Copyright (c) 2004, 2005 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
/*******************************************************************************
 * Copyright (c) 2004, 2005 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.core.internal.content;

import org.eclipse.core.runtime.QualifiedName;
import org.eclipse.core.runtime.content.IContentDescription;

public final class ContentDescription extends BasicDescription {

	private static final String CHARSET_UTF_16 = "UTF-16"; //$NON-NLS-1$
	private static final String CHARSET_UTF_8 = "UTF-8"; //$NON-NLS-1$
	private static final byte FLAG_ALL_OPTIONS = 0x01;
	private static final byte FLAG_IMMUTABLE = 0x02;
	private byte flags;
	private Object keys;
	private Object values;

	public ContentDescription(QualifiedName[] requested, IContentTypeInfo contentTypeInfo) {
		super(contentTypeInfo);
		if (requested == IContentDescription.ALL) {
			flags |= FLAG_ALL_OPTIONS;
			return;
		}
		if (requested.length > 1) {
			keys = requested;
			values = new Object[requested.length];
		} else if (requested.length == 1)
			keys = requested[0];
		// if requested.length == 0 then keys == null (no options to describe!)
	}

	private void assertMutable() {
		if ((flags & FLAG_IMMUTABLE) != 0)
			throw new IllegalStateException("Content description is immutable"); //$NON-NLS-1$
	}

	@Override
	public String getCharset() {
		byte[] bom = (byte[]) getProperty(BYTE_ORDER_MARK);
		if (bom == BOM_UTF_8)
			return CHARSET_UTF_8;
		else if (bom == BOM_UTF_16BE || bom == BOM_UTF_16LE)
			// UTF-16 will properly recognize the BOM
			return CHARSET_UTF_16;
		return (String) getProperty(CHARSET);
	}

	private Object getDescribedProperty(QualifiedName key) {
		// no values have been set
		if (values == null)
			return null;
		// a single property may have been set
		if (keys instanceof QualifiedName)
			return keys.equals(key) ? values : null;
		// multiple properties may have been set
		QualifiedName[] tmpKeys = (QualifiedName[]) this.keys;
		for (int i = 0; i < tmpKeys.length; i++)
			if (tmpKeys[i].equals(key))
				return ((Object[]) values)[i];
		return null;
	}

	@Override
	public Object getProperty(QualifiedName key) {
		Object describedProperty = getDescribedProperty(key);
		if (describedProperty != null)
			return describedProperty;
		return contentTypeInfo.getDefaultProperty(key);
	}

	@Override
	public boolean isRequested(QualifiedName propertyKey) {
		// all options requested
		if ((flags & FLAG_ALL_OPTIONS) != 0)
			return true;
		// no options requested
		if (keys == null)
			return false;
		// a single option requested
		if (keys instanceof QualifiedName)
			return keys.equals(propertyKey);
		// some (but not all) options requested
		QualifiedName[] tmpKeys = (QualifiedName[]) this.keys;
		for (QualifiedName tmpKey : tmpKeys)
			if (tmpKey.equals(propertyKey))
				return true;
		return false;
	}

	boolean isSet() {
		if (keys == null || values == null)
			return false;
		if (keys instanceof QualifiedName)
			return true;
		Object[] tmpValues = (Object[]) this.values;
		for (Object tmpValue : tmpValues)
			if (tmpValue != null)
				return true;
		return false;
	}

	public void markImmutable() {
		assertMutable();
		flags |= FLAG_IMMUTABLE;
	}

	
Overrides content type info object. /** Overrides content type info object. */
	void setContentTypeInfo(IContentTypeInfo info) {
		this.contentTypeInfo = info;
	}

	@Override
	public void setProperty(QualifiedName newKey, Object newValue) {
		assertMutable();
		if (keys == null) {
			if ((flags & FLAG_ALL_OPTIONS) != 0) {
				keys = newKey;
				values = newValue;
			}
			return;
		}
		if (keys.equals(newKey)) {
			values = newValue;
			return;
		}
		if (keys instanceof QualifiedName) {
			if ((flags & FLAG_ALL_OPTIONS) != 0) {
				keys = new QualifiedName[] {(QualifiedName) keys, newKey};
				values = new Object[] {values, newValue};
			}
			return;
		}
		QualifiedName[] tmpKeys = (QualifiedName[]) this.keys;
		for (int i = 0; i < tmpKeys.length; i++)
			if (tmpKeys[i].equals(newKey)) {
				((Object[]) values)[i] = newValue;
				return;
			}
		if ((flags & FLAG_ALL_OPTIONS) == 0)
			return;
		// need to resize arrays
		int currentSize = tmpKeys.length;
		tmpKeys = new QualifiedName[currentSize + 1];
		System.arraycopy(keys, 0, tmpKeys, 0, currentSize);
		Object[] tmpValues = new Object[currentSize + 1];
		System.arraycopy(values, 0, tmpValues, 0, currentSize);
		tmpKeys[tmpKeys.length - 1] = newKey;
		tmpValues[tmpValues.length - 1] = newValue;
		keys = tmpKeys;
		values = tmpValues;
	}

	@Override
	public String toString() {
		StringBuilder result = new StringBuilder("{"); //$NON-NLS-1$
		if (keys != null)
			if (keys instanceof QualifiedName) {
				if (values != null)
					result.append(keys + "=" + values); //$NON-NLS-1$
			} else {
				QualifiedName[] tmpKeys = (QualifiedName[]) keys;
				Object[] tmpValues = (Object[]) values;
				boolean any = false;
				for (int i = 0; i < tmpKeys.length; i++)
					if (tmpValues[i] != null) {
						result.append(tmpKeys[i] + "=" + tmpValues[i] + ","); //$NON-NLS-1$ //$NON-NLS-2$
						any = true;
					}
				if (any)
					result.deleteCharAt(result.length() - 1);
			}
		result.append("} : "); //$NON-NLS-1$
		result.append(contentTypeInfo.getContentType());
		return result.toString();
	}
}