import * as MathUtils from '../math/MathUtils.js';
import { StaticDrawUsage } from '../constants.js';

class InterleavedBuffer {
	constructor(array, stride) {
		this.array = array;
		this.stride = stride;
		this.count = array !== undefined ? array.length / stride : 0;

		this.usage = StaticDrawUsage;
		this.updateRange = { offset: 0, count: -1 };

		this.version = 0;

		this.uuid = MathUtils.generateUUID();
	}

	onUploadCallback() {}

	set needsUpdate(value) {
		if (value === true) this.version++;
	}

	setUsage(value) {
		this.usage = value;

		return this;
	}

	copy(source) {
		this.array = new source.array.constructor(source.array);
		this.count = source.count;
		this.stride = source.stride;
		this.usage = source.usage;

		return this;
	}

	copyAt(index1, attribute, index2) {
		index1 *= this.stride;
		index2 *= attribute.stride;

		for (let i = 0, l = this.stride; i < l; i++) {
			this.array[index1 + i] = attribute.array[index2 + i];
		}

		return this;
	}

	set(value, offset = 0) {
		this.array.set(value, offset);

		return this;
	}

	clone(data) {
		if (data.arrayBuffers === undefined) {
			data.arrayBuffers = {};
		}

		if (this.array.buffer._uuid === undefined) {
			this.array.buffer._uuid = MathUtils.generateUUID();
		}

		if (data.arrayBuffers[this.array.buffer._uuid] === undefined) {
			data.arrayBuffers[this.array.buffer._uuid] = this.array.slice(0).buffer;
		}

		const array = new this.array.constructor(data.arrayBuffers[this.array.buffer._uuid]);

		const ib = new this.constructor(array, this.stride);
		ib.setUsage(this.usage);

		return ib;
	}

	onUpload(callback) {
		this.onUploadCallback = callback;

		return this;
	}

	toJSON(data) {
		if (data.arrayBuffers === undefined) {
			data.arrayBuffers = {};
		}

		// generate UUID for array buffer if necessary

		if (this.array.buffer._uuid === undefined) {
			this.array.buffer._uuid = MathUtils.generateUUID();
		}

		if (data.arrayBuffers[this.array.buffer._uuid] === undefined) {
			data.arrayBuffers[this.array.buffer._uuid] = Array.prototype.slice.call(new Uint32Array(this.array.buffer));
		}

		//

		return {
			uuid: this.uuid,
			buffer: this.array.buffer._uuid,
			type: this.array.constructor.name,
			stride: this.stride,
		};
	}
}

InterleavedBuffer.prototype.isInterleavedBuffer = true;

export { InterleavedBuffer };