import { useCallback, useEffect, useState } from 'react';
import { motion, AnimatePresence } from 'framer-motion';
import {
  Brain, Search, Trash2, Download, Star, Tag, Clock,
  ChevronDown, ChevronUp,
} from 'lucide-react';
import { cardHover, defaultTransition } from '../lib/animations';
import { Button, Badge, EmptyState } from './ui';
import {
  intelligenceClient,
  type MemoryEntry,
  type MemoryType,
  type MemoryStats,
} from '../lib/intelligence-client';
import { useConversationStore } from '../store/chat/conversationStore';

const TYPE_LABELS: Record<MemoryType, { label: string; emoji: string; color: string }> = {
  fact: { label: '事实', emoji: '📋', color: 'bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-300' },
  preference: { label: '偏好', emoji: '⭐', color: 'bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-300' },
  lesson: { label: '经验', emoji: '💡', color: 'bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-300' },
  context: { label: '上下文', emoji: '📌', color: 'bg-purple-100 text-purple-700 dark:bg-purple-900/30 dark:text-purple-300' },
  task: { label: '任务', emoji: '📝', color: 'bg-red-100 text-red-700 dark:bg-red-900/30 dark:text-red-300' },
};

export function MemoryPanel() {
  const currentAgent = useConversationStore((s) => s.currentAgent);
  const agentId = currentAgent?.id || 'zclaw-main';

  const [memories, setMemories] = useState<MemoryEntry[]>([]);
  const [stats, setStats] = useState<MemoryStats | null>(null);
  const [searchQuery, setSearchQuery] = useState('');
  const [filterType, setFilterType] = useState<MemoryType | 'all'>('all');
  const [expandedId, setExpandedId] = useState<string | null>(null);
  const [isExporting, setIsExporting] = useState(false);

  const loadMemories = useCallback(async () => {
    const typeFilter = filterType !== 'all' ? { type: filterType as MemoryType } : {};

    if (searchQuery.trim()) {
      const results = await intelligenceClient.memory.search({
        agentId,
        query: searchQuery,
        limit: 50,
        ...typeFilter,
      });
      setMemories(results);
    } else {
      const results = await intelligenceClient.memory.search({
        agentId,
        limit: 50,
        ...typeFilter,
      });
      setMemories(results);
    }

    const s = await intelligenceClient.memory.stats();
    setStats(s);
  }, [agentId, searchQuery, filterType]);

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

  const handleDelete = async (id: string) => {
    await intelligenceClient.memory.delete(id);
    loadMemories();
  };

  const handleExport = async () => {
    setIsExporting(true);
    try {
      const memories = await intelligenceClient.memory.export();
      const filtered = memories.filter(m => m.agentId === agentId);
      const md = filtered.map(m =>
        `## [${m.type}] ${m.content}\n` +
        `- 重要度: ${m.importance}\n` +
        `- 标签: ${m.tags.join(', ') || '无'}\n` +
        `- 创建时间: ${m.createdAt}\n`
      ).join('\n---\n\n');
      const blob = new Blob([md || '# 无记忆数据'], { type: 'text/markdown' });
      const url = URL.createObjectURL(blob);
      const a = document.createElement('a');
      a.href = url;
      a.download = `zclaw-memory-${agentId}-${new Date().toISOString().slice(0, 10)}.md`;
      a.click();
      URL.revokeObjectURL(url);
    } finally {
      setIsExporting(false);
    }
  };

  const handlePrune = async () => {
    // Find old, low-importance memories and delete them
    const memories = await intelligenceClient.memory.search({
      agentId,
      minImportance: 0,
      limit: 1000,
    });
    const thirtyDaysAgo = Date.now() - 30 * 24 * 60 * 60 * 1000;
    const toDelete = memories.filter(m =>
      new Date(m.createdAt).getTime() < thirtyDaysAgo && m.importance < 3
    );
    for (const m of toDelete) {
      await intelligenceClient.memory.delete(m.id);
    }
    if (toDelete.length > 0) {
      loadMemories();
    }
  };

  return (
    <div className="space-y-3">
      {/* Stats */}
      <motion.div
        whileHover={cardHover}
        transition={defaultTransition}
        className="rounded-xl border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 p-3 shadow-sm"
      >
        <div className="flex items-center justify-between mb-2">
          <h3 className="text-sm font-semibold text-gray-900 dark:text-gray-100 flex items-center gap-1.5">
            <Brain className="w-4 h-4 text-orange-500" />
            Agent 记忆
          </h3>
          <div className="flex gap-1">
            <Button
              variant="ghost"
              size="sm"
              onClick={handleExport}
              disabled={isExporting}
              title="导出记忆"
              aria-label="Export memories"
              className="p-1"
            >
              <Download className="w-3.5 h-3.5" />
            </Button>
            <Button
              variant="ghost"
              size="sm"
              onClick={handlePrune}
              title="清理旧记忆"
              aria-label="Prune old memories"
              className="p-1"
            >
              <Trash2 className="w-3.5 h-3.5" />
            </Button>
          </div>
        </div>

