Copyright (c) 2016, 2017 Google, Inc 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:
  Stefan Xenos (Google) - Initial implementation
/*******************************************************************************
 * Copyright (c) 2016, 2017 Google, Inc 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:
 *   Stefan Xenos (Google) - Initial implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.nd.java.model;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.classfmt.BinaryTypeFormatter;
import org.eclipse.jdt.internal.compiler.classfmt.ElementValuePairInfo;
import org.eclipse.jdt.internal.compiler.codegen.AnnotationTargetTypeConstants;
import org.eclipse.jdt.internal.compiler.env.ClassSignature;
import org.eclipse.jdt.internal.compiler.env.EnumConstantSignature;
import org.eclipse.jdt.internal.compiler.env.IBinaryAnnotation;
import org.eclipse.jdt.internal.compiler.env.IBinaryElementValuePair;
import org.eclipse.jdt.internal.compiler.env.IBinaryField;
import org.eclipse.jdt.internal.compiler.env.IBinaryMethod;
import org.eclipse.jdt.internal.compiler.env.IBinaryNestedType;
import org.eclipse.jdt.internal.compiler.env.IBinaryType;
import org.eclipse.jdt.internal.compiler.env.IBinaryTypeAnnotation;
import org.eclipse.jdt.internal.compiler.env.ITypeAnnotationWalker;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.ExternalAnnotationStatus;
import org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment;
import org.eclipse.jdt.internal.core.nd.IReader;
import org.eclipse.jdt.internal.core.nd.db.IString;
import org.eclipse.jdt.internal.core.nd.java.JavaNames;
import org.eclipse.jdt.internal.core.nd.java.NdAnnotation;
import org.eclipse.jdt.internal.core.nd.java.NdAnnotationValuePair;
import org.eclipse.jdt.internal.core.nd.java.NdConstant;
import org.eclipse.jdt.internal.core.nd.java.NdConstantAnnotation;
import org.eclipse.jdt.internal.core.nd.java.NdConstantArray;
import org.eclipse.jdt.internal.core.nd.java.NdConstantClass;
import org.eclipse.jdt.internal.core.nd.java.NdConstantEnum;
import org.eclipse.jdt.internal.core.nd.java.NdMethod;
import org.eclipse.jdt.internal.core.nd.java.NdMethodException;
import org.eclipse.jdt.internal.core.nd.java.NdMethodParameter;
import org.eclipse.jdt.internal.core.nd.java.NdResourceFile;
import org.eclipse.jdt.internal.core.nd.java.NdType;
import org.eclipse.jdt.internal.core.nd.java.NdTypeAnnotation;
import org.eclipse.jdt.internal.core.nd.java.NdTypeId;
import org.eclipse.jdt.internal.core.nd.java.NdTypeInterface;
import org.eclipse.jdt.internal.core.nd.java.NdTypeParameter;
import org.eclipse.jdt.internal.core.nd.java.NdTypeSignature;
import org.eclipse.jdt.internal.core.nd.java.NdVariable;
import org.eclipse.jdt.internal.core.nd.java.TypeRef;
import org.eclipse.jdt.internal.core.util.CharArrayBuffer;

Implementation of IBinaryType that reads all its content from the index /**
 * Implementation of {@link IBinaryType} that reads all its content from the index
 */
public class IndexBinaryType implements IBinaryType {
	private final TypeRef typeRef;

	private boolean simpleAttributesInitialized;
	private char[] enclosingMethod;
	private char[] enclosingType;
	private char[] fileName;
	private char[] superclassName;
	private int modifiers;
	private boolean isAnonymous;
	private boolean isLocal;
	private boolean isMember;

	private long tagBits;

	private char[] binaryTypeName;

	private static final IBinaryAnnotation[] NO_ANNOTATIONS = new IBinaryAnnotation[0];
	private static final int[] NO_PATH = new int[0];

	public IndexBinaryType(TypeRef type, char[] indexPath) {
		this.typeRef = type;
		this.fileName = indexPath;
	}

	public boolean exists() {
		return this.typeRef.get() != null;
	}

	@Override
	public int getModifiers() {
		initSimpleAttributes();

		return this.modifiers;
	}

	@Override
	public boolean isBinaryType() {
		return true;
	}

	@Override
	public char[] getFileName() {
		return this.fileName;
	}

	@Override
	public IBinaryAnnotation[] getAnnotations() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				return toAnnotationArray(this.typeRef.get().getAnnotations());
			} else {
				return NO_ANNOTATIONS;
			}
		}
	}

	private static IBinaryAnnotation[] toAnnotationArray(List<? extends NdAnnotation> annotations) {
		if (annotations.isEmpty()) {
			return NO_ANNOTATIONS;
		}
		IBinaryAnnotation[] result = new IBinaryAnnotation[annotations.size()];

		for (int idx = 0; idx < result.length; idx++) {
			result[idx] = createBinaryAnnotation(annotations.get(idx));
		}
		return result;
	}

