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

// Licensed under the MIT License.

import { IToken, TokenType } from './types';

class BracePair {

public readonly openBrace: TokenType;

public readonly closeBrace: TokenType;

constructor(openBrace: TokenType, closeBrace: TokenType) {

this.openBrace = openBrace;

this.closeBrace = closeBrace;

}

}

class Stack {

private store: IToken[] = [];

public push(val: IToken) {

this.store.push(val);

}

public pop(): IToken | undefined {

return this.store.pop();

}

public get length(): number {

return this.store.length;

}

}

export class BraceCounter {

private readonly bracePairs: BracePair[] = [

new BracePair(TokenType.OpenBrace, TokenType.CloseBrace),

new BracePair(TokenType.OpenBracket, TokenType.CloseBracket),

new BracePair(TokenType.OpenCurly, TokenType.CloseCurly)

];

private braceStacks: Stack[] = [new Stack(), new Stack(), new Stack()];

public get count(): number {

let c = 0;

for (const s of this.braceStacks) {

c += s.length;

}

return c;

}

public isOpened(type: TokenType): boolean {

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

const pair = this.bracePairs[i];

if (pair.openBrace === type || pair.closeBrace === type) {

return this.braceStacks[i].length > 0;

}

}

return false;

}

public countBrace(brace: IToken): boolean {

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

const pair = this.bracePairs[i];

if (pair.openBrace === brace.type) {

this.braceStacks[i].push(brace);

return true;

}

if (pair.closeBrace === brace.type) {

if (this.braceStacks[i].length > 0) {

this.braceStacks[i].pop();

}

return true;

}

}

return false;

}

}