import com.badlogic.gdx.Input;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.InputListener;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.Touchable;
import com.badlogic.gdx.scenes.scene2d.ui.Skin;
import com.badlogic.gdx.scenes.scene2d.ui.Table;
import com.badlogic.gdx.scenes.scene2d.utils.Align;
import com.badlogic.gdx.scenes.scene2d.utils.Drawable;

/**
 * This is very much like a regular Table, although it has some extra features.
 * It is movable on a Stage, and can be resized by dragging.
 * It can also act modal if needed, and be locked to be inside of the Stage if needed.
 *
 * This is basicly Window from scene2d.ui, with a few modifications.
 *
 * @author Mads Peter Horndrup
 */
public class MovableTable extends Table {

    /** Different flags to define different behaviors */
    private boolean isModal, isResizable, isMovable;

    /** Maximum pixels from the border where the MovableWindow can be resized */
    private int resizeBorder = 8;

    /** Are we currently resizing or moving the MovableWindow?? */
    private boolean dragging;

    /** Should we make sure the MovableWindow stays inside the Viewport?? */
    private boolean keepWithinStage;

    /** What Actors allow the MovableWindow to be dragged */
    protected Actor[] dragActors;

    private MovableTableStyle style;

    /** Used to indicate that side of the MovableWindow that is being resized, and if it's being moved */
    static private final int MOVE = 1 << 5;

    public MovableTable(Skin skin) {
        this(skin.get(MovableTableStyle.class));
        setSkin(skin);
    }

    public MovableTable(Skin skin, String styleName) {
        this(skin.get(styleName, MovableTableStyle.class));
        setSkin(skin);
    }

    public MovableTable(MovableTableStyle closeableWindowStyle) {
        setTouchable(Touchable.enabled);
        setClip(true);
        setStyle(closeableWindowStyle);
        setWidth(150);
        setHeight(150);
        setMovable(true);
        setResizable(false);
        setKeepWithinStage(true);

        dragActors = new Actor[1];
        dragActors[0] = this;

        addCaptureListener(new InputListener() {
            public boolean touchDown(InputEvent event, float x, float y,
                    int pointer, int button) {
                toFront();
                return false;
            }
        });
        addListener(new InputListener() {
            int edge;
            float startX, startY, lastX, lastY;

            public boolean touchDown(InputEvent event, float x, float y,
                    int pointer, int button) {
                Actor hitActor = hit(x,y,true);
                boolean success = false;
                for (Actor a : getDraggableRegions()) {
                    if (hitActor.equals(a)) {
                        success = true;
                    }
                }
                if (!success) {
                    return false;
                }
                if (button == Input.Buttons.LEFT) {
                    int border = resizeBorder;
                    float width = getWidth(), height = getHeight();
                    edge = 0;
                    if (isResizable) {
                        if (x < border)
                            edge |= Align.left;
                        if (x > width - border)
                            edge |= Align.right;
                        if (y < border)
                            edge |= Align.bottom;
                        if (y > height - border)
                            edge |= Align.top;
                        if (edge != 0)
                            border += 25;
                        if (x < border)
                            edge |= Align.left;
                        if (x > width - border)
                            edge |= Align.right;
                        if (y < border)
                            edge |= Align.bottom;
                        if (y > height - border)
                            edge |= Align.top;
                    }
                    if (isMovable
                            && edge == 0    // We are not resizing!
                            && y <= height  // Inside the Window
                            && y >= 0
                            && x >= 0
                            && x <= width)
                        edge = MOVE;
                    dragging = edge != 0;
                    startX = x;
                    startY = y;
                    lastX = x;
                    lastY = y;
                }
                return edge != 0 || isModal;
            }

            public void touchUp(InputEvent event, float x, float y,
                    int pointer, int button) {
                dragging = false;
            }

            public void touchDragged(InputEvent event, float x, float y,
                    int pointer) {
                if (!dragging)
                    return;
                float width = getWidth(), height = getHeight();
                float windowX = getX(), windowY = getY();

                float minWidth = getMinWidth(), maxWidth = getMaxWidth();
                float minHeight = getMinHeight(), maxHeight = getMaxHeight();
                Stage stage = getStage();
                boolean clampPosition = keepWithinStage
                        && getParent() == stage.getRoot();

