NativeScript/packages/core/xhr/index.ts

import * as http from '../http';
import * as types from '../utils/types';
import { Trace } from '../trace';

namespace XMLHttpRequestResponseType {
	export const empty = '';
	export const text = 'text';
	export const json = 'json';
	export const blob = 'blob';
	export const arraybuffer = 'arraybuffer';
}

export class XMLHttpRequest {
	public UNSENT = 0;
	public OPENED = 1;
	public HEADERS_RECEIVED = 2;
	public LOADING = 3;
	public DONE = 4;

	public onabort: (...args: any[]) => void;
	public onerror: (...args: any[]) => void;
	public onload: (...args: any[]) => void;
	public onloadend: (...args: any[]) => void;
	public onloadstart: (...args: any[]) => void;
	public onprogress: (...args: any[]) => void;

	private _options: http.HttpRequestOptions;
	private _readyState: number;
	private _status: number;
	private _response: any;
	private _responseTextReader: Function;
	private _headers: any;
	private _errorFlag: boolean;
	private _sendFlag: boolean;
	private _responseType = '';
	private _overrideMimeType: string;

	private _listeners: Map<string, Array<Function>> = new Map<string, Array<Function>>();

	public onreadystatechange: Function;

	public get upload() {
		return this;
	}

	public get readyState(): number {
		return this._readyState;
	}

	public get responseType(): string {
		return this._responseType;
	}

	public set responseType(value: string) {
		if (value === XMLHttpRequestResponseType.empty || value in XMLHttpRequestResponseType) {
			this._responseType = value;
		} else {
			throw new Error(`Response type of '${value}' not supported.`);
		}
	}

	public get responseText(): string {
		if (this._responseType !== XMLHttpRequestResponseType.empty && this._responseType !== XMLHttpRequestResponseType.text) {
			throw new Error("Failed to read the 'responseText' property from 'XMLHttpRequest': " + "The value is only accessible if the object's 'responseType' is '' or 'text' " + `(was '${this._responseType}').`);
		}

		if (types.isFunction(this._responseTextReader)) {
			return this._responseTextReader();
		}

		return '';
	}

	public get response(): any {
		if (this._responseType === XMLHttpRequestResponseType.empty || this._responseType === XMLHttpRequestResponseType.text) {
			if (this._readyState !== this.LOADING && this._readyState !== this.DONE) {
				return '';
			} else {
				return this._response;
			}
		} else {
			if (this._readyState !== this.DONE) {
				return null;
			} else {
				return this._response;
			}
		}
	}

	public get status(): number {
		return this._status;
	}

	public get statusText(): string {
		if (this._readyState === this.UNSENT || this._readyState === this.OPENED || this._errorFlag) {
			return '';
		}

		return statuses[this._status];
	}

	constructor() {
		this._readyState = this.UNSENT;
	}

	private _loadResponse(r: http.HttpResponse) {
		this._status = r.statusCode;
		this._headers = r.headers;
		this._setReadyState(this.HEADERS_RECEIVED);

		this._setReadyState(this.LOADING);

		this._responseTextReader = () => r.content.toString();

		const contentType = this.getResponseHeader('Content-Type');
		const mimeType = (contentType && contentType.toLowerCase()) || 'text/xml';
		const finalMimeType = this._overrideMimeType || mimeType;

		if (this._responseType === XMLHttpRequestResponseType.json) {
			this._response = r.content.toJSON();
		} else if (this._responseType === XMLHttpRequestResponseType.text || this._responseType === XMLHttpRequestResponseType.empty) {
			this._response = this.responseText;
		} else if (this._responseType === XMLHttpRequestResponseType.arraybuffer) {
			this._response = r.content.toArrayBuffer();
		} else if (this._responseType === XMLHttpRequestResponseType.blob) {
			this._response = new Blob([r.content.toArrayBuffer()], {
				type: finalMimeType,
			});
		}

		this.emitEvent('progress');

		this._sendFlag = false;
		this._setReadyState(this.DONE);
	}

	private emitEvent(eventName: string, ...args: Array<any>) {
		if (types.isFunction(this['on' + eventName])) {
			this['on' + eventName](...args);
		}

		const handlers = this._listeners.get(eventName) || [];
		handlers.forEach((handler) => {
			handler(...args);
		});
	}

	private _setReadyState(value: number) {
		if (this._readyState !== value) {
			this._readyState = value;
			this.emitEvent('readystatechange');
		}

