/*
 * 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.apache.griffin.measure.step.builder.dsl.expr

trait MathExpr extends Expr {}

case class MathFactorExpr(factor: Expr, withBracket: Boolean, aliasOpt: Option[String])
    extends MathExpr
    with AliasableExpr {

  addChild(factor)

  def desc: String = if (withBracket) s"(${factor.desc})" else factor.desc
  def coalesceDesc: String = factor.coalesceDesc
  def alias: Option[String] = aliasOpt
  override def extractSelf: Expr = {
    if (aliasOpt.nonEmpty) this
    else factor.extractSelf
  }

  override def map(func: Expr => Expr): MathFactorExpr = {
    MathFactorExpr(func(factor), withBracket, aliasOpt)
  }
}

case class UnaryMathExpr(oprs: Seq[String], factor: MathExpr) extends MathExpr {

  addChild(factor)

  def desc: String = {
    oprs.foldRight(factor.desc) { (opr, fac) =>
      s"($opr$fac)"
    }
  }
  def coalesceDesc: String = {
    oprs.foldRight(factor.coalesceDesc) { (opr, fac) =>
      s"($opr$fac)"
    }
  }
  override def extractSelf: Expr = {
    if (oprs.nonEmpty) this
    else factor.extractSelf
  }

  override def map(func: Expr => Expr): UnaryMathExpr = {
    UnaryMathExpr(oprs, func(factor).asInstanceOf[MathExpr])
  }
}

case class BinaryMathExpr(factor: MathExpr, tails: Seq[(String, MathExpr)]) extends MathExpr {

  addChildren(factor +: tails.map(_._2))

  def desc: String = {
    val res = tails.foldLeft(factor.desc) { (fac, tail) =>
      val (opr, expr) = tail
      s"$fac $opr ${expr.desc}"
    }
    if (tails.size <= 0) res else s"$res"
  }
  def coalesceDesc: String = {
    val res = tails.foldLeft(factor.coalesceDesc) { (fac, tail) =>
      val (opr, expr) = tail
      s"$fac $opr ${expr.coalesceDesc}"
    }
    if (tails.size <= 0) res else s"$res"
  }
  override def extractSelf: Expr = {
    if (tails.nonEmpty) this
    else factor.extractSelf
  }

  override def map(func: Expr => Expr): BinaryMathExpr = {
    BinaryMathExpr(func(factor).asInstanceOf[MathExpr], tails.map { pair =>
      (pair._1, func(pair._2).asInstanceOf[MathExpr])
    })
  }
}