package targets

import (
	"errors"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

func CreateJunction(linkPath, targetPath string) error {
	if err := os.MkdirAll(filepath.Dir(linkPath), 0o755); err != nil {
		return err
	}
	cmd := exec.Command("cmd.exe", "/c", "mklink", "/J", linkPath, targetPath)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("create junction failed: %w: %s", err, strings.TrimSpace(string(out)))
	}
	return nil
}

func ReadJunctionTarget(linkPath string) (string, error) {
	if _, err := os.Lstat(linkPath); err != nil {
		return "", err
	}
	target, err := os.Readlink(linkPath)
	if err == nil && target != "" {
		return cleanWindowsLinkTarget(target), nil
	}
	evaluated, evalErr := filepath.EvalSymlinks(linkPath)
	if evalErr != nil {
		return "", evalErr
	}
	if samePath(evaluated, linkPath) {
		return "", errors.New("path is not a junction")
	}
	return evaluated, nil
}

func RemoveJunction(linkPath string) error {
	if err := os.Remove(linkPath); err == nil || errors.Is(err, os.ErrNotExist) {
		return nil
	}
	cmd := exec.Command("cmd.exe", "/c", "rmdir", linkPath)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("remove junction failed: %w: %s", err, strings.TrimSpace(string(out)))
	}
	return nil
}

func cleanWindowsLinkTarget(target string) string {
	target = strings.TrimPrefix(target, `\??\`)
	return filepath.Clean(target)
}

func samePath(left, right string) bool {
	leftAbs, leftErr := filepath.Abs(cleanWindowsLinkTarget(left))
	rightAbs, rightErr := filepath.Abs(cleanWindowsLinkTarget(right))
	if leftErr == nil {
		left = leftAbs
	}
	if rightErr == nil {
		right = rightAbs
	}
	return strings.EqualFold(filepath.Clean(left), filepath.Clean(right))
}