/* *******************************************************************
 * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
 * All rights reserved. 
 * This program and the accompanying materials are made available 
 * under the terms of the Eclipse Public License v1.0 
 * which accompanies this distribution and is available at 
 * http://www.eclipse.org/legal/epl-v10.html 
 *  
 * Contributors: 
 *     PARC     initial implementation
 *     Alexandre Vasseur    @AspectJ ITDs
 * ******************************************************************/

package org.aspectj.weaver;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.aspectj.bridge.ISourceLocation;
import org.aspectj.bridge.SourceLocation;
import org.aspectj.util.TypeSafeEnum;

/**
 * This is an abstraction over method/field introduction. It might not have the chops to handle other inter-type declarations. This
 * is the thing that is used on the eclipse side and serialized into a ConcreteTypeMunger.
 */
public abstract class ResolvedTypeMunger {

	protected Kind kind;
	protected ResolvedMember signature;

	/**
	 * The declared signature is filled in when a type munger is parameterized for application to a particular type. It represents
	 * the signature originally declared in the source file.
	 */
	protected ResolvedMember declaredSignature;

	// This list records the occurences (in order) of any names specified in the <>
	// for a target type for the ITD. So for example, for List<C,B,A> this list
	// will be C,B,A - the list is used later to map other occurrences of C,B,A
	// across the intertype declaration to the right type variables in the generic
	// type upon which the itd is being made.
	// might need serializing the class file for binary weaving.
	protected List<String> typeVariableAliases;

	private Set<ResolvedMember> superMethodsCalled = Collections.emptySet();

	private ISourceLocation location;

	private ResolvedType onType = null;

	public ResolvedTypeMunger(Kind kind, ResolvedMember signature) {
		this.kind = kind;
		this.signature = signature;
		UnresolvedType declaringType = signature != null ? signature.getDeclaringType() : null;
		if (declaringType != null) {
			if (declaringType.isRawType()) {
				throw new IllegalStateException("Use generic type, not raw type");
			}
			if (declaringType.isParameterizedType()) {
				throw new IllegalStateException("Use generic type, not parameterized type");
			}
		}
		// boolean aChangeOccurred = false;
		//		
		// UnresolvedType rt = signature.getReturnType();
		// if (rt.isParameterizedType() || rt.isGenericType()) {rt = rt.getRawType();aChangeOccurred=true;}
		// UnresolvedType[] pt = signature.getParameterTypes();
		// for (int i = 0; i < pt.length; i++) {
		// if (pt[i].isParameterizedType() || pt[i].isGenericType()) { pt[i] = pt[i].getRawType();aChangeOccurred=true;}
		// }
		// if (aChangeOccurred) {
		// this.signature = new
		// ResolvedMemberImpl(signature.getKind(),signature.getDeclaringType(),signature.getModifiers(),rt,signature
		// .getName(),pt,signature.getExceptions());
		// }
	}

	public void setSourceLocation(ISourceLocation isl) {
		location = isl;
	}

	public ISourceLocation getSourceLocation() {
		return location;
	}

	// ----

	// fromType is guaranteed to be a non-abstract aspect
	// public ConcreteTypeMunger concretize(World world, ResolvedType aspectType) {
	//    	
	// ConcreteTypeMunger munger = world.concreteTypeMunger(this, aspectType);
	// return munger;
	// }

	public boolean matches(ResolvedType matchType, ResolvedType aspectType) {
		if (onType == null) {
			onType = matchType.getWorld().resolve(getDeclaringType());
			if (onType.isRawType()) {
				onType = onType.getGenericType();
			}
		}
		// System.err.println("matching: " + this + " to " + matchType + " onType = " + onType);
		if (matchType.equals(onType)) {
			if (!onType.isExposedToWeaver()) {
				// if the onType is an interface, and it already has the member we are about
				// to munge, then this is ok...
				boolean ok = (onType.isInterface() && (onType.lookupMemberWithSupersAndITDs(getSignature()) != null));

				if (!ok && onType.getWeaverState() == null) {
					if (matchType.getWorld().getLint().typeNotExposedToWeaver.isEnabled()) {
						matchType.getWorld().getLint().typeNotExposedToWeaver.signal(matchType.getName(), signature
								.getSourceLocation());
					}
				}
			}
			return true;
		}
		// System.err.println("NO MATCH DIRECT");

		if (onType.isInterface()) {
			return matchType.isTopmostImplementor(onType);
		} else {
			return false;
		}
	}

