import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { Injectable, Inject, type OnModuleInit } from '@nestjs/common';
import type { Client as TypesenseClient } from 'typesense';
import { MCP_MODULE_OPTIONS } from './mcp.constants';
import type { McpModuleOptions } from './mcp.module';

@Injectable()
export class McpRegistryService implements OnModuleInit {
  private readonly servers = new Map<string, McpServer>();
  private typesenseClient: TypesenseClient | null = null;

  constructor(
    @Inject(MCP_MODULE_OPTIONS) private readonly options: McpModuleOptions,
  ) {}

  async onModuleInit(): Promise<void> {
    // Lazy import to avoid hard dependency at module load time
    const { createPropertySearchServer } = await import('../property-search/property-search.server');
    const { createMarketAnalyticsServer } = await import('../market-analytics/market-analytics.server');
    const { createValuationServer } = await import('../valuation/valuation.server');
    const { createIndustrialParksServer } = await import('../industrial-parks/industrial-parks.server');
    const { createReportsServer } = await import('../reports/reports.server');

    // Typesense client is injected from the host app via setTypesenseClient
    // If not set by the time servers are needed, tools that require it will fail gracefully
    if (this.typesenseClient) {
      this.servers.set(
        'property-search',
        createPropertySearchServer({
          typesenseClient: this.typesenseClient,
          collectionName: this.options.typesenseCollectionName,
        }),
      );

      this.servers.set(
        'market-analytics',
        createMarketAnalyticsServer({
          typesenseClient: this.typesenseClient,
          collectionName: this.options.typesenseCollectionName,
        }),
      );
    }

    this.servers.set(
      'valuation',
      createValuationServer({
        aiServiceBaseUrl: this.options.aiServiceBaseUrl,
      }),
    );

    if (this.typesenseClient) {
      this.servers.set(
        'industrial-parks',
        createIndustrialParksServer({
          typesenseClient: this.typesenseClient,
          aiServiceBaseUrl: this.options.aiServiceBaseUrl,
        }),
      );
    }

    this.servers.set(
      'reports',
      createReportsServer({
        apiBaseUrl: this.options.apiBaseUrl ?? this.options.aiServiceBaseUrl,
      }),
    );
  }

  setTypesenseClient(client: TypesenseClient): void {
    this.typesenseClient = client;
  }

  getServer(name: string): McpServer | undefined {
    return this.servers.get(name);
  }

  getServerNames(): string[] {
    return Array.from(this.servers.keys());
  }

  getAllServers(): Map<string, McpServer> {
    return this.servers;
  }
}