Copyright (c) 2016, 2017 IBM Corporation 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:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2016, 2017 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.jdt.core.compiler.IProblem;
import org.eclipse.jdt.internal.compiler.lookup.Binding;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.MethodBinding;
import org.eclipse.jdt.internal.compiler.lookup.ModuleBinding;
import org.eclipse.jdt.internal.compiler.lookup.ProblemReasons;
import org.eclipse.jdt.internal.compiler.lookup.ProblemReferenceBinding;
import org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.TypeConstants;

public class ProvidesStatement extends ModuleStatement {

	public TypeReference serviceInterface;
	public TypeReference[] implementations;

	public boolean resolve(BlockScope scope) {
		ModuleDeclaration module = scope.referenceCompilationUnit().moduleDeclaration;
		ModuleBinding src = module.binding;
		TypeBinding infBinding = this.serviceInterface.resolveType(scope);
		boolean hasErrors = false;
		if (infBinding == null || !infBinding.isValidBinding()) {
			return false;
		}
		if (!(infBinding.isClass() || infBinding.isInterface() || infBinding.isAnnotationType())) {
			scope.problemReporter().invalidServiceRef(IProblem.InvalidServiceIntfType, this.serviceInterface);
		}
		ReferenceBinding intf = (ReferenceBinding) this.serviceInterface.resolvedType;
		Set<TypeBinding> impls = new HashSet<>();
		for (int i = 0; i < this.implementations.length; i++) {
			ReferenceBinding impl = (ReferenceBinding) this.implementations[i].resolveType(scope);
			if (impl == null || !impl.isValidBinding() || !impl.canBeSeenBy(scope)) {
				hasErrors = true;
				continue;
			}
			if (!impls.add(impl)) {
				scope.problemReporter().duplicateTypeReference(IProblem.DuplicateServices, this.implementations[i]);
				continue;
			}
			int problemId = ProblemReasons.NoError;
			ModuleBinding declaringModule = impl.module();
			
			if (declaringModule != src) {
				problemId = IProblem.ServiceImplNotDefinedByModule;
			} else if (!impl.isClass() && !impl.isInterface()) {
				problemId = IProblem.InvalidServiceImplType;
			} else if (impl.isNestedType() && !impl.isStatic()) {
				problemId = IProblem.NestedServiceImpl;
			} else {
				MethodBinding provider = impl.getExactMethod(TypeConstants.PROVIDER, Binding.NO_PARAMETERS, scope.compilationUnitScope());
				if (provider != null && (!provider.isValidBinding() || !(provider.isPublic() && provider.isStatic()))) {
					provider = null;
				}
				TypeBinding implType = impl;
				if (provider != null) {
					implType = provider.returnType;
					if (implType instanceof ReferenceBinding && !implType.canBeSeenBy(scope)) {
						ReferenceBinding referenceBinding = (ReferenceBinding) implType;
						scope.problemReporter().invalidType(this.implementations[i], new ProblemReferenceBinding(
								referenceBinding.compoundName, referenceBinding, ProblemReasons.NotVisible));
						hasErrors = true;
					}
				} else {
					if (impl.isAbstract()) {
						problemId = IProblem.AbstractServiceImplementation;
					} else {
						MethodBinding defaultConstructor = impl.getExactConstructor(Binding.NO_PARAMETERS);
						if (defaultConstructor == null || !defaultConstructor.isValidBinding()) {
							problemId = IProblem.ProviderMethodOrConstructorRequiredForServiceImpl;
						} else if (!defaultConstructor.isPublic()) {
							problemId = IProblem.ServiceImplDefaultConstructorNotPublic;
						}
					}
				}
				if (implType.findSuperTypeOriginatingFrom(intf) == null) {
					scope.problemReporter().typeMismatchError(implType, intf, this.implementations[i], null);
					hasErrors = true;
				}
			}
			if (problemId != ProblemReasons.NoError) {
				scope.problemReporter().invalidServiceRef(problemId, this.implementations[i]);
				hasErrors = true;
			}
		}
		return hasErrors;
	}

	public List<TypeBinding> getResolvedImplementations() {
		List<TypeBinding> resolved = new ArrayList<>();
		if (this.implementations != null) {
			for (TypeReference implRef : this.implementations) {
				TypeBinding one = implRef.resolvedType;
				if (one != null)
					resolved.add(one);
			}
		}
		return resolved;
	}

	@Override
	public StringBuffer print(int indent, StringBuffer output) {
		printIndent(indent, output);
		output.append("provides "); //$NON-NLS-1$
		this.serviceInterface.print(0, output);
		//output.append(" "); //$NON-NLS-1$
		//printIndent(indent + 1, output);
		output.append(" with "); //$NON-NLS-1$
		for (int i = 0; i < this.implementations.length; i++) {
			this.implementations[i].print(0, output);
			if (i < this.implementations.length - 1)
				output.append(", "); //$NON-NLS-1$
		}
		output.append(";"); //$NON-NLS-1$
		return output;
	}
}