	@Override
	public IBinaryTypeAnnotation[] getTypeAnnotations() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				return createBinaryTypeAnnotations(type.getTypeAnnotations());
			}
		}
		return null;
	}

	@Override
	public char[] getEnclosingMethod() {
		initSimpleAttributes();

		return this.enclosingMethod;
	}

	@Override
	public char[] getEnclosingTypeName() {
		initSimpleAttributes();

		return this.enclosingType;
	}

	@Override
	public IBinaryField[] getFields() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				List<NdVariable> variables = type.getVariables();

				if (variables.isEmpty()) {
					return null;
				}

				IBinaryField[] result = new IBinaryField[variables.size()];
				for (int fieldIdx = 0; fieldIdx < variables.size(); fieldIdx++) {
					result[fieldIdx] = createBinaryField(variables.get(fieldIdx));
				}
				return result;
			} else {
				return null;
			}
		}
	}

	@Override
	public char[] getGenericSignature() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				if (!type.getFlag(NdType.FLG_GENERIC_SIGNATURE_PRESENT)) {
					return null;
				}
				CharArrayBuffer buffer = new CharArrayBuffer();
				NdTypeParameter.getSignature(buffer, type.getTypeParameters());
				NdTypeSignature superclass = type.getSuperclass();
				if (superclass != null) {
					superclass.getSignature(buffer);
				}
				for (NdTypeInterface nextInterface : type.getInterfaces()) {
					nextInterface.getInterface().getSignature(buffer);
				}
				return buffer.getContents();
			} else {
				return null;
			}
		}
	}

	@Override
	public char[][] getInterfaceNames() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				List<NdTypeInterface> interfaces = type.getInterfaces();

				if (interfaces.isEmpty()) {
					return null;
				}

				char[][] result = new char[interfaces.size()][];
				for (int idx = 0; idx < interfaces.size(); idx++) {
					NdTypeSignature nextInterface = interfaces.get(idx).getInterface();

					result[idx] = nextInterface.getRawType().getBinaryName();
				}
				return result;
			} else {
				return null;
			}
		}
	}

	@Override
	public IBinaryNestedType[] getMemberTypes() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				List<NdType> declaredTypes = type.getTypeId().getDeclaredTypes();
				if (declaredTypes.isEmpty()) {
					return null;
				}

				NdResourceFile resFile = type.getResourceFile();
				IString javaRoot = resFile.getPackageFragmentRoot();

				// Filter out all the declared types which are at different java roots (only keep the ones belonging
				// to the same .jar file or to another .class file in the same folder).
				List<IBinaryNestedType> result = new ArrayList<>();
				for (NdType next : declaredTypes) {
					NdResourceFile nextResFile = next.getResourceFile();

					if (nextResFile.getPackageFragmentRoot().compare(javaRoot, true) == 0) {
						result.add(createBinaryNestedType(next));
					}
				}
				return result.isEmpty() ? null : result.toArray(new IBinaryNestedType[result.size()]);
			} else {
				return null;
			}
		}
	}

	private IBinaryNestedType createBinaryNestedType(NdType next) {
		return new IndexBinaryNestedType(next.getTypeId().getBinaryName(), next.getDeclaringType().getBinaryName(),
				next.getModifiers());
	}

