package main

import (
	"context"
	"encoding/json"
	"log"
	"net/http"
	"os"
	"os/exec"

	"github.com/docker/docker/client"
)

func main() {
	secret := os.Getenv("WEBHOOK_SECRET")

	cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
	if err != nil {
		log.Fatal("failed to create docker client:", err)
	}
	defer cli.Close()

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

		if r.Header.Get("X-Webhook-Secret") != secret {
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}

		// имя контейнера берём из query параметра
		containerName := r.URL.Query().Get("container")
		if containerName == "" {
			http.Error(w, "container parameter is required", http.StatusBadRequest)
			return
		}

		ctx := context.Background()

		// получаем инфо о контейнере чтобы узнать имя образа
		inspect, err := cli.ContainerInspect(ctx, containerName)
		if err != nil {
			log.Printf("failed to inspect container %s: %v", containerName, err)
			http.Error(w, "container not found", http.StatusNotFound)
			return
		}

		imageName := inspect.Config.Image
		log.Printf("Container: %s, Image: %s", containerName, imageName)

		// тянем новый образ
		log.Println("Pulling new image...")
		pull := exec.Command("docker", "pull", imageName)
		pull.Stdout = os.Stdout
		pull.Stderr = os.Stderr
		if err := pull.Run(); err != nil {
			log.Println("pull failed:", err)
			http.Error(w, "pull failed", http.StatusInternalServerError)
			return
		}

		// перезапускаем контейнер
		log.Printf("Restarting container %s...", containerName)
		restart := exec.Command("docker", "restart", containerName)
		restart.Stdout = os.Stdout
		restart.Stderr = os.Stderr
		if err := restart.Run(); err != nil {
			log.Println("restart failed:", err)
			http.Error(w, "restart failed", http.StatusInternalServerError)
			return
		}

		log.Printf("Deploy of %s completed", containerName)
		w.WriteHeader(http.StatusOK)

		json.NewEncoder(w).Encode(map[string]string{
			"status":    "ok",
			"container": containerName,
			"image":     imageName,
		})
	})

	log.Println("Webhook server listening on :9001")
	log.Fatal(http.ListenAndServe(":9001", nil))
}