/*
 * Copyright (C)2005-2019 Haxe Foundation
 *
 * 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 OR COPYRIGHT HOLDERS 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.
 */

package haxe.ds;

@:coreApi class StringMap<T> implements haxe.Constraints.IMap<String, T> {
	private var h:Dynamic;
	private var rh:Dynamic;

	static var reserved = {};

	public function new():Void {
		h = {};
	}

	inline function isReserved(key:String):Bool {
		return untyped __in__(key, reserved);
	}

	public inline function set(key:String, value:T):Void {
		if (isReserved(key))
			setReserved(key, value);
		else
			untyped h[key] = value;
	}

	public inline function get(key:String):Null<T> {
		if (isReserved(key))
			return getReserved(key);
		return untyped h[key];
	}

	public inline function exists(key:String):Bool {
		if (isReserved(key))
			return existsReserved(key);
		return untyped __in__(key, h);
	}

	function setReserved(key:String, value:T):Void {
		if (rh == null)
			rh = {};
		untyped rh["$" + key] = value;
	}

	function getReserved(key:String):Null<T> {
		return rh == null ? null : untyped rh["$" + key];
	}

	function existsReserved(key:String):Bool {
		if (rh == null)
			return false;
		return untyped __in__("$" + key, rh);
	}

	public function remove(key:String):Bool {
		if (isReserved(key)) {
			key = "$" + key;
			if (rh == null || !untyped __in__(key, rh))
				return false;
			untyped __delete__(rh, key);
			return true;
		} else {
			if (!untyped __in__(key, h))
				return false;
			untyped __delete__(h, key);
			return true;
		}
	}

	public inline function keys():Iterator<String> {
		return new StringMapKeysIterator(h, rh);
	}

	public inline function iterator():Iterator<T> {
		return new StringMapValuesIterator<T>(h, rh);
	}

	@:runtime public inline function keyValueIterator():KeyValueIterator<String, T> {
		return new haxe.iterators.MapKeyValueIterator(this);
	}

	public function copy():StringMap<T> {
		var copied = new StringMap();
		for (key in keys())
			copied.set(key, get(key));
		return copied;
	}

	public function toString():String {
		var s = new StringBuf();
		s.add("[");
		var it = keys();
		for (i in it) {
			s.add(i);
			s.add(" => ");
			s.add(Std.string(get(i)));
			if (it.hasNext())
				s.add(", ");
		}
		s.add("]");
		return s.toString();
	}

	public inline function clear():Void {
		h = {};
		rh = null;
	}
	
	public function size():Int {
		var s = 0;
		for(_ in keys()) s++;
		return s;
	}
}

// this version uses __has_next__/__forin__ special SWF opcodes for iteration with no allocation

@:allow(haxe.ds.StringMap)
private class StringMapKeysIterator {
	var h:Dynamic;
	var rh:Dynamic;
	var index:Int;
	var nextIndex:Int;
	var isReserved:Bool;

	inline function new(h:Dynamic, rh:Dynamic):Void {
		this.h = h;
		this.rh = rh;
		this.index = 0;
		isReserved = false;
		hasNext();
	}

	public inline function hasNext():Bool {
		var h = h, index = index; // tmp vars required for __has_next
		var n = untyped __has_next__(h, index);
		if (!n && rh != null) {
			h = this.h = rh;
			index = this.index = 0;
			rh = null;
			isReserved = true;
			n = untyped __has_next__(h, index);
		}
		this.nextIndex = index; // store next index
		return n;
	}

	public inline function next():String {
		var r:String = untyped __forin__(h, nextIndex);
		index = nextIndex;
		if (isReserved)
			r = r.substr(1);
		return r;
	}
}

@:allow(haxe.ds.StringMap)
private class StringMapValuesIterator<T> {
	var h:Dynamic;
	var rh:Dynamic;
	var index:Int;
	var nextIndex:Int;

	inline function new(h:Dynamic, rh:Dynamic):Void {
		this.h = h;
		this.rh = rh;
		this.index = 0;
		hasNext();
	}

	public inline function hasNext():Bool {
		var h = h, index = index; // tmp vars required for __has_next
		var n = untyped __has_next__(h, index);
		if (!n && rh != null) {
			h = this.h = rh;
			index = this.index = 0;
			rh = null;
			n = untyped __has_next__(h, index);
		}
		this.nextIndex = index; // store next index
		return n;
	}

	public inline function next():T {
		var r = untyped __foreach__(h, nextIndex);
		index = nextIndex;
		return r;
	}
}
