package wacc

import parsley.Parsley
import parsley.generic.ErrorBridge
import parsley.ap._
import parsley.position._
import parsley.syntax.zipped._
import cats.data.NonEmptyList

object ast {
  // Expressions
  sealed trait Expr extends RValue {
    val pos: Position
  }
  sealed trait Expr1 extends Expr
  sealed trait Expr2 extends Expr1
  sealed trait Expr3 extends Expr2
  sealed trait Expr4 extends Expr3
  sealed trait Expr5 extends Expr4
  sealed trait Expr6 extends Expr5

  // Atoms
  case class IntLiter(v: Int)(val pos: Position) extends Expr6
  object IntLiter extends ParserBridgePos1[Int, IntLiter]
  case class BoolLiter(v: Boolean)(val pos: Position) extends Expr6
  object BoolLiter extends ParserBridgePos1[Boolean, BoolLiter]
  case class CharLiter(v: Char)(val pos: Position) extends Expr6
  object CharLiter extends ParserBridgePos1[Char, CharLiter]
  case class StrLiter(v: String)(val pos: Position) extends Expr6
  object StrLiter extends ParserBridgePos1[String, StrLiter]
  case class PairLiter()(val pos: Position) extends Expr6
  object PairLiter extends ParserBridgePos0[PairLiter]
  case class Ident(v: String, var uid: Int = -1)(val pos: Position) extends Expr6 with LValue
  object Ident extends ParserBridgePos1[String, Ident] {
    def apply(v: String)(pos: Position): Ident = new Ident(v)(pos)
  }
  case class ArrayElem(name: Ident, indices: NonEmptyList[Expr])(val pos: Position)
      extends Expr6
      with LValue
  object ArrayElem extends ParserBridgePos1[NonEmptyList[Expr], Ident => ArrayElem] {
    def apply(a: NonEmptyList[Expr])(pos: Position): Ident => ArrayElem =
      name => ArrayElem(name, a)(pos)
  }
  case class Parens(expr: Expr)(val pos: Position) extends Expr6
  object Parens extends ParserBridgePos1[Expr, Parens]

  // Unary operators
  sealed trait UnaryOp extends Expr {
    val x: Expr
  }
  case class Negate(x: Expr6)(val pos: Position) extends Expr6 with UnaryOp
  object Negate extends ParserBridgePos1[Expr6, Negate]
  case class Not(x: Expr6)(val pos: Position) extends Expr6 with UnaryOp
  object Not extends ParserBridgePos1[Expr6, Not]
  case class Len(x: Expr6)(val pos: Position) extends Expr6 with UnaryOp
  object Len extends ParserBridgePos1[Expr6, Len]
  case class Ord(x: Expr6)(val pos: Position) extends Expr6 with UnaryOp
  object Ord extends ParserBridgePos1[Expr6, Ord]
  case class Chr(x: Expr6)(val pos: Position) extends Expr6 with UnaryOp
  object Chr extends ParserBridgePos1[Expr6, Chr]

