/*
 * Copyright (C) 2009-2016 The Project Lombok Authors.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package lombok.eclipse.handlers;

import static lombok.core.handlers.HandlerUtil.*;
import static lombok.eclipse.Eclipse.*;
import static lombok.eclipse.handlers.EclipseHandlerUtil.*;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import lombok.AccessLevel;
import lombok.ConfigurationKeys;
import lombok.experimental.Delegate;
import lombok.Getter;
import lombok.core.AST.Kind;
import lombok.core.AnnotationValues;
import lombok.eclipse.EclipseAnnotationHandler;
import lombok.eclipse.EclipseNode;
import lombok.eclipse.agent.PatchDelegate;

import org.eclipse.jdt.internal.compiler.ast.ASTNode;
import org.eclipse.jdt.internal.compiler.ast.AllocationExpression;
import org.eclipse.jdt.internal.compiler.ast.Annotation;
import org.eclipse.jdt.internal.compiler.ast.ArrayTypeReference;
import org.eclipse.jdt.internal.compiler.ast.Assignment;
import org.eclipse.jdt.internal.compiler.ast.BinaryExpression;
import org.eclipse.jdt.internal.compiler.ast.Block;
import org.eclipse.jdt.internal.compiler.ast.CastExpression;
import org.eclipse.jdt.internal.compiler.ast.ConditionalExpression;
import org.eclipse.jdt.internal.compiler.ast.EqualExpression;
import org.eclipse.jdt.internal.compiler.ast.Expression;
import org.eclipse.jdt.internal.compiler.ast.FieldDeclaration;
import org.eclipse.jdt.internal.compiler.ast.IfStatement;
import org.eclipse.jdt.internal.compiler.ast.LocalDeclaration;
import org.eclipse.jdt.internal.compiler.ast.MessageSend;
import org.eclipse.jdt.internal.compiler.ast.MethodDeclaration;
import org.eclipse.jdt.internal.compiler.ast.NullLiteral;
import org.eclipse.jdt.internal.compiler.ast.ParameterizedQualifiedTypeReference;
import org.eclipse.jdt.internal.compiler.ast.QualifiedTypeReference;
import org.eclipse.jdt.internal.compiler.ast.ReturnStatement;
import org.eclipse.jdt.internal.compiler.ast.SingleNameReference;
import org.eclipse.jdt.internal.compiler.ast.SingleTypeReference;
import org.eclipse.jdt.internal.compiler.ast.Statement;
import org.eclipse.jdt.internal.compiler.ast.SynchronizedStatement;
import org.eclipse.jdt.internal.compiler.ast.TypeDeclaration;
import org.eclipse.jdt.internal.compiler.ast.TypeReference;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.lookup.TypeConstants;
import org.mangosdk.spi.ProviderFor;

Handles the lombok.Getter annotation for eclipse. /**
 * Handles the {@code lombok.Getter} annotation for eclipse.
 */
@ProviderFor(EclipseAnnotationHandler.class)
public class HandleGetter extends EclipseAnnotationHandler<Getter> {
	private static final Annotation[] EMPTY_ANNOTATIONS_ARRAY = new Annotation[0];

	public boolean generateGetterForType(EclipseNode typeNode, EclipseNode pos, AccessLevel level, boolean checkForTypeLevelGetter, List<Annotation> onMethod) {
		if (checkForTypeLevelGetter) {
			if (hasAnnotation(Getter.class, typeNode)) {
				//The annotation will make it happen, so we can skip it.
				return true;
			}
		}
		
