using BitMiracle.LibTiff.Classic;
using Microsoft.AspNetCore.Mvc;
using SkiaSharp;
using Microsoft.Data.SqlClient;

namespace Library.Api;

[Route( "Api/Upload/[action]/{id?}" )]
public class UploadApi : APIController
{
	private readonly string m_TempDirectory;

	public UploadApi( ILogger<UserApi> logger , IConfiguration configuration )
		: base( logger , configuration )
	{
		m_TempDirectory = configuration.GetValue<string>( "TempDirectory" ) ?? string.Empty;
	}

	[HttpPost]
	public IActionResult StartUpload( )
	{
		Trace( "/Api/Repository/StartUpload" );
		string session = Guid.NewGuid( ).ToString( ).Replace( "-" , null );
		using FileStream stream = new( m_TempDirectory + session! , FileMode.CreateNew , FileAccess.Write , FileShare.None );
		return Success( session! );
	}

	[HttpPost]
	public IActionResult UploadChunk( string? session , string? payload , long offset )
	{
		if ( session == null )
			return Error( "Invalid call. (session)" );

		if ( !ValidateOffset( session , offset ) )
			return Error( "Invalid call. (Bad offset)" );

		byte[]? bytes = Base64DecodeSafe( payload );
		if ( bytes == null )
			return Error( "Invalid call. (Bad payload)" );

		using FileStream stream = new( m_TempDirectory + session! , FileMode.Append , FileAccess.Write , FileShare.None );
		stream.Write( bytes , 0 , bytes.Length );
		return Success( "OK" );
	}

	private static byte[]? PreprocessMP4( string form_file )
	{
		byte[] file_bytes = System.IO.File.ReadAllBytes( form_file );
		if ( file_bytes.Length < 100 )
			return null;

		return file_bytes;
	}
	
	[HttpPost]
	public IActionResult SaveMP4Attachment( string? session , long offset , int id )
	{
		if ( session == null )
			return Error( "Invalid call. (Invalid parameters)" );

		/*		if ( !ValidateOffset( session , offset ) )
					return Error( "Invalid call. (Bad offset)" );
		*/
		byte [] ? pdf_data_array = PreprocessMP4( m_TempDirectory + session! );
		if ( pdf_data_array == null )
			return Error( "Invalid file" );

		SqlDataReader reader = PrepareSQL(@"update gnm_rec set uuid = REPLACE(NEWID( ),'-',''),data_format='mp4' OUTPUT INSERTED.uuid WHERE id = @id")
			.AddParameter( "@id" , id )
			.ExecuteReader( );

		if ( !reader.Read( ) )
			return Error( "No such attachment!" );

		string? new_uuid = reader.String( 0 );
		if ( string.IsNullOrEmpty( new_uuid ) )
			return Error( "No such attachment!" );

		string original = GetDataDirectory( ) + new_uuid + ".mp4";
		System.IO.File.WriteAllBytes( original , pdf_data_array );

		return Success( new_uuid );
	}

	[HttpPost]
	public IActionResult SaveCoverImage( string? session , long offset , int id )
	{
		if ( session == null )
			return Error( "Invalid call. (Invalid parameters)" );

		if ( !ValidateOffset( session , offset ) )
			return Error( "Invalid call. (Bad offset)" );

		using SKBitmap? bitmap = PreprocessImage( m_TempDirectory + session! );
		if ( bitmap == null )
			return Error( "Invalid image" );

		SqlDataReader reader = PrepareSQL(@"update gnm set uuid = REPLACE(NEWID( ),'-',''),data_format='jpg' OUTPUT INSERTED.uuid WHERE id = @id")
			.AddParameter( "@id" , id )
			.ExecuteReader( );

		if ( !reader.Read( ) )
			return Error( "No such book!" );

		string? new_uuid = reader.String( 0 );
		if ( string.IsNullOrEmpty( new_uuid ) )
			return Error( "No such book!" );

		string original = GetDataDirectory( ) + new_uuid + ".jpg";

		using SKData bitmap_data = bitmap.Encode( SKEncodedImageFormat.Jpeg , 80 );
		byte [] bitmap_data_array = bitmap_data.ToArray( );
		System.IO.File.WriteAllBytes( original , bitmap_data_array );

		return Success( new_uuid );
	}

	[HttpPost]
	public IActionResult SavePDFAttachment( string? session , long offset  , int id )
	{
		if ( session == null )
			return Error( "Invalid call. (Invalid parameters)" );

		if ( !ValidateOffset( session , offset ) )
			return Error( "Invalid call. (Bad offset)" );

		byte [] ? pdf_data_array = PreprocessPDF( m_TempDirectory + session! );
		if ( pdf_data_array == null )
			return Error( "Invalid file" );

