/*
 * Copyright 2013-2019, kaj dijkstra,
 * Author, Kaj Dijkstra.
 * All rights reserved.
 *
 */

import texture				from "./texture.js";
import { math }				from "./math.js";


/**
 * Sampler2D
**/
class sampler2D {

	constructor ( ) {

		this.texture				= null;

		this.id						= ++kepler.samplerId;

		this.alpha					= 1.0;

		this.binded					= false;

		this.anisotropic			= false;

		// If true, do not generate mipmaps (reduces normal-map shimmer)
		this.isNormalMap			= false;
	}

	setViewport ( viewport ) {

		this.viewport				= viewport;
		this.gl						= viewport.gl;

		this.FLIP_Y					= true;

		this.filter					= this.gl.LINEAR;

		this.MIN_FILTER				= this.gl.LINEAR;
		this.MAG_FILTER				= this.gl.LINEAR;

		this.WRAP_S					= this.gl.REPEAT;
		this.WRAP_T					= this.gl.REPEAT;

		this.datatype				= this.gl.RGBA;
		this.format					= this.gl.RGBA;
		this.internalFormat			= this.gl.RGBA;

		this.target					= this.gl.TEXTURE_2D;

		this.type					= this.gl.FLOAT;
	}

	setTarget ( viewport ) {

		var textureObject			= new texture();

		textureObject.setViewport( viewport );

		this.addTexture( textureObject );
	}

	getTexture ( face ) {

		return this.texture;
	}

	getTextures ( ) {

		return [ this.texture ];
	}

	addTexture ( textureObject ) {

		this.texture				= textureObject;
	}

	setType ( type ) {

		// this.texture.type = type;
	}

	setAsNormalMap ( ) {

		this.isNormalMap			= true;
	}

	/**
	 * bind sampler to shader
	 * @param {(shader)} shader
	**/
	bind ( shader ) {

		var txt						= this.texture;
		var data					= this.texture.data;
		var type					= txt.dataType;
		var gl						= this.gl;

		if ( type == "framebuffer" ) {

			// Preserve your original behaviour:
			// framebuffer "data" is already a GL texture handle
			this.texture.glTexture	= this.texture.data;

			// Continue as if it is a normal GL texture object (no texImage2D)
			// NOTE: do NOT change filtering/mips logic here beyond safe defaults.

		} else {

			var width				= txt.width;
			var height				= txt.height;

			// Always assign sampler slot like you did
			this.id					= 1 + shader.samplerId++;

			gl.activeTexture( gl.TEXTURE0 + this.id );

			gl.enable( this.gl.BLEND );
			gl.bindTexture( gl.TEXTURE_2D, txt.glTexture );
			gl.pixelStorei( gl.UNPACK_FLIP_Y_WEBGL, this.FLIP_Y );

			// serialize txt data type
			switch ( type ) {

				case "float":
				{
					this.type = this.gl.FLOAT;

					// WebGL2 prefers sized internal formats for float textures.
					// Keep fallback to gl.RGBA for compatibility if RGBA32F is not present.
					var internal = gl.RGBA32F ? gl.RGBA32F : gl.RGBA;

					gl.texImage2D(
						gl.TEXTURE_2D,
						0,
						internal,
						width,
						height,
						0,
						this.internalFormat,
						this.type,
						data
					);
				}
				break;

				case "int":
				{
					this.type = this.gl.UNSIGNED_BYTE;

					gl.texImage2D(
						gl.TEXTURE_2D,
						0,
						this.format,
						width,
						height,
						0,
						this.internalFormat,
						this.type,
						data
					);
				}
				break;

				case "depth":
				{
					gl.texImage2D(
						gl.TEXTURE_2D,
						0,
						this.gl.DEPTH_COMPONENT,
						width,
						height,
						0,
						this.gl.DEPTH_COMPONENT,
						this.gl.UNSIGNED_SHORT,
						null
					);
				}
				break;

				case "image":
				{
					this.type = this.gl.UNSIGNED_BYTE;

					// Keep your original call shape (works because format == internalFormat == RGBA)
					gl.texImage2D(
						gl.TEXTURE_2D,
						0,
						this.format,
						this.internalFormat,
						this.type,
						data
					);
				}
				break;

				case "canvas":
				{
					gl.texImage2D(
						gl.TEXTURE_2D,
						0,
						this.format,
						width,
						height,
						0,
						this.internalFormat,
						this.UNSIGNED_BYTE,
						data
					);
				}
				break;

				case "COMPRESSED_RGBA":
				{
					var mipmaps = txt.mipmaps;

					for ( var i = 0; i < mipmaps.length; i++ ) {

						var mipmap = mipmaps[i];

						gl.compressedTexImage2D(
							gl.TEXTURE_2D,
							i,
							mipmap.internalFormat,
							mipmap.width,
							mipmap.height,
							0,
							mipmap.byteArray
						);
					}
				}
				break;
			}

			// Anisotropy kept as in your original (disabled)
			if ( this.anisotropic ) {

				// var extension = kepler.extensions.anisotropic;
				// gl.texParameteri( this.gl.TEXTURE_2D, extension.TEXTURE_MAX_ANISOTROPY_EXT, this.anisotropic );
			}

			// POT logic (this is where we apply the safe normal-map fix)
			if ( math.isPowerOfTwo( width ) && math.isPowerOfTwo( height ) ) {

				gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_MAG_FILTER, this.gl.LINEAR );

				if ( this.isNormalMap ) {

					// Safe fix: do not use mipmaps for normal maps
					gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_MIN_FILTER, this.gl.LINEAR );

				} else {

					gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_MIN_FILTER, this.gl.LINEAR_MIPMAP_LINEAR );

					if ( this.type != this.gl.FLOAT ) {

						gl.generateMipmap( gl.TEXTURE_2D );
					}
				}

				gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_WRAP_S, this.WRAP_S );
				gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_WRAP_T, this.WRAP_T );

			} else {

				gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_MIN_FILTER, this.gl.LINEAR );
				gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_WRAP_S, this.gl.CLAMP_TO_EDGE );
				gl.texParameteri( gl.TEXTURE_2D, this.gl.TEXTURE_WRAP_T, this.gl.CLAMP_TO_EDGE );
			}

			gl.bindTexture( gl.TEXTURE_2D, null );

			this.binded = true;

			return;
		}

		// framebuffer path: bind the already-created GL texture handle
		// and apply basic sampling state without re-upload.
		{
			var width_fb				= txt.width;
			var height_fb				= txt.height;

			this.id						= 1 + shader.samplerId++;

			gl.activeTexture( gl.TEXTURE0 + this.id );
			gl.bindTexture( gl.TEXTURE_2D, txt.glTexture );

			// Clamp + linear for attachments (safe default)
			gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR );
			gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR );
			gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE );
			gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE );

			gl.bindTexture( gl.TEXTURE_2D, null );

			this.binded					= true;
		}
	}
}

export { sampler2D as default };