package main

import (
	"errors"
	"flag"
	"os"
	"os/exec"

	"github.com/go-git/go-git/v5"
	"k8s.io/klog"
)

var (
	flagRemote        string
	flagLocalCheckout string
	flagImageName     string
	flagTrigger       string
)

func podmanImageExists(name string) bool {
	cmd := exec.Command("podman", "image", "inspect", name)
	err := cmd.Run()
	if err == nil {
		{
			return true
		}
	}

	if cmd.ProcessState == nil {
		klog.Exitf("Failed to run podman: %v", err)
	}
	return false
}

func podmanBuildImage(name, source string) error {
	cmd := exec.Command("podman", "build", "-t", name, source)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	return cmd.Run()
}

func podmanTagImage(image, target string) error {
	cmd := exec.Command("podman", "tag", image, target)
	return cmd.Run()
}

func main() {
	flag.StringVar(&flagRemote, "remote", "https://git.orga.cebula.camp/infra/site.git", "Git remote path")
	flag.StringVar(&flagLocalCheckout, "local_checkout", "/tmp/ci", "Path to local Git checkout")
	flag.StringVar(&flagImageName, "image_name", "git.orga.cebula.camp/infra/site", "Name of podman image to build")
	flag.StringVar(&flagTrigger, "trigger", "", "Command to run after golden image was updated")
	flag.Parse()

	repo, err := git.PlainClone(flagLocalCheckout, false, &git.CloneOptions{
		URL:      flagRemote,
		Progress: os.Stdout,
		Depth:    1,
	})
	if err != nil {
		if errors.Is(err, git.ErrRepositoryAlreadyExists) {
			repo, err = git.PlainOpen(flagLocalCheckout)
			if err != nil {
				klog.Exitf("Repo open failed: %v", err)
			}
		} else {
			klog.Exitf("Initial clone failed: %v", err)
		}
	}

	wt, err := repo.Worktree()
	if err != nil {
		klog.Exitf("Getting worktree failed: %v", err)
	}

	err = wt.Pull(&git.PullOptions{
		RemoteName:    "origin",
		ReferenceName: "refs/heads/main",
		SingleBranch:  true,
		Force:         true,
	})
	if err != nil {
		if !errors.Is(err, git.NoErrAlreadyUpToDate) {
			klog.Exitf("Pull failed: %v", err)
		}
	}

	ref, err := repo.Head()
	if err != nil {
		klog.Exitf("Getting HEAD failed: %v", err)
	}

	klog.Infof("main at %s", ref.Hash())

	imageName := flagImageName + ":" + ref.Hash().String()
	goldenName := flagImageName + ":golden"
	if podmanImageExists(imageName) {
		klog.Infof("Image %s already exists, exiting", imageName)
		return
	}

	klog.Infof("Building %s...", imageName)
	if err := podmanBuildImage(imageName, flagLocalCheckout); err != nil {
		klog.Exitf("Building %s failed: %v", imageName, err)
	}
	klog.Infof("Succesfully built %s, tagging as %s", imageName, goldenName)

	if err := podmanTagImage(imageName, goldenName); err != nil {
		klog.Exitf("Tagging %s failed: %v", goldenName)
	}

	if flagTrigger != "" {
		cmd := exec.Command("sh", "-c", flagTrigger)
		cmd.Stdout = os.Stdout
		cmd.Stderr = os.Stderr
		if err := cmd.Run(); err != nil {
			klog.Exitf("Trigger failed: %v", err)
		}
	} else {
		klog.Infof("Trigger not defined")
	}
}