namespace PluginBuilder.Util.Extensions;

public static class FileExtensions
{
    private const long _maxFileSize = 1024 * 1024;
    private static readonly string[] _permittedExtensions = { ".jpg", ".jpeg", ".png", ".gif", ".webp", ".svg" };

    public static bool ValidateImageFile(this IFormFile file, out string error, long maxFileSizeInBytes = 1_000_000)
    {
        if (file == null || file.Length == 0)
        {
            error = "No file was uploaded or the file is empty.";
            return false;
        }

        if (!file.FileName.IsFileValidImage())
        {
            error = "Invalid file type. Only images are allowed";
            return false;
        }

        if (!file.FileName.IsValidFileName())
        {
            error = "Could not complete file upload. File has invalid name";
            return false;
        }

        if (file.Length > maxFileSizeInBytes)
        {
            error = $"The uploaded image file should be less than {maxFileSizeInBytes / 1_000_000}MB";
            return false;
        }

        if (!file.ContentType.StartsWith("image/", StringComparison.InvariantCulture))
        {
            error = "The uploaded file needs to be an image (based on the content type)";
            return false;
        }

        error = string.Empty;
        return true;
    }

    public static bool IsValidFileName(this string fileName)
    {
        return !fileName.ToCharArray().Any(c => Path.GetInvalidFileNameChars().Contains(c)
                                                || c == Path.AltDirectorySeparatorChar
                                                || c == Path.DirectorySeparatorChar
                                                || c == Path.PathSeparator
                                                || c == '\\');
    }

    public static bool IsFileValidImage(this string fileName)
    {
        var ext = Path.GetExtension(fileName)?.ToLowerInvariant();
        return !string.IsNullOrEmpty(ext) && _permittedExtensions.Contains(ext);
    }

    public static bool IsImageValidSize(this long imageLength)
    {
        return imageLength <= _maxFileSize;
    }
}