/* ###
 * IP: GHIDRA
 *
 * 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 ghidra.app.util.bin.format.macho.commands;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import ghidra.app.util.bin.format.FactoryBundledWithBinaryReader;
import ghidra.app.util.bin.format.macho.MachConstants;
import ghidra.app.util.bin.format.macho.MachHeader;
import ghidra.app.util.importer.MessageLog;
import ghidra.program.flatapi.FlatProgramAPI;
import ghidra.program.model.address.Address;
import ghidra.program.model.data.*;
import ghidra.program.model.listing.ProgramFragment;
import ghidra.program.model.listing.ProgramModule;
import ghidra.util.exception.DuplicateNameException;
import ghidra.util.task.TaskMonitor;

/**
 * Represents a twolevel_hints_command structure.
 * 
 * @see <a href="https://opensource.apple.com/source/xnu/xnu-4570.71.2/EXTERNAL_HEADERS/mach-o/loader.h.auto.html">mach-o/loader.h</a> 
 */
public class TwoLevelHintsCommand extends LoadCommand {
	private int offset;
	private int nhints;
	private List<TwoLevelHint> hints = new ArrayList<TwoLevelHint>();

	static TwoLevelHintsCommand createTwoLevelHintsCommand(FactoryBundledWithBinaryReader reader)
			throws IOException {
		TwoLevelHintsCommand command =
			(TwoLevelHintsCommand) reader.getFactory().create(TwoLevelHintsCommand.class);
		command.initTwoLevelHintsCommand(reader);
		return command;
	}

	/**
	 * DO NOT USE THIS CONSTRUCTOR, USE create*(GenericFactory ...) FACTORY METHODS INSTEAD.
	 */
	public TwoLevelHintsCommand() {
	}

	private void initTwoLevelHintsCommand(FactoryBundledWithBinaryReader reader)
			throws IOException {
		initLoadCommand(reader);
		offset = reader.readNextInt();
		nhints = reader.readNextInt();

		long index = reader.getPointerIndex();
		reader.setPointerIndex(offset);
		for (int i = 0; i < nhints; ++i) {
			hints.add(TwoLevelHint.createTwoLevelHint(reader));
		}
		reader.setPointerIndex(index);
	}

	public List<TwoLevelHint> getHints() {
		return hints;
	}

	/**
	 * Returns the offset to the hint table.
	 * @return the offset to the hint table
	 */
	public int getOffset() {
		return offset;
	}

	/**
	 * Returns the number of hints in the hint table.
	 * @return the number of hints in the hint table
	 */
	public int getNumberOfHints() {
		return nhints;
	}

	@Override
	public DataType toDataType() throws DuplicateNameException, IOException {
		StructureDataType struct = new StructureDataType(getCommandName(), 0);
		struct.add(DWORD, "cmd", null);
		struct.add(DWORD, "cmdsize", null);
		struct.add(DWORD, "offset", null);
		struct.add(DWORD, "nhints", null);
		struct.setCategoryPath(new CategoryPath(MachConstants.DATA_TYPE_CATEGORY));
		return struct;
	}

	@Override
	public String getCommandName() {
		return "twolevel_hints_command";
	}

	@Override
	public void markup(MachHeader header, FlatProgramAPI api, Address baseAddress, boolean isBinary,
			ProgramModule parentModule, TaskMonitor monitor, MessageLog log) {
		updateMonitor(monitor);
		try {
			if (isBinary) {
				ProgramFragment fragment = createFragment(api, baseAddress, parentModule);
				Address addr = baseAddress.getNewAddress(getStartIndex());
				api.createData(addr, toDataType());

				Address hintStartAddress = baseAddress.add(getOffset());
				Address hintAddress = hintStartAddress;
				for (TwoLevelHint hint : hints) {
					if (monitor.isCancelled()) {
						return;
					}
					DataType hintDT = hint.toDataType();
					api.createData(hintAddress, hintDT);
					api.setPlateComment(hintAddress,
						"Sub-image Index: 0x" + Integer.toHexString(hint.getSubImageIndex()) +
							'\n' + "      TOC Index: 0x" +
							Integer.toHexString(hint.getTableOfContentsIndex()));
					hintAddress = hintAddress.add(hintDT.getLength());
				}
				fragment.move(hintStartAddress, hintAddress.subtract(1));
			}
		}
		catch (Exception e) {
			log.appendMsg("Unable to create " + getCommandName() + " - " + e.getMessage());
		}
	}
}