import { MCPApp, TextResponse, ProgressResponse, LogResponse, z } from "@the-ihor/mcp-sdk-typescript";

const app = new MCPApp({
  name: "my-mcp-server",
  version: "1.0.0",
  transport: {
    host: "localhost",
    port: 3000,
    path: "/mcp"
  }
});

// Create tools with streaming responses
app
  .createTool({
    name: "process-data",
    description: "Process data with real-time progress updates",
    schema: z.object({
      data: z.array(z.string()).describe("Data items to process"),
      delay: z.number().optional().default(100).describe("Processing delay in ms")
    }),
    handler: async function* (args) {
      yield new LogResponse("Starting data processing", "info");
      
      for (let i = 0; i < args.data.length; i++) {
        yield new ProgressResponse(`Processing item ${i + 1}`, i + 1, args.data.length);
        
        // Simulate processing
        await new Promise(resolve => setTimeout(resolve, args.delay));
        
        yield new TextResponse(`Processed: ${args.data[i]}`);
      }
      
      yield new LogResponse("Processing completed", "info");
    }
  })
  .createTool({
    name: "echo",
    description: "Echo back input with optional transformations",
    schema: z.object({
      text: z.string().describe("Text to echo"),
      uppercase: z.boolean().optional().describe("Convert to uppercase"),
      repeat: z.number().min(1).max(10).optional().default(1).describe("Number of repetitions")
    }),
    handler: async function* (args) {
      let result = args.uppercase ? args.text.toUpperCase() : args.text;
      
      for (let i = 0; i < args.repeat; i++) {
        yield new TextResponse(`Echo ${i + 1}: ${result}`);
      }
    }
  });

// Start the server
await app.start();
console.log("🎯 MCP Server running and ready for connections!");

const transport = new StreamableHttpTransport({
  host: "localhost",
  port: 3000,
  path: "/mcp"
});

// Handle transport-level errors
transport.onError((error) => {
  console.error("Transport error:", error.message);
  // Error context: "Server startup failed: ..." 
  // Error context: "Failed to parse JSON-RPC message: ..."
});

// Handle application errors
app.createTool({
  name: "risky-operation",
  schema: z.object({ value: z.number() }),
  handler: async function* (args) {
    try {
      if (args.value < 0) {
        yield new ErrorResponse("Negative values not allowed", "INVALID_INPUT");
        return;
      }
      yield new TextResponse(`Result: ${Math.sqrt(args.value)}`);
    } catch (error) {
      yield new ErrorResponse(`Unexpected error: ${error.message}`, "INTERNAL_ERROR");
    }
  }
});

// Client establishes SSE connection: GET /mcp
// Server returns X-Session-ID header
// Client sends requests with session ID: POST /mcp + X-Session-ID header
// Server routes responses back to correct client via SSE stream

// Will use Bun.serve if running in Bun
// Will use Node.js HTTP server if running in Node.js
const app = new MCPApp({ name: 'my-app', version: '1.0.0' });
await app.start(); // Optimized for your runtime!