		if (this._readyState === this.DONE) {
			this.emitEvent('load');
			this.emitEvent('loadend');
		}
	}

	private _setRequestError(eventName: string, error?: any) {
		this._readyState = this.DONE;

		this._response = error;

		this.emitEvent('readystatechange');

		this.emitEvent(eventName, error);

		this.emitEvent('loadend');
	}

	public addEventListener(eventName: string, handler: Function) {
		if (['abort', 'error', 'load', 'loadend', 'loadstart', 'progress', 'readystatechange'].indexOf(eventName) === -1) {
			if (Trace.isEnabled()) {
				Trace.write('XHR Event not supported: ' + eventName, Trace.categories.Debug, Trace.messageType.warn);
			}
		}

		const handlers = this._listeners.get(eventName) || [];
		handlers.push(handler);
		this._listeners.set(eventName, handlers);
	}

	public removeEventListener(eventName: string, toDetach: Function) {
		let handlers = this._listeners.get(eventName) || [];
		handlers = handlers.filter((handler) => handler !== toDetach);
		this._listeners.set(eventName, handlers);
	}

	public open(method: string, url: string, async?: boolean, user?: string, password?: string) {
		if (types.isString(method) && types.isString(url)) {
			this._options = { url: url, method: method };
			this._options.headers = {};

			if (types.isString(user)) {
				this._options.headers['user'] = user;
			}

			if (types.isString(password)) {
				this._options.headers['password'] = password;
			}

			this._setReadyState(this.OPENED);
		}
	}

	public abort() {
		this._response = null;
		this._responseTextReader = null;
		this._headers = null;
		this._status = null;

		if ((this._readyState === this.OPENED && this._sendFlag) || this._readyState === this.HEADERS_RECEIVED || this._readyState === this.LOADING) {
			this._errorFlag = true;
			this._sendFlag = false;
			this._setRequestError('abort');
		}

		if (this._readyState === this.DONE) {
			this._readyState = this.UNSENT;
		}
	}

	public send(data?: any) {
		this._errorFlag = false;
		this._response = null;
		this._responseTextReader = null;
		this._headers = null;
		this._status = null;

		if (this._readyState !== this.OPENED || this._sendFlag) {
			throw new Error("Failed to execute 'send' on 'XMLHttpRequest': " + "The object's state must be OPENED.");
		}

		if (types.isString(data) && this._options.method !== 'GET') {
			//The Android Java HTTP lib throws an exception if we provide a
			//a request body for GET requests, so we avoid doing that.
			//Browser implementations silently ignore it as well.
			this._options.content = data;
		} else if (data instanceof FormData) {
			this._options.content = (<FormData>data).toString();
		} else if (data instanceof Blob) {
			this.setRequestHeader('Content-Type', data.type);
			this._options.content = Blob.InternalAccessor.getBuffer(data);
		} else if (data instanceof ArrayBuffer) {
			this._options.content = data;
		}

		this._sendFlag = true;

		this.emitEvent('loadstart');

		http
			.request(this._options)
			.then((r) => {
				if (!this._errorFlag && this._sendFlag) {
					this._loadResponse(r);
				}
			})
			.catch((e) => {
				this._errorFlag = true;
				this._sendFlag = false;
				this._setRequestError('error', e);
			});
	}

	public setRequestHeader(header: string, value: string) {
		if (this._readyState !== this.OPENED || this._sendFlag) {
			throw new Error("Failed to execute 'setRequestHeader' on 'XMLHttpRequest': " + "The object's state must be OPENED.");
		}

		if (types.isString(header) && types.isString(value)) {
			this._options.headers[header] = value;
		}
	}

	public getAllResponseHeaders(): string {
		if (this._readyState < 2 || this._errorFlag) {
			return '';
		}

		let result = '';

		for (const i in this._headers) {
			result += i + ': ' + this._headers[i] + '\r\n';
		}

		return result.substr(0, result.length - 2);
	}

	public getResponseHeader(header: string): string {
		if (types.isString(header) && this._readyState > 1 && this._headers && !this._errorFlag) {
			header = header.toLowerCase();
			for (const i in this._headers) {
				if (i.toLowerCase() === header) {
					return this._headers[i];
				}
			}
		}

		return null;
	}

	public overrideMimeType(mime: string) {
		if (this._readyState === this.LOADING || this._readyState === this.DONE) {
			throw new Error("Failed to execute 'overrideMimeType' on 'XMLHttpRequest': " + 'MimeType cannot be overridden when the state is LOADING or DONE.');
		}

