import { Command } from '../Command.js';
import { ObjectLoader } from 'three';

/**
 * @param editor Editor
 * @param object THREE.Object3D
 * @param mapName string
 * @param newMap THREE.Texture
 * @constructor
 */
class SetMaterialMapCommand extends Command {

	constructor( editor, object, mapName, newMap, materialSlot ) {

		super( editor );

		this.type = 'SetMaterialMapCommand';
		this.name = `Set Material.${mapName}`;

		this.object = object;
		this.material = this.editor.getObjectMaterial( object, materialSlot );

		this.oldMap = ( object !== undefined ) ? this.material[ mapName ] : undefined;
		this.newMap = newMap;

		this.mapName = mapName;

	}

	execute() {

		if ( this.oldMap !== null && this.oldMap !== undefined ) this.oldMap.dispose();

		this.material[ this.mapName ] = this.newMap;
		this.material.needsUpdate = true;

		this.editor.signals.materialChanged.dispatch( this.material );

	}

	undo() {

		this.material[ this.mapName ] = this.oldMap;
		this.material.needsUpdate = true;

		this.editor.signals.materialChanged.dispatch( this.material );

	}

	toJSON() {

		const output = super.toJSON( this );

		output.objectUuid = this.object.uuid;
		output.mapName = this.mapName;
		output.newMap = serializeMap( this.newMap );
		output.oldMap = serializeMap( this.oldMap );

		return output;

		// serializes a map (THREE.Texture)

		function serializeMap( map ) {

			if ( map === null || map === undefined ) return null;

			const meta = {
				geometries: {},
				materials: {},
				textures: {},
				images: {}
			};

			const json = map.toJSON( meta );
			const images = extractFromCache( meta.images );
			if ( images.length > 0 ) json.images = images;
			json.sourceFile = map.sourceFile;

			return json;

		}

		// Note: The function 'extractFromCache' is copied from Object3D.toJSON()

		// extract data from the cache hash
		// remove metadata on each item
		// and return as array
		function extractFromCache( cache ) {

			const values = [];
			for ( const key in cache ) {

				const data = cache[ key ];
				delete data.metadata;
				values.push( data );

			}

			return values;

		}

	}

	fromJSON( json ) {

		super.fromJSON( json );

		this.object = this.editor.objectByUuid( json.objectUuid );
		this.mapName = json.mapName;
		this.oldMap = parseTexture( json.oldMap );
		this.newMap = parseTexture( json.newMap );

		function parseTexture( json ) {

			let map = null;
			if ( json !== null ) {

				const loader = new ObjectLoader();
				const images = loader.parseImages( json.images );
				const textures = loader.parseTextures( [ json ], images );
				map = textures[ json.uuid ];
				map.sourceFile = json.sourceFile;

			}

			return map;

		}

	}

}

export { SetMaterialMapCommand };