/*
 * Copyright 2010-2015 JetBrains s.r.o.
 *
 * Licensed 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.jetbrains.kotlin.psi

import com.intellij.lang.ASTNode
import org.jetbrains.kotlin.lexer.JetToken
import org.jetbrains.kotlin.lexer.JetTokens
import com.intellij.psi.util.PsiTreeUtil
import org.jetbrains.kotlin.psi.psiUtil.*

object JetQualifiedExpressionImpl {
    public fun JetQualifiedExpression.getOperationTokenNode(): ASTNode {
        val operationNode = this.getNode()!!.findChildByType(JetTokens.OPERATIONS)
        return operationNode!!
    }

    public fun JetQualifiedExpression.getOperationSign(): JetToken {
        return this.getOperationTokenNode().getElementType() as JetToken
    }

    private fun JetQualifiedExpression.getExpression(afterOperation: Boolean): JetExpression? {
        return getOperationTokenNode().getPsi()?.siblings(afterOperation, false)?.firstOrNull { it is JetExpression } as? JetExpression
    }

    public fun JetQualifiedExpression.getReceiverExpression(): JetExpression {
        return getExpression(false) ?: throw AssertionError("No receiver found: ${getElementTextWithContext()}")
    }

    public fun JetQualifiedExpression.getSelectorExpression(): JetExpression? {
        return getExpression(true)
    }
}
