package main

import (
	"errors"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"runtime"
	"strings"

	"gitea.antoine-langlois.net/datahearth/doggo-fetcher/internal"
	"github.com/sirupsen/logrus"
	"github.com/urfave/cli/v2"
	"golang.org/x/exp/slices"
)

var (
	dgfFolder = strings.ReplaceAll("~/.local/doggofetcher", "~", os.Getenv("HOME"))
	hashFile  = filepath.Join(dgfFolder, "hash.txt")
	aliasFile = filepath.Join(dgfFolder, "alias.txt")
	re        = regexp.MustCompile(`\d*\.?\d*\.?\d(rc|beta)?\d*?`)
	Logger    = &logrus.Logger{
		Out:       os.Stdout,
		Formatter: new(internal.LoggerFormatter),
		Hooks:     make(logrus.LevelHooks),
		Level:     logrus.InfoLevel,
	}
	app = &cli.App{
		Name:  "doggo-fetcher",
		Usage: "I bring you your latest GoLang release with ease and efficiency (like a stick) !",
		Description: `Doggo-fetcher is a utility tool that manage for you your installed GoLang releases.
You can select a specific GoLang release or even set a specific one for directories.`,
		EnableBashCompletion: true,
		Authors: []*cli.Author{
			{
				Name:  "Antoine <DataHearth> Langlois",
				Email: "antoine.l@antoine-langlois.net",
			},
		},
		Suggest: true,
		Version: "0.2.1",
		Commands: []*cli.Command{
			{
				Name:  "use",
				Usage: "Set a specific golang version",
				Description: `Use a specific golang version as primary golang binary for the user.
If the version is not already downloaded, it'll downloaded and installed automatically.`,
				Flags: []cli.Flag{
					&cli.BoolFlag{
						Name:    "latest",
						Aliases: []string{"lts"},
						Usage:   "Use latest release",
					},
					&cli.BoolFlag{
						Name:  "rc",
						Usage: "Allow \"rc\" version to be fetched",
					},
					&cli.BoolFlag{
						Name:  "beta",
						Usage: "Allow \"beta\" version to be fetched",
					},
				},
				Action: use,
			},
			{
				Name:  "init",
				Usage: "Initialize doggofetcher",
				Description: `Initialize doggofetcher by adding a custom path inside your sheel configuration file.
It also creates a folder at "~/.local/doggofetcher" to store your custom golang binaries.`,
				Action: initFunc,
			},
			{
				Name:  "uninstall",
				Usage: "Uninstall golang release",
				Description: `Uninstall current golang release.
It will remove the folder at "~/.local/doggofetcher/go"`,
				Action: uninstall,
			},
			{
				Name:  "ls",
				Usage: "List available releases",
				Description: `List available releases.
It will list all available releases in the "~/.local/doggofetcher/go*" folder.`,
				Action: ls,
			},
			{
				Name:  "remove",
				Usage: "Remove one or more releases",
				Description: `Remove one or more releases.
Release(s) folder will be removed from "~/.local/doggofetcher" and thus not available.`,
				Action: remove,
				Flags: []cli.Flag{
					&cli.BoolFlag{
						Name:    "all",
						Aliases: []string{"a"},
						Usage:   "Remove all releases",
					},
				},
			},
			{
				Name:   "exec",
				Usage:  "Execute a go command",
				Action: execCommand,
			},
			{
				Name:  "ls-remote",
				Usage: "List all remote references",
				Flags: []cli.Flag{
					&cli.BoolFlag{
						Name:  "rc",
						Usage: "Allow \"rc\" version to be fetched",
					},
					&cli.BoolFlag{
						Name:  "beta",
						Usage: "Allow \"beta\" version to be fetched",
					},
				},
				Action: lsRemote,
			},
			{
				Name:   "alias",
				Usage:  "Set an alias for a GoLang version",
				Action: alias,
				Flags: []cli.Flag{
					&cli.BoolFlag{
						Name:    "list",
						Aliases: []string{"l"},
						Usage:   "List all set alias and their version",
					},
					&cli.StringFlag{
						Name:  "get",
						Usage: "Get a version for a given alias",
					},
					&cli.StringSliceFlag{
						Name:  "rename",
						Usage: "Rename an already existing alias",
						Value: nil,
					},
				},
			},
		},
		Flags: []cli.Flag{
			&cli.BoolFlag{Name: "verbose", Aliases: []string{"v"}, Usage: "Enable verbose mode"},
		},
	}
)

