1var Stack = require('./_Stack'),
2    arrayEach = require('./_arrayEach'),
3    assignValue = require('./_assignValue'),
4    baseAssign = require('./_baseAssign'),
5    baseAssignIn = require('./_baseAssignIn'),
6    cloneBuffer = require('./_cloneBuffer'),
7    copyArray = require('./_copyArray'),
8    copySymbols = require('./_copySymbols'),
9    copySymbolsIn = require('./_copySymbolsIn'),
10    getAllKeys = require('./_getAllKeys'),
11    getAllKeysIn = require('./_getAllKeysIn'),
12    getTag = require('./_getTag'),
13    initCloneArray = require('./_initCloneArray'),
14    initCloneByTag = require('./_initCloneByTag'),
15    initCloneObject = require('./_initCloneObject'),
16    isArray = require('./isArray'),
17    isBuffer = require('./isBuffer'),
18    isMap = require('./isMap'),
19    isObject = require('./isObject'),
20    isSet = require('./isSet'),
21    keys = require('./keys'),
22    keysIn = require('./keysIn');
23
24/** Used to compose bitmasks for cloning. */
25var CLONE_DEEP_FLAG = 1,
26    CLONE_FLAT_FLAG = 2,
27    CLONE_SYMBOLS_FLAG = 4;
28
29/** `Object#toString` result references. */
30var argsTag = '[object Arguments]',
31    arrayTag = '[object Array]',
32    boolTag = '[object Boolean]',
33    dateTag = '[object Date]',
34    errorTag = '[object Error]',
35    funcTag = '[object Function]',
36    genTag = '[object GeneratorFunction]',
37    mapTag = '[object Map]',
38    numberTag = '[object Number]',
39    objectTag = '[object Object]',
40    regexpTag = '[object RegExp]',
41    setTag = '[object Set]',
42    stringTag = '[object String]',
43    symbolTag = '[object Symbol]',
44    weakMapTag = '[object WeakMap]';
45
46var arrayBufferTag = '[object ArrayBuffer]',
47    dataViewTag = '[object DataView]',
48    float32Tag = '[object Float32Array]',
49    float64Tag = '[object Float64Array]',
50    int8Tag = '[object Int8Array]',
51    int16Tag = '[object Int16Array]',
52    int32Tag = '[object Int32Array]',
53    uint8Tag = '[object Uint8Array]',
54    uint8ClampedTag = '[object Uint8ClampedArray]',
55    uint16Tag = '[object Uint16Array]',
56    uint32Tag = '[object Uint32Array]';
57
58/** Used to identify `toStringTag` values supported by `_.clone`. */
59var cloneableTags = {};
60cloneableTags[argsTag] = cloneableTags[arrayTag] =
61cloneableTags[arrayBufferTag] = cloneableTags[dataViewTag] =
62cloneableTags[boolTag] = cloneableTags[dateTag] =
63cloneableTags[float32Tag] = cloneableTags[float64Tag] =
64cloneableTags[int8Tag] = cloneableTags[int16Tag] =
65cloneableTags[int32Tag] = cloneableTags[mapTag] =
66cloneableTags[numberTag] = cloneableTags[objectTag] =
67cloneableTags[regexpTag] = cloneableTags[setTag] =
68cloneableTags[stringTag] = cloneableTags[symbolTag] =
69cloneableTags[uint8Tag] = cloneableTags[uint8ClampedTag] =
70cloneableTags[uint16Tag] = cloneableTags[uint32Tag] = true;
71cloneableTags[errorTag] = cloneableTags[funcTag] =
72cloneableTags[weakMapTag] = false;
73
74/**
75 * The base implementation of `_.clone` and `_.cloneDeep` which tracks
76 * traversed objects.
77 *
78 * @private
79 * @param {*} value The value to clone.
80 * @param {boolean} bitmask The bitmask flags.
81 *  1 - Deep clone
82 *  2 - Flatten inherited properties
83 *  4 - Clone symbols
84 * @param {Function} [customizer] The function to customize cloning.
85 * @param {string} [key] The key of `value`.
86 * @param {Object} [object] The parent object of `value`.
87 * @param {Object} [stack] Tracks traversed objects and their clone counterparts.
88 * @returns {*} Returns the cloned value.
89 */
90function baseClone(value, bitmask, customizer, key, object, stack) {
91  var result,
92      isDeep = bitmask & CLONE_DEEP_FLAG,
93      isFlat = bitmask & CLONE_FLAT_FLAG,
94      isFull = bitmask & CLONE_SYMBOLS_FLAG;
95
96  if (customizer) {
97    result = object ? customizer(value, key, object, stack) : customizer(value);
98  }
99  if (result !== undefined) {
100    return result;
101  }
102  if (!isObject(value)) {
103    return value;
104  }
105  var isArr = isArray(value);
106  if (isArr) {
107    result = initCloneArray(value);
108    if (!isDeep) {
109      return copyArray(value, result);
110    }
111  } else {
112    var tag = getTag(value),
113        isFunc = tag == funcTag || tag == genTag;
114
115    if (isBuffer(value)) {
116      return cloneBuffer(value, isDeep);
117    }
118    if (tag == objectTag || tag == argsTag || (isFunc && !object)) {
119      result = (isFlat || isFunc) ? {} : initCloneObject(value);
120      if (!isDeep) {
121        return isFlat
122          ? copySymbolsIn(value, baseAssignIn(result, value))
123          : copySymbols(value, baseAssign(result, value));
124      }
125    } else {
126      if (!cloneableTags[tag]) {
127        return object ? value : {};
128      }
129      result = initCloneByTag(value, tag, isDeep);
130    }
131  }
132  // Check for circular references and return its corresponding clone.
133  stack || (stack = new Stack);
134  var stacked = stack.get(value);
135  if (stacked) {
136    return stacked;
137  }
138  stack.set(value, result);
139
140  if (isSet(value)) {
141    value.forEach(function(subValue) {
142      result.add(baseClone(subValue, bitmask, customizer, subValue, value, stack));
143    });
144  } else if (isMap(value)) {
145    value.forEach(function(subValue, key) {
146      result.set(key, baseClone(subValue, bitmask, customizer, key, value, stack));
147    });
148  }
149
150  var keysFunc = isFull
151    ? (isFlat ? getAllKeysIn : getAllKeys)
152    : (isFlat ? keysIn : keys);
153
154  var props = isArr ? undefined : keysFunc(value);
155  arrayEach(props || value, function(subValue, key) {
156    if (props) {
157      key = subValue;
158      subValue = value[key];
159    }
160    // Recursively populate clone (susceptible to call stack limits).
161    assignValue(result, key, baseClone(subValue, bitmask, customizer, key, value, stack));
162  });
163  return result;
164}
165
166module.exports = baseClone;
167