	@Override
	public IBinaryMethod[] getMethods() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				List<NdMethod> methods = type.getMethodsInDeclarationOrder();

				if (methods.isEmpty()) {
					return null;
				}

				IBinaryMethod[] result = new IBinaryMethod[methods.size()];
				for (int idx = 0; idx < result.length; idx++) {
					result[idx] = createBinaryMethod(methods.get(idx));
				}

				return result;
			} else {
				return null;
			}
		}
	}

	@Override
	public char[][][] getMissingTypeNames() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				IString string = type.getMissingTypeNames();
				if (string.length() == 0) {
					return null;
				}
				char[] missingTypeNames = string.getChars();
				char[][] paths = CharOperation.splitOn(',', missingTypeNames);
				char[][][] result = new char[paths.length][][];
				for (int idx = 0; idx < paths.length; idx++) {
					result[idx] = CharOperation.splitOn('/', paths[idx]);
				}
				return result;
			} else {
				return null;
			}
		}
	}

	@Override
	public char[] getName() {
		initSimpleAttributes();

		return this.binaryTypeName;
	}

	@Override
	public char[] getSourceName() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				return type.getSourceName();
			} else {
				return new char[0];
			}
		}
	}

	@Override
	public char[] getSuperclassName() {
		initSimpleAttributes();

		return this.superclassName;
	}

	@Override
	public long getTagBits() {
		initSimpleAttributes();

		return this.tagBits;
	}

	@Override
	public boolean isAnonymous() {
		initSimpleAttributes();

		return this.isAnonymous;
	}

	@Override
	public boolean isLocal() {
		initSimpleAttributes();

		return this.isLocal;
	}

	@Override
	public boolean isMember() {
		initSimpleAttributes();

		return this.isMember;
	}

	@Override
	public char[] sourceFileName() {
		try (IReader rl = this.typeRef.lock()) {
			NdType type = this.typeRef.get();
			if (type != null) {
				char[] result = type.getSourceFileName().getChars();
				if (result.length == 0) {
					return null;
				}
				return result;
			} else {
				return null;
			}
		}
	}

	@Override
	public ITypeAnnotationWalker enrichWithExternalAnnotationsFor(ITypeAnnotationWalker walker, Object member,
			LookupEnvironment environment) {
		return walker;
	}

	private IBinaryMethod createBinaryMethod(NdMethod ndMethod) {
		return IndexBinaryMethod.create().setAnnotations(toAnnotationArray(ndMethod.getAnnotations()))
				.setModifiers(ndMethod.getModifiers()).setIsConstructor(ndMethod.isConstructor())
				.setArgumentNames(getArgumentNames(ndMethod)).setDefaultValue(unpackValue(ndMethod.getDefaultValue()))
				.setExceptionTypeNames(getExceptionTypeNames(ndMethod))
				.setGenericSignature(getGenericSignatureFor(ndMethod))
				.setMethodDescriptor(ndMethod.getMethodDescriptor())
				.setParameterAnnotations(getParameterAnnotations(ndMethod))
				.setSelector(ndMethod.getSelector()).setTagBits(ndMethod.getTagBits())
				.setIsClInit(ndMethod.isClInit()).setTypeAnnotations(createBinaryTypeAnnotations(ndMethod.getTypeAnnotations()));
	}

	private static IBinaryTypeAnnotation[] createBinaryTypeAnnotations(List<? extends NdTypeAnnotation> typeAnnotations) {
		if (typeAnnotations.isEmpty()) {
			return null;
		}
		IBinaryTypeAnnotation[] result = new IBinaryTypeAnnotation[typeAnnotations.size()];
		int idx = 0;
		for (NdTypeAnnotation next : typeAnnotations) {
			IBinaryAnnotation annotation = createBinaryAnnotation(next);
			int[] typePath = getTypePath(next.getTypePath());
			int info = 0;
			int info2 = 0;
			switch (next.getTargetType()) {
				case AnnotationTargetTypeConstants.CLASS_TYPE_PARAMETER:
				case AnnotationTargetTypeConstants.METHOD_TYPE_PARAMETER:
					info = next.getTargetInfoArg0();
					break;
				case AnnotationTargetTypeConstants.CLASS_EXTENDS:
					info = next.getTarget();
					break;
				case AnnotationTargetTypeConstants.CLASS_TYPE_PARAMETER_BOUND:
				case AnnotationTargetTypeConstants.METHOD_TYPE_PARAMETER_BOUND:
					info = next.getTargetInfoArg0();
					info2 = next.getTargetInfoArg1();
					break;
				case AnnotationTargetTypeConstants.FIELD:
				case AnnotationTargetTypeConstants.METHOD_RETURN:
				case AnnotationTargetTypeConstants.METHOD_RECEIVER:
					break;
				case AnnotationTargetTypeConstants.METHOD_FORMAL_PARAMETER :
					info = next.getTarget();
					break;
				case AnnotationTargetTypeConstants.THROWS :
					info = next.getTarget();
					break;

