package cmd

import (
	"context"
	"errors"
	"fmt"
	"io"
	"os"

	"github.com/charmbracelet/huh"
	"github.com/charmbracelet/lipgloss"
	"github.com/google/go-github/v72/github"
	"github.com/spf13/cobra"
)

const gitignoreFileName = ".gitignore"

// newCmd represents the new command.
var newCmd = &cobra.Command{
	Use:   "new",
	Short: "Create a new .gitignore file",
	Args:  cobra.NoArgs,
	RunE: func(cmd *cobra.Command, args []string) error {
		return runNewCommand(cmd, args)
	},
}

func init() {
	rootCmd.AddCommand(newCmd)
}

// runNewCommand is the handler for the 'new' command.
// It retrieves available .gitignore templates from GitHub, prompts the user to select one,
// and writes the selected template to a new .gitignore file.
func runNewCommand(cmd *cobra.Command, _ []string) error {
	client, ok := getClientFromContext(cmd.Context())
	if !ok {
		return errors.New("failed to get GitHub client from context")
	}

	templates, _, err := client.Gitignores.List(context.Background())
	if err != nil {
		return fmt.Errorf("error listing gitignore templates: %w", err)
	}

	var selection string
	if err := runPrompt(templates, &selection); err != nil {
		return fmt.Errorf("error running selection prompt: %w", err)
	}

	content, _, err := client.Gitignores.Get(context.Background(), selection)
	if err != nil {
		return fmt.Errorf("error retrieving gitignore template '%s': %w", selection, err)
	}

	f, err := os.OpenFile(gitignoreFileName, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o600)
	if err != nil {
		return fmt.Errorf("error opening file '%s': %w", gitignoreFileName, err)
	}
	defer f.Close()

	if err = commitGitignore(content, f); err != nil {
		return fmt.Errorf("error committing gitignore file: %w", err)
	}

	style := lipgloss.NewStyle().
		Bold(true).
		Foreground(lipgloss.Color("#7D56F4")) // nolint: misspell

	fmt.Println(style.Render("Created"), selection, style.Render(".gitignore file ✓"))

	return nil
}

// runPrompt is a helper function to run the selection prompt for .gitignore templates.
func runPrompt(templates []string, selection *string) error {
	var options []huh.Option[string]
	for _, template := range templates {
		options = append(options, huh.NewOption(template, template))
	}

	selectionPrompt := huh.NewSelect[string]().
		Title("Select a .gitignore template").
		Options(options...).
		Value(selection)

	if err := selectionPrompt.Run(); err != nil {
		return fmt.Errorf("error running selection prompt: %w", err)
	}
	return nil
}

// commitGitignore writes the content of the selected gitignore template to the .gitignore file.
func commitGitignore(content *github.Gitignore, w io.Writer) error {
	if _, err := fmt.Fprintf(w, "# Generated by ignr-cli: github.com/onyx-and-iris/ignr-cli\n"); err != nil {
		return fmt.Errorf("error writing header to file '%s': %w", gitignoreFileName, err)
	}

	if _, err := fmt.Fprintf(w, "%s", *content.Source); err != nil {
		return fmt.Errorf("error writing to file '%s': %w", gitignoreFileName, err)
	}

	if _, err := fmt.Fprintf(w, "\n# End of ignr-cli\n"); err != nil {
		return fmt.Errorf("error writing footer to file '%s': %w", gitignoreFileName, err)
	}

	return nil
}