// http://wiki.commonjs.org/wiki/Unit_Testing/1.0
//
// THIS IS NOT TESTED NOR LIKELY TO WORK OUTSIDE V8!
//
// Originally from narwhal.js (http://narwhaljs.org)
// Copyright (c) 2009 Thomas Robinson <280north.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the 'Software'), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

/**
 * Assertions
 * @module assert
 * @memberOf module:buildin
 */

// UTILITY
const compare = process.binding('buffer').compare;
const util = require('util');
const Buffer = require('buffer').Buffer;
const pToString = (obj) => Object.prototype.toString.call(obj);

// 1. The assert module provides functions that throw
// AssertionError's when particular conditions are not met. The
// assert module must conform to the following interface.

const assert = module.exports = ok;

// 2. The AssertionError is defined in assert.
// new assert.AssertionError({ message: message,
//                             actual: actual,
//                             expected: expected })

assert.AssertionError = function AssertionError(options) {
  this.name = 'AssertionError';
  this.actual = options.actual;
  this.expected = options.expected;
  this.operator = options.operator;

  if (options.message) {
    this.message = options.message;
    this.generatedMessage = false;
  } else {
    this.message = getMessage(this);
    this.generatedMessage = true;
  }
  var stackStartFunction = options.stackStartFunction || fail;
 if (Error.captureStackTrace) {
    // Chrome and NodeJS
    Error.captureStackTrace(this, stackStartFunction);
  } else {
     // FF, IE 10+ and Safari 6+. Fallback for others
     let tmp_stack = (new Error).stack.split("\n").slice(1),
         re = /^(.*?)@(.*?):(.*?)$/.exec(tmp_stack[1]); //[undef, undef, this.fileName, this.lineNumber] = re
     this.fileName = re[2];
     this.lineNumber = re[3];
     this.stack = tmp_stack.join("\n");
 }
};

// assert.AssertionError instanceof Error
util.inherits(assert.AssertionError, Error);

function truncate(s, n) {
  return s.slice(0, n);
}

function getMessage(self) {
  return truncate(util.inspect(self.actual), 128) + ' ' +
         self.operator + ' ' +
         truncate(util.inspect(self.expected), 128);
}

// At present only the three keys mentioned above are used and
// understood by the spec. Implementations or sub modules can pass
// other keys to the AssertionError's constructor - they will be
// ignored.

// 3. All of the following functions must throw an AssertionError
// when a corresponding condition is not met, with a message that
// may be undefined if not provided.  All assertion methods provide
// both the actual and expected values to the assertion error for
// display purposes.

/**
 * Throws an exception that displays the values for actual and expected separated by the provided operator.
 * @param actual
 * @param expected
 * @param message
 * @param operator
 * @param stackStartFunction
 */
function fail(actual, expected, message, operator, stackStartFunction) {
  throw new assert.AssertionError({
    message: message,
    actual: actual,
    expected: expected,
    operator: operator,
    stackStartFunction: stackStartFunction
  });
}

// EXTENSION! allows for well behaved errors defined elsewhere.
assert.fail = fail;

// 4. Pure assertion tests whether a value is truthy, as determined
// by !!guard.
// assert.ok(guard, message_opt);
// This statement is equivalent to assert.equal(true, !!guard,
// message_opt);. To test strictly for the value true, use
// assert.strictEqual(true, guard, message_opt);.
/**
 * Tests if value is truthy, it is equivalent to assert.equal(true, !!value, message);
 * @param value
 * @param message
 */
function ok(value, message) {
  if (!value) fail(value, true, message, '==', assert.ok);
}
assert.ok = ok;

// 5. The equality assertion tests shallow, coercive equality with
// ==.
// assert.equal(actual, expected, message_opt);

/**
 * Tests shallow, coercive equality with the equal comparison operator ( == ).
 * @param actual
 * @param expected
 * @param {String} [message]
 */
module.exports.equal = function equal(actual, expected, message) {
  if (actual != expected) fail(actual, expected, message, '==', assert.equal);
};

// 6. The non-equality assertion tests for whether two objects are not equal
// with != assert.notEqual(actual, expected, message_opt);

/**
 * Tests shallow, coercive non-equality with the not equal comparison operator ( != ).
 * @param actual
 * @param expected
 * @param [message]
 */
module.exports.notEqual = function notEqual(actual, expected, message) {
  if (actual == expected) {
    fail(actual, expected, message, '!=', assert.notEqual);
  }
};

// 7. The equivalence assertion tests a deep equality relation.
// assert.deepEqual(actual, expected, message_opt);

/**
 * Tests for deep equality.
 * @param actual
 * @param expected
 * @param [message]
 */
module.exports.deepEqual = function deepEqual(actual, expected, message) {
  if (!_deepEqual(actual, expected, false)) {
    fail(actual, expected, message, 'deepEqual', assert.deepEqual);
  }
};

