package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"os/exec"
	"time"
)

var (
	configPath  string
	serverAddr  string
	originalApp string
)

func main() {
	flag.StringVar(&configPath, "config", "config.json", "path to config file")
	flag.StringVar(&serverAddr, "addr", ":9090", "address for config server")
	flag.StringVar(&originalApp, "app", "./override", "path to the original app")
	flag.Parse()

	http.HandleFunc("/api/config", handleConfig)
	http.HandleFunc("/api/restart", handleRestart)
	http.HandleFunc("/api/start", start)
	http.HandleFunc("/api/stop", stop)
	http.HandleFunc("/_ping", handlePing)
	http.Handle("/", http.FileServer(http.Dir("web")))

	log.Printf("Config server starting on %s", serverAddr)
	log.Fatal(http.ListenAndServe(serverAddr, nil))
}

func handleConfig(w http.ResponseWriter, r *http.Request) {
	if r.Method == http.MethodGet {
		config, err := LoadConfig(configPath)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		_, err = w.Write(config)
		if err != nil {
			return
		}
	} else if r.Method == http.MethodPost {
		var newConfig map[string]interface{}
		err := json.NewDecoder(r.Body).Decode(&newConfig)
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}
		err = SaveConfig(configPath, newConfig)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.WriteHeader(http.StatusOK)
	} else {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
	}
}

func handleRestart(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	cmd := exec.Command(originalApp)
	err := cmd.Start()
	if err != nil {
		http.Error(w, "Failed to restart the application", http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
	_, err = w.Write([]byte("Application restarted"))
	if err != nil {
		return
	}
}

func start(w http.ResponseWriter, r *http.Request) {
	cmd := exec.Command("override")
	err := cmd.Start()
	if err != nil {
		http.Error(w, "Failed to start override: "+err.Error(), http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusOK)
}

func stop(w http.ResponseWriter, r *http.Request) {
	cmd := exec.Command("pkill", "override")
	err := cmd.Run()
	if err != nil {
		http.Error(w, "Failed to stop override: "+err.Error(), http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusOK)
}

func handlePing(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	bindAddress := r.URL.Query().Get("bind")
	protocol := r.URL.Query().Get("protocol")

	if bindAddress == "" {
		http.Error(w, "bind address is required", http.StatusBadRequest)
		return
	}

	if protocol == "" {
		protocol = "http" // 默认使用http
	}

	url := fmt.Sprintf("%s://%s/_ping", protocol, bindAddress)

	client := &http.Client{
		Timeout: 5 * time.Second,
	}

	resp, err := client.Get(url)
	if err != nil {
		w.WriteHeader(http.StatusServiceUnavailable)
		err := json.NewEncoder(w).Encode(map[string]string{
			"msg": fmt.Sprintf("无法连接到服务器: %v", err),
		})
		if err != nil {
			return
		}
		return
	}
	defer func(Body io.ReadCloser) {
		err := Body.Close()
		if err != nil {

		}
	}(resp.Body)

	if resp.StatusCode == http.StatusOK {
		w.WriteHeader(http.StatusOK)
		err := json.NewEncoder(w).Encode(map[string]interface{}{
			"msg": "服务器已启动并正常运行",
			"data": map[string]interface{}{
				"now": time.Now().Unix(),
				"ns1": "200 OK",
			},
		})
		if err != nil {
			return
		}
	} else {
		w.WriteHeader(http.StatusBadGateway)
		err := json.NewEncoder(w).Encode(map[string]string{
			"msg": fmt.Sprintf("服务器响应异常: %s", resp.Status),
		})
		if err != nil {
			return
		}
	}
}