/*
 * ConnectBot: simple, powerful, open-source SSH client for Android
 * Copyright 2007 Kenny Root, Jeffrey Sharkey
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.connectbot;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PixelXorXfermode;
import android.graphics.RectF;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.inputmethod.BaseInputConnection;
import android.view.inputmethod.EditorInfo;
import android.view.inputmethod.InputConnection;
import android.widget.Toast;
import de.mud.terminal.VDUBuffer;

import org.connectbot.service.FontSizeChangedListener;
import org.connectbot.service.TerminalBridge;
import org.connectbot.service.TerminalKeyListener;
import org.connectbot.util.SelectionArea;

/**
 * User interface {@link View} for showing a TerminalBridge in an {@link Activity}. Handles drawing
 * bitmap updates and passing keystrokes down to terminal.
 *
 * @author jsharkey
 */
public class TerminalView extends View implements FontSizeChangedListener {

  private final Context context;
  public final TerminalBridge bridge;
  private final Paint paint;
  private final Paint cursorPaint;
  private final Paint cursorStrokePaint;

  // Cursor paints to distinguish modes
  private Path ctrlCursor, altCursor, shiftCursor;
  private RectF tempSrc, tempDst;
  private Matrix scaleMatrix;
  private static final Matrix.ScaleToFit scaleType = Matrix.ScaleToFit.FILL;

  private Toast notification = null;
  private String lastNotification = null;
  private volatile boolean notifications = true;

  public TerminalView(Context context, TerminalBridge bridge) {
    super(context);

    this.context = context;
    this.bridge = bridge;
    paint = new Paint();

    setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
    setFocusable(true);
    setFocusableInTouchMode(true);

    cursorPaint = new Paint();
    cursorPaint.setColor(bridge.getForegroundColor());
    cursorPaint.setXfermode(new PixelXorXfermode(bridge.getBackgroundColor()));
    cursorPaint.setAntiAlias(true);

    cursorStrokePaint = new Paint(cursorPaint);
    cursorStrokePaint.setStrokeWidth(0.1f);
    cursorStrokePaint.setStyle(Paint.Style.STROKE);

    /*
     * Set up our cursor indicators on a 1x1 Path object which we can later transform to our
     * character width and height
     */
    // TODO make this into a resource somehow
    shiftCursor = new Path();
    shiftCursor.lineTo(0.5f, 0.33f);
    shiftCursor.lineTo(1.0f, 0.0f);

    altCursor = new Path();
    altCursor.moveTo(0.0f, 1.0f);
    altCursor.lineTo(0.5f, 0.66f);
    altCursor.lineTo(1.0f, 1.0f);

    ctrlCursor = new Path();
    ctrlCursor.moveTo(0.0f, 0.25f);
    ctrlCursor.lineTo(1.0f, 0.5f);
    ctrlCursor.lineTo(0.0f, 0.75f);

    // For creating the transform when the terminal resizes
    tempSrc = new RectF();
    tempSrc.set(0.0f, 0.0f, 1.0f, 1.0f);
    tempDst = new RectF();
    scaleMatrix = new Matrix();

    bridge.addFontSizeChangedListener(this);

    // connect our view up to the bridge
    setOnKeyListener(bridge.getKeyHandler());
  }

  public void destroy() {
    // tell bridge to destroy its bitmap
    bridge.parentDestroyed();
  }

  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);

    bridge.parentChanged(this);

    scaleCursors();
  }

  public void onFontSizeChanged(float size) {
    scaleCursors();
  }

  private void scaleCursors() {
    // Create a scale matrix to scale our 1x1 representation of the cursor
    tempDst.set(0.0f, 0.0f, bridge.charWidth, bridge.charHeight);
    scaleMatrix.setRectToRect(tempSrc, tempDst, scaleType);
  }

  @Override
  public void onDraw(Canvas canvas) {
    if (bridge.getBitmap() != null) {
      // draw the bitmap
      bridge.onDraw();

      // draw the bridge bitmap if it exists
      canvas.drawBitmap(bridge.getBitmap(), 0, 0, paint);

