namespace HyperBooru.Services;

public interface IConfigService {
    public string DataPath      { get; }
    public string DbPath        { get; }
    public string MediaBasePath { get; }

    public string GetPath(Media media);
    public string GetPath(Media media, int width, int height);
}

public class ConfigService : IConfigService {
    private IConfiguration config;

    private const string AppName = "HyperBooru";

    public string DataPath {
        get {
            #if DEBUG
            return "Data";
            #else
            string? path = config["DataPath"];
            if(path is not null)
                return path;

            switch(Environment.OSVersion.Platform) {
                case PlatformID.Win32NT:
                    return Path.Join(
                        Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData),
                        AppName);
                case PlatformID.Unix:
                    return $"/var/lib/{AppName.ToLower()}";
                default:
                    throw new NotImplementedException(
                        $"Unknown Operating System: {Environment.OSVersion.Platform}");
            }
            #endif
        }
    }

    public string DbPath =>
        Path.Join(DataPath, $"{AppName}.db");

    public string MediaBasePath =>
        Path.Join(DataPath, "media");

    public string ThumbnailBasePath =>
        Path.Join(DataPath, "thumb");

    public ConfigService(IConfiguration config) {
        this.config = config;
        InitDirectoryStructure();
    }

    public string GetPath(Media media) {
        var fileInfo = new FileInfo(Path.Join(
            MediaBasePath,
            media.Guid.ToString().Substring(0, 2),
            media.Guid.ToString().Substring(2, 2),
            media.Guid.ToString()));

        Directory.CreateDirectory(fileInfo.Directory.FullName);
        return fileInfo.FullName;
    }

    public string GetPath(Media media, int width, int height) {
        var fileInfo = new FileInfo(Path.Join(
            ThumbnailBasePath,
            media.Guid.ToString().Substring(0, 2),
            media.Guid.ToString().Substring(2, 2),
            $"{media.Guid.ToString()}-{width}-{height}"));

        Directory.CreateDirectory(fileInfo.Directory.FullName);
        return fileInfo.FullName;
    }

    private void InitDirectoryStructure() {
        Directory.CreateDirectory(DataPath);
        Directory.CreateDirectory(MediaBasePath);
    }
}