		TypeDeclaration typeDecl = null;
		if (typeNode.get() instanceof TypeDeclaration) typeDecl = (TypeDeclaration) typeNode.get();
		int modifiers = typeDecl == null ? 0 : typeDecl.modifiers;
		boolean notAClass = (modifiers &
				(ClassFileConstants.AccInterface | ClassFileConstants.AccAnnotation)) != 0;
		
		if (typeDecl == null || notAClass) {
			pos.addError("@Getter is only supported on a class, an enum, or a field.");
			return false;
		}
		
		for (EclipseNode field : typeNode.down()) {
			if (fieldQualifiesForGetterGeneration(field)) generateGetterForField(field, pos.get(), level, false, onMethod);
		}
		return true;
	}
	
	public static boolean fieldQualifiesForGetterGeneration(EclipseNode field) {
		if (field.getKind() != Kind.FIELD) return false;
		FieldDeclaration fieldDecl = (FieldDeclaration) field.get();
		return filterField(fieldDecl);
	}
	
	
Generates a getter on the stated field. Used by HandleData. The difference between this call and the handle method is as follows: If there is a lombok.Getter annotation on the field, it is used and the same rules apply (e.g. warning if the method already exists, stated access level applies). If not, the getter is still generated if it isn't already there, though there will not be a warning if its already there. The default access level is used. /**
	 * Generates a getter on the stated field.
	 * 
	 * Used by {@link HandleData}.
	 * 
	 * The difference between this call and the handle method is as follows:
	 * 
	 * If there is a {@code lombok.Getter} annotation on the field, it is used and the
	 * same rules apply (e.g. warning if the method already exists, stated access level applies).
	 * If not, the getter is still generated if it isn't already there, though there will not
	 * be a warning if its already there. The default access level is used.
	 */
	public void generateGetterForField(EclipseNode fieldNode, ASTNode pos, AccessLevel level, boolean lazy, List<Annotation> onMethod) {
		if (hasAnnotation(Getter.class, fieldNode)) {
			//The annotation will make it happen, so we can skip it.
			return;
		}
		
		createGetterForField(level, fieldNode, fieldNode, pos, false, lazy, onMethod);
	}
	
	public void handle(AnnotationValues<Getter> annotation, Annotation ast, EclipseNode annotationNode) {
		handleFlagUsage(annotationNode, ConfigurationKeys.GETTER_FLAG_USAGE, "@Getter");
		
		EclipseNode node = annotationNode.up();
		Getter annotationInstance = annotation.getInstance();
		AccessLevel level = annotationInstance.value();
		boolean lazy = annotationInstance.lazy();
		if (lazy) handleFlagUsage(annotationNode, ConfigurationKeys.GETTER_LAZY_FLAG_USAGE, "@Getter(lazy=true)");
		
		if (level == AccessLevel.NONE) {
			if (lazy) annotationNode.addWarning("'lazy' does not work with AccessLevel.NONE.");
			return;
		}
		
		if (node == null) return;
		
		List<Annotation> onMethod = unboxAndRemoveAnnotationParameter(ast, "onMethod", "@Getter(onMethod", annotationNode);
		
		switch (node.getKind()) {
		case FIELD:
			createGetterForFields(level, annotationNode.upFromAnnotationToFields(), annotationNode, annotationNode.get(), true, lazy, onMethod);
			break;
		case TYPE:
			if (lazy) annotationNode.addError("'lazy' is not supported for @Getter on a type.");
			generateGetterForType(node, annotationNode, level, false, onMethod);
			break;
		}
	}
	
	public void createGetterForFields(AccessLevel level, Collection<EclipseNode> fieldNodes, EclipseNode errorNode, ASTNode source, boolean whineIfExists, boolean lazy, List<Annotation> onMethod) {
		for (EclipseNode fieldNode : fieldNodes) {
			createGetterForField(level, fieldNode, errorNode, source, whineIfExists, lazy, onMethod);
		}
	}
	
	public void createGetterForField(AccessLevel level,
			EclipseNode fieldNode, EclipseNode errorNode, ASTNode source, boolean whineIfExists, boolean lazy, List<Annotation> onMethod) {
		if (fieldNode.getKind() != Kind.FIELD) {
			errorNode.addError("@Getter is only supported on a class or a field.");
			return;
		}
		
