import { Injectable, Logger } from '@nestjs/common';
import { allowedWecomPluginMcpTools } from '@dukang/shared-types';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
import type { IncomingMessage, ServerResponse } from 'node:http';
import { WECOM_PLUGIN_MCP_TOOL_DEFS } from './wecom-plugin-mcp.tools';
import type { WecomPluginQueryService } from './wecom-plugin-query.service';
import type { WecomPluginRuntime } from './wecom-plugin.types';
import { wecomPluginCaller } from './wecom-plugin.util';

export function createWecomPluginMcpServer(
  query: WecomPluginQueryService,
  plugin: WecomPluginRuntime,
  wecomUserId: string,
): McpServer {
  const server = new McpServer({
    name: plugin.name || 'dukang-wecom-plugin',
    version: '1.0.0',
  });
  const allowed = new Set(allowedWecomPluginMcpTools(plugin.permissions));
  const ctx = { query, plugin, wecomUserId };
  for (const def of WECOM_PLUGIN_MCP_TOOL_DEFS) {
    if (!allowed.has(def.name)) continue;
    server.registerTool(
      def.name,
      { title: def.name, description: def.description, inputSchema: def.inputSchema },
      async (args) => def.invoke(ctx, (args ?? {}) as Record<string, unknown>),
    );
  }
  return server;
}

@Injectable()
export class WecomPluginMcpFactory {
  private readonly logger = new Logger(WecomPluginMcpFactory.name);

  constructor(private readonly query: WecomPluginQueryService) {}

  async handle(
    req: IncomingMessage & { body?: unknown; headers: IncomingMessage['headers'] },
    res: ServerResponse,
    plugin: WecomPluginRuntime,
  ): Promise<void> {
    const server = createWecomPluginMcpServer(this.query, plugin, wecomPluginCaller(req));
    const transport = new StreamableHTTPServerTransport({
      sessionIdGenerator: undefined,
    });
    res.on('close', () => {
      void transport.close();
      void server.close();
    });
    try {
      await server.connect(transport);
      await transport.handleRequest(req, res, req.body);
    } catch (e) {
      const message = e instanceof Error ? e.message : String(e);
      this.logger.error(`wecom plugin MCP failed: ${message}`);
      if (!res.headersSent) {
        res.statusCode = 500;
        res.setHeader('Content-Type', 'application/json');
        res.end(
          JSON.stringify({
            jsonrpc: '2.0',
            error: { code: -32603, message },
            id: null,
          }),
        );
      }
    }
  }
}