// 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'

// UTILITY
var compare = process.binding('buffer').compare
var util = require('util')
var Buffer = require('buffer').Buffer
var pSlice = Array.prototype.slice

// 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.

var 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
  Error.captureStackTrace(this, stackStartFunction)
}

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

function truncate (s, n) {
  if (typeof s === 'string') {
    return s.length < n ? s : s.slice(0, n)
  } else {
    return s
  }
}

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.

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);.

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)

assert.equal = function equal (actual, expected, message) {
  if (actual != expected) fail(actual, expected, message, '==', assert.equal) // eslint-disable-line
}

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

assert.notEqual = function notEqual (actual, expected, message) {
  if (actual == expected) { // eslint-disable-line
    fail(actual, expected, message, '!=', assert.notEqual)
  }
}

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

assert.deepEqual = function deepEqual (actual, expected, message) {
  if (!_deepEqual(actual, expected, false)) {
    fail(actual, expected, message, 'deepEqual', assert.deepEqual)
  }
}

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

function _deepEqual (actual, expected, strict) {
  // 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

  // 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 // eslint-disable-line

  // 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 {
    return objEquiv(actual, expected, strict)
  }
}

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

function objEquiv (a, b, strict) {
  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
  }
  var aIsArgs = isArguments(a)
  var bIsArgs = isArguments(b)
  if ((aIsArgs && !bIsArgs) || (!aIsArgs && bIsArgs)) {
    return false
  }
  if (aIsArgs) {
    a = pSlice.call(a)
    b = pSlice.call(b)
    return _deepEqual(a, b, strict)
  }
  var ka = Object.keys(a)
  var 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)) return false
  }
  return true
}

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

assert.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)
  } else if (actual instanceof expected) {
    return true
  } else if (expected.call({}, actual) === true) {
    return true
  }

  return false
}

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

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

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

  try {
    block()
  } catch (e) {
    actual = e
  }

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

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

  if (!shouldThrow && expectedException(actual, expected)) {
    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)

assert.throws = function (block, error, message) {
  _throws.apply(this, [true].concat(pSlice.call(arguments)))
}

// EXTENSION! This is annoying to write outside this module.
assert.doesNotThrow = function (block, message) {
  _throws.apply(this, [false].concat(pSlice.call(arguments)))
}

assert.ifError = function (err) { if (err) throw err }
