package main

import (
	"bytes"
	"flag"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

var (
	repo = ""
	commit = ""
)

func init() {
	flag.StringVar(&repo, "repo", "", "")
	flag.StringVar(&commit, "commit", "", "")
}

func main() {
	flag.Parse()

	log.SetFlags(0)

	defer log.Println("Exiting craft")
	log.Println("Starting craft")

	workbench := prepareWorkbench(repo, commit)
	defer os.RemoveAll(workbench)
	craft(workbench)
}

func runCommand(dir string, name string, args ...string) {
	log.Printf("%s %s\n", name, strings.Join(args, " "))
	command := exec.Command(name, args...)
	command.Dir = dir
	command.Stderr = os.Stderr
	command.Stdout = os.Stdout
	err := command.Run()
	if err != nil {
		log.Fatal(err)
	}
}

func craft(workbench string) {
	script := `#!/bin/sh

source craft.sh
build
`

	cmd := exec.Command("busybox", "ash")
	cmd.Dir = workbench
	cmd.Stdin = bytes.NewBufferString(script)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	err := cmd.Run()
	if err != nil {
		log.Fatal(err)
	}
}

func prepareWorkbench(repo string, commit string) string {
	workbench, err := os.MkdirTemp("", "*-craft")
	if err != nil {
		log.Fatal(err)
	}

	runCommand(
		workbench,
		"git",
		"clone",
		repo,
		workbench,
	)

	runCommand(
		workbench,
		"git",
		"--git-dir",
		filepath.Join(workbench, ".git"),
		"--work-tree",
		workbench,
		"checkout",
		commit,
	)

	runCommand(
		workbench,
		"git",
		"--git-dir",
		filepath.Join(workbench, ".git"),
		"--work-tree",
		workbench,
		"submodule",
		"update",
		"--depth=1",
		"--init",
		"--recursive",
	)

	return workbench
}