				default:
					throw new IllegalStateException("Target type not handled " + next.getTargetType()); //$NON-NLS-1$
			}
			result[idx++] = new IndexBinaryTypeAnnotation(next.getTargetType(), info, info2, typePath, annotation);
		}
		return result;
	}

	private static int[] getTypePath(byte[] typePath) {
		if (typePath.length == 0) {
			return NO_PATH;
		}
		int[] result = new int[typePath.length];
		for (int idx = 0; idx < typePath.length; idx++) {
			result[idx] = typePath[idx];
		}
		return result;
	}

	private static char[] getGenericSignatureFor(NdMethod method) {
		if (!method.hasAllFlags(NdMethod.FLG_GENERIC_SIGNATURE_PRESENT)) {
			return null;
		}
		CharArrayBuffer result = new CharArrayBuffer();
		method.getGenericSignature(result, method.hasAllFlags(NdMethod.FLG_THROWS_SIGNATURE_PRESENT));
		return result.getContents();
	}
	
	private char[][] getArgumentNames(NdMethod ndMethod) {
		// Unlike what its JavaDoc says, IBinaryType returns an empty array if no argument names are available, so
		// we replicate this weird undocumented corner case here.
		char[][] result = ndMethod.getParameterNames();
		int lastNonEmpty = -1;
		for (int idx = 0; idx < result.length; idx++) {
			if (result[idx] != null && result[idx].length != 0) {
				lastNonEmpty = idx;
			}
		}

		if (lastNonEmpty != result.length - 1) {
			char[][] newResult = new char[lastNonEmpty + 1][];
			System.arraycopy(result, 0, newResult, 0, lastNonEmpty + 1);
			return newResult;
		}
		return result;
	}

	private IBinaryAnnotation[][] getParameterAnnotations(NdMethod ndMethod) {
		List<NdMethodParameter> parameters = ndMethod.getMethodParameters();
		if (parameters.isEmpty()) {
			return null;
		}

		IBinaryAnnotation[][] result = new IBinaryAnnotation[parameters.size()][];
		for (int idx = 0; idx < parameters.size(); idx++) {
			NdMethodParameter next = parameters.get(idx);

			result[idx] = toAnnotationArray(next.getAnnotations());
		}

		// int newLength = result.length;
		// while (newLength > 0 && result[newLength - 1] == null) {
		// --newLength;
		// }
		//
		// if (newLength < result.length) {
		// if (newLength == 0) {
		// return null;
		// }
		// IBinaryAnnotation[][] newResult = new IBinaryAnnotation[newLength][];
		// System.arraycopy(result, 0, newResult, 0, newLength);
		// result = newResult;
		// }

		return result;
	}

	private char[][] getExceptionTypeNames(NdMethod ndMethod) {
		List<NdMethodException> exceptions = ndMethod.getExceptions();

		// Although the JavaDoc for IBinaryMethod says that the exception list will be null if empty,
		// the implementation in MethodInfo returns an empty array rather than null. We copy the
		// same behavior here in case something is relying on it. Uncomment the following if the "null"
		// version is deemed correct.

		// if (exceptions.isEmpty()) {
		// return null;
		// }

		char[][] result = new char[exceptions.size()][];
		for (int idx = 0; idx < exceptions.size(); idx++) {
			NdMethodException next = exceptions.get(idx);

			result[idx] = next.getExceptionType().getRawType().getBinaryName();
		}
		return result;
	}

	public static IBinaryField createBinaryField(NdVariable ndVariable) {
		char[] name = ndVariable.getName().getChars();
		Constant constant = null;
		NdConstant ndConstant = ndVariable.getConstant();
		if (ndConstant != null) {
			constant = ndConstant.getConstant();
		}
		if (constant == null) {
			constant = Constant.NotAConstant;
		}

		NdTypeSignature type = ndVariable.getType();

		IBinaryTypeAnnotation[] typeAnnotationArray = createBinaryTypeAnnotations(ndVariable.getTypeAnnotations());

		IBinaryAnnotation[] annotations = toAnnotationArray(ndVariable.getAnnotations());

