/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.codehaus.groovy.transform.tailrec

import groovy.transform.CompileStatic
import org.codehaus.groovy.ast.ClassNode
import org.codehaus.groovy.ast.expr.Expression
import org.codehaus.groovy.ast.expr.VariableExpression
import org.codehaus.groovy.ast.stmt.ContinueStatement
import org.codehaus.groovy.ast.stmt.ExpressionStatement
import org.codehaus.groovy.ast.stmt.Statement

import java.lang.reflect.Modifier

import static org.codehaus.groovy.ast.tools.GeneralUtils.classX
import static org.codehaus.groovy.ast.tools.GeneralUtils.declS
import static org.codehaus.groovy.ast.tools.GeneralUtils.localVarX
import static org.codehaus.groovy.ast.tools.GeneralUtils.propX
import static org.codehaus.groovy.ast.tools.GeneralUtils.throwS
import static org.codehaus.groovy.ast.tools.GeneralUtils.varX

/**
 * Helping to create a few standard AST constructs
 */
@CompileStatic
class AstHelper {
    static ExpressionStatement createVariableDefinition(String variableName, ClassNode variableType, Expression value, boolean variableShouldBeFinal = false) {
        def newVariable = localVarX(variableName, variableType)
        if (variableShouldBeFinal)
            newVariable.modifiers = Modifier.FINAL
        (ExpressionStatement) declS(newVariable, value)
    }

    static ExpressionStatement createVariableAlias(String aliasName, ClassNode variableType, String variableName) {
        createVariableDefinition(aliasName, variableType, varX(variableName, variableType))
    }

    static VariableExpression createVariableReference(Map variableSpec) {
        varX((String) variableSpec.name, (ClassNode) variableSpec.type)
    }

    /**
     * This statement should make the code jump to surrounding while loop's start label
     * Does not work from within Closures
     */
    static Statement recurStatement() {
        //continue _RECUR_HERE_
        new ContinueStatement(org.codehaus.groovy.transform.tailrec.InWhileLoopWrapper.LOOP_LABEL)
    }

    /**
     * This statement will throw exception which will be caught and redirected to jump to surrounding while loop's start label
     * Also works from within Closures but is a tiny bit slower
     */
    static Statement recurByThrowStatement() {
        // throw InWhileLoopWrapper.LOOP_EXCEPTION
        throwS(propX(classX(InWhileLoopWrapper), 'LOOP_EXCEPTION'))
    }
}