/**
 * Generally identical to assert.deepEqual() with two exceptions.
 * First, primitive values are compared using the strict equality operator ( === ).
 * Second, object comparisons include a strict equality check of their prototypes.
 * @param actual
 * @param expected
 * @param [message]
 */
assert.deepStrictEqual = function deepStrictEqual(actual, expected, message) {
  if (!_deepEqual(actual, expected, true)) {
    fail(actual, expected, message, 'deepStrictEqual', assert.deepStrictEqual);
  }
};

function _deepEqual(actual, expected, strict, memos) {
  // 7.1. All identical values are equivalent, as determined by ===.
  if (actual === expected) {
    return true;
  } else if (actual instanceof Buffer && expected instanceof Buffer) {
    return compare(actual, expected) === 0;
// UB SEPCIFIC
  } else if (actual instanceof ArrayBuffer && expected instanceof ArrayBuffer) {
      if (actual.byteLength != expected.byteLength) return false;
      var aBuf = new Uint8Array(actual), eBuf = new Uint8Array(expected);

      for (var i = 0; i < aBuf.length; i++) {
          if (aBuf[i] !== eBuf[i]) return false;
      }

      return true;
  // 7.2. If the expected value is a Date object, the actual value is
  // equivalent if it is also a Date object that refers to the same time.
  } else if (util.isDate(actual) && util.isDate(expected)) {
    return actual.getTime() === expected.getTime();

  // 7.3 If the expected value is a RegExp object, the actual value is
  // equivalent if it is also a RegExp object with the same source and
  // properties (`global`, `multiline`, `lastIndex`, `ignoreCase`).
  } else if (util.isRegExp(actual) && util.isRegExp(expected)) {
    return actual.source === expected.source &&
           actual.global === expected.global &&
           actual.multiline === expected.multiline &&
           actual.lastIndex === expected.lastIndex &&
           actual.ignoreCase === expected.ignoreCase;

  // 7.4. Other pairs that do not both pass typeof value == 'object',
  // equivalence is determined by ==.
  } else if ((actual === null || typeof actual !== 'object') &&
             (expected === null || typeof expected !== 'object')) {
    return strict ? actual === expected : actual == expected;

  // If both values are instances of typed arrays, wrap their underlying
  // ArrayBuffers in a Buffer each to increase performance
  // This optimization requires the arrays to have the same type as checked by
  // Object.prototype.toString (aka pToString). Never perform binary
  // comparisons for Float*Arrays, though, since e.g. +0 === -0 but their
  // bit patterns are not identical.
  } else if (ArrayBuffer.isView(actual) && ArrayBuffer.isView(expected) &&
             pToString(actual) === pToString(expected) &&
             !(actual instanceof Float32Array ||
               actual instanceof Float64Array)) {
    return compare(Buffer.from(actual.buffer,
                               actual.byteOffset,
                               actual.byteLength),
                   Buffer.from(expected.buffer,
                               expected.byteOffset,
                               expected.byteLength)) === 0;

  // 7.5 For all other Object pairs, including Array objects, equivalence is
  // determined by having the same number of owned properties (as verified
  // with Object.prototype.hasOwnProperty.call), the same set of keys
  // (although not necessarily the same order), equivalent values for every
  // corresponding key, and an identical 'prototype' property. Note: this
  // accounts for both named and indexed properties on Arrays.
  } else {
    memos = memos || {actual: [], expected: []};

    const actualIndex = memos.actual.indexOf(actual);
    if (actualIndex !== -1) {
      if (actualIndex === memos.expected.indexOf(expected)) {
        return true;
      }
    }

    memos.actual.push(actual);
    memos.expected.push(expected);

    return objEquiv(actual, expected, strict, memos);
  }
}

function isArguments(object) {
  return Object.prototype.toString.call(object) == '[object Arguments]';
}

function objEquiv(a, b, strict, actualVisitedObjects) {
  if (a === null || a === undefined || b === null || b === undefined)
    return false;
  // if one is a primitive, the other must be same
  if (util.isPrimitive(a) || util.isPrimitive(b))
    return a === b;
  if (strict && Object.getPrototypeOf(a) !== Object.getPrototypeOf(b))
    return false;
  const aIsArgs = isArguments(a);
  const bIsArgs = isArguments(b);
  if ((aIsArgs && !bIsArgs) || (!aIsArgs && bIsArgs))
    return false;
  const ka = Object.keys(a);
  const kb = Object.keys(b);
  var key, i;
  // having the same number of owned properties (keys incorporates
  // hasOwnProperty)
  if (ka.length !== kb.length)
    return false;
  //the same set of keys (although not necessarily the same order),
  ka.sort();
  kb.sort();
  //~~~cheap key test
  for (i = ka.length - 1; i >= 0; i--) {
    if (ka[i] !== kb[i])
      return false;
  }
  //equivalent values for every corresponding key, and
  //~~~possibly expensive deep test
  for (i = ka.length - 1; i >= 0; i--) {
    key = ka[i];
    if (!_deepEqual(a[key], b[key], strict, actualVisitedObjects))
      return false;
  }
  return true;
}

