/*******************************************************************************
 * Copyright (c) 2004, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal.console;

import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.graphics.Color;
import org.eclipse.ui.console.ConsolePlugin;
import org.eclipse.ui.console.IOConsoleInputStream;
import org.eclipse.ui.console.IOConsoleOutputStream;

/**
 * A region in an IOConsole's document.
 *
 * @since 3.1
 */
public class IOConsolePartition implements ITypedRegion {
	public static final String OUTPUT_PARTITION_TYPE = ConsolePlugin.getUniqueIdentifier() + ".io_console_output_partition_type"; //$NON-NLS-1$
	public static final String INPUT_PARTITION_TYPE = ConsolePlugin.getUniqueIdentifier() + ".io_console_input_partition_type"; //$NON-NLS-1$

	/**
	 * The data contained by this partition.
	 */
	private StringBuffer buffer;
	private String type;
	private int offset;
	/**
	 * Output partitions are all read only.
	 * Input partitions are read only once they have been appended to the console's input stream.
	 */
	private boolean readOnly;

	/**
	 * Only one of inputStream or outputStream will be null depending on the partitions type.
	 */
	private IOConsoleOutputStream outputStream;
	private IOConsoleInputStream inputStream;
	private int length;

	/**
	 * Creates a new partition to contain output to console.
	 */
	public IOConsolePartition(IOConsoleOutputStream outputStream, int length) {
		this.outputStream = outputStream;
		this.length = length;
		this.type = OUTPUT_PARTITION_TYPE;
		this.readOnly = true;
	}

	/**
	 * Creates a new partition to contain input from a console
	 */
	public IOConsolePartition(IOConsoleInputStream inputStream, String text) {
		this.inputStream = inputStream;
		buffer = new StringBuffer(text);
		length = text.length();
		this.type = INPUT_PARTITION_TYPE;
		this.readOnly = false;
	}

	/**
	 * Inserts a string into this partition.
	 * @param s The string to insert
	 * @param offset the offset in the partition
	 */
	public void insert(String s, int insertOffset) {
		if (insertOffset < 0) {
			insertOffset = 0;
		} else if (insertOffset > buffer.length()) {
			insertOffset = buffer.length();
		}
		buffer.insert(insertOffset, s);
		length += s.length();
	}

	/**
	 * Deletes data from this partition.
	 * @param delOffset
	 * @param delLength
	 */
	public void delete(int delOffset, int delLength) {
		buffer.delete(delOffset, delOffset+delLength);
		length -= delLength;
	}

	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.text.ITypedRegion#getType()
	 */
	@Override
	public String getType() {
		return type;
	}

	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.text.IRegion#getLength()
	 */
	@Override
	public int getLength() {
		return length;
	}

	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.text.IRegion#getOffset()
	 */
	@Override
	public int getOffset() {
		return offset;
	}

	/**
	 * Sets this partitions offset in the document.
	 *
	 * @param offset This partitions offset in the document.
	 */
	public void setOffset(int offset) {
		this.offset = offset;
	}

	/**
	 * Sets this partition's length.
	 *
	 * @param length
	 */
	public void setLength(int length) {
		this.length = length;
	}

	/**
	 * Returns the data contained in this partition.
	 * @return The data contained in this partition.
	 */
	public String getString() {
		return buffer.toString();
	}

	/**
	 * Returns a StyleRange object which may be used for setting the style
	 * of this partition in a viewer.
	 */
	public StyleRange getStyleRange(int rangeOffset, int rangeLength) {
		return new StyleRange(rangeOffset, rangeLength, getColor(), null, getFontStyle());
	}

	/**
	 *  Returns the font of the input stream if the type of the partition
	 * is <code>INPUT_PARTITION_TYPE</code>, otherwise it returns the output
	 * stream font
	 *
	 * @return the font of one of the backing streams
	 */
	private int getFontStyle() {
		if (type.equals(INPUT_PARTITION_TYPE)) {
			return inputStream.getFontStyle();
		}
		return outputStream.getFontStyle();
	}

	/**
	 * Returns the colour of the input stream if the type of the partition
	 * is <code>INPUT_PARTITION_TYPE</code>, otherwise it returns the output
	 * stream colour
	 *
	 * @return the colour of one of the backing streams
	 */
	public Color getColor() {
		if (type.equals(INPUT_PARTITION_TYPE)) {
			return inputStream.getColor();
		}
		return outputStream.getColor();
	}

	/**
	 * Returns if this partition is read-only.
	 *
	 * @see org.eclipse.ui.console.IConsoleDocumentPartitioner#isReadOnly(int)
	 * @return if this partition is read-only
	 */
	public boolean isReadOnly() {
		return readOnly;
	}

	/**
	 * Sets the read-only state of this partition to <code>true</code>.
	 *
	 * @see org.eclipse.ui.console.IConsoleDocumentPartitioner#isReadOnly(int)
	 */
	public void setReadOnly() {
		readOnly = true;
	}

	/**
	 * Clears the contents of the buffer
	 */
	public void clearBuffer() {
		buffer.setLength(0);
	}

	/**
	 * Returns the underlying output stream
	 *
	 * @return the underlying output stream
	 */
	IOConsoleOutputStream getStream() {
		return outputStream;
	}
}