/*
Copyright (c) 2014 - 2016 The Regents of the University of
California (Regents). All Rights Reserved.  Redistribution and use in
source and binary forms, with or without modification, are permitted
provided that the following conditions are met:
   * Redistributions of source code must retain the above
     copyright notice, this list of conditions and the following
     two paragraphs of disclaimer.
   * Redistributions in binary form must reproduce the above
     copyright notice, this list of conditions and the following
     two paragraphs of disclaimer in the documentation and/or other materials
     provided with the distribution.
   * Neither the name of the Regents nor the names of its contributors
     may be used to endorse or promote products derived from this
     software without specific prior written permission.
IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
REGENTS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF
ANY, PROVIDED HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION
TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
MODIFICATIONS.
*/

package firrtl

import scala.collection.Seq
import Utils._
import firrtl.ir._
import WrappedExpression._
import WrappedWidth._

trait Kind
case class WireKind() extends Kind
case class PoisonKind() extends Kind 
case class RegKind() extends Kind
case class InstanceKind() extends Kind
case class PortKind() extends Kind
case class NodeKind() extends Kind
case class MemKind(ports: Seq[String]) extends Kind
case class ExpKind() extends Kind

trait Gender
case object MALE extends Gender
case object FEMALE extends Gender
case object BIGENDER extends Gender
case object UNKNOWNGENDER extends Gender

case class WRef(name: String, tpe: Type, kind: Kind, gender: Gender) extends Expression {
  def serialize: String = name
}
case class WSubField(exp: Expression, name: String, tpe: Type, gender: Gender) extends Expression {
  def serialize: String = s"${exp.serialize}.$name"
}
case class WSubIndex(exp: Expression, value: Int, tpe: Type, gender: Gender) extends Expression {
  def serialize: String = s"${exp.serialize}[$value]"
}
case class WSubAccess(exp: Expression, index: Expression, tpe: Type, gender: Gender) extends Expression {
  def serialize: String = s"${exp.serialize}[${index.serialize}]"
}
case class WVoid() extends Expression {
  def tpe = UnknownType
  def serialize: String = "VOID"
}
case class WInvalid() extends Expression {
  def tpe = UnknownType
  def serialize: String = "INVALID"
}
// Useful for splitting then remerging references
case object EmptyExpression extends Expression {
  def tpe = UnknownType
  def serialize: String = "EMPTY"
}
case class WDefInstance(info: Info, name: String, module: String, tpe: Type) extends Statement with IsDeclaration {
  def serialize: String = s"inst $name of $module" + info.serialize
}

// Resultant width is the same as the maximum input width
case object Addw extends PrimOp { override def toString = "addw" }
// Resultant width is the same as the maximum input width
case object Subw extends PrimOp { override def toString = "subw" }
// Resultant width is the same as input argument width
case object Dshlw extends PrimOp { override def toString = "dshlw" }
// Resultant width is the same as input argument width
case object Shlw extends PrimOp { override def toString = "shlw" }

object WrappedExpression {
   def apply (e:Expression) = new WrappedExpression(e)
   def we (e:Expression) = new WrappedExpression(e)
   def weq (e1:Expression,e2:Expression) = we(e1) == we(e2)
}
class WrappedExpression (val e1:Expression) {
   override def equals (we:Any) = {
      we match {
         case (we:WrappedExpression) => {
            (e1,we.e1) match {
               case (e1:UIntLiteral,e2:UIntLiteral) => if (e1.value == e2.value) eqw(e1.width,e2.width) else false
               case (e1:SIntLiteral,e2:SIntLiteral) => if (e1.value == e2.value) eqw(e1.width,e2.width) else false
               case (e1:WRef,e2:WRef) => e1.name equals e2.name
               case (e1:WSubField,e2:WSubField) => (e1.name equals e2.name) && weq(e1.exp,e2.exp)
               case (e1:WSubIndex,e2:WSubIndex) => (e1.value == e2.value) && weq(e1.exp,e2.exp)
               case (e1:WSubAccess,e2:WSubAccess) => weq(e1.index,e2.index) && weq(e1.exp,e2.exp)
               case (e1:WVoid,e2:WVoid) => true
               case (e1:WInvalid,e2:WInvalid) => true
               case (e1:DoPrim,e2:DoPrim) => {
                  var are_equal = e1.op == e2.op
                  (e1.args,e2.args).zipped.foreach{ (x,y) => { if (!weq(x,y)) are_equal = false }}
                  (e1.consts,e2.consts).zipped.foreach{ (x,y) => { if (x != y) are_equal = false }}
                  are_equal
               }
               case (e1:Mux,e2:Mux) => weq(e1.cond,e2.cond) && weq(e1.tval,e2.tval) && weq(e1.fval,e2.fval)
               case (e1:ValidIf,e2:ValidIf) => weq(e1.cond,e2.cond) && weq(e1.value,e2.value)
               case (e1,e2) => false
            }
         }
         case _ => false
      }
   }
   override def hashCode = e1.serialize.hashCode
   override def toString = e1.serialize
}
      

case class VarWidth(name: String) extends Width {
  def serialize: String = name
}
case class PlusWidth(arg1: Width, arg2: Width) extends Width {
  def serialize: String = "(" + arg1.serialize + " + " + arg2.serialize + ")"
}
case class MinusWidth(arg1: Width, arg2: Width) extends Width {
  def serialize: String = "(" + arg1.serialize + " - " + arg2.serialize + ")"
}
case class MaxWidth(args: Seq[Width]) extends Width {
  def serialize: String = args map (_.serialize) mkString ("max(", ", ", ")")
}
case class MinWidth(args: Seq[Width]) extends Width {
  def serialize: String = args map (_.serialize) mkString ("min(", ", ", ")")
}
case class ExpWidth(arg1: Width) extends Width {
  def serialize: String = "exp(" + arg1.serialize + " )"
}

