package main

import (
	"context"
	"flag"
	"fmt"
	"net/url"
	"os"
	"path/filepath"
	"strings"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing/filemode"
	"github.com/go-git/go-git/v5/plumbing/object"
	"github.com/go-git/go-git/v5/storage/memory"
	yamlcodec "go.unistack.org/micro-codec-yaml/v3"
	flagconfig "go.unistack.org/micro-config-flag/v3"
	"go.unistack.org/micro/v3/config"
	"go.unistack.org/micro/v3/logger"
	"go.unistack.org/micro/v3/logger/slog"
)

type Config struct {
	DstDir string `default:"." flag:"name=dstdir,desc='destination dir',default='.'"`
	Action string `default:"update" flag:"name=action,desc='action',default='update'"`
	Clean  bool   `default:"false" flag:"name=clean,desc='cleaup destination dir',default='false'"`
}

func main() {
	var err error

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	cfg := &Config{}

	log := slog.NewLogger()
	if err = log.Init(); err != nil {
		log.Fatal(ctx, err)
	}

	logger.DefaultLogger = log

	if err = config.Load(ctx, []config.Config{
		config.NewConfig(config.Struct(cfg)),
		flagconfig.NewConfig(config.Struct(cfg), config.Codec(yamlcodec.NewCodec())),
	}); err != nil {
		log.Fatal(ctx, err)
	}

	if cfg.DstDir == "" || cfg.DstDir == "." {
		if cfg.DstDir, err = os.Getwd(); err != nil {
			log.Fatal(ctx, err)
		}
		log.Info(ctx, "dstdir not specified, use current dir: %s", cfg.DstDir)
	}

	flagUrl := strings.Join(flag.Args(), " ")

	u, err := url.Parse(flagUrl)
	if err != nil {
		log.Fatal(ctx, err)
	}

	var rev string
	if idx := strings.Index(u.Path, "@"); idx > 0 {
		rev = u.Path[idx+1:]
	}

	cloneOpts := &git.CloneOptions{
		URL:      flagUrl,
		Progress: os.Stdout,
	}

	if len(rev) == 0 {
		cloneOpts.SingleBranch = true
		cloneOpts.Depth = 1
	}

	if err := cloneOpts.Validate(); err != nil {
		log.Fatal(ctx, err)
	}

	log.Info(ctx, `try to fetch `+flagUrl)
	repo, err := git.CloneContext(ctx, memory.NewStorage(), nil, cloneOpts)
	if err != nil {
		log.Fatal(ctx, err)
	}

	ref, err := repo.Head()
	if err != nil {
		log.Fatal(ctx, "failed to get head: %v", err)
	}

	fmt.Println(ref.Hash())
	commit, err := repo.CommitObject(ref.Hash())
	if err != nil {
		log.Fatal(ctx, "failed to get commit: %v", err)
	}

	tree, err := commit.Tree()
	if err != nil {
		log.Fatal(ctx, err)
	}

	if err := os.MkdirAll(cfg.DstDir, os.FileMode(0o755)); err != nil {
		log.Fatal(ctx, "failed to create dir: %v", err)
	}

	if cfg.Clean {
		if err := cleanDir(ctx, cfg.DstDir); err != nil {
			log.Fatal(ctx, "failed to clean dir: %v", err)
		}
	}

	err = tree.Files().ForEach(func(file *object.File) error {
		if file == nil {
			return fmt.Errorf("file pointer is nil")
		}

		fmode, err := file.Mode.ToOSFileMode()
		if err != nil {
			return err
		}

		switch file.Mode {
		case filemode.Executable:
			return writeFile(ctx, file, cfg.DstDir, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, fmode)
		case filemode.Dir:
			return os.MkdirAll(filepath.Join(cfg.DstDir, file.Name), fmode)
		case filemode.Regular:
			return writeFile(ctx, file, cfg.DstDir, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, fmode)
		default:
			return fmt.Errorf("unsupported filetype %v for %s", file.Mode, file.Name)
		}
	})
	if err != nil {
		log.Fatal(ctx, "failed to exctract file: %v", err)
	}
}