Copyright (c) 2002, 2013 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) 2002, 2013 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.core.util;

import java.util.Locale;
import java.util.Map;

import org.eclipse.jdt.core.compiler.CategorizedProblem;
import org.eclipse.jdt.internal.compiler.CompilationResult;
import org.eclipse.jdt.internal.compiler.DefaultErrorHandlingPolicies;
import org.eclipse.jdt.internal.compiler.ast.ASTNode;
import org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration;
import org.eclipse.jdt.internal.compiler.ast.ConstructorDeclaration;
import org.eclipse.jdt.internal.compiler.ast.Expression;
import org.eclipse.jdt.internal.compiler.batch.CompilationUnit;
import org.eclipse.jdt.internal.compiler.env.ICompilationUnit;
import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
import org.eclipse.jdt.internal.compiler.problem.DefaultProblemFactory;
import org.eclipse.jdt.internal.compiler.problem.ProblemReporter;

Utility class to parse different code snippets
/**
 * Utility class to parse different code snippets
 */
public class CodeSnippetParsingUtil {

	public RecordedParsingInformation recordedParsingInformation;
	public boolean ignoreMethodBodies;
	
	public CodeSnippetParsingUtil(boolean ignoreMethodBodies) {
		this.ignoreMethodBodies = ignoreMethodBodies;
	}

	public CodeSnippetParsingUtil() {
		this(false);
	}

	private RecordedParsingInformation getRecordedParsingInformation(CompilationResult compilationResult, int[][] commentPositions) {
		int problemsCount = compilationResult.problemCount;
		CategorizedProblem[] problems = null;
		if (problemsCount != 0) {
			final CategorizedProblem[] compilationResultProblems = compilationResult.problems;
			if (compilationResultProblems.length == problemsCount) {
				problems = compilationResultProblems;
			} else {
				System.arraycopy(compilationResultProblems, 0, (problems = new CategorizedProblem[problemsCount]), 0, problemsCount);
			}
		}
		return new RecordedParsingInformation(problems, compilationResult.getLineSeparatorPositions(), commentPositions);
	}

	public ASTNode[] parseClassBodyDeclarations(char[] source, Map<String, String> settings, boolean recordParsingInformation) {
		return parseClassBodyDeclarations(source, 0, source.length, settings, recordParsingInformation, false);
	}

	public ASTNode[] parseClassBodyDeclarations(
			char[] source,
			int offset,
			int length,
			Map<String, String> settings,
			boolean recordParsingInformation,
			boolean enabledStatementRecovery) {
		if (source == null) {
			throw new IllegalArgumentException();
		}
		CompilerOptions compilerOptions = new CompilerOptions(settings);
		compilerOptions.ignoreMethodBodies = this.ignoreMethodBodies;
		final ProblemReporter problemReporter = new ProblemReporter(
					DefaultErrorHandlingPolicies.proceedWithAllProblems(),
					compilerOptions,
					new DefaultProblemFactory(Locale.getDefault()));

		CommentRecorderParser parser = new CommentRecorderParser(problemReporter, false);
		parser.setMethodsFullRecovery(false);
		parser.setStatementsRecovery(enabledStatementRecovery);

		ICompilationUnit sourceUnit =
			new CompilationUnit(
				source,
				"", //$NON-NLS-1$
				compilerOptions.defaultEncoding);

		CompilationResult compilationResult = new CompilationResult(sourceUnit, 0, 0, compilerOptions.maxProblemsPerUnit);
		final CompilationUnitDeclaration compilationUnitDeclaration = new CompilationUnitDeclaration(problemReporter, compilationResult, source.length);
		ASTNode[] result = parser.parseClassBodyDeclarations(source, offset, length, compilationUnitDeclaration);

		if (recordParsingInformation) {
			this.recordedParsingInformation = getRecordedParsingInformation(compilationResult, compilationUnitDeclaration.comments);
		}
		return result;
	}

	public CompilationUnitDeclaration parseCompilationUnit(char[] source, Map<String, String> settings, boolean recordParsingInformation) {
		if (source == null) {
			throw new IllegalArgumentException();
		}
		CompilerOptions compilerOptions = new CompilerOptions(settings);
		compilerOptions.ignoreMethodBodies = this.ignoreMethodBodies;
		CommentRecorderParser parser =
			new CommentRecorderParser(
				new ProblemReporter(
					DefaultErrorHandlingPolicies.proceedWithAllProblems(),
					compilerOptions,
					new DefaultProblemFactory(Locale.getDefault())),
			false);

