//-----------------------------------------------------------------------------
// Window_ScrollText
//
// The window for displaying scrolling text. No frame is displayed, but it
// is handled as a window for convenience.
/**
 * The window for displaying scrolling text. No frame is displayed, but it is handled as a window for convenience.
 *
 * @class
 * @extends Window_Base
 */
function Window_ScrollText() {
    this.initialize(...arguments);
}

Window_ScrollText.prototype = Object.create(Window_Base.prototype);
Window_ScrollText.prototype.constructor = Window_ScrollText;

Window_ScrollText.prototype.initialize = function(rect) {
    Window_Base.prototype.initialize.call(this, new Rectangle());
    this.opacity = 0;
    this.hide();
    this._reservedRect = rect;
    this._text = "";
    this._maxBitmapHeight = 2048;
    this._allTextHeight = 0;
    this._blockHeight = 0;
    this._blockIndex = 0;
    this._scrollY = 0;
};

Window_ScrollText.prototype.update = function() {
    Window_Base.prototype.update.call(this);
    if ($gameMessage.scrollMode()) {
        if (this._text) {
            this.updateMessage();
        }
        if (!this._text && $gameMessage.hasText()) {
            this.startMessage();
        }
    }
};

/**
 * Starts the message
 */
Window_ScrollText.prototype.startMessage = function() {
    this._text = $gameMessage.allText();
    if (this._text) {
        this.updatePlacement();
        this._allTextHeight = this.textSizeEx(this._text).height;
        this._blockHeight = this._maxBitmapHeight - this.height;
        this._blockIndex = 0;
        this.origin.y = this._scrollY = -this.height;
        this.createContents();
        this.refresh();
        this.show();
    } else {
        $gameMessage.clear();
    }
};

/**
 * Refreshes the window
 */
Window_ScrollText.prototype.refresh = function() {
    const rect = this.baseTextRect();
    const y = rect.y - this._scrollY + (this._scrollY % this._blockHeight);
    this.contents.clear();
    this.drawTextEx(this._text, rect.x, y, rect.width);
};

/**
 * Updates the placement of the window
 */
Window_ScrollText.prototype.updatePlacement = function() {
    const rect = this._reservedRect;
    this.move(rect.x, rect.y, rect.width, rect.height);
};

/**
 * Gets the height of the window contents
 *
 * @return {number} The height of the contents of the window
 */
Window_ScrollText.prototype.contentsHeight = function() {
    if (this._allTextHeight > 0) {
        return Math.min(this._allTextHeight, this._maxBitmapHeight);
    } else {
        return 0;
    }
};

/**
 * Updates the message
 */
Window_ScrollText.prototype.updateMessage = function() {
    this._scrollY += this.scrollSpeed();
    if (this._scrollY >= this._allTextHeight) {
        this.terminateMessage();
    } else {
        const blockIndex = Math.floor(this._scrollY / this._blockHeight);
        if (blockIndex > this._blockIndex) {
            this._blockIndex = blockIndex;
            this.refresh();
        }
        this.origin.y = this._scrollY % this._blockHeight;
    }
};

/**
 * Gets the speed of the scroll effect
 *
 * @return {number} The speed of the scroll effect
 */
Window_ScrollText.prototype.scrollSpeed = function() {
    let speed = $gameMessage.scrollSpeed() / 2;
    if (this.isFastForward()) {
        speed *= this.fastForwardRate();
    }
    return speed;
};

/**
 * Checks if the window should fast forward
 *
 * @return {boolean} True if the window should fast forward
 */
Window_ScrollText.prototype.isFastForward = function() {
    if ($gameMessage.scrollNoFast()) {
        return false;
    } else {
        return (
            Input.isPressed("ok") ||
            Input.isPressed("shift") ||
            TouchInput.isPressed()
        );
    }
};

/**
 * Gets the rate of the fast forward
 *
 * @return {number} The fast forward rate
 */
Window_ScrollText.prototype.fastForwardRate = function() {
    return 3;
};

/**
 * Ends the message
 */
Window_ScrollText.prototype.terminateMessage = function() {
    this._text = null;
    $gameMessage.clear();
    this.hide();
};