package main

import (
	"context"
	"log"
	"net/http"
	"os"
	"strings"
	"time"

	"github.com/modelcontextprotocol/go-sdk/mcp"
)

func main() {
	server := mcp.NewServer(&mcp.Implementation{
		Name:    "picoclaw-integration-streamable-server",
		Version: "1.0.0",
	}, nil)

	mcp.AddTool(server, &mcp.Tool{
		Name:        "echo",
		Description: "Echo back the provided message",
	}, func(ctx context.Context, req *mcp.CallToolRequest, args map[string]any) (*mcp.CallToolResult, any, error) {
		message, _ := args["message"].(string)
		return &mcp.CallToolResult{
			Content: []mcp.Content{
				&mcp.TextContent{Text: message},
			},
		}, nil, nil
	})

	streamable := mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
		return server
	}, &mcp.StreamableHTTPOptions{
		JSONResponse: envBool("STREAMABLE_JSON_RESPONSE", true),
	})

	mux := http.NewServeMux()
	mux.Handle("/mcp", streamable)
	mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("ok"))
	})

	srv := &http.Server{
		Addr:              ":8080",
		Handler:           mux,
		ReadHeaderTimeout: 5 * time.Second,
	}

	log.Printf("streamable MCP integration server listening on %s", srv.Addr)
	if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
		log.Fatal(err)
	}
}

func envBool(name string, fallback bool) bool {
	value := strings.TrimSpace(strings.ToLower(os.Getenv(name)))
	if value == "" {
		return fallback
	}

	switch value {
	case "1", "true", "yes", "on":
		return true
	case "0", "false", "no", "off":
		return false
	default:
		return fallback
	}
}