		FieldDeclaration field = (FieldDeclaration) fieldNode.get();
		if (lazy) {
			if ((field.modifiers & ClassFileConstants.AccPrivate) == 0 || (field.modifiers & ClassFileConstants.AccFinal) == 0) {
				errorNode.addError("'lazy' requires the field to be private and final.");
				return;
			}
			if ((field.modifiers & ClassFileConstants.AccTransient) != 0) {
				errorNode.addError("'lazy' is not supported on transient fields.");
				return;
			}
			if (field.initialization == null) {
				errorNode.addError("'lazy' requires field initialization.");
				return;
			}
		}
		
		TypeReference fieldType = copyType(field.type, source);
		boolean isBoolean = isBoolean(fieldType);
		String getterName = toGetterName(fieldNode, isBoolean);
		
		if (getterName == null) {
			errorNode.addWarning("Not generating getter for this field: It does not fit your @Accessors prefix list.");
			return;
		}
		
		int modifier = toEclipseModifier(level) | (field.modifiers & ClassFileConstants.AccStatic);
		
		for (String altName : toAllGetterNames(fieldNode, isBoolean)) {
			switch (methodExists(altName, fieldNode, false, 0)) {
			case EXISTS_BY_LOMBOK:
				return;
			case EXISTS_BY_USER:
				if (whineIfExists) {
					String altNameExpl = "";
					if (!altName.equals(getterName)) altNameExpl = String.format(" (%s)", altName);
					errorNode.addWarning(
						String.format("Not generating %s(): A method with that name already exists%s", getterName, altNameExpl));
				}
				return;
			default:
			case NOT_EXISTS:
				//continue scanning the other alt names.
			}
		}
		
		MethodDeclaration method = createGetter((TypeDeclaration) fieldNode.up().get(), fieldNode, getterName, modifier, source, lazy, onMethod);
		
		injectMethod(fieldNode.up(), method);
	}
	
	public static Annotation[] findDelegatesAndMarkAsHandled(EclipseNode fieldNode) {
		List<Annotation> delegates = new ArrayList<Annotation>();
		for (EclipseNode child : fieldNode.down()) {
			if (annotationTypeMatches(Delegate.class, child)) {
				Annotation delegate = (Annotation)child.get();
				PatchDelegate.markHandled(delegate);
				delegates.add(delegate);
			}
		}
		return delegates.toArray(EMPTY_ANNOTATIONS_ARRAY);
	}
	
	public MethodDeclaration createGetter(TypeDeclaration parent, EclipseNode fieldNode, String name, int modifier, ASTNode source, boolean lazy, List<Annotation> onMethod) {
		// Remember the type; lazy will change it;
		TypeReference returnType = copyType(((FieldDeclaration) fieldNode.get()).type, source);
		
		Statement[] statements;
		if (lazy) {
			statements = createLazyGetterBody(source, fieldNode);
		} else {
			statements = createSimpleGetterBody(source, fieldNode);
		}
		
		MethodDeclaration method = new MethodDeclaration(parent.compilationResult);
		method.modifiers = modifier;
		method.returnType = returnType;
		method.annotations = null;
		method.arguments = null;
		method.selector = name.toCharArray();
		method.binding = null;
		method.thrownExceptions = null;
		method.typeParameters = null;
		method.bits |= ECLIPSE_DO_NOT_TOUCH_FLAG;
		method.bodyStart = method.declarationSourceStart = method.sourceStart = source.sourceStart;
		method.bodyEnd = method.declarationSourceEnd = method.sourceEnd = source.sourceEnd;
		method.statements = statements;
		
		EclipseHandlerUtil.registerCreatedLazyGetter((FieldDeclaration) fieldNode.get(), method.selector, returnType);
		
