package cmd

import (
	"fmt"
	"os/exec"
	"runtime"

	"forgejo.zerova.net/public/fgj-sid/internal/api"
	"forgejo.zerova.net/public/fgj-sid/internal/config"
	"github.com/spf13/cobra"
)

var openCmd = &cobra.Command{
	Use:     "open [issue-or-pr-number]",
	Aliases: []string{"o"},
	Short:   "Open a repository, issue, or pull request in a browser",
	Long: `Open the repository page in a web browser. When an issue or pull request
number is given, that page is opened instead.

Repository is auto-detected from the current git context, or specified with -R.`,
	Example: `  # Open the current repository
  fgj open

  # Open a specific repository
  fgj open -R owner/repo

  # Open issue or PR #42 (Forgejo routes both via the same number)
  fgj open 42
  fgj open '#42'

  # Print the URL instead of launching a browser
  fgj open 42 --url`,
	Args: cobra.MaximumNArgs(1),
	RunE: runOpen,
}

func init() {
	rootCmd.AddCommand(openCmd)
	addRepoFlags(openCmd)
	openCmd.Flags().Bool("url", false, "Print URL instead of opening a browser")
}

func runOpen(cmd *cobra.Command, args []string) error {
	repo, _ := cmd.Flags().GetString("repo")
	owner, name, err := parseRepo(repo)
	if err != nil {
		return err
	}

	cfg, err := config.Load()
	if err != nil {
		return err
	}

	client, err := api.NewClientFromConfig(cfg, "", getDetectedHost(), getCwd())
	if err != nil {
		return err
	}

	url := fmt.Sprintf("https://%s/%s/%s", client.Hostname(), owner, name)

	if len(args) == 1 {
		num, err := parseIssueArg(args[0])
		if err != nil {
			return fmt.Errorf("invalid issue or PR number %q: %w", args[0], err)
		}
		issue, _, err := client.GetIssue(owner, name, num)
		if err != nil {
			return fmt.Errorf("failed to look up #%d: %w", num, err)
		}
		kind := "issues"
		if issue.PullRequest != nil {
			kind = "pulls"
		}
		url = fmt.Sprintf("https://%s/%s/%s/%s/%d", client.Hostname(), owner, name, kind, num)
	}

	printOnly, _ := cmd.Flags().GetBool("url")
	if printOnly || !ios.IsStdoutTTY() {
		fmt.Fprintln(ios.Out, url)
		return nil
	}

	if err := launchBrowser(url); err != nil {
		fmt.Fprintf(ios.ErrOut, "Could not open browser (%v); URL: %s\n", err, url)
		return nil
	}
	fmt.Fprintf(ios.ErrOut, "Opening %s in your browser.\n", url)
	return nil
}

// launchBrowser opens url in the OS default browser.
func launchBrowser(url string) error {
	var cmd *exec.Cmd
	switch runtime.GOOS {
	case "darwin":
		cmd = exec.Command("open", url)
	case "windows":
		cmd = exec.Command("cmd", "/c", "start", "", url)
	default:
		cmd = exec.Command("xdg-open", url)
	}
	return cmd.Start()
}