		CharArrayBuffer signature = new CharArrayBuffer();
		if (ndVariable.hasVariableFlag(NdVariable.FLG_GENERIC_SIGNATURE_PRESENT)) {
			type.getSignature(signature);
		}

		long tagBits = ndVariable.getTagBits();
		return new IndexBinaryField(annotations, constant, signature.getContents(), ndVariable.getModifiers(), name,
				tagBits, typeAnnotationArray, type.getRawType().getFieldDescriptor().getChars());
	}

	public static IBinaryAnnotation createBinaryAnnotation(NdAnnotation ndAnnotation) {
		List<NdAnnotationValuePair> elementValuePairs = ndAnnotation.getElementValuePairs();

		final IBinaryElementValuePair[] resultingPair = new IBinaryElementValuePair[elementValuePairs.size()];

		for (int idx = 0; idx < elementValuePairs.size(); idx++) {
			NdAnnotationValuePair next = elementValuePairs.get(idx);

			resultingPair[idx] = new ElementValuePairInfo(next.getName().getChars(), unpackValue(next.getValue()));
		}

		final char[] binaryName = JavaNames.fieldDescriptorToBinaryName(
				ndAnnotation.getType().getRawType().getFieldDescriptor().getChars());

		return new IBinaryAnnotation() {
			@Override
			public char[] getTypeName() {
				return binaryName;
			}

			@Override
			public IBinaryElementValuePair[] getElementValuePairs() {
				return resultingPair;
			}

			@Override
			public String toString() {
				return BinaryTypeFormatter.annotationToString(this);
			}
		};
	}

	public void initSimpleAttributes() {
		if (!this.simpleAttributesInitialized) {
			this.simpleAttributesInitialized = true;

			try (IReader rl = this.typeRef.lock()) {
				NdType type = this.typeRef.get();
				if (type != null) {
					IString declaringMethod = type.getDeclaringMethod();

					if (declaringMethod.length() != 0) {
						char[] methodName = declaringMethod.getChars();
						this.enclosingMethod = methodName;
						this.enclosingType = type.getDeclaringType().getBinaryName();
					} else {
						NdTypeId typeId = type.getDeclaringType();

						if (typeId != null) {
							this.enclosingType = typeId.getBinaryName();
						}
					}

					this.modifiers = type.getModifiers();
					this.isAnonymous = type.isAnonymous();
					this.isLocal = type.isLocal();
					this.isMember = type.isMember();
					this.tagBits = type.getTagBits();

					NdTypeSignature superclass = type.getSuperclass();
					if (superclass != null) {
						this.superclassName = superclass.getRawType().getBinaryName();
					} else {
						this.superclassName = null;
					}

					this.binaryTypeName = JavaNames.fieldDescriptorToBinaryName(type.getFieldDescriptor().getChars());
				} else {
					this.binaryTypeName = JavaNames.fieldDescriptorToBinaryName(this.typeRef.getFieldDescriptor());
				}
			}
		}
	}

	private static Object unpackValue(NdConstant value) {
		if (value == null) {
			return null;
		}
		if (value instanceof NdConstantAnnotation) {
			NdConstantAnnotation annotation = (NdConstantAnnotation) value;

			return createBinaryAnnotation(annotation.getValue());
		}
		if (value instanceof NdConstantArray) {
			NdConstantArray array = (NdConstantArray) value;

			List<NdConstant> arrayContents = array.getValue();

			Object[] result = new Object[arrayContents.size()];
			for (int idx = 0; idx < arrayContents.size(); idx++) {
				result[idx] = unpackValue(arrayContents.get(idx));
			}
			return result;
		}
		if (value instanceof NdConstantEnum) {
			NdConstantEnum ndConstantEnum = (NdConstantEnum) value;

			NdTypeSignature signature = ndConstantEnum.getType();

			return new EnumConstantSignature(signature.getRawType().getBinaryName(), ndConstantEnum.getValue());
		}
		if (value instanceof NdConstantClass) {
			NdConstantClass constant = (NdConstantClass) value;

			return new ClassSignature(constant.getValue().getRawType().getBinaryName());
		}

		return value.getConstant();
	}

	@Override
	public ExternalAnnotationStatus getExternalAnnotationStatus() {
		return ExternalAnnotationStatus.NOT_EEA_CONFIGURED;
	}

	@Override
	public char[] getModule() {
		// TODO Auto-generated method stub
		return null;
	}
}