"use strict";

var customError      = require("es5-ext/error/custom")
  , defineLength     = require("es5-ext/function/_define-length")
  , partial          = require("es5-ext/function/#/partial")
  , copy             = require("es5-ext/object/copy")
  , normalizeOpts    = require("es5-ext/object/normalize-options")
  , callable         = require("es5-ext/object/valid-callable")
  , d                = require("d")
  , WeakMap          = require("es6-weak-map")
  , resolveLength    = require("./resolve-length")
  , extensions       = require("./registered-extensions")
  , resolveResolve   = require("./resolve-resolve")
  , resolveNormalize = require("./resolve-normalize");

var slice = Array.prototype.slice, defineProperties = Object.defineProperties;

module.exports = function (memoize) {
	return function (fn /*, options*/) {
		var map, length, options = normalizeOpts(arguments[1]), memoized, resolve, normalizer;

		callable(fn);

		// Do not memoize already memoized function
		if (hasOwnProperty.call(fn, "__memoized__") && !options.force) return fn;

		length = resolveLength(options.length, fn.length, options.async && extensions.async);
		options.length = length ? length - 1 : 0;
		map = new WeakMap();

		if (options.resolvers) resolve = resolveResolve(options.resolvers);
		if (options.normalizer) normalizer = resolveNormalize(options.normalizer);

		if (
			length === 1 &&
			!normalizer &&
			!options.async &&
			!options.dispose &&
			!options.maxAge &&
			!options.max &&
			!options.refCounter
		) {
			return defineProperties(
				function (obj) {
					var result, args = arguments;
					if (resolve) args = resolve(args);
					obj = args[0];
					if (map.has(obj)) return map.get(obj);
					result = fn.apply(this, args);
					if (map.has(obj)) {
						throw customError("Circular invocation", "CIRCULAR_INVOCATION");
					}
					map.set(obj, result);
					return result;
				},
				{
					__memoized__: d(true),
					delete: d(function (obj) {
						if (resolve) obj = resolve(arguments)[0];
						return map.delete(obj);
					})
				}
			);
		}
		memoized = defineProperties(
			defineLength(function (obj) {
				var memoizer, args = arguments;
				if (resolve) {
					args = resolve(args);
					obj = args[0];
				}
				memoizer = map.get(obj);
				if (!memoizer) {
					if (normalizer) {
						options = copy(options);
						options.normalizer = copy(normalizer);
						options.normalizer.get = partial.call(options.normalizer.get, obj);
						options.normalizer.set = partial.call(options.normalizer.set, obj);
						if (options.normalizer.delete) {
							options.normalizer.delete = partial.call(
								options.normalizer.delete,
								obj
							);
						}
					}
					map.set(obj, memoizer = memoize(partial.call(fn, obj), options));
				}
				return memoizer.apply(this, slice.call(args, 1));
			}, length),
			{
				__memoized__: d(true),
				delete: d(
					defineLength(function (obj) {
						var memoizer, args = arguments;
						if (resolve) {
							args = resolve(args);
							obj = args[0];
						}
						memoizer = map.get(obj);
						if (!memoizer) return;
						memoizer.delete.apply(this, slice.call(args, 1));
					}, length)
				)
			}
		);
		if (!options.refCounter) return memoized;
		defineProperties(memoized, {
			deleteRef: d(
				defineLength(function (obj) {
					var memoizer, args = arguments;
					if (resolve) {
						args = resolve(args);
						obj = args[0];
					}
					memoizer = map.get(obj);
					if (!memoizer) return null;
					return memoizer.deleteRef.apply(this, slice.call(args, 1));
				}, length)
			),
			getRefCount: d(
				defineLength(function (obj) {
					var memoizer, args = arguments;
					if (resolve) {
						args = resolve(args);
						obj = args[0];
					}
					memoizer = map.get(obj);
					if (!memoizer) return 0;
					return memoizer.getRefCount.apply(this, slice.call(args, 1));
				}, length)
			)
		});
		return memoized;
	};
};