/*
 * Copyright (c) 2008, intarsys consulting GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * - Neither the name of intarsys nor the names of its contributors may be used
 *   to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package de.intarsys.nativec.jna;

import com.sun.jna.Function;
import com.sun.jna.NativeLong;
import com.sun.jna.Pointer;
import com.sun.jna.WString;

import de.intarsys.nativec.api.CLong;
import de.intarsys.nativec.api.INativeFunction;
import de.intarsys.nativec.api.INativeHandle;
import de.intarsys.nativec.api.CWideString;
import de.intarsys.nativec.type.INativeObject;
import de.intarsys.nativec.type.INativeType;
import de.intarsys.nativec.type.NativeObject;
import de.intarsys.nativec.type.NativeType;

public class JnaNativeFunction implements INativeFunction {

	private Function function;

	public JnaNativeFunction(Function function) {
		this.function = function;
	}

	protected Function getFunction() {
		return function;
	}

	public <T> T invoke(Class<T> returnType, Object... objects) {
		for (int i = 0; i < objects.length; i++) {
			Object object = objects[i];
			if (object instanceof INativeObject) {
				JnaNativeHandle handle = (JnaNativeHandle) ((INativeObject) object)
						.getNativeHandle();
				if (handle == null) {
					objects[i] = null;
				} else {
					objects[i] = handle.getPointer();
				}
			} else if (object instanceof INativeHandle) {
				JnaNativeHandle handle = (JnaNativeHandle) object;
				objects[i] = handle.getPointer();
			} else if (object instanceof CWideString) {
				objects[i] = new WString(((CWideString) object).getString());
			} else if (object instanceof CLong) {
				objects[i] = new NativeLong(((CLong) object).longValue());
			}
		}
		// if (Log.isLoggable(Level.FINE)) {
		// Log.log(Level.FINE, "jna invoke " + function.getName());
		// }
		T result;
		if (CWideString.class.isAssignableFrom(returnType)) {
			WString wstring = (WString) function.invoke(WString.class, objects);
			result = (T) new CWideString(wstring.toString());
		} else if (CLong.class.isAssignableFrom(returnType)) {
			NativeLong nativeLong = (NativeLong) function.invoke(
					NativeLong.class, objects);
			result = (T) new CLong(nativeLong.longValue());
		} else if (NativeObject.class.isAssignableFrom(returnType)) {
			Pointer pointer = (Pointer) function.invoke(Pointer.class, objects);
			if (pointer == null) {
				result = null;
			} else {
				INativeHandle handle = new JnaNativeHandle(pointer);
				INativeType type = NativeType.lookup(returnType);
				if (type == null) {
					throw new IllegalArgumentException("no type for '"
							+ returnType + "'");
				}
				result = (T) type.createNative(handle);
			}
		} else if (INativeHandle.class.isAssignableFrom(returnType)) {
			Pointer pointer = (Pointer) function.invoke(Pointer.class, objects);
			if (pointer == null) {
				result = null;
			} else {
				result = (T) new JnaNativeHandle(pointer);
			}
		} else {
			result = (T) function.invoke(returnType, objects);
		}
		return result;
	}
}