package cmd

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"sort"
	"strings"

	"github.com/AlecAivazis/survey/v2"
	"github.com/go-git/go-git/v5"
	"github.com/peterbourgon/ff/v3/ffcli"
)

var (
	treeURL   = "https://github.com/go-gitea/gitea/tree/%s"
	versionRe = regexp.MustCompile(`v\d+\.\d+\.\d+`)
)

func (h *Handler) Tag() *ffcli.Command {
	fs := flag.NewFlagSet("tag", flag.ContinueOnError)
	pushFlag := fs.Bool("push", false, "Push immediately")
	fs.BoolVar(pushFlag, "p", *pushFlag, "--push")
	return &ffcli.Command{
		Name:       "tag",
		FlagSet:    fs,
		ShortUsage: "tag <branch>",
		ShortHelp:  "tag makes a signed tag for `branch`",
		Exec: func(ctx context.Context, args []string) error {
			if err := h.checkInit(); err != nil {
				return err
			}
			h.fetch(ctx)

			var branch string
			if len(args) > 0 {
				branch = args[0]
			}

			if branch == "" {
				var branches []string
				remote, err := h.repo().Remote("upstream")
				if err != nil {
					return err
				}
				refs, err := remote.List(&git.ListOptions{})
				if err != nil {
					return err
				}
				for _, ref := range refs {
					if ref.Name().IsBranch() {
						branches = append(branches, strings.TrimPrefix(ref.Name().String(), "refs/heads/"))
					}
				}
				sort.Strings(branches)
				if err := survey.AskOne(&survey.Select{
					Message: "Branch",
					Options: branches,
				}, &branch, survey.WithValidator(survey.Required)); err != nil {
					return err
				}
			}
			if !strings.HasPrefix(branch, "release") {
				if !strings.HasPrefix(branch, "v") {
					branch = fmt.Sprintf("v%s", branch)
				}
				branch = fmt.Sprintf("release/%s", branch)
			}

			var version string
			if err := survey.AskOne(&survey.Input{
				Message: "Version",
			}, &version, survey.WithValidator(func(ans any) error {
				if !versionRe.MatchString(fmt.Sprint(ans)) {
					return errors.New("version isn't valid v$maj.$min.$")
				}
				return nil
			})); err != nil {
				return err
			}

			workspaceName := fmt.Sprintf("release-%s", version)
			if err := h.Branch().ParseAndRun(ctx, []string{"--base", branch, workspaceName}); err != nil {
				return err
			}

			var changelog string
			if err := survey.AskOne(&survey.Editor{
				Message:  "Changelog",
				FileName: "*.md",
			}, &changelog, survey.WithValidator(survey.Required)); err != nil {
				return err
			}

			fi, err := os.Create(filepath.Join(h.Config.WorkspaceBranch(workspaceName), "release.notes"))
			if err != nil {
				return err
			}
			if _, err := fi.WriteString(changelog); err != nil {
				return err
			}
			if err := fi.Close(); err != nil {
				return err
			}

			if err := run(ctx, h.Config.WorkspaceBranch(workspaceName), "git", "tag", "-s", "-F", "release.notes", version); err != nil {
				return err
			}

			if *pushFlag {
				return run(ctx, h.Config.WorkspaceBranch(workspaceName), "git", "push", "upstream", version)
			}

			fmt.Printf("cd %s && git push upstream %s \n", h.Config.WorkspaceBranch(workspaceName), version)
			return nil
		},
	}
}