		/* Generate annotations that must  be put on the generated method, and attach them. */ {
			Annotation[] deprecated = null;
			if (isFieldDeprecated(fieldNode)) {
				deprecated = new Annotation[] { generateDeprecatedAnnotation(source) };
			}
			
			method.annotations = copyAnnotations(source,
				onMethod.toArray(new Annotation[0]),
				findCopyableAnnotations(fieldNode),
				findDelegatesAndMarkAsHandled(fieldNode),
				deprecated);
		}
		
		method.traverse(new SetGeneratedByVisitor(source), parent.scope);
		return method;
	}

	public Statement[] createSimpleGetterBody(ASTNode source, EclipseNode fieldNode) {
		FieldDeclaration field = (FieldDeclaration) fieldNode.get();
		Expression fieldRef = createFieldAccessor(fieldNode, FieldAccess.ALWAYS_FIELD, source);
		Statement returnStatement = new ReturnStatement(fieldRef, field.sourceStart, field.sourceEnd);
		return new Statement[] {returnStatement};
	}
	
	private static final char[][] AR = fromQualifiedName("java.util.concurrent.atomic.AtomicReference");
	
	public static final java.util.Map<String, char[][]> TYPE_MAP;
	static {
		Map<String, char[][]> m = new HashMap<String, char[][]>();
		m.put("int", fromQualifiedName("java.lang.Integer"));
		m.put("double", fromQualifiedName("java.lang.Double"));
		m.put("float", fromQualifiedName("java.lang.Float"));
		m.put("short", fromQualifiedName("java.lang.Short"));
		m.put("byte", fromQualifiedName("java.lang.Byte"));
		m.put("long", fromQualifiedName("java.lang.Long"));
		m.put("boolean", fromQualifiedName("java.lang.Boolean"));
		m.put("char", fromQualifiedName("java.lang.Character"));
		TYPE_MAP = Collections.unmodifiableMap(m);
	}
	
	private static char[] valueName = "value".toCharArray();
	private static char[] actualValueName = "actualValue".toCharArray();
	
	private static final int PARENTHESIZED = (1 << ASTNode.ParenthesizedSHIFT) & ASTNode.ParenthesizedMASK;
	
	public Statement[] createLazyGetterBody(ASTNode source, EclipseNode fieldNode) {
		/*
		java.lang.Object value = this.fieldName.get();
		if (value == null) {
			synchronized (this.fieldName) {
				value = this.fieldName.get();
				if (value == null) {
					final RawValueType actualValue = INITIALIZER_EXPRESSION;
					[IF PRIMITIVE]
					value = actualValue;
					[ELSE]
					value = actualValue == null ? this.fieldName : actualValue;
					[END IF]
					this.fieldName.set(value);
				}
			}
		}
		[IF PRIMITIVE]
		return (BoxedValueType) value;
		[ELSE]
		return (BoxedValueType) (value == this.fieldName ? null : value);
		[END IF]
		*/
		
		FieldDeclaration field = (FieldDeclaration) fieldNode.get();
		int pS = source.sourceStart, pE = source.sourceEnd;
		long p = (long)pS << 32 | pE;
		
		TypeReference rawComponentType = copyType(field.type, source);
		TypeReference boxedComponentType = null;
		boolean isPrimitive = false;
		if (field.type instanceof SingleTypeReference && !(field.type instanceof ArrayTypeReference)) {
			char[][] newType = TYPE_MAP.get(new String(((SingleTypeReference)field.type).token));
			if (newType != null) {
				boxedComponentType = new QualifiedTypeReference(newType, poss(source, 3));
				isPrimitive = true;
			}
		}
		if (boxedComponentType == null) boxedComponentType = copyType(field.type, source);
		boxedComponentType.sourceStart = pS; boxedComponentType.sourceEnd = boxedComponentType.statementEnd = pE;
		
		Statement[] statements = new Statement[3];
		
