//=============================================================================
// SnakeFollower.js
// ----------------------------------------------------------------------------
// Copyright (c) 2015-2017 Triacontane
// This software is released under the MIT License.
// http://opensource.org/licenses/mit-license.php
// ----------------------------------------------------------------------------
// Version
// 1.0.0 2017/09/26 初版
// ----------------------------------------------------------------------------
// [Blog]   : https://triacontane.blogspot.jp/
// [Twitter]: https://twitter.com/triacontane/
// [GitHub] : https://github.com/triacontane/
//=============================================================================

/*:
@url https://triacontane.blogspot.com/
@plugindesc Snake Follower Plugin
@author Triacontane
@license MIT License

@help
English Help Translator: munokura
This is an unofficial English translation of the plugin help,
created to support global RPG Maker users.
Feedback is welcome to improve translation quality
(see: https://github.com/munokura/triacontane-MV-plugins ).
Original plugin by Triacontane.
Please check the latest official version at:
https://triacontane.blogspot.com
-----
SnakeFollower.js

Prevents followers and players from overlapping.
Can be used to implement snake games.

This plugin does not have any plugin commands.

Terms of Use:
You may modify and redistribute this plugin without permission from the
author, and there are no restrictions on its use (commercial, 18+, etc.).
This plugin is now yours.

@param 有効スイッチID
@text Valid Switch ID
@desc The switch number that enables the plugin function. If you specify 0, it will always be enabled.
@type switch
@default 0
*/

/*:ja
@plugindesc スネークフォロワープラグイン
@author トリアコンタン

@param 有効スイッチID
@desc プラグインの機能が有効になるスイッチ番号です。0を指定すると常に有効となります。
@default 0
@type switch

@help SnakeFollower.js

フォロワーとプレイヤーが重なることができなくなります。
スネークゲームの実装に使えます。

このプラグインにはプラグインコマンドはありません。

利用規約：
 作者に無断で改変、再配布が可能で、利用形態（商用、18禁利用等）
 についても制限はありません。
 このプラグインはもうあなたのものです。
*/

(function () {
    'use strict';
    var pluginName = 'SnakeFollower';

    //=============================================================================
    // ローカル関数
    //  プラグインパラメータやプラグインコマンドパラメータの整形やチェックをします
    //=============================================================================
    var getParamString = function (paramNames) {
        if (!Array.isArray(paramNames)) paramNames = [paramNames];
        for (var i = 0; i < paramNames.length; i++) {
            var name = PluginManager.parameters(pluginName)[paramNames[i]];
            if (name) return name;
        }
        alert('Fail to load plugin parameter of ' + pluginName);
        return null;
    };

    var getParamNumber = function (paramNames, min, max) {
        var value = getParamString(paramNames);
        if (arguments.length < 2) min = -Infinity;
        if (arguments.length < 3) max = Infinity;
        return (parseInt(value) || 0).clamp(min, max);
    };

    //=============================================================================
    // パラメータの取得と整形
    //=============================================================================
    var param = {};
    param.validateSwitchId = getParamNumber(['ValidateSwitchId', '有効スイッチID'], 0);

    var _Game_Player_isCollidedWithCharacters = Game_Player.prototype.isCollidedWithCharacters;
    Game_Player.prototype.isCollidedWithCharacters = function (x, y) {
        return _Game_Player_isCollidedWithCharacters.apply(this, arguments) || this.isCollidedWithFollowers(x, y);
    };

    Game_Player.prototype.isCollidedWithFollowers = function (x, y) {
        return this.isValidSnake() && this._followers.isSomeoneCollided(x, y) && !this.isThrough();
    };

    Game_Player.prototype.isValidSnake = function (x, y) {
        return param.validateSwitchId === 0 || $gameSwitches.value(param.validateSwitchId);
    };
})();