//go:build mage

package main

import (
	"errors"
	"fmt"
	"io/fs"
	"os"
	"path/filepath"
	"slices"
)

const (
	dirModePerm fs.FileMode = 0o700
)

// Directories ensure that the directories specified in the configuration is present within the home directory.
func Directories() error {
	config, err := newConfig()
	if err != nil {
		return fmt.Errorf("unable to load the configuration: %w", err)
	}

	userHome, err := os.UserHomeDir()
	if err != nil {
		return fmt.Errorf("unable to get the user's home directory: %w", err)
	}

	directories := make([]string, 0)

	if config.Directories.UseDefaultDirectories{
		defaultHomeDirs := homeDirectories(userHome, defaultDirectories())
		directories = append(directories, defaultHomeDirs...)
	}

	if config.Directories.IncludeXDGDirectories{
		directories = append(directories, xdgDirectories()...)
	}

	if len(config.Directories.AdditionalDirectories) != 0 {
		additionalHomeDirs := homeDirectories(userHome, config.Directories.AdditionalDirectories)
		directories = append(directories, additionalHomeDirs...)
	}

	for _, dir := range slices.All(directories) {
		if err := ensureDirectory(dir); err != nil {
			return fmt.Errorf("unable to ensure that %s is present: %w", dir, err)
		}

		fmt.Printf("Successfully ensured %s is present.\n", dir)
	}

	return nil
}

func ensureDirectory(path string) error {
	info, err := os.Stat(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			if err := os.Mkdir(path, dirModePerm); err != nil {
				return fmt.Errorf("unable to create the directory: %w", err)
			}

			return nil
		}

		return fmt.Errorf(
			"received an unexpected error after attempting to get the directory information: %w",
			err,
		)
	}

	if !info.IsDir() {
		return errors.New("the path exists but it is not a directory")
	}

	if info.Mode().Perm() != dirModePerm {
		if err := os.Chmod(path, dirModePerm); err != nil {
			return fmt.Errorf("unable to update the directory's mode to %d: %w", dirModePerm, err)
		}
	}

	return nil
}

func defaultDirectories() []string {
	return []string{
		".local",
		".local/bin",
		"Applications",
		"Documents",
		"Downloads",
		"Games",
		"Git",
		"Music",
		"Pictures",
		"Templates",
		"Videos",
	}
}

func homeDirectories(userHome string, directories []string) []string{
	absolutePaths := make([]string, len(directories))

	for ind := range slices.All(directories) {
		absolutePaths[ind] = filepath.Join(userHome, directories[ind])
	}

	return absolutePaths
}

func xdgDirectories() []string {
	xdgEnvVars := []string{
		"XDG_DATA_HOME",
		"XDG_CONFIG_HOME",
		"XDG_CACHE_HOME",
		"XDG_STATE_HOME",
	}

	directories := make([]string, 0)

	for _, envVar := range slices.All(xdgEnvVars) {
		directory := os.Getenv(envVar)
		if directory != "" {
			directories = append(directories, directory)
		}
	}

	return directories
}