  // Binary operators
  sealed trait BinaryOp extends Expr {
    val x: Expr
    val y: Expr
  }
  case class Add(x: Expr4, y: Expr5)(val pos: Position) extends Expr4 with BinaryOp
  object Add extends ParserBridgePos2[Expr4, Expr5, Add]
  case class Sub(x: Expr4, y: Expr5)(val pos: Position) extends Expr4 with BinaryOp
  object Sub extends ParserBridgePos2[Expr4, Expr5, Sub]
  case class Mul(x: Expr5, y: Expr6)(val pos: Position) extends Expr5 with BinaryOp
  object Mul extends ParserBridgePos2[Expr5, Expr6, Mul]
  case class Div(x: Expr5, y: Expr6)(val pos: Position) extends Expr5 with BinaryOp
  object Div extends ParserBridgePos2[Expr5, Expr6, Div]
  case class Mod(x: Expr5, y: Expr6)(val pos: Position) extends Expr5 with BinaryOp
  object Mod extends ParserBridgePos2[Expr5, Expr6, Mod]
  case class Greater(x: Expr4, y: Expr4)(val pos: Position) extends Expr3 with BinaryOp
  object Greater extends ParserBridgePos2[Expr4, Expr4, Greater]
  case class GreaterEq(x: Expr4, y: Expr4)(val pos: Position) extends Expr3 with BinaryOp
  object GreaterEq extends ParserBridgePos2[Expr4, Expr4, GreaterEq]
  case class Less(x: Expr4, y: Expr4)(val pos: Position) extends Expr3 with BinaryOp
  object Less extends ParserBridgePos2[Expr4, Expr4, Less]
  case class LessEq(x: Expr4, y: Expr4)(val pos: Position) extends Expr3 with BinaryOp
  object LessEq extends ParserBridgePos2[Expr4, Expr4, LessEq]
  case class Eq(x: Expr3, y: Expr3)(val pos: Position) extends Expr2 with BinaryOp
  object Eq extends ParserBridgePos2[Expr3, Expr3, Eq]
  case class Neq(x: Expr3, y: Expr3)(val pos: Position) extends Expr2 with BinaryOp
  object Neq extends ParserBridgePos2[Expr3, Expr3, Neq]
  case class And(x: Expr2, y: Expr1)(val pos: Position) extends Expr1 with BinaryOp
  object And extends ParserBridgePos2[Expr2, Expr1, And]
  case class Or(x: Expr1, y: Expr)(val pos: Position) extends Expr with BinaryOp
  object Or extends ParserBridgePos2[Expr1, Expr, Or]

  // Types
  sealed trait Type
  sealed trait BaseType extends Type with PairElemType
  case class IntType()(val pos: Position) extends BaseType
  object IntType extends ParserBridgePos0[IntType]
  case class BoolType()(val pos: Position) extends BaseType
  object BoolType extends ParserBridgePos0[BoolType]
  case class CharType()(val pos: Position) extends BaseType
  object CharType extends ParserBridgePos0[CharType]
  case class StringType()(val pos: Position) extends BaseType
  object StringType extends ParserBridgePos0[StringType]
  case class ArrayType(elemType: Type, dimensions: Int)(val pos: Position)
      extends Type
      with PairElemType
  object ArrayType extends ParserBridgePos1[Int, Type => ArrayType] {
    def apply(a: Int)(pos: Position): Type => ArrayType = elemType => ArrayType(elemType, a)(pos)
  }
  case class PairType(fst: PairElemType, snd: PairElemType)(val pos: Position) extends Type
  object PairType extends ParserBridgePos2[PairElemType, PairElemType, PairType]

  sealed trait PairElemType
  case class UntypedPairType()(val pos: Position) extends PairElemType
  object UntypedPairType extends ParserBridgePos0[UntypedPairType]

  // waccadoodledo
  case class Program(funcs: List[FuncDecl], main: NonEmptyList[Stmt])(val pos: Position)
  object Program extends ParserBridgePos2[List[FuncDecl], NonEmptyList[Stmt], Program]

  // Function Definitions
  case class FuncDecl(
      returnType: Type,
      name: Ident,
      params: List[Param],
      body: NonEmptyList[Stmt]
  )(val pos: Position)
  object FuncDecl
      extends ParserBridgePos2[
        List[Param],
        NonEmptyList[Stmt],
        ((Type, Ident)) => FuncDecl
      ] {
    def apply(params: List[Param], body: NonEmptyList[Stmt])(
        pos: Position
    ): ((Type, Ident)) => FuncDecl =
      (returnType, name) => FuncDecl(returnType, name, params, body)(pos)
  }

  case class Param(paramType: Type, name: Ident)(val pos: Position)
  object Param extends ParserBridgePos2[Type, Ident, Param]

