using BitMiracle.LibTiff.Classic;
using Microsoft.AspNetCore.Mvc;
using SkiaSharp;
using System.Buffers.Text;
using Microsoft.Data.SqlClient;
using System.IO;

namespace Library.Api;

[Route( "Api/Repository/[action]/{id?}" )]
public class RepositoryApi : APIController
{
	public RepositoryApi( ILogger<UserApi> logger , IConfiguration configuration )
		: base( logger , configuration )
	{
	}

	[HttpPost]
	[DisableRequestSizeLimit]
	public IActionResult UploadCoverImage( int id , List<IFormFile>? file )
	{
		Trace( "/Api/Repository/UploadCoverImage" );
		if ( file == null || file.Count <= 0 )
			return Error( "Missing file" );

		using SKBitmap? bitmap = PreprocessImage( file[0] );
		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]
	[DisableRequestSizeLimit]
	public IActionResult UploadPDFAttachment( int id , List<IFormFile>? file )
	{
		Trace( "/Api/Repository/UploadPDFAttachment" );
		if ( file == null || file.Count <= 0 )
			return Error( "Missing file" );

		byte [] ? pdf_data_array = PreprocessPDF( file[0] );
		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]
	[DisableRequestSizeLimit]
	public IActionResult UploadImageAttachment( int id , List<IFormFile>? file )
	{
		Trace( "/Api/Repository/UploadImageAttachment" );
		if ( file == null || file.Count <= 0 )
			return Error( "Missing file" );

		using SKBitmap? bitmap = PreprocessImage( file[0] );
		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 SKBitmap? PreprocessImage( IFormFile form_file )
	{
		SKBitmap? bitmap = SKBitmap.Decode( form_file.OpenReadStream( ) );
		if ( bitmap == null )
		{
			bitmap = ConvertTiffToSKBitmap( form_file.OpenReadStream( ) );
			if ( bitmap == null )
				return null;
		}

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

		return bitmap;
	}

	private static byte[]? PreprocessPDF( IFormFile form_file )
	{
		using MemoryStream file_contents = new( );
		form_file.CopyTo( file_contents );

		byte[] file_bytes = file_contents.ToArray( );
		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;
	}

	public static SKBitmap? ConvertTiffToSKBitmap( Stream tifImage )
	{
		SKColor[] pixels;
		int width, height;
		// open a Tiff stored in the memory stream, and grab its pixels
		using ( Tiff tifImg = Tiff.ClientOpen( "in-memory" , "r" , tifImage , 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
		};
	}
}