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

// Licensed under the MIT License.

'use strict';

import * as assert from 'assert';

// tslint:disable-next-line:import-name

import Char from 'typescript-char';

import { CharacterStream } from '../../client/language/characterStream';

import { TextIterator } from '../../client/language/textIterator';

import { ICharacterStream } from '../../client/language/types';

// tslint:disable-next-line:max-func-body-length

suite('Language.CharacterStream', () => {

test('Iteration (string)', async () => {

const content = 'some text';

const cs = new CharacterStream(content);

testIteration(cs, content);

});

test('Iteration (iterator)', async () => {

const content = 'some text';

const cs = new CharacterStream(new TextIterator(content));

testIteration(cs, content);

});

test('Positioning', async () => {

const content = 'some text';

const cs = new CharacterStream(content);

assert.equal(cs.position, 0);

cs.advance(1);

assert.equal(cs.position, 1);

cs.advance(1);

assert.equal(cs.position, 2);

cs.advance(2);

assert.equal(cs.position, 4);

cs.advance(-3);

assert.equal(cs.position, 1);

cs.advance(-3);

assert.equal(cs.position, 0);

cs.advance(100);

assert.equal(cs.position, content.length);

});

test('Characters', async () => {

const content = 'some \ttext "" \' \' \n text \r\n more text';

const cs = new CharacterStream(content);

for (let i = 0; i < content.length; i += 1) {

assert.equal(cs.currentChar, content.charCodeAt(i));

assert.equal(cs.nextChar, i < content.length - 1 ? content.charCodeAt(i + 1) : 0);

assert.equal(cs.prevChar, i > 0 ? content.charCodeAt(i - 1) : 0);

assert.equal(cs.lookAhead(2), i < content.length - 2 ? content.charCodeAt(i + 2) : 0);

assert.equal(cs.lookAhead(-2), i > 1 ? content.charCodeAt(i - 2) : 0);

const ch = content.charCodeAt(i);

const isLineBreak = ch === Char.LineFeed || ch === Char.CarriageReturn;

assert.equal(cs.isAtWhiteSpace(), ch === Char.Tab || ch === Char.Space || isLineBreak);

assert.equal(cs.isAtLineBreak(), isLineBreak);

assert.equal(cs.isAtString(), ch === Char.SingleQuote || ch === Char.DoubleQuote);

cs.moveNext();

}

});

test('Skip', async () => {

const content = 'some \ttext "" \' \' \n text \r\n more text';

const cs = new CharacterStream(content);

cs.skipWhitespace();

assert.equal(cs.position, 0);

cs.skipToWhitespace();

assert.equal(cs.position, 4);

cs.skipToWhitespace();

assert.equal(cs.position, 4);

cs.skipWhitespace();

assert.equal(cs.position, 6);

cs.skipLineBreak();

assert.equal(cs.position, 6);

cs.skipToEol();

assert.equal(cs.position, 18);

cs.skipLineBreak();

assert.equal(cs.position, 19);

});

});

function testIteration(cs: ICharacterStream, content: string) {

assert.equal(cs.position, 0);

assert.equal(cs.length, content.length);

assert.equal(cs.isEndOfStream(), false);

for (let i = -2; i < content.length + 2; i += 1) {

const ch = cs.charCodeAt(i);

if (i < 0 || i >= content.length) {

assert.equal(ch, 0);

} else {

assert.equal(ch, content.charCodeAt(i));

}

}

for (let i = 0; i < content.length; i += 1) {

assert.equal(cs.isEndOfStream(), false);

assert.equal(cs.position, i);

assert.equal(cs.currentChar, content.charCodeAt(i));

cs.moveNext();

}

assert.equal(cs.isEndOfStream(), true);

assert.equal(cs.position, content.length);

}