        {stats && (
          <div className="grid grid-cols-3 gap-2 text-center">
            <div className="bg-gray-50 dark:bg-gray-700/50 rounded-lg p-1.5">
              <div className="text-lg font-bold text-orange-600">{stats.totalEntries}</div>
              <div className="text-[10px] text-gray-500">总记忆</div>
            </div>
            <div className="bg-gray-50 dark:bg-gray-700/50 rounded-lg p-1.5">
              <div className="text-lg font-bold text-blue-600">{stats.byType['fact'] || 0}</div>
              <div className="text-[10px] text-gray-500">事实</div>
            </div>
            <div className="bg-gray-50 dark:bg-gray-700/50 rounded-lg p-1.5">
              <div className="text-lg font-bold text-amber-600">{stats.byType['preference'] || 0}</div>
              <div className="text-[10px] text-gray-500">偏好</div>
            </div>
          </div>
        )}
      </motion.div>

      {/* Search & Filter */}
      <div className="space-y-2">
        <div className="relative">
          <Search className="absolute left-2.5 top-1/2 -translate-y-1/2 w-3.5 h-3.5 text-gray-400" />
          <input
            type="text"
            value={searchQuery}
            onChange={(e) => setSearchQuery(e.target.value)}
            placeholder="搜索记忆..."
            className="w-full text-sm border border-gray-200 dark:border-gray-600 rounded-lg pl-8 pr-3 py-1.5 bg-white dark:bg-gray-800 text-gray-900 dark:text-gray-100 focus:outline-none focus:ring-1 focus:ring-orange-400"
          />
        </div>
        <div className="flex gap-1 flex-wrap">
          <FilterChip
            label="全部"
            active={filterType === 'all'}
            onClick={() => setFilterType('all')}
          />
          {(Object.keys(TYPE_LABELS) as MemoryType[]).map((type) => (
            <FilterChip
              key={type}
              label={`${TYPE_LABELS[type].emoji} ${TYPE_LABELS[type].label}`}
              active={filterType === type}
              onClick={() => setFilterType(type)}
            />
          ))}
        </div>
      </div>

      {/* Memory List */}
      <div className="space-y-2">
        {memories.length > 0 ? (
          <AnimatePresence initial={false}>
            {memories.map((entry) => (
              <MemoryCard
                key={entry.id}
                entry={entry}
                expanded={expandedId === entry.id}
                onToggle={() => setExpandedId(expandedId === entry.id ? null : entry.id)}
                onDelete={() => handleDelete(entry.id)}
              />
            ))}
          </AnimatePresence>
        ) : (
          <EmptyState
            icon={<Brain className="w-8 h-8" />}
            title={searchQuery ? '未找到匹配的记忆' : '暂无记忆'}
            description={searchQuery ? '尝试不同的搜索词' : '与 Agent 交流后，记忆会自动积累'}
            className="py-6"
          />
        )}
      </div>
    </div>
  );
}

function MemoryCard({
  entry,
  expanded,
  onToggle,
  onDelete,
}: {
  entry: MemoryEntry;
  expanded: boolean;
  onToggle: () => void;
  onDelete: () => void;
}) {
  const typeInfo = TYPE_LABELS[entry.type];
  const importanceStars = Math.round(entry.importance / 2);
  const timeAgo = getTimeAgo(entry.createdAt);

  return (
    <motion.div
      layout
      initial={{ opacity: 0, y: 8 }}
      animate={{ opacity: 1, y: 0 }}
      exit={{ opacity: 0, y: -8 }}
      className="rounded-lg border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 shadow-sm overflow-hidden"
    >
      <div
        className="px-3 py-2 cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-700/50 transition-colors"
        onClick={onToggle}
      >
        <div className="flex items-start gap-2">
          <span className={`text-[10px] font-medium px-1.5 py-0.5 rounded-full ${typeInfo.color}`}>
            {typeInfo.emoji} {typeInfo.label}
          </span>
          <div className="flex-1 min-w-0">
            <p className="text-sm text-gray-800 dark:text-gray-200 line-clamp-2">{entry.content}</p>
          </div>
          {expanded ? (
            <ChevronUp className="w-3.5 h-3.5 text-gray-400 flex-shrink-0 mt-0.5" />
          ) : (
            <ChevronDown className="w-3.5 h-3.5 text-gray-400 flex-shrink-0 mt-0.5" />
          )}
        </div>