		this._overrideMimeType = mime;
	}
}

const statuses = {
	100: 'Continue',
	101: 'Switching Protocols',
	200: 'OK',
	201: 'Created',
	202: 'Accepted',
	203: 'Non - Authoritative Information',
	204: 'No Content',
	205: 'Reset Content',
	206: 'Partial Content',
	300: 'Multiple Choices',
	301: 'Moved Permanently',
	302: 'Found',
	303: 'See Other',
	304: 'Not Modified',
	305: 'Use Proxy',
	307: 'Temporary Redirect',
	400: 'Bad Request',
	401: 'Unauthorized',
	402: 'Payment Required',
	403: 'Forbidden',
	404: 'Not Found',
	405: 'Method Not Allowed',
	406: 'Not Acceptable',
	407: 'Proxy Authentication Required',
	408: 'Request Timeout',
	409: 'Conflict',
	410: 'Gone',
	411: 'Length Required',
	412: 'Precondition Failed',
	413: 'Request Entity Too Large',
	414: 'Request - URI Too Long',
	415: 'Unsupported Media Type',
	416: 'Requested Range Not Satisfiable',
	417: 'Expectation Failed',
	500: 'Internal Server Error',
	501: 'Not Implemented',
	502: 'Bad Gateway',
	503: 'Service Unavailable',
	504: 'Gateway Timeout',
	505: 'HTTP Version Not Supported',
};

export class FormData {
	private _data: Map<string, any>;

	constructor() {
		this._data = new Map<string, any>();
	}

	append(name: string, value: any) {
		this._data.set(name, value);
	}

	toString(): string {
		const arr = new Array<string>();

		this._data.forEach(function (value, name, map) {
			arr.push(`${encodeURIComponent(name)}=${encodeURIComponent(value)}`);
		});

		return arr.join('&');
	}
}

export class Blob {
	// Note: only for use by XHR
	public static InternalAccessor = class {
		public static getBuffer(blob: Blob) {
			return blob._buffer;
		}
	};

	private _buffer: Uint8Array;
	private _size: number;
	private _type: string;

	public get size() {
		return this._size;
	}
	public get type() {
		return this._type;
	}

	constructor(chunks: Array<BufferSource | DataView | Blob | string> = [], opts: { type?: string } = {}) {
		const dataChunks: Uint8Array[] = [];
		for (const chunk of chunks) {
			if (chunk instanceof Blob) {
				dataChunks.push(chunk._buffer);
			} else if (typeof chunk === 'string') {
				const textEncoder = new TextEncoder();
				dataChunks.push(textEncoder.encode(chunk));
			} else if (chunk instanceof DataView) {
				dataChunks.push(new Uint8Array(chunk.buffer.slice(0)));
			} else if (chunk instanceof ArrayBuffer || ArrayBuffer.isView(chunk)) {
				dataChunks.push(new Uint8Array(ArrayBuffer.isView(chunk) ? chunk.buffer.slice(0) : chunk.slice(0)));
			} else {
				const textEncoder = new TextEncoder();
				dataChunks.push(textEncoder.encode(String(chunk)));
			}
		}

		const size = dataChunks.reduce((size, chunk) => size + chunk.byteLength, 0);
		const buffer = new Uint8Array(size);
		let offset = 0;
		for (let i = 0; i < dataChunks.length; i++) {
			const chunk = dataChunks[i];
			buffer.set(chunk, offset);
			offset += chunk.byteLength;
		}

		this._buffer = buffer;
		this._size = this._buffer.byteLength;

		this._type = opts.type || '';
		if (/[^\u0020-\u007E]/.test(this._type)) {
			this._type = '';
		} else {
			this._type = this._type.toLowerCase();
		}
	}

	public arrayBuffer(): Promise<ArrayBuffer> {
		return Promise.resolve(this._buffer);
	}

	public text(): Promise<string> {
		const textDecoder = new TextDecoder();

		return Promise.resolve(textDecoder.decode(this._buffer));
	}

	public slice(start?: number, end?: number, type?: string): Blob {
		const slice = this._buffer.slice(start || 0, end || this._buffer.length);

		return new Blob([slice], { type: type });
	}

	public stream() {
		throw new Error('stream is currently not supported');
	}

	public toString() {
		return '[object Blob]';
	}

	[Symbol.toStringTag] = 'Blob';
}

export class File extends Blob {
	private _name: string;
	private _lastModified: number;