	// ----

	@Override
	public String toString() {
		return "ResolvedTypeMunger(" + getKind() + ", " + getSignature() + ")";
		// .superMethodsCalled + ")";
	}

	// ----

	public static ResolvedTypeMunger read(VersionedDataInputStream s, ISourceContext context) throws IOException {
		Kind kind = Kind.read(s);
		if (kind == Field) {
			return NewFieldTypeMunger.readField(s, context);
		} else if (kind == Method) {
			return NewMethodTypeMunger.readMethod(s, context);
		} else if (kind == Constructor) {
			return NewConstructorTypeMunger.readConstructor(s, context);
		} else if (kind == MethodDelegate) {
			return MethodDelegateTypeMunger.readMethod(s, context, false);
		} else if (kind == FieldHost) {
			return MethodDelegateTypeMunger.FieldHostTypeMunger.readFieldHost(s, context);
		} else if (kind == MethodDelegate2) {
			return MethodDelegateTypeMunger.readMethod(s, context, true);
		} else if (kind == InnerClass) {
			return NewMemberClassTypeMunger.readInnerClass(s, context);
		} else {
			throw new RuntimeException("unimplemented");
		}
	}

	protected static Set<ResolvedMember> readSuperMethodsCalled(VersionedDataInputStream s) throws IOException {
		Set<ResolvedMember> ret = new HashSet<>();
		int n = -1;
		if (s.isAtLeast169()) {
			n = s.readByte();
		} else {
			n = s.readInt();
		}
		if (n < 0) {
			throw new BCException("Problem deserializing type munger");
		}
		for (int i = 0; i < n; i++) {
			ret.add(ResolvedMemberImpl.readResolvedMember(s, null));
		}
		return ret;
	}

	protected final void writeSuperMethodsCalled(CompressingDataOutputStream s) throws IOException {
		if (superMethodsCalled == null || superMethodsCalled.size() == 0) {
			s.writeByte(0);
			return;
		}
		List<ResolvedMember> ret = new ArrayList<>(superMethodsCalled);
		Collections.sort(ret);
		int n = ret.size();
		s.writeByte(n);
		for (ResolvedMember m : ret) {
			m.write(s);
		}
	}

	protected static ISourceLocation readSourceLocation(VersionedDataInputStream s) throws IOException {
		// Location persistence for type mungers was added after 1.2.1 was shipped...
		if (s.getMajorVersion() < AjAttribute.WeaverVersionInfo.WEAVER_VERSION_MAJOR_AJ150) {
			return null;
		}
		SourceLocation ret = null;
		ObjectInputStream ois = null;
		try {
			// This logic copes with the location missing from the attribute - an EOFException will
			// occur on the next line and we ignore it.
			byte b = 0;
			// if we aren't on 1.6.9 or we are on 1.6.9 but not compressed, then read as object stream
			if (!s.isAtLeast169() || (b = s.readByte()) == 0) {
				ois = new ObjectInputStream(s);
				boolean validLocation = (Boolean) ois.readObject();
				if (validLocation) {
					File f = (File) ois.readObject();
					Integer ii = (Integer) ois.readObject();
					Integer offset = (Integer) ois.readObject();
					ret = new SourceLocation(f, ii);
					ret.setOffset(offset);
				}
			} else {
				boolean validLocation = b == 2;
				if (validLocation) {
					String path = s.readUtf8(s.readShort());
					File f = new File(path);
					ret = new SourceLocation(f, s.readInt());
					int offset = s.readInt();
					ret.setOffset(offset);
				}
			}

		} catch (EOFException eof) {
			return null; // This exception occurs if processing an 'old style' file where the
			// type munger attributes don't include the source location.
		} catch (IOException ioe) {
			// Something went wrong, maybe this is an 'old style' file that doesnt attach locations to mungers?
			// (but I thought that was just an EOFException?)
			ioe.printStackTrace();
			return null;
		} catch (ClassNotFoundException e) {
		} finally {
			if (ois != null) {
				ois.close();
			}
		}
		return ret;
	}