object WrappedType {
   def apply (t:Type) = new WrappedType(t)
   def wt (t:Type) = apply(t)
}
class WrappedType (val t:Type) {
   def wt (tx:Type) = new WrappedType(tx)
   override def equals (o:Any) : Boolean = {
      o match {
         case (t2:WrappedType) => {
            (t,t2.t) match {
               case (t1:UIntType,t2:UIntType) => true
               case (t1:SIntType,t2:SIntType) => true
               case (ClockType, ClockType) => true
               case (t1:VectorType,t2:VectorType) => (wt(t1.tpe) == wt(t2.tpe) && t1.size == t2.size)
               case (t1:BundleType,t2:BundleType) => {
                  var ret = true
                  (t1.fields,t2.fields).zipped.foreach{ (f1,f2) => {
                     if (f1.flip != f2.flip) ret = false
                     if (f1.name != f2.name) ret = false
                     if (wt(f1.tpe) != wt(f2.tpe)) ret = false
                  }}
                  if (t1.fields.size != t2.fields.size) ret = false
                  ret
               }
               case (t1,t2) => false
            }
         }
         case _ => false
      }
   }
}

object WrappedWidth {
   def eqw (w1:Width,w2:Width) : Boolean = {
      (new WrappedWidth(w1)) == (new WrappedWidth(w2))
   }
}
   
class WrappedWidth (val w:Width) {
   override def toString = {
      w match {
         case (w:VarWidth) => w.name
         case (w:MaxWidth) => "max(" + w.args.map(_.toString).reduce(_ + _) + ")"
         case (w:MinWidth) => "min(" + w.args.map(_.toString).reduce(_ + _) + ")"
         case (w:PlusWidth) => "(" + w.arg1 + " + " + w.arg2 + ")"
         case (w:MinusWidth) => "(" + w.arg1 + " - " + w.arg2 + ")"
         case (w:ExpWidth) => "exp(" + w.arg1 + ")"
         case (w:IntWidth) => w.width.toString
         case UnknownWidth => "?"
      }
   }
   def ww (w:Width) : WrappedWidth = new WrappedWidth(w)
   override def equals (o:Any) : Boolean = {
      o match {
         case (w2:WrappedWidth) => {
            (w,w2.w) match {
               case (w1:VarWidth,w2:VarWidth) => w1.name.equals(w2.name)
               case (w1:MaxWidth,w2:MaxWidth) => {
                  var ret = true
                  if (w1.args.size != w2.args.size) ret = false
                  else {
                     for (a1 <- w1.args) {
                        var found = false
                        for (a2 <- w2.args) { if (eqw(a1,a2)) found = true }
                        if (found == false) ret = false
                     }
                  }
                  ret
               }
               case (w1:MinWidth,w2:MinWidth) => {
                  var ret = true
                  if (w1.args.size != w2.args.size) ret = false
                  else {
                     for (a1 <- w1.args) {
                        var found = false
                        for (a2 <- w2.args) { if (eqw(a1,a2)) found = true }
                        if (found == false) ret = false
                     }
                  }
                  ret
               }
               case (w1:IntWidth,w2:IntWidth) => w1.width == w2.width
               case (w1:PlusWidth,w2:PlusWidth) => 
                  (ww(w1.arg1) == ww(w2.arg1) && ww(w1.arg2) == ww(w2.arg2)) || (ww(w1.arg1) == ww(w2.arg2) && ww(w1.arg2) == ww(w2.arg1))
               case (w1:MinusWidth,w2:MinusWidth) => 
                  (ww(w1.arg1) == ww(w2.arg1) && ww(w1.arg2) == ww(w2.arg2)) || (ww(w1.arg1) == ww(w2.arg2) && ww(w1.arg2) == ww(w2.arg1))
               case (w1:ExpWidth,w2:ExpWidth) => ww(w1.arg1) == ww(w2.arg1)
               case (UnknownWidth, UnknownWidth) => true
               case (w1,w2) => false
            }
         }
         case _ => false
      }
   }
}

trait Constraint
class WGeq(val loc:Width,val exp:Width) extends Constraint {
   override def toString = {
      val wloc = new WrappedWidth(loc)
      val wexp = new WrappedWidth(exp)
      wloc.toString + " >= " + wexp.toString
   }
}
object WGeq {
   def apply (loc:Width,exp:Width) = new WGeq(loc,exp)
}

abstract class MPortDir extends FirrtlNode
case object MInfer extends MPortDir {
  def serialize: String = "infer"
}
case object MRead extends MPortDir {
  def serialize: String = "read"
}
case object MWrite extends MPortDir {
  def serialize: String = "write"
}
case object MReadWrite extends MPortDir {
  def serialize: String = "rdwr"
}

case class CDefMemory(
    info: Info,
    name: String,
    tpe: Type,
    size: Int,
    seq: Boolean) extends Statement {
  def serialize: String = (if (seq) "smem" else "cmem") +
    s" $name : ${tpe.serialize} [$size]" + info.serialize
}
case class CDefMPort(info: Info,
    name: String,
    tpe: Type,
    mem: String,
    exps: Seq[Expression],
    direction: MPortDir) extends Statement {
  def serialize: String = {
    val dir = direction.serialize
    s"$dir mport $name = $mem[${exps(0).serialize}], ${exps(1).serialize}" + info.serialize
  }
}