var toStringFunction = Function.prototype.toString;
var create = Object.create;
var toStringObject = Object.prototype.toString;
/**
 * @classdesc Fallback cache for when WeakMap is not natively supported
 */
var LegacyCache = /** @class */ (function () {
    function LegacyCache() {
        this._keys = [];
        this._values = [];
    }
    LegacyCache.prototype.has = function (key) {
        return !!~this._keys.indexOf(key);
    };
    LegacyCache.prototype.get = function (key) {
        return this._values[this._keys.indexOf(key)];
    };
    LegacyCache.prototype.set = function (key, value) {
        this._keys.push(key);
        this._values.push(value);
    };
    return LegacyCache;
}());
function createCacheLegacy() {
    return new LegacyCache();
}
function createCacheModern() {
    return new WeakMap();
}
/**
 * Get a new cache object to prevent circular references.
 */
var createCache = typeof WeakMap !== 'undefined' ? createCacheModern : createCacheLegacy;
/**
 * Get an empty version of the object with the same prototype it has.
 */
function getCleanClone(prototype) {
    if (!prototype) {
        return create(null);
    }
    var Constructor = prototype.constructor;
    if (Constructor === Object) {
        return prototype === Object.prototype ? {} : create(prototype);
    }
    if (~toStringFunction.call(Constructor).indexOf('[native code]')) {
        try {
            return new Constructor();
        }
        catch (_a) { }
    }
    return create(prototype);
}
function getRegExpFlagsLegacy(regExp) {
    var flags = '';
    if (regExp.global) {
        flags += 'g';
    }
    if (regExp.ignoreCase) {
        flags += 'i';
    }
    if (regExp.multiline) {
        flags += 'm';
    }
    if (regExp.unicode) {
        flags += 'u';
    }
    if (regExp.sticky) {
        flags += 'y';
    }
    return flags;
}
function getRegExpFlagsModern(regExp) {
    return regExp.flags;
}
/**
 * Get the flags to apply to the copied regexp.
 */
var getRegExpFlags = /test/g.flags === 'g' ? getRegExpFlagsModern : getRegExpFlagsLegacy;
function getTagLegacy(value) {
    var type = toStringObject.call(value);
    return type.substring(8, type.length - 1);
}
function getTagModern(value) {
    return value[Symbol.toStringTag] || getTagLegacy(value);
}
/**
 * Get the tag of the value passed, so that the correct copier can be used.
 */
var getTag = typeof Symbol !== 'undefined' ? getTagModern : getTagLegacy;

var defineProperty = Object.defineProperty, getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor, getOwnPropertyNames = Object.getOwnPropertyNames, getOwnPropertySymbols = Object.getOwnPropertySymbols;
var _a = Object.prototype, hasOwnProperty = _a.hasOwnProperty, propertyIsEnumerable = _a.propertyIsEnumerable;
var SUPPORTS_SYMBOL = typeof getOwnPropertySymbols === 'function';
function getStrictPropertiesModern(object) {
    return getOwnPropertyNames(object).concat(getOwnPropertySymbols(object));
}
/**
 * Get the properites used when copying objects strictly. This includes both keys and symbols.
 */
var getStrictProperties = SUPPORTS_SYMBOL
    ? getStrictPropertiesModern
    : getOwnPropertyNames;
/**
 * Striclty copy all properties contained on the object.
 */
function copyOwnPropertiesStrict(value, clone, state) {
    var properties = getStrictProperties(value);
    for (var index = 0, length_1 = properties.length, property = void 0, descriptor = void 0; index < length_1; ++index) {
        property = properties[index];
        if (property === 'callee' || property === 'caller') {
            continue;
        }
        descriptor = getOwnPropertyDescriptor(value, property);
        if (!descriptor) {
            // In extra edge cases where the property descriptor cannot be retrived, fall back to
            // the loose assignment.
            clone[property] = state.copier(value[property], state);
            continue;
        }
        // Only clone the value if actually a value, not a getter / setter.
        if (!descriptor.get && !descriptor.set) {
            descriptor.value = state.copier(descriptor.value, state);
        }
        try {
            defineProperty(clone, property, descriptor);
        }
        catch (error) {
            // Tee above can fail on node in edge cases, so fall back to the loose assignment.
            clone[property] = descriptor.value;
        }
    }
    return clone;
}
/**
 * Deeply copy the indexed values in the array.
