/*
 * Copyright (C) 2020 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.handleExperimentalFlagUsage;
import static lombok.eclipse.Eclipse.ECLIPSE_DO_NOT_TOUCH_FLAG;
import static lombok.eclipse.handlers.EclipseHandlerUtil.*;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

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.Argument;
import org.eclipse.jdt.internal.compiler.ast.Expression;
import org.eclipse.jdt.internal.compiler.ast.FieldDeclaration;
import org.eclipse.jdt.internal.compiler.ast.MessageSend;
import org.eclipse.jdt.internal.compiler.ast.MethodDeclaration;
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.TypeDeclaration;
import org.eclipse.jdt.internal.compiler.ast.TypeReference;
import org.eclipse.jdt.internal.compiler.ast.Wildcard;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.lookup.ExtraCompilerModifiers;
import org.eclipse.jdt.internal.compiler.lookup.TypeIds;
import org.mangosdk.spi.ProviderFor;

import lombok.AccessLevel;
import lombok.ConfigurationKeys;
import lombok.core.AnnotationValues;
import lombok.core.AST.Kind;
import lombok.core.configuration.CheckerFrameworkVersion;
import lombok.core.handlers.HandlerUtil.FieldAccess;
import lombok.eclipse.Eclipse;
import lombok.eclipse.EclipseAnnotationHandler;
import lombok.eclipse.EclipseNode;
import lombok.experimental.WithBy;

@ProviderFor(EclipseAnnotationHandler.class)
public class HandleWithBy extends EclipseAnnotationHandler<WithBy> {
	public boolean generateWithByForType(EclipseNode typeNode, EclipseNode pos, AccessLevel level, boolean checkForTypeLevelWithBy) {
		if (checkForTypeLevelWithBy) {
			if (hasAnnotation(WithBy.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 | ClassFileConstants.AccEnum)) != 0;
		
		if (typeDecl == null || notAClass) {
			pos.addError("@WithBy is only supported on a class or a field.");
			return false;
		}
		
		for (EclipseNode field : typeNode.down()) {
			if (field.getKind() != Kind.FIELD) continue;
			FieldDeclaration fieldDecl = (FieldDeclaration) field.get();
			if (!filterField(fieldDecl)) continue;
			
			//Skip final fields.
			if ((fieldDecl.modifiers & ClassFileConstants.AccFinal) != 0 && fieldDecl.initialization != null) continue;
			
			generateWithByForField(field, pos, level);
		}
		return true;
	}
	
	
	
Generates a withBy on the stated field. Used by HandleValue. The difference between this call and the handle method is as follows: If there is a lombok.experimental.WithBy 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 with method 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 withBy on the stated field.
	 * 
	 * Used by {@link HandleValue}.
	 * 
	 * The difference between this call and the handle method is as follows:
	 * 
	 * If there is a {@code lombok.experimental.WithBy} 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 with method 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 generateWithByForField(EclipseNode fieldNode, EclipseNode sourceNode, AccessLevel level) {
		for (EclipseNode child : fieldNode.down()) {
			if (child.getKind() == Kind.ANNOTATION) {
				if (annotationTypeMatches(WithBy.class, child)) {
					//The annotation will make it happen, so we can skip it.
					return;
				}
			}
		}
		
		List<Annotation> empty = Collections.emptyList();
		createWithByForField(level, fieldNode, sourceNode, false, empty);
	}
	
	@Override public void handle(AnnotationValues<WithBy> annotation, Annotation ast, EclipseNode annotationNode) {
		handleExperimentalFlagUsage(annotationNode, ConfigurationKeys.WITHBY_FLAG_USAGE, "@WithBy");
		
		EclipseNode node = annotationNode.up();
		AccessLevel level = annotation.getInstance().value();
		if (level == AccessLevel.NONE || node == null) return;
		
		List<Annotation> onMethod = unboxAndRemoveAnnotationParameter(ast, "onMethod", "@WithBy(onMethod", annotationNode);
		
		switch (node.getKind()) {
		case FIELD:
			createWithByForFields(level, annotationNode.upFromAnnotationToFields(), annotationNode, true, onMethod);
			break;
		case TYPE:
			if (!onMethod.isEmpty()) {
				annotationNode.addError("'onMethod' is not supported for @WithBy on a type.");
			}
			generateWithByForType(node, annotationNode, level, false);
			break;
		}
	}
	
	public void createWithByForFields(AccessLevel level, Collection<EclipseNode> fieldNodes, EclipseNode sourceNode, boolean whineIfExists, List<Annotation> onMethod) {
		for (EclipseNode fieldNode : fieldNodes) {
			createWithByForField(level, fieldNode, sourceNode, whineIfExists, onMethod);
		}
	}
	
	public void createWithByForField(
		AccessLevel level, EclipseNode fieldNode, EclipseNode sourceNode,
		boolean whineIfExists, List<Annotation> onMethod) {
		
