Copyright (c) 2005, 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
   Stephan Herrmann - Contribution for
							Bug 425183 - [1.8][inference] make CaptureBinding18 safe
							Bug 462025 - [null][test] create tests for manipulating external null annotations
/*******************************************************************************
 * Copyright (c) 2005, 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
 *	   Stephan Herrmann - Contribution for
 *								Bug 425183 - [1.8][inference] make CaptureBinding18 safe
 *								Bug 462025 - [null][test] create tests for manipulating external null annotations
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import java.util.ArrayList;

import org.eclipse.jdt.core.Signature;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ast.Wildcard;
import org.eclipse.jdt.internal.compiler.codegen.ConstantPool;

/*
 * Converts a binding key into a signature
 */
@SuppressWarnings({"rawtypes", "unchecked"})
public class KeyToSignature extends BindingKeyParser {

	public static final int SIGNATURE = 0;
	public static final int TYPE_ARGUMENTS = 1;
	public static final int DECLARING_TYPE = 2;
	public static final int THROWN_EXCEPTIONS = 3;

	public StringBuffer signature = new StringBuffer();
	private int kind;
	private boolean asBinarySignature = false; // '.' vs. '/' and '$'
	private ArrayList arguments = new ArrayList();
	private ArrayList typeArguments = new ArrayList();
	private ArrayList typeParameters = new ArrayList();
	private ArrayList thrownExceptions = new ArrayList();
	private int mainTypeStart = -1;
	private int mainTypeEnd;
	private int typeSigStart = -1;

	public KeyToSignature(BindingKeyParser parser) {
		super(parser);
		KeyToSignature keyToSignature = (KeyToSignature) parser;
		this.kind = keyToSignature.kind;
		this.asBinarySignature = keyToSignature.asBinarySignature;
	}

	public KeyToSignature(String key, int kind) {
		super(key);
		this.kind = kind;
	}

	public KeyToSignature(String key, int kind, boolean asBinarySignature) {
		super(key);
		this.kind = kind;
		this.asBinarySignature = asBinarySignature;
	}

	@Override
	public void consumeArrayDimension(char[] brakets) {
		this.signature.append(brakets);
	}

	@Override
	public void consumeBaseType(char[] baseTypeSig) {
		this.typeSigStart = this.signature.length();
		this.signature.append(baseTypeSig);
	}

	@Override
	public void consumeCapture(int position) {
		this.signature.append('!');
		this.signature.append(((KeyToSignature) this.arguments.get(0)).signature);
	}

	@Override
	public void consumeCapture18ID(int id, int position) {
		// see https://bugs.eclipse.org/429264
		this.signature.append("!*"); // pretend a 'capture-of ?' //$NON-NLS-1$
	}

	@Override
	public void consumeLocalType(char[] uniqueKey) {
		this.signature = new StringBuffer();
		// remove trailing semi-colon as it is added later in comsumeType()
		uniqueKey = CharOperation.subarray(uniqueKey, 0, uniqueKey.length-1);
		if (!this.asBinarySignature)
			CharOperation.replace(uniqueKey, '/', '.');
		this.signature.append(uniqueKey);
	}

	@Override
	public void consumeMethod(char[] selector, char[] methodSignature) {
		this.arguments = new ArrayList();
		this.typeArguments = new ArrayList();
		if (!this.asBinarySignature)
			CharOperation.replace(methodSignature, '/', '.');
		switch(this.kind) {
			case SIGNATURE:
				this.signature = new StringBuffer();
				this.signature.append(methodSignature);
				break;
			case THROWN_EXCEPTIONS:
				if (CharOperation.indexOf('^', methodSignature) > 0) {
					char[][] types = Signature.getThrownExceptionTypes(methodSignature);
					int length = types.length;
					for (int i=0; i<length; i++) {
						this.thrownExceptions.add(new String(types[i]));
					}
				}
				break;
		}
	}

	@Override
	public void consumeMemberType(char[] simpleTypeName) {
		this.signature.append('$');
		this.signature.append(simpleTypeName);
	}

	@Override
	public void consumePackage(char[] pkgName) {
		this.signature.append(pkgName);
	}