	protected final void writeSourceLocation(CompressingDataOutputStream s) throws IOException {
		if (s.canCompress()) {
			s.writeByte(1 + (location == null ? 0 : 1)); // 1==compressed no location 2==compressed with location
			if (location != null) {
				s.writeCompressedPath(location.getSourceFile().getPath());
				s.writeInt(location.getLine());
				s.writeInt(location.getOffset());
			}
		} else {
			s.writeByte(0);
			ObjectOutputStream oos = new ObjectOutputStream(s);
			oos.writeObject(location != null);
			if (location != null) {
				oos.writeObject(location.getSourceFile());
				oos.writeObject(location.getLine());
				oos.writeObject(location.getOffset());
			}
			oos.flush();
			oos.close();
		}
	}

	public abstract void write(CompressingDataOutputStream s) throws IOException;

	public Kind getKind() {
		return kind;
	}

	public static class Kind extends TypeSafeEnum {
		/* private */Kind(String name, int key) {
			super(name, key);
		}

		public static Kind read(DataInputStream s) throws IOException {
			int key = s.readByte();
			switch (key) {
			case 1:
				return Field;
			case 2:
				return Method;
			case 5:
				return Constructor;
			case 9:
				return MethodDelegate;
			case 10:
				return FieldHost;
			case 11:
				return MethodDelegate2;
			case 12:
				return InnerClass;
			}
			throw new BCException("bad kind: " + key);
		}

		@Override
		public String toString() {
			// we want MethodDelegate to appear as Method in WeaveInfo messages
			// TODO we may want something for fieldhost ?
			if (getName().startsWith(MethodDelegate.getName())) {// startsWith will cover MethodDelegate2 as well
				return Method.toString();
			} else {
				return super.toString();
			}
		}
	}

	// ---- fields

	public static final Kind Field = new Kind("Field", 1);
	public static final Kind Method = new Kind("Method", 2);
	public static final Kind Constructor = new Kind("Constructor", 5);
	// not serialized, only created during concretization of aspects
	public static final Kind PerObjectInterface = new Kind("PerObjectInterface", 3);
	public static final Kind PrivilegedAccess = new Kind("PrivilegedAccess", 4);
	public static final Kind Parent = new Kind("Parent", 6);
	// PTWIMPL not serialized, used during concretization of aspects
	public static final Kind PerTypeWithinInterface = new Kind("PerTypeWithinInterface", 7);
	public static final Kind AnnotationOnType = new Kind("AnnotationOnType", 8); // not serialized
	public static final Kind MethodDelegate = new Kind("MethodDelegate", 9);// serialized, @AJ ITDs
	public static final Kind FieldHost = new Kind("FieldHost", 10);// serialized, @AJ ITDs
	public static final Kind MethodDelegate2 = new Kind("MethodDelegate2", 11);// serialized, @AJ ITDs
	public static final Kind InnerClass = new Kind("InnerClass", 12);

	public static final String SUPER_DISPATCH_NAME = "superDispatch";

	public void setSuperMethodsCalled(Set<ResolvedMember> c) {
		this.superMethodsCalled = c;
	}

	public Set<ResolvedMember> getSuperMethodsCalled() {
		return superMethodsCalled;
	}

	public ResolvedMember getSignature() {
		return signature;
	}

	// ----

	public ResolvedMember getMatchingSyntheticMember(Member member, ResolvedType aspectType) {
		if ((getSignature() != null) && getSignature().isPublic() && member.equals(getSignature())) {
			return getSignature();
		}

		return null;
	}

	public boolean changesPublicSignature() {
		return kind == Field || kind == Method || kind == Constructor;
	}

	public boolean needsAccessToTopmostImplementor() {
		if (kind == Field) {
			return true;
		} else if (kind == Method) {
			return !signature.isAbstract();
		} else {
			return false;
		}
	}

	protected static List<String> readInTypeAliases(VersionedDataInputStream s) throws IOException {
		if (s.getMajorVersion() >= AjAttribute.WeaverVersionInfo.WEAVER_VERSION_MAJOR_AJ150) {
			int count = -1;
			if (s.isAtLeast169()) {
				count = s.readByte();
			} else {
				count = s.readInt();
			}
			if (count != 0) {
				List<String> aliases = new ArrayList<>();
				for (int i = 0; i < count; i++) {
					aliases.add(s.readUTF());
				}
				return aliases;
			}
		}
		return null;
	}

	protected final void writeOutTypeAliases(DataOutputStream s) throws IOException {
		// Write any type variable aliases
		if (typeVariableAliases == null || typeVariableAliases.size() == 0) {
			s.writeByte(0);
		} else {
			s.writeByte(typeVariableAliases.size());
			for (String element : typeVariableAliases) {
				s.writeUTF(element);
			}
		}
	}

	public List<String> getTypeVariableAliases() {
		return typeVariableAliases;
	}

	protected void setTypeVariableAliases(List<String> typeVariableAliases) {
		this.typeVariableAliases = typeVariableAliases;
	}

	public boolean hasTypeVariableAliases() {
		return (typeVariableAliases != null && typeVariableAliases.size() > 0);
	}

