import { FileText, Globe, RefreshCw, Wrench } from 'lucide-react';
import { useCallback, useEffect, useState } from 'react';
import { useConfigStore } from '../../store/configStore';
import { silentErrorHandler } from '../../lib/error-utils';
import {
  listMcpServices,
  startMcpService,
  stopMcpService,
  type McpServiceConfig,
  type McpServiceStatus,
  type McpToolInfo,
} from '../../lib/mcp-client';

export function MCPServices() {
  const quickConfig = useConfigStore((s) => s.quickConfig);
  const saveQuickConfig = useConfigStore((s) => s.saveQuickConfig);

  const services = quickConfig.mcpServices || [];
  const [runningServices, setRunningServices] = useState<McpServiceStatus[]>([]);
  const [loading, setLoading] = useState<string | null>(null);
  const [expandedTools, setExpandedTools] = useState<Set<string>>(new Set());

  // Fetch running services on mount
  const refreshRunning = useCallback(async () => {
    try {
      const running = await listMcpServices();
      setRunningServices(running);
    } catch {
      // MCP might not be available yet
      setRunningServices([]);
    }
  }, []);

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

  const toggleTools = (name: string) => {
    setExpandedTools((prev) => {
      const next = new Set(prev);
      if (next.has(name)) next.delete(name);
      else next.add(name);
      return next;
    });
  };

  const toggleService = async (id: string) => {
    const svc = services.find((s) => s.id === id);
    if (!svc) return;

    setLoading(id);
    try {
      if (svc.enabled) {
        // Currently enabled → stop it
        await stopMcpService(svc.name || svc.id).catch(() => {});
      } else {
        // Currently disabled → start it
        const config: McpServiceConfig = {
          name: svc.name || svc.id,
          command: svc.command || '',
          args: svc.args,
          env: svc.env,
          cwd: svc.cwd,
        };
        await startMcpService(config);
      }
      // Update config flag
      const nextServices = services.map((s) =>
        s.id === id ? { ...s, enabled: !s.enabled } : s
      );
      await saveQuickConfig({ mcpServices: nextServices });
      // Refresh running status
      await refreshRunning();
    } catch (err) {
      console.error('[MCP] Toggle failed:', err);
    } finally {
      setLoading(null);
    }
  };

  // Build a map of service name → running status for quick lookup
  const runningMap = new Map(runningServices.map((rs) => [rs.name, rs]));

  return (
    <div className="max-w-3xl">
      <div className="flex justify-between items-center mb-4">
        <h1 className="text-xl font-bold text-gray-900">MCP 服务</h1>
        <div className="flex items-center gap-2">
          <span className="text-xs text-gray-400">
            {runningServices.length} 个运行中 / {services.length} 个已声明
          </span>
          <button
            onClick={() => refreshRunning().catch(() => {})}
            className="p-1.5 rounded-lg hover:bg-gray-100 transition-colors"
            title="刷新状态"
          >
            <RefreshCw className="w-3.5 h-3.5 text-gray-400" />
          </button>
        </div>
      </div>
      <div className="text-xs text-gray-500 mb-6">
        MCP（模型上下文协议）服务为 Agent 扩展外部工具 — 文件系统、数据库、网页搜索等。
      </div>

      <div className="bg-white rounded-xl border border-gray-200 divide-y divide-gray-100 shadow-sm mb-6">
        {services.length > 0 ? services.map((svc) => {
          const isRunning = runningMap.has(svc.name || svc.id);
          const status = runningMap.get(svc.name || svc.id);
          const isLoading = loading === svc.id;
          const showTools = expandedTools.has(svc.id);

          return (
            <div key={svc.id}>
              <div className="flex justify-between items-center p-4">
                <div className="flex items-center gap-3">
                  {svc.id === 'filesystem'
                    ? <FileText className="w-4 h-4 text-gray-500" />
                    : <Globe className="w-4 h-4 text-gray-500" />}
                  <div>
                    <div className="text-sm text-gray-900">{svc.name}</div>
                    <div className="text-xs text-gray-400 mt-0.5">
                      {svc.id}
                      {svc.command && (
                        <span className="ml-2 text-gray-300">|</span>
                      )}
                      {svc.command && (
                        <span className="ml-2 font-mono text-gray-400">{svc.command}</span>
                      )}
                    </div>
                  </div>
                </div>
                <div className="flex gap-2 items-center">
                  {isRunning && status && (
                    <button
                      onClick={() => toggleTools(svc.id)}
                      className="flex items-center gap-1 text-xs px-2 py-1 rounded-full bg-blue-50 text-blue-600 hover:bg-blue-100 transition-colors"
                    >
                      <Wrench className="w-3 h-3" />
                      {status.tool_count} 工具
                    </button>
                  )}
                  <span className={`text-xs px-2 py-1 rounded-full ${
                    isLoading ? 'bg-yellow-50 text-yellow-600' :
                    isRunning ? 'bg-green-50 text-green-600' :
                    svc.enabled ? 'bg-amber-50 text-amber-600' :
                    'bg-gray-100 text-gray-500'
                  }`}>
                    {isLoading ? '处理中...' :
                     isRunning ? '运行中' :
                     svc.enabled ? '已启用' : '已停用'}
                  </span>
                  <button
                    onClick={() => toggleService(svc.id).catch(silentErrorHandler('MCPServices'))}
                    disabled={isLoading}
                    className="text-xs px-3 py-1.5 border border-gray-200 rounded-lg hover:bg-gray-50 transition-colors disabled:opacity-50"
                  >
                    {svc.enabled ? '停用' : '启用'}
                  </button>
                </div>
              </div>
              {/* Expanded tools list */}
              {showTools && status && status.tools.length > 0 && (
                <div className="px-4 pb-3 border-t border-gray-50">
                  <div className="text-xs text-gray-500 mb-2 mt-2">已发现的工具：</div>
                  <div className="space-y-1">
                    {status.tools.map((tool: McpToolInfo) => (
                      <div key={`${tool.service_name}-${tool.tool_name}`} className="flex items-start gap-2 text-xs py-1">
                        <Wrench className="w-3 h-3 text-gray-400 mt-0.5 shrink-0" />
                        <div>
                          <span className="font-medium text-gray-700">{tool.tool_name}</span>
                          {tool.description && (
                            <span className="text-gray-400 ml-2">{tool.description}</span>
                          )}
                        </div>
                      </div>
                    ))}
                  </div>
                </div>
              )}
            </div>
          );
        }) : (
          <div className="p-8 text-center">
            <div className="text-sm text-gray-400 mb-2">尚未配置 MCP 服务</div>
            <div className="text-xs text-gray-300">
              MCP 服务为 Agent 扩展外部工具能力。可通过编辑配置文件
              <code className="mx-1 text-gray-500 bg-gray-100 px-1 rounded">config/mcp.toml</code>
              添加服务。
            </div>
          </div>
        )}
      </div>

      <div className="text-xs text-amber-700 bg-amber-50 rounded-lg p-3">
        新增/删除服务尚未在桌面端 UI 接入。可通过编辑 config/mcp.toml 手动添加 MCP 服务配置，重启后生效。
      </div>
    </div>
  );
}