        <div className="flex items-center gap-3 mt-1.5 text-[10px] text-gray-500 dark:text-gray-400">
          <span className="flex items-center gap-0.5">
            <Star className="w-3 h-3" />
            {'★'.repeat(importanceStars)}{'☆'.repeat(5 - importanceStars)}
          </span>
          <span className="flex items-center gap-0.5">
            <Clock className="w-3 h-3" />
            {timeAgo}
          </span>
          {entry.tags.length > 0 && (
            <span className="flex items-center gap-0.5">
              <Tag className="w-3 h-3" />
              {entry.tags.slice(0, 2).join(', ')}
            </span>
          )}
        </div>
      </div>

      <AnimatePresence>
        {expanded && (
          <motion.div
            initial={{ height: 0, opacity: 0 }}
            animate={{ height: 'auto', opacity: 1 }}
            exit={{ height: 0, opacity: 0 }}
            transition={{ duration: 0.2 }}
            className="border-t border-gray-100 dark:border-gray-700"
          >
            <div className="px-3 py-2 space-y-2 text-xs">
              <div className="grid grid-cols-2 gap-2">
                <div>
                  <span className="text-gray-500">重要性</span>
                  <span className="ml-1 font-medium">{entry.importance}/10</span>
                </div>
                <div>
                  <span className="text-gray-500">来源</span>
                  <span className="ml-1 font-medium">{entry.source === 'auto' ? '自动' : entry.source === 'user' ? '用户' : '反思'}</span>
                </div>
                <div>
                  <span className="text-gray-500">访问</span>
                  <span className="ml-1 font-medium">{entry.accessCount}次</span>
                </div>
                <div>
                  <span className="text-gray-500">创建</span>
                  <span className="ml-1 font-medium">{new Date(entry.createdAt).toLocaleDateString('zh-CN')}</span>
                </div>
              </div>
              {entry.tags.length > 0 && (
                <div className="flex flex-wrap gap-1">
                  {entry.tags.map((tag) => (
                    <Badge key={tag} variant="default">{tag}</Badge>
                  ))}
                </div>
              )}
              <div className="flex justify-end">
                <Button
                  variant="ghost"
                  size="sm"
                  onClick={(e: React.MouseEvent) => {
                    e.stopPropagation();
                    onDelete();
                  }}
                  className="text-red-500 hover:text-red-700 hover:bg-red-50 dark:hover:bg-red-900/20 text-xs px-2 py-1"
                >
                  <Trash2 className="w-3 h-3 mr-1" />
                  删除
                </Button>
              </div>
            </div>
          </motion.div>
        )}
      </AnimatePresence>
    </motion.div>
  );
}

function FilterChip({
  label,
  active,
  onClick,
}: {
  label: string;
  active: boolean;
  onClick: () => void;
}) {
  return (
    <button
      onClick={onClick}
      className={`text-[10px] px-2 py-0.5 rounded-full border transition-colors ${
        active
          ? 'bg-orange-100 border-orange-300 text-orange-700 dark:bg-orange-900/30 dark:border-orange-700 dark:text-orange-300'
          : 'bg-gray-50 border-gray-200 text-gray-600 hover:bg-gray-100 dark:bg-gray-800 dark:border-gray-600 dark:text-gray-400'
      }`}
    >
      {label}
    </button>
  );
}

function getTimeAgo(isoDate: string): string {
  const now = Date.now();
  const then = new Date(isoDate).getTime();
  const diffMs = now - then;

  const minutes = Math.floor(diffMs / 60_000);
  if (minutes < 1) return '刚刚';
  if (minutes < 60) return `${minutes}分钟前`;

  const hours = Math.floor(minutes / 60);
  if (hours < 24) return `${hours}小时前`;

  const days = Math.floor(hours / 24);
  if (days < 30) return `${days}天前`;

  const months = Math.floor(days / 30);
  return `${months}个月前`;
}