// 8. The non-equivalence assertion tests for any deep inequality.
// assert.notDeepEqual(actual, expected, message_opt);

/**
 * Tests for any deep inequality.
 * @param actual
 * @param expected
 * @param [message]
 */
module.exports.notDeepEqual = function notDeepEqual(actual, expected, message) {
  if (_deepEqual(actual, expected, false)) {
    fail(actual, expected, message, 'notDeepEqual', assert.notDeepEqual);
  }
};

assert.notDeepStrictEqual = notDeepStrictEqual;
function notDeepStrictEqual(actual, expected, message) {
  if (_deepEqual(actual, expected, true)) {
    fail(actual, expected, message, 'notDeepStrictEqual', notDeepStrictEqual);
  }
}


// 9. The strict equality assertion tests strict equality, as determined by ===.
// assert.strictEqual(actual, expected, message_opt);

assert.strictEqual = function strictEqual(actual, expected, message) {
  if (actual !== expected) {
    fail(actual, expected, message, '===', assert.strictEqual);
  }
};

// 10. The strict non-equality assertion tests for strict inequality, as
// determined by !==.  assert.notStrictEqual(actual, expected, message_opt);

assert.notStrictEqual = function notStrictEqual(actual, expected, message) {
  if (actual === expected) {
    fail(actual, expected, message, '!==', assert.notStrictEqual);
  }
};

function expectedException(actual, expected) {
  if (!actual || !expected) {
    return false;
  }

  if (Object.prototype.toString.call(expected) == '[object RegExp]') {
    return expected.test(actual);
  }

  try {
    if (actual instanceof expected) {
      return true;
    }
  } catch (e) {
    // Ignore.  The instanceof check doesn't work for arrow functions.
  }

  if (Error.isPrototypeOf(expected)) {
    return false;
  }

  return expected.call({}, actual) === true;
}

function _tryBlock(block) {
  var error;
  try {
    block();
  } catch (e) {
    error = e;
  }
  return error;
}

function _throws(shouldThrow, block, expected, message) {
  var actual;

  if (typeof block !== 'function') {
    throw new TypeError('"block" argument must be a function');
  }

  if (typeof expected === 'string') {
    message = expected;
    expected = null;
  }

  actual = _tryBlock(block);

  message = (expected && expected.name ? ' (' + expected.name + ').' : '.') +
            (message ? ' ' + message : '.');

  if (shouldThrow && !actual) {
    fail(actual, expected, 'Missing expected exception' + message);
  }

  const userProvidedMessage = typeof message === 'string';
  const isUnwantedException = !shouldThrow && util.isError(actual);
  const isUnexpectedException = !shouldThrow && actual && !expected;

  if ((isUnwantedException &&
      userProvidedMessage &&
      expectedException(actual, expected)) ||
      isUnexpectedException) {
    fail(actual, expected, 'Got unwanted exception' + message);
  }

  if ((shouldThrow && actual && expected &&
      !expectedException(actual, expected)) || (!shouldThrow && actual)) {
    throw actual;
  }
}

// 11. Expected to throw an error:
// assert.throws(block, Error_opt, message_opt);
/**
 * Expects block to throw an error. error can be constructor, RegExp or validation function.
 *
 * Validate instanceof using constructor:
 *
 *      assert.throws(function() {
 *         throw new Error("Wrong value");
 *      }, Error);
 *
 * Validate error message using RegExp:
 *
 *      assert.throws(function() {
 *         throw new Error("Wrong value");
 *      }, /error/);
 *
 * Custom error validation:
 *
 *      assert.throws(
 *      function() {
 *         throw new Error("Wrong value");
 *       },
 *      function(err) {
 *         if ( (err instanceof Error) && /value/.test(err) ) {
 *           return true;
 *         }
 *       },
 *      "unexpected error"
 *      );
 *
 * @param block
 * @param [error]
 * @param [message]
 */
module.exports.throws = function(block, /*optional*/error, /*optional*/message) {
  _throws(true, block, error, message);
};

// EXTENSION! This is annoying to write outside this module.
/**
 * Expects block not to throw an error, see assert.throws for details.
 * @param block
 * @param [error]
 * @param [message]
 */
module.exports.doesNotThrow = function(block, /*optional*/error, /*optional*/message) {
  _throws(false, block, error, message);
};

/**
 * Tests if value is not a false value, throws if it is a true value. Useful when testing the first argument, error in callbacks.
 * @param err
 */
module.exports.ifError = function(err) { if (err) {throw err;}};
