/*******************************************************************************
 * This file is part of logisim-evolution.
 *
 *   logisim-evolution is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   logisim-evolution is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with logisim-evolution.  If not, see <http://www.gnu.org/licenses/>.
 *
 *   Original code by Carl Burch (http://www.cburch.com), 2011.
 *   Subsequent modifications by :
 *     + Haute École Spécialisée Bernoise
 *       http://www.bfh.ch
 *     + Haute École du paysage, d'ingénierie et d'architecture de Genève
 *       http://hepia.hesge.ch/
 *     + Haute École d'Ingénierie et de Gestion du Canton de Vaud
 *       http://www.heig-vd.ch/
 *   The project is currently maintained by :
 *     + REDS Institute - HEIG-VD
 *       Yverdon-les-Bains, Switzerland
 *       http://reds.heig-vd.ch
 *******************************************************************************/

package com.cburch.logisim.std.memory;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;

import com.cburch.logisim.data.BitWidth;
import com.cburch.logisim.data.Bounds;
import com.cburch.logisim.data.Value;
import com.cburch.logisim.instance.InstancePainter;
import com.cburch.logisim.instance.InstancePoker;
import com.cburch.logisim.instance.InstanceState;
import com.cburch.logisim.instance.StdAttr;

public class ShiftRegisterPoker extends InstancePoker {
	private int loc;

	private int computeStage(InstanceState state, MouseEvent e) {
		BitWidth widObj = state.getAttributeValue(StdAttr.WIDTH);
		Bounds bds = state.getInstance().getBounds();

		int len = (widObj.getWidth() + 3) / 4;
		int boxXpos = ((ShiftRegister.SymbolWidth - 30) / 2 + 30) - (len * 4);
		int boxXend = boxXpos + 2 + len * 8;
		int y = e.getY() - bds.getY() - 80;
		if (y < 0)
			return -1;
		int x = e.getX() - bds.getX() - 10;
		if ((x < boxXpos) || (x > boxXend))
			return -1;
		return (y / 20);
	}

	@Override
	public boolean init(InstanceState state, MouseEvent e) {
		loc = computeStage(state, e);
		return loc >= 0;
	}

	@Override
	public void keyTyped(InstanceState state, KeyEvent e) {
		int loc = this.loc;
		if (loc < 0)
			return;
		char c = e.getKeyChar();
		if (c == ' ') {
			Integer lenObj = state.getAttributeValue(ShiftRegister.ATTR_LENGTH);
			if (loc < lenObj.intValue() - 1) {
				this.loc = loc + 1;
				state.fireInvalidated();
			}
		} else if (c == '\u0008') {
			if (loc > 0) {
				this.loc = loc - 1;
				state.fireInvalidated();
			}
		} else {
			try {
				int val = Integer.parseInt("" + e.getKeyChar(), 16);
				BitWidth widObj = state.getAttributeValue(StdAttr.WIDTH);
				ShiftRegisterData data = (ShiftRegisterData) state.getData();
				int i = data.getLength() - 1 - loc;
				int value = data.get(i).toIntValue();
				value = ((value * 16) + val) & widObj.getMask();
				Value valObj = Value.createKnown(widObj, value);
				data.set(i, valObj);
				state.fireInvalidated();
			} catch (NumberFormatException ex) {
				return;
			}
		}
	}

	@Override
	public void mousePressed(InstanceState state, MouseEvent e) {
		loc = computeStage(state, e);
	}

	@Override
	public void mouseReleased(InstanceState state, MouseEvent e) {
		int oldLoc = loc;
		if (oldLoc < 0)
			return;
		BitWidth widObj = state.getAttributeValue(StdAttr.WIDTH);
		if (widObj.equals(BitWidth.ONE)) {
			int newLoc = computeStage(state, e);
			if (oldLoc == newLoc) {
				ShiftRegisterData data = (ShiftRegisterData) state.getData();
				int i = data.getLength() - 1 - loc;
				Value v = data.get(i);
				if (v == Value.FALSE)
					v = Value.TRUE;
				else
					v = Value.FALSE;
				data.set(i, v);
				state.fireInvalidated();
			}
		}
	}

	@Override
	public void paint(InstancePainter painter) {
		int loc = this.loc;
		if (loc < 0)
			return;
		BitWidth widObj = painter.getAttributeValue(StdAttr.WIDTH);
		Bounds bds = painter.getInstance().getBounds();
		int len = (widObj.getWidth() + 3) / 4;
		int boxXpos = ((ShiftRegister.SymbolWidth - 30) / 2 + 30) - (len * 4)
				+ bds.getX() + 10;
		int y = bds.getY() + 82 + loc * 20;
		Graphics g = painter.getGraphics();
		g.setColor(Color.RED);
		g.drawRect(boxXpos, y, 2 + len * 8, 16);
	}
}