		ASTNode source = sourceNode.get();
		if (fieldNode.getKind() != Kind.FIELD) {
			sourceNode.addError("@WithBy is only supported on a class or a field.");
			return;
		}
		
		EclipseNode typeNode = fieldNode.up();
		boolean makeAbstract = typeNode != null && typeNode.getKind() == Kind.TYPE && (((TypeDeclaration) typeNode.get()).modifiers & ClassFileConstants.AccAbstract) != 0;
		
		FieldDeclaration field = (FieldDeclaration) fieldNode.get();
		TypeReference fieldType = copyType(field.type, source);
		boolean isBoolean = isBoolean(fieldType);
		String withName = toWithByName(fieldNode, isBoolean);
		
		if (withName == null) {
			fieldNode.addWarning("Not generating a withXBy method for this field: It does not fit your @Accessors prefix list.");
			return;
		}
		
		if ((field.modifiers & ClassFileConstants.AccStatic) != 0) {
			fieldNode.addWarning("Not generating " + withName + " for this field: With methods cannot be generated for static fields.");
			return;
		}
		
		if ((field.modifiers & ClassFileConstants.AccFinal) != 0 && field.initialization != null) {
			fieldNode.addWarning("Not generating " + withName + " for this field: With methods cannot be generated for final, initialized fields.");
			return;
		}
		
		if (field.name != null && field.name.length > 0 && field.name[0] == '$') {
			fieldNode.addWarning("Not generating " + withName + " for this field: With methods cannot be generated for fields starting with $.");
			return;
		}
		
		for (String altName : toAllWithByNames(fieldNode, isBoolean)) {
			switch (methodExists(altName, fieldNode, false, 1)) {
			case EXISTS_BY_LOMBOK:
				return;
			case EXISTS_BY_USER:
				if (whineIfExists) {
					String altNameExpl = "";
					if (!altName.equals(withName)) altNameExpl = String.format(" (%s)", altName);
					fieldNode.addWarning(
						String.format("Not generating %s(): A method with that name already exists%s", withName, altNameExpl));
				}
				return;
			default:
			case NOT_EXISTS:
				//continue scanning the other alt names.
			}
		}
		
		int modifier = toEclipseModifier(level);
		
		MethodDeclaration method = createWithBy((TypeDeclaration) fieldNode.up().get(), fieldNode, withName, modifier, sourceNode, onMethod, makeAbstract);
		injectMethod(fieldNode.up(), method);
	}
	
	private static final char[][] NAME_JUF_FUNCTION = Eclipse.fromQualifiedName("java.util.function.Function");
	private static final char[][] NAME_JUF_OP = Eclipse.fromQualifiedName("java.util.function.UnaryOperator");
	private static final char[][] NAME_JUF_DOUBLEOP = Eclipse.fromQualifiedName("java.util.function.DoubleUnaryOperator");
	private static final char[][] NAME_JUF_INTOP = Eclipse.fromQualifiedName("java.util.function.IntUnaryOperator");
	private static final char[][] NAME_JUF_LONGOP = Eclipse.fromQualifiedName("java.util.function.LongUnaryOperator");
	private static final char[] NAME_CHAR = {'c', 'h', 'a', 'r'};
	private static final char[] NAME_SHORT = {'s', 'h', 'o', 'r', 't'};
	private static final char[] NAME_BYTE = {'b', 'y', 't', 'e'};
	private static final char[] NAME_INT = {'i', 'n', 't'};
	private static final char[] NAME_LONG = {'l', 'o', 'n', 'g'};
	private static final char[] NAME_DOUBLE = {'d', 'o', 'u', 'b', 'l', 'e'};
	private static final char[] NAME_FLOAT = {'f', 'l', 'o', 'a', 't'};
	private static final char[] NAME_BOOLEAN = {'b', 'o', 'o', 'l', 'e', 'a', 'n'};
	private static final char[][] NAME_JAVA_LANG_BOOLEAN = Eclipse.fromQualifiedName("java.lang.Boolean");
	private static final char[] NAME_APPLY = {'a', 'p', 'p', 'l', 'y'};
	private static final char[] NAME_APPLY_AS_INT = {'a', 'p', 'p', 'l', 'y', 'A', 's', 'I', 'n', 't'};
	private static final char[] NAME_APPLY_AS_LONG = {'a', 'p', 'p', 'l', 'y', 'A', 's', 'L', 'o', 'n', 'g'};
	private static final char[] NAME_APPLY_AS_DOUBLE = {'a', 'p', 'p', 'l', 'y', 'A', 's', 'D', 'o', 'u', 'b', 'l', 'e'};
	private static final char[] NAME_TRANSFORMER = {'t', 'r', 'a', 'n', 's', 'f', 'o', 'r', 'm', 'e', 'r'};