                if ((edge & MOVE) != 0) { // We are moving!
                    float amountX = x - startX, amountY = y - startY;
                    windowX += amountX;
                    windowY += amountY;
                }
                if ((edge & Align.left) != 0) { // We are resizing!
                    float amountX = x - startX;
                    if (width - amountX < minWidth)
                        amountX = -(minWidth - width);
                    if (clampPosition && windowX + amountX < 0)
                        amountX = -windowX;
                    width -= amountX;
                    windowX += amountX;
                }
                if ((edge & Align.bottom) != 0) {
                    float amountY = y - startY;
                    if (height - amountY < minHeight)
                        amountY = -(minHeight - height);
                    if (clampPosition && windowY + amountY < 0)
                        amountY = -windowY;
                    height -= amountY;
                    windowY += amountY;
                }
                if ((edge & Align.right) != 0) {
                    float amountX = x - lastX;
                    if (width + amountX < minWidth)
                        amountX = minWidth - width;
                    if (clampPosition
                            && windowX + width + amountX > stage.getWidth())
                        amountX = stage.getWidth() - windowX - width;
                    width += amountX;
                }
                if ((edge & Align.top) != 0) {
                    float amountY = y - lastY;
                    if (height + amountY < minHeight)
                        amountY = minHeight - height;
                    if (clampPosition
                            && windowY + height + amountY > stage.getHeight())
                        amountY = stage.getHeight() - windowY - height;
                    height += amountY;
                }
                lastX = x;
                lastY = y;
                setBounds(Math.round(windowX), Math.round(windowY),
                        Math.round(width), Math.round(height));
            }

            public boolean mouseMoved(InputEvent event, float x, float y) {
                return isModal;
            }

            public boolean scrolled(InputEvent event, float x, float y,
                    int amount) {
                return isModal;
            }

            public boolean keyDown(InputEvent event, int keycode) {
                return isModal;
            }

            public boolean keyUp(InputEvent event, int keycode) {
                return isModal;
            }

            public boolean keyTyped(InputEvent event, char character) {
                return isModal;
            }
        });
    }

    /**
     * Checks if the Window is within the Stage. If not, it is pushed inside.
     */
    private void keepWithinStage () {
        if (!keepWithinStage) return;
        Stage stage = getStage();
        if (getParent() == stage.getRoot()) {
            float parentWidth = stage.getWidth();
            float parentHeight = stage.getHeight();
            if (getX() < 0) setX(0);
            if (getRight() > parentWidth) setX(parentWidth - getWidth());
            if (getY() < 0) setY(0);
            if (getTop() > parentHeight) setY(parentHeight - getHeight());
        }
    }

    /**
     * @return  The Actor that was hit first.
     */
    public Actor hit (float x, float y, boolean touchable) {
        Actor hit = super.hit(x, y, touchable);
        if (hit == null && isModal && (!touchable || getTouchable() == Touchable.enabled)) return this;
        return hit;
    }

    /**
     * This method is used to determine what Actors can be clicked to drag the dialog.
     * This is to prevent dragging inside the content of the MovableWindow.
     * @return  An Array of Actors that can be used to drag the MovableWindow.
     */
    protected Actor[] getDraggableRegions() {
        return dragActors;
    }

    /**
     * Renders the beautiful Table.
     */
    public void draw(Batch batch, float parentAlpha) {
        keepWithinStage();
        super.draw(batch, parentAlpha);
    }

    public void setStyle(MovableTableStyle style) {
        if (style == null) throw new IllegalArgumentException("style cannot be null.");
        this.style = style;
        setBackground(style.background);
        invalidateHierarchy(); // This one is questionable!
    }

    public MovableTableStyle getStyle () {
        return style;
    }

    public boolean isModal() {
        return isModal;
    }

    public void setModal(boolean isModal) {
        this.isModal = isModal;
    }

    public boolean isResizable() {
        return isResizable;
    }

    public void setResizable(boolean isResizable) {
        this.isResizable = isResizable;
    }

    public boolean isMovable() {
        return isMovable;
    }

    public void setMovable(boolean isMovable) {
        this.isMovable = isMovable;
    }

    public boolean isKeepWithinStage() {
        return keepWithinStage;
    }

    public void setKeepWithinStage(boolean keepWithinStage) {
        this.keepWithinStage = keepWithinStage;
    }

    static public class MovableTableStyle {

        public Drawable background;
    }
}