		/* java.lang.Object value = this.fieldName.get(); */ {
			LocalDeclaration valueDecl = new LocalDeclaration(valueName, pS, pE);
			valueDecl.type = new QualifiedTypeReference(TypeConstants.JAVA_LANG_OBJECT, poss(source, 3));
			valueDecl.type.sourceStart = pS; valueDecl.type.sourceEnd = valueDecl.type.statementEnd = pE;
			
			MessageSend getter = new MessageSend();
			getter.sourceStart = pS; getter.statementEnd = getter.sourceEnd = pE;
			getter.selector = new char[] {'g', 'e', 't'};
			getter.receiver = createFieldAccessor(fieldNode, FieldAccess.ALWAYS_FIELD, source);
			
			valueDecl.initialization = getter;
			statements[0] = valueDecl;
		}
		
		/*
		if (value == null) {
			synchronized (this.fieldName) {
				value = this.fieldName.get();
				if (value == null) { 
					final ValueType actualValue = INITIALIZER_EXPRESSION;
					[IF PRIMITIVE]
					value = actualValue;
					[ELSE]
					value = actualValue == null ? this.fieldName : actualValue;
					[END IF]
					this.fieldName.set(value);
				}
			}
		}
		 */ {
			EqualExpression cond = new EqualExpression(
					new SingleNameReference(valueName, p), new NullLiteral(pS, pE),
					BinaryExpression.EQUAL_EQUAL);
			Block then = new Block(0);
			Expression lock = createFieldAccessor(fieldNode, FieldAccess.ALWAYS_FIELD, source);
			Block inner = new Block(0);
			inner.statements = new Statement[2];
			/* value = this.fieldName.get(); */ {
				MessageSend getter = new MessageSend();
				getter.sourceStart = pS; getter.sourceEnd = getter.statementEnd = pE;
				getter.selector = new char[] {'g', 'e', 't'};
				getter.receiver = createFieldAccessor(fieldNode, FieldAccess.ALWAYS_FIELD, source);
				Assignment assign = new Assignment(new SingleNameReference(valueName, p), getter, pE);
				assign.sourceStart = pS; assign.statementEnd = assign.sourceEnd = pE;
				inner.statements[0] = assign;
			}
			/* if (value == null) */ {
				EqualExpression innerCond = new EqualExpression(
						new SingleNameReference(valueName, p), new NullLiteral(pS, pE),
						BinaryExpression.EQUAL_EQUAL);
				innerCond.sourceStart = pS; innerCond.sourceEnd = innerCond.statementEnd = pE;
				Block innerThen = new Block(0);
				innerThen.statements = new Statement[3];
				/* final ValueType actualValue = INITIALIZER_EXPRESSION */ {
					LocalDeclaration actualValueDecl = new LocalDeclaration(actualValueName, pS, pE);
					actualValueDecl.type = rawComponentType;
					actualValueDecl.type.sourceStart = pS; actualValueDecl.type.sourceEnd = actualValueDecl.type.statementEnd = pE;
					actualValueDecl.initialization = field.initialization;
					actualValueDecl.modifiers = ClassFileConstants.AccFinal;
					innerThen.statements[0] = actualValueDecl;
				}
				/* [IF PRIMITIVE] value = actualValue; */ {
					if (isPrimitive) {
						Assignment innerAssign = new Assignment(new SingleNameReference(valueName, p), new SingleNameReference(actualValueName, p), pE);
						innerAssign.sourceStart = pS; innerAssign.statementEnd = innerAssign.sourceEnd = pE;
						innerThen.statements[1] = innerAssign;
					}
				}
				/* [ELSE] value = actualValue == null ? this.fieldName : actualValue; */ {
					if (!isPrimitive) {
						EqualExpression avIsNull = new EqualExpression(
								new SingleNameReference(actualValueName, p), new NullLiteral(pS, pE),
								BinaryExpression.EQUAL_EQUAL);
						avIsNull.sourceStart = pS; avIsNull.sourceEnd = avIsNull.statementEnd = pE;
						Expression fieldRef = createFieldAccessor(fieldNode, FieldAccess.ALWAYS_FIELD, source);
						ConditionalExpression ternary = new ConditionalExpression(avIsNull, fieldRef, new SingleNameReference(actualValueName, p));
						ternary.sourceStart = pS; ternary.sourceEnd = ternary.statementEnd = pE;
						Assignment innerAssign = new Assignment(new SingleNameReference(valueName, p), ternary, pE);
						innerAssign.sourceStart = pS; innerAssign.statementEnd = innerAssign.sourceEnd = pE;
						innerThen.statements[1] = innerAssign;
					}
				}
				
