/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow strict-local
 * @format
 */

'use strict';

const symbolicateStackTrace = require('symbolicateStackTrace');

import type {StackFrame} from 'parseErrorStack';

type CacheKey = string;

export type Stack = Array<StackFrame>;

const cache: Map<CacheKey, Promise<Stack>> = new Map();

const YellowBoxSymbolication = {
  symbolicate(stack: Stack): Promise<Stack> {
    const key = getCacheKey(stack);

    let promise = cache.get(key);
    if (promise == null) {
      promise = symbolicateStackTrace(stack).then(sanitize);
      cache.set(key, promise);
    }

    return promise;
  },
};

const getCacheKey = (stack: Stack): CacheKey => {
  return JSON.stringify(stack);
};

/**
 * Sanitize because sometimes, `symbolicateStackTrace` gives us invalid values.
 */
const sanitize = (maybeStack: mixed): Stack => {
  if (!Array.isArray(maybeStack)) {
    throw new Error('Expected stack to be an array.');
  }
  const stack = [];
  for (const maybeFrame of maybeStack) {
    if (typeof maybeFrame !== 'object' || maybeFrame == null) {
      throw new Error('Expected each stack frame to be an object.');
    }
    if (typeof maybeFrame.column !== 'number' && maybeFrame.column != null) {
      throw new Error('Expected stack frame `column` to be a nullable number.');
    }
    if (typeof maybeFrame.file !== 'string') {
      throw new Error('Expected stack frame `file` to be a string.');
    }
    if (typeof maybeFrame.lineNumber !== 'number') {
      throw new Error('Expected stack frame `lineNumber` to be a number.');
    }
    if (typeof maybeFrame.methodName !== 'string') {
      throw new Error('Expected stack frame `methodName` to be a string.');
    }
    stack.push({
      column: maybeFrame.column,
      file: maybeFrame.file,
      lineNumber: maybeFrame.lineNumber,
      methodName: maybeFrame.methodName,
    });
  }
  return stack;
};

module.exports = YellowBoxSymbolication;