Iavra Respawn

/*:
 * @plugindesc A simple respawn mechanic, that revives the player and teleports them to a specific point after death.
 * <Iavra Respawn>
 * @author Iavra
 *
 * @param Variable Id
 * @desc Id of the variable to be used to store the lives of the player. If it is 0 or less, the player can't respawn.
 * @default 1
 *
 * @param Notetag
 * @desc Tag to be used in map descriptions, that defines the respawn point for the player.
 * @default respawn
 *
 * @param Window Position
 * @desc Y coordinate of the command window displayed during the gameover scene. It will be horizontally centered.
 * @default 400
 *
 * @param Label Retry
 * @desc Text to be displayed for the "Retry" option. {retries} will be replaced with the number or retries available.
 * @default Retry ({retries} left)
 *
 * @param Label Title
 * @desc Text to be displayed for the "To Title" option.
 * @default To Title
 *
 * @help
 * On gameover, a window will be displayed, that lets the player decide between going back to title and respawning.
 * Respawn is only available, if the number of retries is higher than 0. The current number of retries is stored in a
 * variable indicated by the parameter "Variable Id".
 *
 * On respawn, all actors are healed to full and the player is transfered to a location indicated by a notetag in the
 * map notebox. The tag can be used with 2 or 3 parameters:
 *
 * <respawn mapId x y>     Teleports the player to the given position on the given map.
 * <respawn x y>           Teleports the player to the given position on the current map.
 *
 * You can register custom callbacks to be executed on respawn with the following function:
 *
 * IAVRA.RESPAWN.registerCallback(fn);
 */

var IAVRA = IAVRA || {};

(function($) {
    "use strict";

    /**
     * Retrieve plugin parameters independent from the plugin's actual filename.
     */
    var _params = $plugins.filter(function(p) { return p.description.contains('<Iavra Respawn>'); })[0].parameters;
    var _param_variableId = parseInt(_params['Variable Id']) || 0;
    var _param_notetag = _params['Notetag'];
    var _param_position = parseInt(_params['Window Position']) || 0;
    var _param_labelRetry = _params['Label Retry'];
    var _param_labelTitle = _params['Label Title'];

    /**
     * Regex used to read notetags from map notes. Will only recognize the first occurence of the note.
     */
    var _regex = new RegExp('<' + _param_notetag + '[ ]+(\\d+)[ ]+(\\d+)(?:[ ]+(\\d+))?>');

    /**
     * Returns the current number of respawns available.
     */
    var _numRetries = function() { return Math.max($gameVariables.value(_param_variableId), 0); };

    /**
     * On retry, reduce the number of respawns available and execute all registered callbacks.
     */
    var _retry = function() {
        $gameVariables.setValue(_param_variableId, Math.max($gameVariables.value(_param_variableId) - 1, 0));
        $.RESPAWN.callbacks.forEach(function(callback) { callback(); });
    };

    //=============================================================================
    // IAVRA.RESPAWN
    //=============================================================================

    $.RESPAWN = {
        /**
         * Stores all callbacks, that should be executed on respawn.
         */
        callbacks: [],
        /**
         * Registers a new callbacks, to be executed on respawn.
         */
        registerCallback: function(c) { this.callbacks.push(c); },
        /**
         * Removes a registered callbacks.
         */
        removeCallback: function(c) { var i = this.callbacks.indexOf(c); if(i > -1) { this.callbacks.splice(i, 1); } },
        /**
         * The window, that gets displayed during Scene_Gameover to select between respawn and going back to title.
         */
        Window_Retry: function() { this.initialize.apply(this, arguments); }
    };

    //=============================================================================
    // IAVRA.RESPAWN.Window_Retry
    //=============================================================================

    (function($) {

        ($.prototype = Object.create(Window_Command.prototype)).constructor = $;

        /**
         * The window is horizontally centered and starts closed, so it can be opened when starting the scene.
         */
        $.prototype.initialize = function() {
            Window_Command.prototype.initialize.call(this, 0, _param_position);
            this.x = (Graphics.boxWidth - this.width) / 2;
            this.openness = 0;
        };

        /**
         * The windows has 2 commands, one of which gets disabled if no retries are available to the player.
         */
        $.prototype.makeCommandList = function() {
            this.addCommand(_param_labelRetry.replace('{retries}', _numRetries()), 'retry', _numRetries() > 0);
            this.addCommand(_param_labelTitle, 'title', true);
        };

    })($.RESPAWN.Window_Retry);

    //=============================================================================
    // Scene_Gameover
    //=============================================================================

    (function($) {

        /**
         * Add our window to Scene_Gameover and set the command handlers.
         */
        var alias_create = $.prototype.create;
        $.prototype.create = function() {
            alias_create.call(this);
            this.addChild(this._iavra_retry_commandWindow = new IAVRA.RESPAWN.Window_Retry());
            this._iavra_retry_commandWindow.setHandler('retry', _retry.bind(this));
            this._iavra_retry_commandWindow.setHandler('title', this.gotoTitle.bind(this));
        };

        /**
         * On start, open the window for a little extra effect.
         */
        var alias_start = $.prototype.start;
        $.prototype.start = function() {
            alias_start.call(this);
            this._iavra_retry_commandWindow.open();
        };

        /**
         * If we wouldn't overwrite this, the scene would end as soon, as the user presses a button.
         */
        $.prototype.isTriggered = function() { return false; };

    })(Scene_Gameover);

    //=============================================================================
    // register basic callbacks
    //=============================================================================

    /**
     * On retry, recover all actors to full.
     */
    $.RESPAWN.registerCallback(function() { $gameParty.members().forEach(function(actor) { actor.recoverAll(); }); });

    /**
     * On retry, teleport the player to the given location, as indicated by the map notetag. If no tag is present, the
     * current player location is used, instead.
     */
    $.RESPAWN.registerCallback(function() {
        var match = !$dataMap ? null : _regex.exec($dataMap.note);
        if(match) {
            if(match[3] !== undefined) { $gamePlayer.reserveTransfer(match[1]|0, match[2]|0, match[3]|0, null, 0); }
            else { $gamePlayer.reserveTransfer($gameMap.mapId(), match[1]|0, match[2]|0, null, 0); }
        };
        SceneManager.goto(Scene_Map);
    });

})(IAVRA);