		SqlDataReader reader = PrepareSQL(@"update gnm_rec set uuid = REPLACE(NEWID( ),'-',''),data_format='pdf' OUTPUT INSERTED.uuid WHERE id = @id")
			.AddParameter( "@id" , id )
			.ExecuteReader( );

		if ( !reader.Read( ) )
			return Error( "No such attachment!" );

		string? new_uuid = reader.String( 0 );
		if ( string.IsNullOrEmpty( new_uuid ) )
			return Error( "No such attachment!" );

		string original = GetDataDirectory( ) + new_uuid + ".pdf";
		System.IO.File.WriteAllBytes( original , pdf_data_array );

		return Success( new_uuid );
	}

	[HttpPost]
	public IActionResult SaveImageAttachment( string? session , long offset , int id )
	{
		if ( session == null )
			return Error( "Invalid call. (Invalid parameters)" );

		if ( !ValidateOffset( session , offset ) )
			return Error( "Invalid call. (Bad offset)" );

		using SKBitmap? bitmap = PreprocessImage( m_TempDirectory + session! );
		if ( bitmap == null )
			return Error( "Invalid image" );

		SqlDataReader reader = PrepareSQL(@"update gnm_rec set uuid = REPLACE(NEWID( ),'-',''),data_format='jpg' OUTPUT INSERTED.uuid WHERE id = @id")
			.AddParameter( "@id" , id )
			.ExecuteReader( );

		if ( !reader.Read( ) )
			return Error( "No such attachment!" );

		string? new_uuid = reader.String( 0 );
		if ( string.IsNullOrEmpty( new_uuid ) )
			return Error( "No such attachment!" );

		string original = GetDataDirectory( ) + new_uuid + ".jpg";

		using SKData bitmap_data = bitmap.Encode( SKEncodedImageFormat.Jpeg , 80 );
		byte [] bitmap_data_array = bitmap_data.ToArray( );
		System.IO.File.WriteAllBytes( original , bitmap_data_array );

		return Success( new_uuid );
	}

	private static byte[]? Base64DecodeSafe( string? b )
	{
		if ( b == null )
			return null;

		try
		{
			return Convert.FromBase64String( b! );
		}
		catch ( Exception )
		{
		}

		return null;
	}

	private bool ValidateOffset( string session , long expected )
	{
		try
		{
			FileInfo fi = new( m_TempDirectory + session );
			return fi.Length == expected;
		}
		catch ( Exception )
		{
		}

		return false;
	}

	private static SKBitmap? PreprocessImage( string local_file )
	{
		SKBitmap? bitmap = SKBitmap.Decode( local_file );
		if ( bitmap == null )
		{
			bitmap = ConvertTiffToSKBitmap( local_file );
			if ( bitmap == null )
				return null;
		}

		if ( bitmap!.IsEmpty || bitmap.IsNull || bitmap.Width < 16 || bitmap.Height < 16 )
			return null;

		return bitmap;
	}

	private static SKBitmap? ConvertTiffToSKBitmap( string local_file )
	{
		SKColor[] pixels;
		int width, height;
		// open a Tiff stored in the memory stream, and grab its pixels
		using ( Tiff tifImg = Tiff.ClientOpen( local_file , "r" , null , new TiffStream( ) ) )
		{
			FieldValue[] value = tifImg.GetField(TiffTag.IMAGEWIDTH);
			width = value[0].ToInt( );

			value = tifImg.GetField( TiffTag.IMAGELENGTH );
			height = value[0].ToInt( );

			// Read the image into the memory buffer 
			int[] raster = new int[width * height];
			if ( !tifImg.ReadRGBAImageOriented( width , height , raster , Orientation.TOPLEFT ) )
			{
				// Not a valid TIF image.
			}
			// store the pixels
			pixels = new SKColor[width * height];
			for ( int y = 0 ; y < height ; y++ )
			{
				for ( int x = 0 ; x < width ; x++ )
				{
					int arrayOffset = y * width + x;
					int rgba = raster[arrayOffset];
					pixels[arrayOffset] = new SKColor( (byte)Tiff.GetR( rgba ) , (byte)Tiff.GetG( rgba ) , (byte)Tiff.GetB( rgba ) , (byte)Tiff.GetA( rgba ) );
				}
			}
		}

		return new SKBitmap( width , height )
		{
			Pixels = pixels
		};
	}

	private static byte[]? PreprocessPDF( string form_file )
	{
		byte[] file_bytes = System.IO.File.ReadAllBytes( form_file );
		if ( file_bytes.Length < 10 )
			return null;

		if ( file_bytes[0] != (byte)'%' || file_bytes[1] != (byte)'P' || file_bytes[2] != 'D' || file_bytes[3] != 'F' )
			return null;

		return file_bytes;
	}
}