func main() {
	cli.VersionFlag = &cli.BoolFlag{
		Name:    "version",
		Aliases: []string{"V"},
		Usage:   "print the version",
	}

	if err := app.Run(os.Args); err != nil {
		Logger.Fatalln(err)
	}
}

func use(ctx *cli.Context) error {
	if err := checkInitialized(); err != nil {
		return err
	}

	if ctx.Bool("verbose") {
		Logger.Level = logrus.DebugLevel
	}

	alias, err := internal.NewAlias(aliasFile)
	if err != nil {
		return err
	}

	var release string
	if ctx.NArg() == 0 {
		if !ctx.Bool("latest") {
			return errors.New("a release is required if \"--latest|--lts\" is not passed")
		}
		release = internal.LTS
	} else {
		release = ctx.Args().First()
		if !re.Match([]byte(release)) {
			release = alias.GetAliasVersion(release)
			if release == "" {
				return fmt.Errorf("release doesn't match \"%s\" format nor is an existing alias", re.String())
			}
		}
	}

	release, err = internal.NewTags(release, ctx.Context).GetRelease(ctx.Bool("beta"), ctx.Bool("rc"))
	if err != nil {
		return err
	}

	hash, err := internal.NewHash(hashFile)
	if err != nil {
		return err
	}
	r := internal.NewRelease(release, filepath.Join(dgfFolder, release))

	if err := r.CheckReleaseExists(); err != nil {
		if err != internal.ErrReleaseNotFound {
			return err
		}

		Logger.Info("Release not found, downloading...")
		if err := r.DownloadRelease(); err != nil {
			return err
		}

		Logger.Info("Release downloaded, installing...")
		if err := r.ExtractRelease(); err != nil {
			return err
		}

		Logger.Debug("Release installed, generating hash...")
		h, err := hash.GetFolderHash(r.GetReleaseFolder())
		if err != nil {
			return err
		}
		if err := hash.AddHash(r.GetReleaseFolder(), h); err != nil {
			return err
		}
	} else {
		Logger.Debug("Release found, checking hash...")
		h, err := hash.GetFolderHash(r.GetReleaseFolder())
		if err != nil {
			return err
		}

		if err := hash.CompareReleaseHash(r.GetReleaseFolder(), h); err != nil {
			if err == internal.ErrHashNotFound {
				Logger.Warnln("Hash not found in hash table, adding...")
				if err := hash.AddHash(r.GetReleaseFolder(), h); err != nil {
					return err
				}
			} else if err == internal.ErrHashInvalid {
				Logger.Warnln("Hash invalid, replacing...")
				if err := hash.ReplaceHash(r.GetReleaseFolder(), h); err != nil {
					return err
				}
			} else {
				return err
			}
		}
	}

	Logger.Info("Setting golang binary")
	if err := internal.UpdateRelease(filepath.Join(dgfFolder, "go"), r.GetReleaseFolder()); err != nil {
		return err
	}

	Logger.Info("Everything done!")
	return nil
}

func initFunc(ctx *cli.Context) error {
	if ctx.Bool("verbose") {
		Logger.Level = logrus.DebugLevel
	}

	Logger.WithField("folder", dgfFolder).Infoln("Initializing doggofetcher folder")

	if err := os.MkdirAll(dgfFolder, 0755); err != nil {
		return err
	}
	f, err := os.Create(hashFile)
	if err != nil {
		return err
	}
	f.Close()

	f, err = os.Create(aliasFile)
	if err != nil {
		return err
	}
	f.Close()

	Logger.Infoln("Add doggofetcher to your shell configuration file with the following command:")
	fmt.Fprintln(os.Stdout, "\n# doggofetcher section")
	fmt.Fprintf(os.Stdout, "export PATH=%s:$PATH\n", filepath.Join(dgfFolder, "go", "bin"))

	return nil
}

func uninstall(ctx *cli.Context) error {
	return os.RemoveAll(filepath.Join(dgfFolder, "go"))
}

func ls(ctx *cli.Context) error {
	if err := checkInitialized(); err != nil {
		return err
	}

	if ctx.Bool("verbose") {
		Logger.Level = logrus.DebugLevel
	}

	items, err := os.ReadDir(dgfFolder)
	if err != nil {
		return err
	}

	for _, i := range items {
		if i.IsDir() && i.Name() != "go" {
			fmt.Println(strings.Replace(i.Name(), "go", "", 1))
		}
	}