      VDUBuffer buffer = bridge.getVDUBuffer();

      // also draw cursor if visible
      if (buffer.isCursorVisible()) {

        int cursorColumn = buffer.getCursorColumn();
        final int cursorRow = buffer.getCursorRow();

        final int columns = buffer.getColumns();

        if (cursorColumn == columns) {
          cursorColumn = columns - 1;
        }

        if (cursorColumn < 0 || cursorRow < 0) {
          return;
        }

        int currentAttribute = buffer.getAttributes(cursorColumn, cursorRow);
        boolean onWideCharacter = (currentAttribute & VDUBuffer.FULLWIDTH) != 0;

        int x = cursorColumn * bridge.charWidth;
        int y = (buffer.getCursorRow() + buffer.screenBase - buffer.windowBase) * bridge.charHeight;

        // Save the current clip and translation
        canvas.save();

        canvas.translate(x, y);
        canvas.clipRect(0, 0, bridge.charWidth * (onWideCharacter ? 2 : 1), bridge.charHeight);
        canvas.drawPaint(cursorPaint);

        // Make sure we scale our decorations to the correct size.
        canvas.concat(scaleMatrix);

        int metaState = bridge.getKeyHandler().getMetaState();

        if ((metaState & TerminalKeyListener.META_SHIFT_ON) != 0) {
          canvas.drawPath(shiftCursor, cursorStrokePaint);
        } else if ((metaState & TerminalKeyListener.META_SHIFT_LOCK) != 0) {
          canvas.drawPath(shiftCursor, cursorPaint);
        }

        if ((metaState & TerminalKeyListener.META_ALT_ON) != 0) {
          canvas.drawPath(altCursor, cursorStrokePaint);
        } else if ((metaState & TerminalKeyListener.META_ALT_LOCK) != 0) {
          canvas.drawPath(altCursor, cursorPaint);
        }

        if ((metaState & TerminalKeyListener.META_CTRL_ON) != 0) {
          canvas.drawPath(ctrlCursor, cursorStrokePaint);
        } else if ((metaState & TerminalKeyListener.META_CTRL_LOCK) != 0) {
          canvas.drawPath(ctrlCursor, cursorPaint);
        }

        // Restore previous clip region
        canvas.restore();
      }

      // draw any highlighted area
      if (bridge.isSelectingForCopy()) {
        SelectionArea area = bridge.getSelectionArea();
        canvas.save(Canvas.CLIP_SAVE_FLAG);
        canvas.clipRect(area.getLeft() * bridge.charWidth, area.getTop() * bridge.charHeight,
            (area.getRight() + 1) * bridge.charWidth, (area.getBottom() + 1) * bridge.charHeight);
        canvas.drawPaint(cursorPaint);
        canvas.restore();
      }
    }
  }

  public void notifyUser(String message) {
    if (!notifications) {
      return;
    }

    if (notification != null) {
      // Don't keep telling the user the same thing.
      if (lastNotification != null && lastNotification.equals(message)) {
        return;
      }

      notification.setText(message);
      notification.show();
    } else {
      notification = Toast.makeText(context, message, Toast.LENGTH_SHORT);
      notification.show();
    }

    lastNotification = message;
  }

  /**
   * Ask the {@link TerminalBridge} we're connected to to resize to a specific size.
   *
   * @param width
   * @param height
   */
  public void forceSize(int width, int height) {
    bridge.resizeComputed(width, height, getWidth(), getHeight());
  }

  /**
   * Sets the ability for the TerminalView to display Toast notifications to the user.
   *
   * @param value
   *          whether to enable notifications or not
   */
  public void setNotifications(boolean value) {
    notifications = value;
  }

  @Override
  public boolean onCheckIsTextEditor() {
    return true;
  }

  @Override
  public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
    outAttrs.imeOptions |= EditorInfo.IME_FLAG_NO_EXTRACT_UI | EditorInfo.IME_FLAG_NO_ENTER_ACTION
        | EditorInfo.IME_ACTION_NONE;
    outAttrs.inputType = EditorInfo.TYPE_NULL;
    return new BaseInputConnection(this, false);
  }
}