryTypeLabel(type)}
          size="small"
          sx={{
            height: 14,
            fontSize: 9,
            bgcolor: MEMORY_TYPE_COLORS[type] + '22',
            color: MEMORY_TYPE_COLORS[type],
            '& .MuiChip-label': { px: 0.5 },
          }}
        />
        {typeof item.importance === 'number' && (
          <Chip
            label={`I ${(item.importance ?? 0).toFixed(2)}`}
            size="small"
            sx={{
              height: 14,
              fontSize: 9,
              bgcolor: importanceColor(item.importance) + '22',
              color: importanceColor(item.importance),
              '& .MuiChip-label': { px: 0.5, fontFamily: 'monospace' },
            }}
          />
        )}
        {createdAt > 0 && (
          <Typography
            variant="caption"
            sx={{ ml: 'auto', fontSize: 9, color: 'text.disabled', fontFamily: 'monospace' }}
          >
            {formatTime(createdAt)}
          </Typography>
        )}
        <IconButton
          className="delete-btn"
          size="small"
          onClick={() => onDelete(type, getId(item))}
          sx={{
            opacity: 0,
            transition: 'opacity 150ms',
            p: 0.25,
            '&:hover': { color: 'error.main' },
          }}
        >
          <Trash2 size={11} />
        </IconButton>
      </Stack>
      <Typography
        variant="caption"
        sx={{
          fontSize: 11,
          color: 'text.primary',
          display: 'block',
          lineHeight: 1.4,
          wordBreak: 'break-word',
        }}
      >
        {truncate(item.content, 100)}
      </Typography>
    </Box>
  );
}

function MemorySearchItem({
  item,
  onDelete,
}: {
  item: SearchResult;
  onDelete: (type: MemoryType, id: string) => void;
}): React.JSX.Element {
  return (
    <Box
      sx={{
        px: 1,
        py: 0.75,
        borderRadius: 1,
        bgcolor: 'background.default',
        border: '1px solid',
        borderColor: 'divider',
        '&:hover .delete-btn': { opacity: 1 },
      }}
    >
      <Stack direction="row" spacing={0.5} sx={{ mb: 0.25, alignItems: 'center' }}>
        <Chip
          label={memoryTypeLabel(item.type)}
          size="small"
          sx={{
            height: 14,
            fontSize: 9,
            bgcolor: MEMORY_TYPE_COLORS[item.type] + '22',
            color: MEMORY_TYPE_COLORS[item.type],
            '& .MuiChip-label': { px: 0.5 },
          }}
        />
        <Chip
          label={`R ${(item.relevanceScore ?? 0).toFixed(2)}`}
          size="small"
          sx={{
            height: 14,
            fontSize: 9,
            bgcolor: '#22d3ee22',
            color: '#22d3ee',
            '& .MuiChip-label': { px: 0.5, fontFamily: 'monospace' },
          }}
        />
        <Chip
          label={`I ${(item.importance ?? 0).toFixed(2)}`}
          size="small"
          sx={{
            height: 14,
            fontSize: 9,
            bgcolor: importanceColor(item.importance) + '22',
            color: importanceColor(item.importance),
            '& .MuiChip-label': { px: 0.5, fontFamily: 'monospace' },
          }}
        />
        {item.createdAt > 0 && (
          <Typography
            variant="caption"
            sx={{ ml: 'auto', fontSize: 9, color: 'text.disabled', fontFamily: 'monospace' }}
          >
            {formatTime(item.createdAt)}
          </Typography>
        )}
        <IconButton
          className="delete-btn"
          size="small"
          aria-label="删除该记忆"
          onClick={() => onDelete(item.type, item.id)}
          sx={{
            opacity: 0,
            transition: 'opacity 150ms',
            p: 0.25,
            '&:hover': { color: 'error.main' },
          }}
        >
          <Trash2 size={11} />
        </IconButton>
      </Stack>
      <Typography
        variant="caption"
        sx={{
          fontSize: 11,
          color: 'text.primary',
          display: 'block',
          lineHeight: 1.4,
          wordBreak: 'break-word',
        }}
      >
        {truncate(item.content, 100)}
      </Typography>
    </Box>
  );
}