/*
 * 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 com.five_ten_sg.connectbot.bean;

import de.mud.terminal.VDUBuffer;

/**
 * @author Kenny Root
 * Keep track of a selection area for the terminal copying mechanism.
 * If the orientation is flipped one way, swap the bottom and top or
 * left and right to keep it in the correct orientation.
 */
public class SelectionArea {
    private int top;
    private int bottom;
    private int left;
    private int right;
    private int maxColumns;
    private int maxRows;
    private boolean selectingOrigin;

    public SelectionArea() {
        reset();
    }

    public final void reset() {
        top = left = bottom = right = 0;
        selectingOrigin = true;
    }

    /**
     * @param columns
     * @param rows
     */
    public void setBounds(int columns, int rows) {
        maxColumns = columns - 1;
        maxRows = rows - 1;
    }

    private int checkBounds(int value, int max) {
        if (value < 0)
            return 0;
        else if (value > max)
            return max;
        else
            return value;
    }

    public boolean isSelectingOrigin() {
        return selectingOrigin;
    }

    public void finishSelectingOrigin() {
        selectingOrigin = false;
    }

    public void decrementRow() {
        if (selectingOrigin)
            setTop(top - 1);
        else
            setBottom(bottom - 1);
    }

    public void incrementRow() {
        if (selectingOrigin)
            setTop(top + 1);
        else
            setBottom(bottom + 1);
    }

    public void setRow(int row) {
        if (selectingOrigin)
            setTop(row);
        else
            setBottom(row);
    }

    private void setTop(int top) {
        this.top = bottom = checkBounds(top, maxRows);
    }

    public int getTop() {
        return Math.min(top, bottom);
    }

    private void setBottom(int bottom) {
        this.bottom = checkBounds(bottom, maxRows);
    }

    public int getBottom() {
        return Math.max(top, bottom);
    }

    public void decrementColumn() {
        if (selectingOrigin)
            setLeft(left - 1);
        else
            setRight(right - 1);
    }

    public void incrementColumn() {
        if (selectingOrigin)
            setLeft(left + 1);
        else
            setRight(right + 1);
    }

    public void setColumn(int column) {
        if (selectingOrigin)
            setLeft(column);
        else
            setRight(column);
    }

    private void setLeft(int left) {
        this.left = right = checkBounds(left, maxColumns);
    }

    public int getLeft() {
        return Math.min(left, right);
    }

    private void setRight(int right) {
        this.right = checkBounds(right, maxColumns);
    }

    public int getRight() {
        return Math.max(left, right);
    }

    public String copyFrom(VDUBuffer vb) {
        int size = (getRight() - getLeft() + 1) * (getBottom() - getTop() + 1);
        StringBuffer buffer = new StringBuffer(size);

        for (int y = getTop(); y <= getBottom(); y++) {
            int lastNonSpace = buffer.length();

            for (int x = getLeft(); x <= getRight(); x++) {
                // only copy printable chars
                char c = vb.getChar(x, y);

                if (!Character.isDefined(c) ||
                        (Character.isISOControl(c) && c != '\t'))
                    c = ' ';

                if (c != ' ')
                    lastNonSpace = buffer.length();

                buffer.append(c);
            }

            // Don't leave a bunch of spaces in our copy buffer.
            if (buffer.length() > lastNonSpace)
                buffer.delete(lastNonSpace + 1, buffer.length());

            if (y != bottom)
                buffer.append("\n");
        }

        return buffer.toString();
    }

    @Override
    public String toString() {
        StringBuilder buffer = new StringBuilder();
        buffer.append("SelectionArea[top=");
        buffer.append(top);
        buffer.append(", bottom=");
        buffer.append(bottom);
        buffer.append(", left=");
        buffer.append(left);
        buffer.append(", right=");
        buffer.append(right);
        buffer.append(", maxColumns=");
        buffer.append(maxColumns);
        buffer.append(", maxRows=");
        buffer.append(maxRows);
        buffer.append(", isSelectingOrigin=");
        buffer.append(isSelectingOrigin());
        buffer.append("]");
        return buffer.toString();
    }
}