 */
function copyArrayLoose(array, state) {
    var clone = new state.Constructor();
    // set in the cache immediately to be able to reuse the object recursively
    state.cache.set(array, clone);
    for (var index = 0, length_2 = array.length; index < length_2; ++index) {
        clone[index] = state.copier(array[index], state);
    }
    return clone;
}
/**
 * Deeply copy the indexed values in the array, as well as any custom properties.
 */
function copyArrayStrict(array, state) {
    var clone = new state.Constructor();
    // set in the cache immediately to be able to reuse the object recursively
    state.cache.set(array, clone);
    return copyOwnPropertiesStrict(array, clone, state);
}
/**
 * Copy the contents of the ArrayBuffer.
 */
function copyArrayBuffer(arrayBuffer, _state) {
    return arrayBuffer.slice(0);
}
/**
 * Create a new Blob with the contents of the original.
 */
function copyBlob(blob, _state) {
    return blob.slice(0, blob.size, blob.type);
}
/**
 * Create a new DataView with the contents of the original.
 */
function copyDataView(dataView, state) {
    return new state.Constructor(copyArrayBuffer(dataView.buffer));
}
/**
 * Create a new Date based on the time of the original.
 */
function copyDate(date, state) {
    return new state.Constructor(date.getTime());
}
/**
 * Deeply copy the keys and values of the original.
 */
function copyMapLoose(map, state) {
    var clone = new state.Constructor();
    // set in the cache immediately to be able to reuse the object recursively
    state.cache.set(map, clone);
    map.forEach(function (value, key) {
        clone.set(key, state.copier(value, state));
    });
    return clone;
}
/**
 * Deeply copy the keys and values of the original, as well as any custom properties.
 */
function copyMapStrict(map, state) {
    return copyOwnPropertiesStrict(map, copyMapLoose(map, state), state);
}
function copyObjectLooseLegacy(object, state) {
    var clone = getCleanClone(state.prototype);
    // set in the cache immediately to be able to reuse the object recursively
    state.cache.set(object, clone);
    for (var key in object) {
        if (hasOwnProperty.call(object, key)) {
            clone[key] = state.copier(object[key], state);
        }
    }
    return clone;
}
function copyObjectLooseModern(object, state) {
    var clone = getCleanClone(state.prototype);
    // set in the cache immediately to be able to reuse the object recursively
    state.cache.set(object, clone);
    for (var key in object) {
        if (hasOwnProperty.call(object, key)) {
            clone[key] = state.copier(object[key], state);
        }
    }
    var symbols = getOwnPropertySymbols(object);
    for (var index = 0, length_3 = symbols.length, symbol = void 0; index < length_3; ++index) {
        symbol = symbols[index];
        if (propertyIsEnumerable.call(object, symbol)) {
            clone[symbol] = state.copier(object[symbol], state);
        }
    }
    return clone;
}
/**
 * Deeply copy the properties (keys and symbols) and values of the original.
 */
var copyObjectLoose = SUPPORTS_SYMBOL
    ? copyObjectLooseModern
    : copyObjectLooseLegacy;
/**
 * Deeply copy the properties (keys and symbols) and values of the original, as well
 * as any hidden or non-enumerable properties.
 */
function copyObjectStrict(object, state) {
    var clone = getCleanClone(state.prototype);
    // set in the cache immediately to be able to reuse the object recursively
    state.cache.set(object, clone);
    return copyOwnPropertiesStrict(object, clone, state);
}
/**
 * Create a new primitive wrapper from the value of the original.
 */
function copyPrimitiveWrapper(primitiveObject, state) {
    return new state.Constructor(primitiveObject.valueOf());
}
/**
 * Create a new RegExp based on the value and flags of the original.
 */
function copyRegExp(regExp, state) {
    var clone = new state.Constructor(regExp.source, getRegExpFlags(regExp));
    clone.lastIndex = regExp.lastIndex;
    return clone;
}
/**
 * Return the original value (an identity function).
 *
 * @note
 * THis is used for objects that cannot be copied, such as WeakMap.
 */
function copySelf(value, _state) {
    return value;
}
/**
 * Deeply copy the values of the original.
