/*
 *   Copyright IDMesh Authors
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"net/http"
	"os"
)

const (
	ServeAddr = ":80"

	EnvKeyConfigFilePath = "CONFIG_FILE_PATH"
)

func main() {
	config, err := loadConfig()
	if err != nil {
		log.Fatalf("fail to load config: %v", err)
	}

	server, err := NewRelayServer(config)
	if err != nil {
		log.Fatalf("fail to make server: %v", err)
	}

	log.Println("app serve at:", ServeAddr)

	err = http.ListenAndServe(ServeAddr, server)
	if err != nil {
		if errors.Is(err, http.ErrServerClosed) {
			return
		}
		log.Fatalf("fail to serve: %v", err)
	}
}

func loadConfig() (cfg Config, err error) {
	configFilePath := os.Getenv(EnvKeyConfigFilePath)
	if configFilePath == "" {
		configFilePath = "/data/idmesh/settings.json"
	}

	raw, err := os.ReadFile(configFilePath)
	if err != nil {
		return Config{}, fmt.Errorf("fail to read config file: %v", err)
	}

	err = json.Unmarshal(raw, &cfg)
	if err != nil {
		return Config{}, fmt.Errorf("fail to decode config file: %v", err)
	}
	return
}