package main

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net"
	"net/http"
	"os/signal"
	"path"
	"strings"
	"syscall"
)

func main() {
	ctx, can := signal.NotifyContext(context.Background(), syscall.SIGINT)
	defer can()

	cfg, err := newConfig()
	if err != nil {
		panic(err)
	}

	if err := run(ctx, cfg); err != nil && ctx.Err() == nil {
		panic(err)
	}
}

func run(ctx context.Context, cfg Config) error {
	select {
	case <-ctx.Done():
		return ctx.Err()
	case err := <-listenAndServe(ctx, cfg):
		return err
	}
}

func listenAndServe(ctx context.Context, cfg Config) chan error {
	s := http.Server{
		Addr:    fmt.Sprintf(":%d", cfg.Port),
		Handler: http.HandlerFunc(newHandler(cfg)),
		BaseContext: func(net.Listener) context.Context {
			return ctx
		},
	}

	errc := make(chan error)
	go func() {
		defer close(errc)
		errc <- s.ListenAndServe()
	}()

	return errc
}

func newHandler(cfg Config) http.HandlerFunc {
	mux := http.NewServeMux()

	mux.Handle("POST /api/v1/events/{src}/{$}", http.HandlerFunc(newHandlerPostAPIV1Events(cfg)))

	return func(w http.ResponseWriter, r *http.Request) {
		b, _ := io.ReadAll(r.Body)
		log.Printf("%s %s | %s", r.Method, r.URL, b)
		mux.ServeHTTP(w, r)
	}
}

func newHandlerPostAPIV1Events(cfg Config) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		src := path.Base(strings.TrimSuffix(r.URL.Path, "/"))
		json.NewEncoder(w).Encode(map[string]any{"src": src})
	}
}