/*---------------------------------------------------------------------------------------------

* Copyright (c) Microsoft Corporation. All rights reserved.

* Licensed under the MIT License. See License.txt in the project root for license information.

*--------------------------------------------------------------------------------------------*/

import { VSBufferReadableStream, VSBufferReadable, VSBuffer } from 'vs/base/common/buffer';

import { Readable } from 'stream';

import { isUndefinedOrNull } from 'vs/base/common/types';

import { UTF8, UTF8_with_bom, UTF8_BOM, UTF16be, UTF16le_BOM, UTF16be_BOM, UTF16le, UTF_ENCODING } from 'vs/base/node/encoding';

export function streamToNodeReadable(stream: VSBufferReadableStream): Readable {

return new class extends Readable {

private listening = false;

_read(size?: number): void {

if (!this.listening) {

this.listening = true;

// Data

stream.on('data', data => {

try {

if (!this.push(data.buffer)) {

stream.pause(); // pause the stream if we should not push anymore

}

} catch (error) {

this.emit(error);

}

});

// End

stream.on('end', () => {

try {

this.push(null); // signal EOS

} catch (error) {

this.emit(error);

}

});

// Error

stream.on('error', error => this.emit('error', error));

}

// ensure the stream is flowing

stream.resume();

}

_destroy(error: Error | null, callback: (error: Error | null) => void): void {

stream.destroy();

callback(null);

}

};

}

export function nodeReadableToString(stream: NodeJS.ReadableStream): Promise<string> {

return new Promise((resolve, reject) => {

let result = '';

stream.on('data', chunk => result += chunk);

stream.on('error', reject);

stream.on('end', () => resolve(result));

});

}

export function nodeStreamToVSBufferReadable(stream: NodeJS.ReadWriteStream, addBOM?: { encoding: UTF_ENCODING }): VSBufferReadable {

let bytesRead = 0;

let done = false;

return {

read(): VSBuffer | null {

if (done) {

return null;

}

const res = stream.read();

if (isUndefinedOrNull(res)) {

done = true;

// If we are instructed to add a BOM but we detect that no

// bytes have been read, we must ensure to return the BOM

// ourselves so that we comply with the contract.

if (bytesRead === 0 && addBOM) {

switch (addBOM.encoding) {

case UTF8:

case UTF8_with_bom:

return VSBuffer.wrap(Buffer.from(UTF8_BOM));

case UTF16be:

return VSBuffer.wrap(Buffer.from(UTF16be_BOM));

case UTF16le:

return VSBuffer.wrap(Buffer.from(UTF16le_BOM));

}

}

return null;

}

// Handle String

if (typeof res === 'string') {

bytesRead += res.length;

return VSBuffer.fromString(res);

}

// Handle Buffer

else {

bytesRead += res.byteLength;

return VSBuffer.wrap(res);

}

}

};

}