	public MethodDeclaration createWithBy(TypeDeclaration parent, EclipseNode fieldNode, String name, int modifier, EclipseNode sourceNode, List<Annotation> onMethod, boolean makeAbstract) {
		ASTNode source = sourceNode.get();
		if (name == null) return null;
		FieldDeclaration field = (FieldDeclaration) fieldNode.get();
		int pS = source.sourceStart, pE = source.sourceEnd;
		long p = (long) pS << 32 | pE;
		MethodDeclaration method = new MethodDeclaration(parent.compilationResult);
		if (makeAbstract) modifier = modifier | ClassFileConstants.AccAbstract | ExtraCompilerModifiers.AccSemicolonBody;
		method.modifiers = modifier;
		method.returnType = cloneSelfType(fieldNode, source);
		if (method.returnType == null) return null;
		
		Annotation[] deprecated = null, checkerFramework = null;
		if (isFieldDeprecated(fieldNode)) deprecated = new Annotation[] { generateDeprecatedAnnotation(source) };
		if (getCheckerFrameworkVersion(fieldNode).generateSideEffectFree()) checkerFramework = new Annotation[] { generateNamedAnnotation(source, CheckerFrameworkVersion.NAME__SIDE_EFFECT_FREE) };
		
		char[][] functionalInterfaceName = null;
		int requiredCast = -1;
		TypeReference parameterizer = null;
		boolean superExtendsStyle = true;
		char[] applyMethodName = NAME_APPLY;
		
		if (field.type instanceof SingleTypeReference) {
			char[] token = ((SingleTypeReference) field.type).token;
			if (Arrays.equals(token, NAME_CHAR)) {
				requiredCast = TypeIds.T_char;
				functionalInterfaceName = NAME_JUF_INTOP;
			} else if (Arrays.equals(token, NAME_SHORT)) {
				requiredCast = TypeIds.T_short;
				functionalInterfaceName = NAME_JUF_INTOP;
			} else if (Arrays.equals(token, NAME_BYTE)) {
				requiredCast = TypeIds.T_byte;
				functionalInterfaceName = NAME_JUF_INTOP;
			} else if (Arrays.equals(token, NAME_INT)) {
				functionalInterfaceName = NAME_JUF_INTOP;
			} else if (Arrays.equals(token, NAME_LONG)) {
				functionalInterfaceName = NAME_JUF_LONGOP;
			} else if (Arrays.equals(token, NAME_FLOAT)) {
				requiredCast = TypeIds.T_float;
				functionalInterfaceName = NAME_JUF_DOUBLEOP;
			} else if (Arrays.equals(token, NAME_DOUBLE)) {
				functionalInterfaceName = NAME_JUF_DOUBLEOP;
			} else if (Arrays.equals(token, NAME_BOOLEAN)) {
				functionalInterfaceName = NAME_JUF_OP;
				parameterizer = new QualifiedTypeReference(NAME_JAVA_LANG_BOOLEAN, new long[] {0, 0, 0});
				superExtendsStyle = false;
			}
		}
		
		if (functionalInterfaceName == NAME_JUF_INTOP) applyMethodName = NAME_APPLY_AS_INT;
		if (functionalInterfaceName == NAME_JUF_LONGOP) applyMethodName = NAME_APPLY_AS_LONG;
		if (functionalInterfaceName == NAME_JUF_DOUBLEOP) applyMethodName = NAME_APPLY_AS_DOUBLE;
		if (functionalInterfaceName == null) {
			functionalInterfaceName = NAME_JUF_FUNCTION;
			parameterizer = copyType(field.type, source);
		}
		
