namespace Mizuki.Services;

/// <summary>
/// The service responsible for managing file uploads.
/// </summary>
public class DriveService
{
    /// <summary>
    /// The path to the uploads folder.
    /// </summary>
    private const string UploadsFolder = "./uploads";

    /// <summary>
    /// The drive service.
    /// </summary>
    public DriveService()
    {
        if (!Directory.Exists(UploadsFolder))
            Directory.CreateDirectory(UploadsFolder);
    }
    
    /// <summary>
    /// Opens a file by its filename.
    /// </summary>
    /// <param name="filename">Its filename.</param>
    /// <returns>The file's stream.</returns>
    public Stream? OpenFileByFilename(string filename)
    {
        var actualFilename = Path.GetFileName(filename);
        var path = Path.Combine(UploadsFolder, actualFilename);
        if (!File.Exists(path))
            return null;

        return File.OpenRead(path);
    }
    
    /// <summary>
    /// Deletes a file by its filename.
    /// </summary>
    /// <param name="filename">Its filename.</param>
    public void DeleteFileByFilename(string filename)
    {
        var actualFilename = Path.GetFileName(filename);
        var path = Path.Combine(UploadsFolder, actualFilename);
        if (!File.Exists(path))
            return;

        File.Delete(path);
    }

    /// <summary>
    /// Saves a file with the given filename.
    /// </summary>
    /// <param name="filename">The filename.</param>
    /// <param name="fileStream">The file stream.</param>
    public void SaveFileByFilename(string filename, Stream fileStream)
    {
        var actualFilename = Path.GetFileName(filename);
        var path = Path.Combine(UploadsFolder, actualFilename);
        using var writeStream = File.OpenWrite(path);
        fileStream.CopyTo(writeStream);
    }
}