import { strict as assert } from "assert";

function getOpener(type: string):string {
  switch (type) {
    case ")":
      return "("
    case "]":
      return "[";
    case "}":
      return "{"
    default:
      return "";
  }
}

/**
 *
 * @param bracket
 * Return the lower priority brackets for a given bracket
 */
function getLower(bracket:string):Array<string> {
  switch (bracket) {
    case "]":
      return ["("]
    case "}":
      return ["(", "["]
    default:
      return []
  }
}

/**
 *
 * @param bracket the actual bracket in the bracket list
 * @param bracketMapKeys array of openned brackets from the list
 * check if it has lower priority bracket openned in the bracket list
 */

function hasLower(bracket:string, bracketMapKeys:Array<string>):boolean {
  const lower:Array<string> = getLower(bracket);
  for (let i=0; i < lower.length; i++) {
    if (bracketMapKeys.includes(lower[i])) return true;
  }
  return false;
}

function bracketTester(data: string): boolean {
  const openers = ['{', '[', '('];
  const brackets = data.split(" ");
  let bracketMap = {};
  for (let i in brackets) {
    let element = brackets[i];
    if (openers.includes(element)) {
      if (bracketMap[element]){
        return false;
      } else {
        bracketMap[element] = true;
      }
    } else {
      if (hasLower(element, Object.keys(bracketMap))) {
        return false;
      }
      const opener = getOpener(element)
      if (bracketMap[opener]) {
        delete bracketMap[opener]
      } else {
        return false;
      }
    }
  }
  return !Object.keys(bracketMap).length;
}

const data = {
  "{ [ ] ( ) }": true,
  "{ [ ( ] ) }": false,
  "{ [ }": false,
  "} ( )": false
}

for (let brackets in data) {
  assert(bracketTester(brackets) === data[brackets], `Fail: ${brackets}`);

}