		method.annotations = copyAnnotations(source, onMethod.toArray(new Annotation[0]), checkerFramework, deprecated);
		TypeReference fType = null;
		if (parameterizer != null && superExtendsStyle) {
			Wildcard w1 = new Wildcard(Wildcard.SUPER);
			w1.bound = parameterizer;
			Wildcard w2 = new Wildcard(Wildcard.EXTENDS);
			w2.bound = copyType(field.type, source);
			TypeReference[][] ta = new TypeReference[functionalInterfaceName.length][];
			ta[functionalInterfaceName.length - 1] = new TypeReference[] {w1, w2};
			long[] ps = new long[functionalInterfaceName.length];
			fType = new ParameterizedQualifiedTypeReference(functionalInterfaceName, ta, 0, ps);
		}
		if (parameterizer != null && !superExtendsStyle) {
			TypeReference[][] ta = new TypeReference[functionalInterfaceName.length][];
			ta[functionalInterfaceName.length - 1] = new TypeReference[] {parameterizer};
			long[] ps = new long[functionalInterfaceName.length];
			fType = new ParameterizedQualifiedTypeReference(functionalInterfaceName, ta, 0, ps);
		}
		if (parameterizer == null) {
			long[] ps = new long[functionalInterfaceName.length];
			fType = new QualifiedTypeReference(functionalInterfaceName, ps);
		}
		
		Argument param = new Argument(NAME_TRANSFORMER, p, fType, ClassFileConstants.AccFinal);
		param.sourceStart = pS; param.sourceEnd = pE;
		method.arguments = new Argument[] { param };
		method.selector = name.toCharArray();
		method.binding = null;
		method.thrownExceptions = null;
		method.typeParameters = null;
		method.bits |= ECLIPSE_DO_NOT_TOUCH_FLAG;
		
		if (!makeAbstract) {
			List<Expression> args = new ArrayList<Expression>();
			for (EclipseNode child : fieldNode.up().down()) {
				if (child.getKind() != Kind.FIELD) continue;
				FieldDeclaration childDecl = (FieldDeclaration) child.get();
				// Skip fields that start with $
				if (childDecl.name != null && childDecl.name.length > 0 && childDecl.name[0] == '$') continue;
				long fieldFlags = childDecl.modifiers;
				// Skip static fields.
				if ((fieldFlags & ClassFileConstants.AccStatic) != 0) continue;
				// Skip initialized final fields.
				if (((fieldFlags & ClassFileConstants.AccFinal) != 0) && childDecl.initialization != null) continue;
				if (child.get() == fieldNode.get()) {
					MessageSend ms = new MessageSend();
					ms.receiver = new SingleNameReference(NAME_TRANSFORMER, 0);
					ms.selector = applyMethodName;
					ms.arguments = new Expression[] {createFieldAccessor(child, FieldAccess.ALWAYS_FIELD, source)};
					if (requiredCast != -1) {
						args.add(makeCastExpression(ms, TypeReference.baseTypeReference(requiredCast, 0), source));
					} else {
						args.add(ms);
					}
				} else {
					args.add(createFieldAccessor(child, FieldAccess.ALWAYS_FIELD, source));
				}
			}
			
			AllocationExpression constructorCall = new AllocationExpression();
			constructorCall.arguments = args.toArray(new Expression[0]);
			constructorCall.type = cloneSelfType(fieldNode, source);
			
			Statement returnStatement = new ReturnStatement(constructorCall, pS, pE);
			method.bodyStart = method.declarationSourceStart = method.sourceStart = source.sourceStart;
			method.bodyEnd = method.declarationSourceEnd = method.sourceEnd = source.sourceEnd;
			
			List<Statement> statements = new ArrayList<Statement>(5);
			if (hasNonNullAnnotations(fieldNode)) {
				Statement nullCheck = generateNullCheck(field, sourceNode, null);
				if (nullCheck != null) statements.add(nullCheck);
			}
			statements.add(returnStatement);
			
			method.statements = statements.toArray(new Statement[0]);
		}
		
		createRelevantNonNullAnnotation(sourceNode, param);
		createRelevantNonNullAnnotation(fieldNode, method);
		
		method.traverse(new SetGeneratedByVisitor(source), parent.scope);
		copyJavadoc(fieldNode, method, CopyJavadoc.WITH_BY);
		return method;
	}
}