package main

import (
	"context"
	"errors"
	"flag"
	"log"
	"net"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"
)

type bridge struct {
	binary string
	dir    string
	mcpURL string
}

func main() {
	if err := run(); err != nil {
		log.Print(err)
		os.Exit(1)
	}
}

func run() error {
	b := &bridge{}
	addr := flag.String("listen", "127.0.0.1:8080", "HTTP listen address")
	flag.StringVar(&b.binary, "codex", "codex", "Codex executable")
	flag.StringVar(&b.dir, "workdir", ".", "Codex working directory")
	flag.StringVar(&b.mcpURL, "mcp-url", "", "AgentGateway MCP endpoint; otherwise use Codex configuration")
	flag.Parse()
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	s := &http.Server{Addr: *addr, Handler: b.handler(), ReadHeaderTimeout: 10 * time.Second, BaseContext: func(net.Listener) context.Context { return ctx }}
	stopped := make(chan error, 1)
	go func() { stopped <- s.ListenAndServe() }()
	var serveErr error
	select {
	case err := <-stopped:
		if !errors.Is(err, http.ErrServerClosed) {
			serveErr = err
		}
	case <-ctx.Done():
	}
	stop()
	shutdown, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	return errors.Join(serveErr, s.Shutdown(shutdown))
}

func (b *bridge) handler() http.Handler {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusOK) })
	mux.HandleFunc("GET /v1/models", b.models)
	mux.HandleFunc("POST /v1/chat/completions", b.chat)
	return mux
}