	@Override
	public void consumeParameterizedGenericMethod() {
		this.typeArguments = this.arguments;
		int typeParametersSize = this.arguments.size();
		if (typeParametersSize > 0) {
			int sigLength = this.signature.length();
			char[] methodSignature = new char[sigLength];
			this.signature.getChars(0, sigLength, methodSignature, 0);
			char[][] typeParameterSigs = Signature.getTypeParameters(methodSignature);
			if (typeParameterSigs.length != typeParametersSize)
				return;
			this.signature = new StringBuffer();

			// type parameters
			for (int i = 0; i < typeParametersSize; i++)
				typeParameterSigs[i] = CharOperation.concat(Signature.C_TYPE_VARIABLE,Signature.getTypeVariable(typeParameterSigs[i]), Signature.C_SEMICOLON);
			int paramStart = CharOperation.indexOf(Signature.C_PARAM_START, methodSignature);
			char[] typeParametersString = CharOperation.subarray(methodSignature, 0, paramStart);
			this.signature.append(typeParametersString);

			// substitute parameters
			this.signature.append(Signature.C_PARAM_START);
			char[][] parameters = Signature.getParameterTypes(methodSignature);
			for (int i = 0, parametersLength = parameters.length; i < parametersLength; i++)
				substitute(parameters[i], typeParameterSigs, typeParametersSize);
			this.signature.append(Signature.C_PARAM_END);

			// substitute return type
			char[] returnType = Signature.getReturnType(methodSignature);
			substitute(returnType, typeParameterSigs, typeParametersSize);

			// substitute exceptions
			char[][] exceptions = Signature.getThrownExceptionTypes(methodSignature);
			for (int i = 0, exceptionsLength = exceptions.length; i < exceptionsLength; i++) {
				this.signature.append(Signature.C_EXCEPTION_START);
				substitute(exceptions[i], typeParameterSigs, typeParametersSize);
			}

		}
	}

	/*
	 * Substitutes the type variables referenced in the given parameter (a parameterized type signature) with the corresponding
	 * type argument.
	 * Appends the given parameter if it is not a parameterized type signature.
	 */
	private void substitute(char[] parameter, char[][] typeParameterSigs, int typeParametersLength) {
		for (int i = 0; i < typeParametersLength; i++) {
			if (CharOperation.equals(parameter, typeParameterSigs[i])) {
				String typeArgument = ((KeyToSignature) this.arguments.get(i)).signature.toString();
				this.signature.append(typeArgument);
				return;
			}
		}
		int genericStart = CharOperation.indexOf(Signature.C_GENERIC_START, parameter);
		if (genericStart > -1) {
			this.signature.append(CharOperation.subarray(parameter, 0, genericStart));
			char[][] parameters = Signature.getTypeArguments(parameter);
			this.signature.append(Signature.C_GENERIC_START);
			for (int j = 0, paramsLength = parameters.length; j < paramsLength; j++)
				substitute(parameters[j], typeParameterSigs, typeParametersLength);
			this.signature.append(Signature.C_GENERIC_END);
			this.signature.append(Signature.C_SEMICOLON);
		} else {
			// handle array, wildcard and capture
			int index = 0;
			int length = parameter.length;
			loop: while (index < length) {
				char current = parameter[index];
				switch (current) {
					case Signature.C_CAPTURE:
					case Signature.C_EXTENDS:
					case Signature.C_SUPER:
					case Signature.C_ARRAY:
						this.signature.append(current);
						index++;
						break;
					default:
						break loop;
				}
			}
			if (index > 0)
				substitute(CharOperation.subarray(parameter, index, length), typeParameterSigs, typeParametersLength);
			else
				this.signature.append(parameter);
		}
	}

	@Override
	public void consumeParameterizedType(char[] simpleTypeName, boolean isRaw) {
		if (simpleTypeName != null) {
			// member type
			this.signature.append(this.asBinarySignature ? '$' : '.');
			this.signature.append(simpleTypeName);
		}
		if (!isRaw) {
			this.signature.append('<');
			int length = this.arguments.size();
			for (int i = 0; i < length; i++) {
				this.signature.append(((KeyToSignature) this.arguments.get(i)).signature);
			}
			this.signature.append('>');
			this.typeArguments = this.arguments;
			this.arguments = new ArrayList();
		}
	}

	@Override
	public void consumeParser(BindingKeyParser parser) {
		this.arguments.add(parser);
	}

	@Override
	public void consumeField(char[] fieldName) {
		if (this.kind == SIGNATURE) {
			this.signature = ((KeyToSignature) this.arguments.get(0)).signature;
		}
	}

