package main

import (
	"fmt"
	"log"
	"net/http"
	"os"
	"strings"
	"time"
)

func main() {
	addr := envOr("LISTEN_ADDR", ":8085")
	writeToken, err := readSecretFile("RECEIVER_WRITE_TOKEN_FILE")
	if err != nil {
		log.Fatal(err)
	}
	readToken, err := readSecretFile("RECEIVER_READ_TOKEN_FILE")
	if err != nil {
		log.Fatal(err)
	}
	server, err := newReceiverServer(envOr("RECEIPT_DIRECTORY", "/var/lib/notification-receiver"), writeToken, readToken, time.Now)
	if err != nil {
		log.Fatal(err)
	}
	log.Printf("notification-receiver listening on %s", addr)
	if err = http.ListenAndServe(addr, server.routes()); err != nil {
		log.Fatal(err)
	}
}

func readSecretFile(name string) (string, error) {
	path := os.Getenv(name)
	if path == "" {
		return "", fmt.Errorf("%s is required", name)
	}
	value, err := os.ReadFile(path)
	if err != nil {
		return "", fmt.Errorf("read %s: %w", name, err)
	}
	secret := strings.TrimSpace(string(value))
	if secret == "" {
		return "", fmt.Errorf("%s is empty", name)
	}
	return secret, nil
}
func envOr(name, fallback string) string {
	if value := os.Getenv(name); value != "" {
		return value
	}
	return fallback
}