/**
 * 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';

// ===== 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'];

const MEMORY_TYPE_LABELS: Record<MemoryType, string> = {
  episodic: '情景记忆',
  semantic: '语义记忆',
  working: '工作记忆',
};

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);
  const [expanded, setExpanded] = useState<MemoryType | 'all'>('all');

  // 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 ?? '加载记忆失败');
        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 ?? '加载记忆失败');
    }
  }, []);

  // 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 ?? '搜索失败');
      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-toast').then((mod) => mod.default.error(res.error ?? '删除失败')).catch(() => {});
        return;
      }
      await loadMemories();
    } catch (err) {
      import('metona-toast').then((mod) => mod.default.error((err as Error).message ?? '删除失败')).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' }}>
            记忆搜索
          </Typography>
          <Typography variant="caption" sx={{ ml: 'auto', color: 'text.disabled', fontSize: 10 }}>
            {searchResults.length} 条结果
          </Typography>
        </Stack>

        <TextField
          size="small"
          fullWidth
          value={searchQuery}
          onChange={(e) => setSearchQuery(e.target.value)}
          onKeyDown={(e) => { if (e.key === 'Enter') handleSearch(); }}
          placeholder="搜索记忆..."
          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' }}>清除</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' }}>
              搜索中...
            </Typography>
          ) : searchResults.length === 0 ? (
            <Typography variant="caption" sx={{ textAlign: 'center', py: 2, color: 'text.disabled' }}>
              无匹配结果
            </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' }}>
          记忆库
        </Typography>
        <Typography variant="caption" sx={{ ml: 'auto', color: 'text.disabled', fontSize: 10 }}>
          {totalCount} 条
        </Typography>
      </Stack>

      <TextField
        size="small"
        fullWidth
        value={searchQuery}
        onChange={(e) => setSearchQuery(e.target.value)}
        onKeyDown={(e) => { if (e.key === 'Enter') handleSearch(); }}
        placeholder="搜索记忆..."
        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={expanded === type || expanded === 'all'}
                onChange={(_, isExpanded) => setExpanded(isExpanded ? type : 'all')}
                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' }}>
                      {MEMORY_TYPE_LABELS[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);
  const importance = item.importance ?? 0;

  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={MEMORY_TYPE_LABELS[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={MEMORY_TYPE_LABELS[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"
          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>
  );
}