				/* this.fieldName.set(value); */ {
					MessageSend setter = new MessageSend();
					setter.sourceStart = pS; setter.sourceEnd = setter.statementEnd =  pE;
					setter.receiver = createFieldAccessor(fieldNode, FieldAccess.ALWAYS_FIELD, source);
					setter.selector = new char[] { 's', 'e', 't' };
					setter.arguments = new Expression[] {
							new SingleNameReference(valueName, p)};
					innerThen.statements[2] = setter;
				}
				
				IfStatement innerIf = new IfStatement(innerCond, innerThen, pS, pE);
				inner.statements[1] = innerIf;
			}
			
			SynchronizedStatement sync = new SynchronizedStatement(lock, inner, pS, pE);
			then.statements = new Statement[] {sync};
			
			IfStatement ifStatement = new IfStatement(cond, then, pS, pE);
			statements[1] = ifStatement;
		}
		
		/* [IF PRIMITIVE] return (BoxedValueType)value; */ {
			if (isPrimitive) {
				CastExpression cast = makeCastExpression(new SingleNameReference(valueName, p), boxedComponentType, source);
				statements[2] = new ReturnStatement(cast, pS, pE);
			}
		}
		/* [ELSE] return (BoxedValueType)(value == this.fieldName ? null : value); */ {
			if (!isPrimitive) {
				EqualExpression vIsThisFieldName = new EqualExpression(
						new SingleNameReference(valueName, p), createFieldAccessor(fieldNode, FieldAccess.ALWAYS_FIELD, source),
						BinaryExpression.EQUAL_EQUAL);
				vIsThisFieldName.sourceStart = pS; vIsThisFieldName.sourceEnd = vIsThisFieldName.statementEnd = pE;
				ConditionalExpression ternary = new ConditionalExpression(vIsThisFieldName, new NullLiteral(pS, pE), new SingleNameReference(valueName, p));
				ternary.sourceStart = pS; ternary.sourceEnd = ternary.statementEnd = pE;
				ternary.bits |= PARENTHESIZED;
				CastExpression cast = makeCastExpression(ternary, boxedComponentType, source);
				statements[2] = new ReturnStatement(cast, pS, pE);
			}
		}
		
		// update the field type and init last
			
		/* 	private final java.util.concurrent.atomic.AtomicReference<java.lang.Object> fieldName = new java.util.concurrent.atomic.AtomicReference<java.lang.Object>(); */ {
			TypeReference innerType = new QualifiedTypeReference(TypeConstants.JAVA_LANG_OBJECT, poss(source, 3));
			TypeReference[][] typeParams = new TypeReference[5][];
			typeParams[4] = new TypeReference[] {innerType};
			TypeReference type = new ParameterizedQualifiedTypeReference(AR, typeParams, 0, poss(source, 5));
			
			// Some magic here
			type.sourceStart = -1; type.sourceEnd = -2;
			
			field.type = type;
			AllocationExpression init = new AllocationExpression();
			// Some magic here
			init.sourceStart = field.initialization.sourceStart; init.sourceEnd = init.statementEnd = field.initialization.sourceEnd;
			init.type = copyType(type, source);
			field.initialization = init;
		}
		return statements;
	}
}