//go:build mage

package main

import (
	"fmt"
	"os"
	"path/filepath"
	"slices"
	"strings"

	"codeflow.dananglin.me.uk/linux-home/manager/magefiles/internal/config"
	"codeflow.dananglin.me.uk/linux-home/manager/magefiles/internal/walk"
	"github.com/magefile/mage/sh"
)

// Externalconfigs downloads and manages neovim configuration from a remote git repository.
func Externalconfigs() error {
	cfg, err := config.NewConfig()
	if err != nil {
		return fmt.Errorf(
			"unable to load the configuration: %w",
			err,
		)
	}

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

	for _, externalConfig := range slices.All(cfg.ExternalConfigurations) {
		if err := manageExternalConfig(externalConfig, homeConfigDir); err != nil {
			return fmt.Errorf("received an error while processing %s: %w", externalConfig.Label, err)
		}
	}

	return nil
}

func manageExternalConfig(cfg config.ExternalConfig, homeConfigDir string) error {
	clonedRepo, err := downloadRepo(cfg.GitRepoURL, cfg.GitRef)
	if err != nil {
		return fmt.Errorf("unable to clone the git repository: %w", err)
	}

	defer os.RemoveAll(clonedRepo)

	fmt.Println("Git repository cloned to:", clonedRepo)

	validationFunc := func(relativePath string) bool {
		split := strings.SplitN(relativePath, "/", 2)

		if len(split) < 1 {
			return false
		}

		rootPath := split[0]

		return rootPath == cfg.GitRepoPath
	}

	if err = filepath.WalkDir(
		clonedRepo,
		walk.CopyFiles(homeConfigDir, clonedRepo, rootManagedDir, validationFunc),
	); err != nil {
		return fmt.Errorf("received an error while copying the files: %w", err)
	}

	return nil
}

func downloadRepo(repoURL, repoRef string) (string, error) {
	cloneDir, err := os.MkdirTemp("/tmp", "config-")
	if err != nil {
		return "", fmt.Errorf("unable to create the temporary directory: %w", err)
	}

	git := sh.RunCmd("git", "-C", cloneDir)

	commands := [][]string{
		{"init"},
		{"remote", "add", "origin", repoURL},
		{"fetch", "origin", repoRef},
		{"checkout", "FETCH_HEAD"},
	}

	for _, command := range slices.All(commands) {
		if err := git(command...); err != nil {
			return "", err
		}
	}

	if err := os.RemoveAll(filepath.Join(cloneDir, ".git")); err != nil {
		return "", fmt.Errorf("unable to remove the .git folder: %w", err)
	}

	return cloneDir, nil
}