package server

import (
	"context"
	"fmt"
	"log/slog"
	"os"
	"os/signal"
	"syscall"

	"ops-mcp/internal/tool"

	"github.com/mark3labs/mcp-go/server"
)

const version = "0.1.0"

// Run 启动 MCP Server。
func Run(transport string, tools ...tool.Tool) error {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	sigCh := make(chan os.Signal, 1)
	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
	go func() {
		sig := <-sigCh
		slog.Info("received signal, shutting down", "signal", sig)
		cancel()
	}()

	registry := NewRegistry()
	for _, t := range tools {
		if err := registry.Register(t); err != nil {
			return fmt.Errorf("register: %w", err)
		}
	}

	sysTool := tool.NewSystemTool(version, registry)
	if err := registry.Register(sysTool); err != nil {
		return fmt.Errorf("register system: %w", err)
	}

	if err := registry.InitializeAll(ctx); err != nil {
		return fmt.Errorf("initialize: %w", err)
	}
	defer func() {
		for _, err := range registry.ShutdownAll(ctx) {
			slog.Error("shutdown error", "err", err)
		}
	}()

	mcpServer := server.NewMCPServer("ops-mcp", version, server.WithLogging())

	if err := registry.RegisterAll(mcpServer); err != nil {
		return fmt.Errorf("register all: %w", err)
	}

	switch transport {
	case "stdio":
		slog.Info("starting MCP server", "transport", "stdio")
		return server.ServeStdio(mcpServer)
	case "sse":
		slog.Info("starting MCP server", "transport", "sse", "addr", ":8080")
		return server.NewSSEServer(mcpServer).Start(":8080")
	default:
		return fmt.Errorf("unknown transport: %s", transport)
	}
}