package main

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

const listenAddress = ":8080"

func main() {
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()

	logger := log.Default()
	if err := run(ctx, os.Getenv("WEBHOOK_URL"), listenAddress, logger); err != nil && !errors.Is(err, http.ErrServerClosed) {
		logger.Fatalf("Server stopped unexpectedly: %v", err)
	}
}

func run(ctx context.Context, webhookURL, address string, logger *log.Logger) error {
	app, err := newApplication(applicationConfig{WebhookURL: webhookURL, Logger: logger})
	if err != nil {
		return fmt.Errorf("configuration failed: %w", err)
	}
	listener, err := netListen("tcp", address)
	if err != nil {
		return fmt.Errorf("listen on %s: %w", address, err)
	}
	logger.Printf("Starting server on %s", address)
	return serve(ctx, newHTTPServer(app.handler()), listener)
}