	return nil
}

func remove(ctx *cli.Context) error {
	if err := checkInitialized(); err != nil {
		return err
	}

	if ctx.Bool("verbose") {
		Logger.Level = logrus.DebugLevel
	}

	entries, err := os.ReadDir(dgfFolder)
	if err != nil {
		return err
	}

	releasesPath := []string{}
	if ctx.Bool("all") {
		for _, e := range entries {
			if !e.IsDir() || !strings.Contains(e.Name(), "go") || e.Name() == "go" {
				continue
			}

			releasesPath = append(releasesPath, filepath.Join(dgfFolder, e.Name()))
		}
	} else {
		found := slices.ContainsFunc(entries, func(e os.DirEntry) bool {
			return e.IsDir() && e.Name() == fmt.Sprintf("go%s", ctx.Args().First())
		})
		if !found {
			return fmt.Errorf("release %s not found", ctx.Args().First())
		}
		releasesPath = append(releasesPath, filepath.Join(dgfFolder, fmt.Sprintf("go%s", ctx.Args().First())))
	}

	hash, err := internal.NewHash(hashFile)
	if err != nil {
		return err
	}

	for _, e := range releasesPath {
		Logger.Infof("Removing %s...", filepath.Base(e))
		if err := os.RemoveAll(e); err != nil {
			return err
		}
		if err := hash.RemoveHash(e); err != nil {
			return err
		}
	}

	if strings.Contains(runtime.Version(), ctx.Args().First()) {
		Logger.Infoln("Removing installed version...")
		if err := os.RemoveAll(filepath.Join(dgfFolder, "go")); err != nil {
			return fmt.Errorf("could not remove installed release: %s", err)
		}
	}

	Logger.Infoln("All done!")

	return nil
}

func execCommand(ctx *cli.Context) error {
	if err := checkInitialized(); err != nil {
		return err
	}

	if ctx.Bool("verbose") {
		Logger.Level = logrus.DebugLevel
	}

	if ctx.NArg() == 0 {
		return errors.New("a release is required")
	}

	release := ctx.Args().First()
	if !re.Match([]byte(release)) {
		return errors.New("release doesn't match \"\\d*\\.?\\d*\\.?\\d(rc|beta)?\\d*?\" format")
	}

	cmd := exec.Command(filepath.Join(dgfFolder, fmt.Sprintf("go%s", release), "bin", "go"), ctx.Args().Tail()...)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	return cmd.Run()
}

func lsRemote(ctx *cli.Context) error {
	refs, err := internal.NewTags("", ctx.Context).GetTagsRef()
	if err != nil {
		return err
	}

	for _, r := range refs {
		ref := r.GetRef()
		if (!ctx.Bool("rc") && strings.Contains(ref, "rc")) || (!ctx.Bool("beta") && strings.Contains(ref, "beta")) {
			continue
		}

		fmt.Println(strings.ReplaceAll(strings.Split(ref, "/")[2], "go", ""))
	}

	return nil
}

func alias(ctx *cli.Context) error {
	if err := checkInitialized(); err != nil {
		return err
	}

	alias, err := internal.NewAlias(aliasFile)
	if err != nil {
		return err
	}
	if ctx.Bool("list") {
		for a, v := range alias.GetAllAlias() {
			fmt.Printf("alias: %s | version: %s\n", a, v)
		}
		return nil
	} else if a := ctx.String("get"); a != "" {
		fmt.Printf("alias: %s | version: %s\n", a, alias.GetAliasVersion(a))
		return nil
	} else if values := ctx.StringSlice("rename"); len(values) != 0 {
		if len(values) != 2 {
			return errors.New("rename takes 2 parameters")
		}

		if err := alias.RenameAlias(ctx.Args().Get(0), ctx.Args().Get(1)); err != nil {
			return err
		}
	} else {
		if ctx.NArg() != 2 {
			return errors.New("an alias needs an alias name and a golang version")
		}

		alias.SetAlias(ctx.Args().Get(0), ctx.Args().Get(1))
	}

	return alias.WriteAliasFile()
}

func checkInitialized() error {
	fi, err := os.Stat(dgfFolder)
	if err != nil {
		if os.IsNotExist(err) {
			return fmt.Errorf("\"%s\" not initialized. Initialize it with \"doggo-fetcher init\"", dgfFolder)
		}

		return err
	}
	if !fi.IsDir() {
		return fmt.Errorf("\"%s\" is not a directory", dgfFolder)
	}

	return nil
}