	public get name() {
		return this._name;
	}

	public get lastModified() {
		return this._lastModified;
	}

	constructor(chunks: Array<BufferSource | DataView | Blob | string>, name: string, opts: { type?: string; lastModified?: number } = {}) {
		super(chunks, opts);
		this._name = name.replace(/\//g, ':');
		this._lastModified = opts.lastModified ? new Date(opts.lastModified).valueOf() : Date.now();
	}

	public toString() {
		return '[object File]';
	}

	[Symbol.toStringTag] = 'File';
}

export class FileReader {
	public EMPTY = 0;
	public LOADING = 1;
	public DONE = 2;

	public onabort: (...args: any[]) => void;
	public onerror: (...args: any[]) => void;
	public onload: (...args: any[]) => void;
	public onloadend: (...args: any[]) => void;
	public onloadstart: (...args: any[]) => void;
	public onprogress: (...args: any[]) => void;

	private _readyState: number;
	private _result: string | ArrayBuffer | null;

	private _listeners: Map<string, Array<Function>> = new Map<string, Array<Function>>();

	public get readyState(): number {
		return this._readyState;
	}

	public get result(): string | ArrayBuffer | null {
		return this._result;
	}

	constructor() {
		//
	}

	private _array2base64(input: Uint8Array): string {
		const byteToCharMap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';

		const output = [];

		for (let i = 0; i < input.length; i += 3) {
			const byte1 = input[i];
			const haveByte2 = i + 1 < input.length;
			const byte2 = haveByte2 ? input[i + 1] : 0;
			const haveByte3 = i + 2 < input.length;
			const byte3 = haveByte3 ? input[i + 2] : 0;

			const outByte1 = byte1 >> 2;
			const outByte2 = ((byte1 & 0x03) << 4) | (byte2 >> 4);
			let outByte3 = ((byte2 & 0x0f) << 2) | (byte3 >> 6);
			let outByte4 = byte3 & 0x3f;

			if (!haveByte3) {
				outByte4 = 64;

				if (!haveByte2) {
					outByte3 = 64;
				}
			}

			output.push(byteToCharMap[outByte1], byteToCharMap[outByte2], byteToCharMap[outByte3], byteToCharMap[outByte4]);
		}

		return output.join('');
	}

	private _read(blob, kind) {
		if (!(blob instanceof Blob)) {
			throw new TypeError(`Failed to execute '${kind}' on 'FileReader': parameter 1 is not of type 'Blob'.`);
		}

		this._result = '';

		setTimeout(() => {
			this._readyState = this.LOADING;
			this.emitEvent('load');
			this.emitEvent('loadend');
		});
	}

	private emitEvent(eventName: string, ...args: Array<any>) {
		if (types.isFunction(this['on' + eventName])) {
			this['on' + eventName](...args);
		}

		const handlers = this._listeners.get(eventName) || [];
		handlers.forEach((handler) => {
			handler(...args);
		});
	}

	public addEventListener(eventName: string, handler: Function) {
		if (['abort', 'error', 'load', 'loadend', 'loadstart', 'progress'].indexOf(eventName) === -1) {
			throw new Error('Event not supported: ' + eventName);
		}

		const handlers = this._listeners.get(eventName) || [];
		handlers.push(handler);
		this._listeners.set(eventName, handlers);
	}

	public removeEventListener(eventName: string, toDetach: Function) {
		let handlers = this._listeners.get(eventName) || [];
		handlers = handlers.filter((handler) => handler !== toDetach);
		this._listeners.set(eventName, handlers);
	}

	public readAsDataURL(blob: Blob) {
		this._read(blob, 'readAsDataURL');
		this._result = `data:${blob.type};base64,${this._array2base64(Blob.InternalAccessor.getBuffer(blob))}`;
	}

	public readAsText(blob: Blob) {
		this._read(blob, 'readAsText');
		const textDecoder = new TextDecoder();
		this._result = textDecoder.decode(Blob.InternalAccessor.getBuffer(blob));
	}

	public readAsArrayBuffer(blob: Blob) {
		this._read(blob, 'readAsArrayBuffer');
		this._result = Blob.InternalAccessor.getBuffer(blob).buffer.slice(0);
	}

	public abort() {
		//
	}

	public toString() {
		return '[object FileReader]';
	}

	[Symbol.toStringTag] = 'FileReader';
}