	/**
	 * return true if type variables are specified with the target type for this ITD. e.g. this would return true:
	 * "int I&lt;A,B&gt;.m() { return 42; }"
	 */
	public boolean sharesTypeVariablesWithGenericType() {
		return (typeVariableAliases != null && typeVariableAliases.size() > 0);
	}

	/**
	 * Parameterizes a resolved type munger for a particular usage of its target type (this is used when the target type is generic
	 * and the ITD shares type variables with the target) see ConcreteTypeMunger.parameterizedFor
	 */
	public ResolvedTypeMunger parameterizedFor(ResolvedType target) {
		throw new BCException("Dont call parameterizedFor on a type munger of this kind: " + this.getClass());
	}

	// ResolvedType genericType = target;
	// if (target.isRawType() || target.isParameterizedType()) genericType = genericType.getGenericType();
	// ResolvedMember parameterizedSignature = null;
	// // If we are parameterizing it for a generic type, we just need to 'swap the letters' from the ones used
	// // in the original ITD declaration to the ones used in the actual target type declaration.
	// if (target.isGenericType()) {
	// TypeVariable vars[] = target.getTypeVariables();
	// UnresolvedTypeVariableReferenceType[] varRefs = new UnresolvedTypeVariableReferenceType[vars.length];
	// for (int i = 0; i < vars.length; i++) {
	// varRefs[i] = new UnresolvedTypeVariableReferenceType(vars[i]);
	// }
	// parameterizedSignature = getSignature().parameterizedWith(varRefs,genericType,true,typeVariableAliases);
	// } else {
	// // For raw and 'normal' parameterized targets (e.g. Interface, Interface<String>)
	// parameterizedSignature =
	// getSignature().parameterizedWith(target.getTypeParameters(),genericType,target.isParameterizedType(),typeVariableAliases);
	// }
	// return new NewMethodTypeMunger(parameterizedSignature,getSuperMethodsCalled(),typeVariableAliases);
	// }
	// /**
	// * see ResolvedTypeMunger.parameterizedFor(ResolvedType)
	// */
	// public ResolvedTypeMunger parameterizedFor(ResolvedType target) {
	// ResolvedType genericType = target;
	// if (target.isRawType() || target.isParameterizedType()) genericType = genericType.getGenericType();
	// ResolvedMember parameterizedSignature =
	// getSignature().parameterizedWith(target.getTypeParameters(),genericType,target.isParameterizedType(),typeVariableAliases);
	// return new NewFieldTypeMunger(parameterizedSignature,getSuperMethodsCalled(),typeVariableAliases);
	// }

	public void setDeclaredSignature(ResolvedMember rm) {
		declaredSignature = rm;
	}

	public ResolvedMember getDeclaredSignature() {
		return declaredSignature;
	}

	/**
	 * A late munger has to be done after shadow munging since which shadows are matched can affect the operation of the late
	 * munger. e.g. perobjectinterfacemunger
	 */
	public boolean isLateMunger() {
		return false;
	}

	/**
	 * Some type mungers are created purely to help with the implementation of shadow mungers. For example to support the cflow()
	 * pointcut we create a new cflow field in the aspect, and that is added via a BcelCflowCounterFieldAdder.
	 * 
	 * During compilation we need to compare sets of type mungers, and if some only come into existence after the 'shadowy' type
	 * things have been processed, we need to ignore them during the comparison.
	 * 
	 * Returning true from this method indicates the type munger exists to support 'shadowy' stuff - and so can be ignored in some
	 * comparison.
	 */
	public boolean existsToSupportShadowMunging() {
		return false;
	}

	public ResolvedTypeMunger parameterizeWith(Map<String, UnresolvedType> m, World w) {
		throw new BCException("Dont call parameterizeWith() on a type munger of this kind: " + this.getClass());
	}

	public UnresolvedType getDeclaringType() {
		return getSignature().getDeclaringType();
	}

}