/**
 * Klaviyo MCP Server Class
 * Implements lazy-loaded tool modules for optimal performance
 */

import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from '@modelcontextprotocol/sdk/types.js';
import { KlaviyoClient } from './client/index.js';

type ToolModule = any[];

export class KlaviyoMCPServer {
  private server: Server;
  private client: KlaviyoClient;
  private toolModules: Map<string, () => Promise<ToolModule>>;
  private loadedTools: any[] | null = null;

  constructor(client: KlaviyoClient) {
    this.client = client;
    this.toolModules = new Map();

    this.server = new Server(
      {
        name: '@mcpengine/klaviyo',
        version: '1.0.0',
      },
      {
        capabilities: {
          tools: {},
        },
      }
    );

    this.setupToolModules();
    this.setupHandlers();
  }

  private setupToolModules() {
    // Register lazy-loaded tool modules
    this.toolModules.set('profiles', async () => {
      const module = await import('./tools/klaviyo_profiles.js');
      return module.profileTools(this.client);
    });

    this.toolModules.set('lists', async () => {
      const module = await import('./tools/klaviyo_lists.js');
      return module.listTools(this.client);
    });

    this.toolModules.set('segments', async () => {
      const module = await import('./tools/klaviyo_segments.js');
      return module.segmentTools(this.client);
    });

    this.toolModules.set('campaigns', async () => {
      const module = await import('./tools/klaviyo_campaigns.js');
      return module.campaignTools(this.client);
    });

    this.toolModules.set('flows', async () => {
      const module = await import('./tools/klaviyo_flows.js');
      return module.flowTools(this.client);
    });

    this.toolModules.set('templates', async () => {
      const module = await import('./tools/klaviyo_templates.js');
      return module.templateTools(this.client);
    });

    this.toolModules.set('metrics', async () => {
      const module = await import('./tools/klaviyo_metrics.js');
      return module.metricTools(this.client);
    });

    this.toolModules.set('events', async () => {
      const module = await import('./tools/klaviyo_events.js');
      return module.eventTools(this.client);
    });

    this.toolModules.set('catalogs', async () => {
      const module = await import('./tools/klaviyo_catalogs.js');
      return module.catalogTools(this.client);
    });

    this.toolModules.set('forms', async () => {
      const module = await import('./tools/klaviyo_forms.js');
      return module.formTools(this.client);
    });

    this.toolModules.set('tags', async () => {
      const module = await import('./tools/klaviyo_tags.js');
      return module.tagTools(this.client);
    });

    this.toolModules.set('reporting', async () => {
      const module = await import('./tools/klaviyo_reporting.js');
      return module.reportingTools(this.client);
    });
  }

  private async loadAllTools(): Promise<any[]> {
    if (this.loadedTools) {
      return this.loadedTools;
    }

    const allTools: any[] = [];
    
    for (const [name, loader] of this.toolModules.entries()) {
      const tools = await loader();
      allTools.push(...tools);
    }

    this.loadedTools = allTools;
    return allTools;
  }

  private setupHandlers() {
    this.server.setRequestHandler(ListToolsRequestSchema, async () => {
      const allTools = await this.loadAllTools();
      
      return {
        tools: allTools.map((tool) => ({
          name: tool.name,
          description: tool.description,
          inputSchema: tool.inputSchema,
        })),
      };
    });

    this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
      const allTools = await this.loadAllTools();
      const tool = allTools.find((t) => t.name === request.params.name);
      
      if (!tool) {
        throw new Error(`Unknown tool: ${request.params.name}`);
      }

      try {
        const result = await tool.execute(request.params.arguments || {});
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify(result, null, 2),
            },
          ],
        };
      } catch (error: any) {
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify(
                {
                  error: error.message || 'Unknown error',
                  details: error.response?.data || error.toString(),
                },
                null,
                2
              ),
            },
          ],
          isError: true,
        };
      }
    });
  }

  async connect(transport: any) {
    await this.server.connect(transport);
  }
}