 */
function copySetLoose(set, state) {
    var clone = new state.Constructor();
    // set in the cache immediately to be able to reuse the object recursively
    state.cache.set(set, clone);
    set.forEach(function (value) {
        clone.add(state.copier(value, state));
    });
    return clone;
}
/**
 * Deeply copy the values of the original, as well as any custom properties.
 */
function copySetStrict(set, state) {
    return copyOwnPropertiesStrict(set, copySetLoose(set, state), state);
}

var isArray = Array.isArray;
var assign = Object.assign;
var getPrototypeOf = Object.getPrototypeOf || (function (obj) { return obj.__proto__; });
var DEFAULT_LOOSE_OPTIONS = {
    array: copyArrayLoose,
    arrayBuffer: copyArrayBuffer,
    blob: copyBlob,
    dataView: copyDataView,
    date: copyDate,
    error: copySelf,
    map: copyMapLoose,
    object: copyObjectLoose,
    regExp: copyRegExp,
    set: copySetLoose,
};
var DEFAULT_STRICT_OPTIONS = assign({}, DEFAULT_LOOSE_OPTIONS, {
    array: copyArrayStrict,
    map: copyMapStrict,
    object: copyObjectStrict,
    set: copySetStrict,
});
/**
 * Get the copiers used for each specific object tag.
 */
function getTagSpecificCopiers(options) {
    return {
        Arguments: options.object,
        Array: options.array,
        ArrayBuffer: options.arrayBuffer,
        Blob: options.blob,
        Boolean: copyPrimitiveWrapper,
        DataView: options.dataView,
        Date: options.date,
        Error: options.error,
        Float32Array: options.arrayBuffer,
        Float64Array: options.arrayBuffer,
        Int8Array: options.arrayBuffer,
        Int16Array: options.arrayBuffer,
        Int32Array: options.arrayBuffer,
        Map: options.map,
        Number: copyPrimitiveWrapper,
        Object: options.object,
        Promise: copySelf,
        RegExp: options.regExp,
        Set: options.set,
        String: copyPrimitiveWrapper,
        WeakMap: copySelf,
        WeakSet: copySelf,
        Uint8Array: options.arrayBuffer,
        Uint8ClampedArray: options.arrayBuffer,
        Uint16Array: options.arrayBuffer,
        Uint32Array: options.arrayBuffer,
        Uint64Array: options.arrayBuffer,
    };
}
/**
 * Create a custom copier based on the object-specific copy methods passed.
 */
function createCopier(options) {
    var normalizedOptions = assign({}, DEFAULT_LOOSE_OPTIONS, options);
    var tagSpecificCopiers = getTagSpecificCopiers(normalizedOptions);
    var array = tagSpecificCopiers.Array, object = tagSpecificCopiers.Object;
    function copier(value, state) {
        state.prototype = state.Constructor = undefined;
        if (!value || typeof value !== 'object') {
            return value;
        }
        if (state.cache.has(value)) {
            return state.cache.get(value);
        }
        state.prototype = getPrototypeOf(value);
        state.Constructor = state.prototype && state.prototype.constructor;
        // plain objects
        if (!state.Constructor || state.Constructor === Object) {
            return object(value, state);
        }
        // arrays
        if (isArray(value)) {
            return array(value, state);
        }
        var tagSpecificCopier = tagSpecificCopiers[getTag(value)];
        if (tagSpecificCopier) {
            return tagSpecificCopier(value, state);
        }
        return typeof value.then === 'function' ? value : object(value, state);
    }
    return function copy(value) {
        return copier(value, {
            Constructor: undefined,
            cache: createCache(),
            copier: copier,
            prototype: undefined,
        });
    };
}
/**
 * Create a custom copier based on the object-specific copy methods passed, defaulting to the
 * same internals as `copyStrict`.
 */
function createStrictCopier(options) {
    return createCopier(assign({}, DEFAULT_STRICT_OPTIONS, options));
}
/**
 * Copy an value deeply as much as possible, where strict recreation of object properties
 * are maintained. All properties (including non-enumerable ones) are copied with their
 * original property descriptors on both objects and arrays.
 */
var copyStrict = createStrictCopier({});
/**
 * Copy an value deeply as much as possible.
 */
var index = createCopier({});

export { copyStrict, createCopier, createStrictCopier, index as default };
//# sourceMappingURL=index.mjs.map