		ICompilationUnit sourceUnit =
			new CompilationUnit(
				source,
				"", //$NON-NLS-1$
				compilerOptions.defaultEncoding);
		final CompilationResult compilationResult = new CompilationResult(sourceUnit, 0, 0, compilerOptions.maxProblemsPerUnit);
		CompilationUnitDeclaration compilationUnitDeclaration = parser.dietParse(sourceUnit, compilationResult);

		if (recordParsingInformation) {
			this.recordedParsingInformation = getRecordedParsingInformation(compilationResult, compilationUnitDeclaration.comments);
		}

		if (compilationUnitDeclaration.ignoreMethodBodies) {
			compilationUnitDeclaration.ignoreFurtherInvestigation = true;
			// if initial diet parse did not work, no need to dig into method bodies.
			return compilationUnitDeclaration;
		}

		//fill the methods bodies in order for the code to be generated
		//real parse of the method....
		parser.scanner.setSource(compilationResult);
		org.eclipse.jdt.internal.compiler.ast.TypeDeclaration[] types = compilationUnitDeclaration.types;
		if (types != null) {
			for (int i = 0, length = types.length; i < length; i++) {
				types[i].parseMethods(parser, compilationUnitDeclaration);
			}
		}

		if (recordParsingInformation) {
			this.recordedParsingInformation.updateRecordedParsingInformation(compilationResult);
		}
		return compilationUnitDeclaration;
	}

	public Expression parseExpression(char[] source, Map<String, String> settings, boolean recordParsingInformation) {
		return parseExpression(source, 0, source.length, settings, recordParsingInformation);
	}

	public Expression parseExpression(char[] source, int offset, int length, Map<String, String> settings, boolean recordParsingInformation) {

		if (source == null) {
			throw new IllegalArgumentException();
		}
		CompilerOptions compilerOptions = new CompilerOptions(settings);
		// in this case we don't want to ignore method bodies since we are parsing only an expression
		final ProblemReporter problemReporter = new ProblemReporter(
					DefaultErrorHandlingPolicies.proceedWithAllProblems(),
					compilerOptions,
					new DefaultProblemFactory(Locale.getDefault()));

		CommentRecorderParser parser = new CommentRecorderParser(problemReporter, false);

		ICompilationUnit sourceUnit =
			new CompilationUnit(
				source,
				"", //$NON-NLS-1$
				compilerOptions.defaultEncoding);

		CompilationResult compilationResult = new CompilationResult(sourceUnit, 0, 0, compilerOptions.maxProblemsPerUnit);
		CompilationUnitDeclaration unit = new CompilationUnitDeclaration(problemReporter, compilationResult, source.length);
		Expression result = parser.parseExpression(source, offset, length, unit, true /* record line separators */);

		if (recordParsingInformation) {
			this.recordedParsingInformation = getRecordedParsingInformation(compilationResult, unit.comments);
		}
		return result;
	}

	public ConstructorDeclaration parseStatements(char[] source, Map<String, String> settings, boolean recordParsingInformation, boolean enabledStatementRecovery) {
		return parseStatements(source, 0, source.length, settings, recordParsingInformation, enabledStatementRecovery);
	}

	public ConstructorDeclaration parseStatements(
			char[] source,
			int offset,
			int length,
			Map<String, String> settings,
			boolean recordParsingInformation,
			boolean enabledStatementRecovery) {
		if (source == null) {
			throw new IllegalArgumentException();
		}
		CompilerOptions compilerOptions = new CompilerOptions(settings);
		// in this case we don't want to ignore method bodies since we are parsing only statements
		final ProblemReporter problemReporter = new ProblemReporter(
					DefaultErrorHandlingPolicies.proceedWithAllProblems(),
					compilerOptions,
					new DefaultProblemFactory(Locale.getDefault()));
		CommentRecorderParser parser = new CommentRecorderParser(problemReporter, false);
		parser.setMethodsFullRecovery(false);
		parser.setStatementsRecovery(enabledStatementRecovery);

		ICompilationUnit sourceUnit =
			new CompilationUnit(
				source,
				"", //$NON-NLS-1$
				compilerOptions.defaultEncoding);

		final CompilationResult compilationResult = new CompilationResult(sourceUnit, 0, 0, compilerOptions.maxProblemsPerUnit);
		CompilationUnitDeclaration compilationUnitDeclaration = new CompilationUnitDeclaration(problemReporter, compilationResult, length);

		ConstructorDeclaration constructorDeclaration = new ConstructorDeclaration(compilationResult);
		constructorDeclaration.sourceEnd  = -1;
		constructorDeclaration.declarationSourceEnd = offset + length - 1;
		constructorDeclaration.bodyStart = offset;
		constructorDeclaration.bodyEnd = offset + length - 1;

		parser.scanner.setSource(compilationResult);
		parser.scanner.resetTo(offset, offset + length);
		parser.parse(constructorDeclaration, compilationUnitDeclaration, true);

		if (recordParsingInformation) {
			this.recordedParsingInformation = getRecordedParsingInformation(compilationResult, compilationUnitDeclaration.comments);
		}
		return constructorDeclaration;
	}
}