	@Override
	public void consumeException() {
		int size = this.arguments.size();
		if (size > 0) {
			for (int i=0; i<size; i++) {
				this.thrownExceptions.add(((KeyToSignature) this.arguments.get(i)).signature.toString());
			}
			this.arguments = new ArrayList();
			this.typeArguments = new ArrayList();
		}
	}

	@Override
	public void consumeFullyQualifiedName(char[] fullyQualifiedName) {
		this.typeSigStart = this.signature.length();
		this.signature.append('L');
		if (!this.asBinarySignature)
			fullyQualifiedName = CharOperation.replaceOnCopy(fullyQualifiedName, '/', '.');
		this.signature.append(fullyQualifiedName);
	}

	@Override
	public void consumeSecondaryType(char[] simpleTypeName) {
		this.signature.append('~');
		this.mainTypeStart = this.signature.lastIndexOf(this.asBinarySignature ? "/" : ".") + 1; //$NON-NLS-1$ //$NON-NLS-2$
		if (this.mainTypeStart == 0) {
			this.mainTypeStart = 1; // default package (1 for the 'L')
			int i = 0;
			// we need to preserve the array if needed
			while (this.signature.charAt(i) == Signature.C_ARRAY) {
				this.mainTypeStart ++;
				i++;
			}
		}
		this.mainTypeEnd = this.signature.length();
		this.signature.append(simpleTypeName);
	}

	@Override
	public void consumeType() {
		// remove main type if needed
		if (this.mainTypeStart != -1) {
			this.signature.replace(this.mainTypeStart, this.mainTypeEnd, ""); //$NON-NLS-1$
		}
		// parameter types
		int length = this.typeParameters.size();
		if (length > 0) {
			StringBuffer typeParametersSig = new StringBuffer();
			typeParametersSig.append('<');
			for (int i = 0; i < length; i++) {
				char[] typeParameterSig = Signature.createTypeParameterSignature(
						(char[]) this.typeParameters.get(i),
						new char[][]{ ConstantPool.ObjectSignature });
				typeParametersSig.append(typeParameterSig);
				// TODO (jerome) add type parameter bounds in binding key
			}
			typeParametersSig.append('>');
			this.signature.insert(this.typeSigStart, typeParametersSig.toString());
			this.typeParameters = new ArrayList();
		}
		this.signature.append(';');
	}

	@Override
	public void consumeTypeParameter(char[] typeParameterName) {
		this.typeParameters.add(typeParameterName);
	}

	@Override
	public void consumeTypeVariable(char[] position, char[] typeVariableName) {
		this.signature = new StringBuffer();
		this.signature.append('T');
		this.signature.append(typeVariableName);
		this.signature.append(';');
	}

	@Override
	public void consumeTypeWithCapture() {
		KeyToSignature keyToSignature = (KeyToSignature) this.arguments.get(0);
		this.signature = keyToSignature.signature;
		this.arguments = keyToSignature.arguments;
		this.typeArguments = keyToSignature.typeArguments;
		this.thrownExceptions = keyToSignature.thrownExceptions;
	}

	@Override
	public void consumeWildCard(int wildCardKind) {
		// don't put generic type in signature
		this.signature = new StringBuffer();
		switch (wildCardKind) {
			case Wildcard.UNBOUND:
				this.signature.append('*');
				break;
			case Wildcard.EXTENDS:
				this.signature.append('+');
				this.signature.append(((KeyToSignature) this.arguments.get(0)).signature);
				break;
			case Wildcard.SUPER:
				this.signature.append('-');
				this.signature.append(((KeyToSignature) this.arguments.get(0)).signature);
				break;
			default:
				// malformed
				return;
		}
	}

	public String[] getThrownExceptions() {
		int length = this.thrownExceptions.size();
		String[] result = new String[length];
		for (int i = 0; i < length; i++) {
			result[i] = (String) this.thrownExceptions.get(i);
		}
		return result;
	}

	public String[] getTypeArguments() {
		int length = this.typeArguments.size();
		String[] result = new String[length];
		for (int i = 0; i < length; i++) {
			result[i] = ((KeyToSignature) this.typeArguments.get(i)).signature.toString();
		}
		return result;
	}

	@Override
	public BindingKeyParser newParser() {
		return new KeyToSignature(this);
	}

	@Override
	public String toString() {
		return this.signature.toString();
	}

}