package app

import (
	"context"
	"fmt"
	"io"
	"os"
	"strings"

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

	"forge.lclr.dev/AI/xdebug-mcp/internal/cache"
	"forge.lclr.dev/AI/xdebug-mcp/internal/tools"
	"forge.lclr.dev/AI/xdebug-mcp/mcpgen"
)

func Run(_ context.Context, args []string, version string) error {
	c := cache.New(cache.DefaultCapacity)
	return dispatch(args, version, c, os.Stdout)
}

func dispatch(args []string, version string, c *cache.Cache, stdout io.Writer) error {
	cmd := "mcp"
	if len(args) > 0 {
		cmd = strings.TrimSpace(args[0])
	}

	switch cmd {
	case "", "mcp":
		return runMCP(c, version)
	case "version":
		_, err := fmt.Fprintln(stdout, version)
		return err
	case "help", "-h", "--help":
		_, err := fmt.Fprintf(stdout,
			"%s\n\nUsage:\n  %s [command]\n\nCommands:\n  mcp      Run the MCP server (default)\n  version  Print the version\n\nOptions:\n  -h, --help  Show this help\n",
			mcpgen.DefaultDescription,
			mcpgen.BinaryName,
		)
		return err
	default:
		return fmt.Errorf("unknown command %q — run '%s --help' for usage", cmd, mcpgen.BinaryName)
	}
}

func runMCP(c *cache.Cache, version string) error {
	s := server.NewMCPServer(mcpgen.BinaryName, version)
	s.AddTool(tools.AnalyzeTool(), tools.AnalyzeHandler(c))
	s.AddTool(tools.CallersTool(), tools.CallersHandler(c))
	s.AddTool(tools.CalleesTool(), tools.CalleesHandler(c))
	return server.ServeStdio(s)
}