  // Statements
  sealed trait Stmt
  case class Skip()(val pos: Position) extends Stmt
  object Skip extends ParserBridgePos0[Skip]
  case class VarDecl(varType: Type, name: Ident, value: RValue)(val pos: Position) extends Stmt
  object VarDecl extends ParserBridgePos3[Type, Ident, RValue, VarDecl]
  case class Assign(lhs: LValue, value: RValue)(val pos: Position) extends Stmt
  object Assign extends ParserBridgePos2[LValue, RValue, Assign]
  case class Read(lhs: LValue)(val pos: Position) extends Stmt
  object Read extends ParserBridgePos1[LValue, Read]
  case class Free(expr: Expr)(val pos: Position) extends Stmt
  object Free extends ParserBridgePos1[Expr, Free]
  case class Return(expr: Expr)(val pos: Position) extends Stmt
  object Return extends ParserBridgePos1[Expr, Return]
  case class Exit(expr: Expr)(val pos: Position) extends Stmt
  object Exit extends ParserBridgePos1[Expr, Exit]
  case class Print(expr: Expr, newline: Boolean)(val pos: Position) extends Stmt
  object Print extends ParserBridgePos2[Expr, Boolean, Print]
  case class If(cond: Expr, thenStmt: NonEmptyList[Stmt], elseStmt: NonEmptyList[Stmt])(
      val pos: Position
  ) extends Stmt
  object If extends ParserBridgePos3[Expr, NonEmptyList[Stmt], NonEmptyList[Stmt], If]
  case class While(cond: Expr, body: NonEmptyList[Stmt])(val pos: Position) extends Stmt
  object While extends ParserBridgePos2[Expr, NonEmptyList[Stmt], While]
  case class Block(stmt: NonEmptyList[Stmt])(val pos: Position) extends Stmt
  object Block extends ParserBridgePos1[NonEmptyList[Stmt], Block]

  sealed trait LValue {
    val pos: Position
  }

  sealed trait RValue
  case class ArrayLiter(elems: List[Expr])(val pos: Position) extends RValue
  object ArrayLiter extends ParserBridgePos1[List[Expr], ArrayLiter]
  case class NewPair(fst: Expr, snd: Expr)(val pos: Position) extends RValue
  object NewPair extends ParserBridgePos2[Expr, Expr, NewPair]
  case class Call(name: Ident, args: List[Expr])(val pos: Position) extends RValue
  object Call extends ParserBridgePos2[Ident, List[Expr], Call]

  sealed trait PairElem extends LValue with RValue
  case class Fst(elem: LValue)(val pos: Position) extends PairElem
  object Fst extends ParserBridgePos1[LValue, Fst]
  case class Snd(elem: LValue)(val pos: Position) extends PairElem
  object Snd extends ParserBridgePos1[LValue, Snd]

  // Parser bridges
  case class Position(line: Int, column: Int)

  trait ParserSingletonBridgePos[+A] extends ErrorBridge {
    protected def con(pos: (Int, Int)): A
    infix def from(op: Parsley[?]): Parsley[A] = error(pos.map(con) <~ op)
    final def <#(op: Parsley[?]): Parsley[A] = this from op
  }

  trait ParserBridgePos0[+A] extends ParserSingletonBridgePos[A] {
    def apply()(pos: Position): A

    override final def con(pos: (Int, Int)): A =
      apply()(Position(pos._1, pos._2))
  }

  trait ParserBridgePos1[-A, +B] extends ParserSingletonBridgePos[A => B] {
    def apply(a: A)(pos: Position): B
    def apply(a: Parsley[A]): Parsley[B] = error(ap1(pos.map(con), a))

    override final def con(pos: (Int, Int)): A => B =
      this.apply(_)(Position(pos._1, pos._2))
  }

  trait ParserBridgePos2[-A, -B, +C] extends ParserSingletonBridgePos[(A, B) => C] {
    def apply(a: A, b: B)(pos: Position): C
    def apply(a: Parsley[A], b: => Parsley[B]): Parsley[C] = error(
      ap2(pos.map(con), a, b)
    )

    override final def con(pos: (Int, Int)): (A, B) => C =
      apply(_, _)(Position(pos._1, pos._2))
  }

  trait ParserBridgePos3[-A, -B, -C, +D] extends ParserSingletonBridgePos[(A, B, C) => D] {
    def apply(a: A, b: B, c: C)(pos: Position): D
    def apply(a: Parsley[A], b: => Parsley[B], c: => Parsley[C]): Parsley[D] = error(
      ap3(pos.map(con), a, b, c)
    )

    override final def con(pos: (Int, Int)): (A, B, C) => D =
      apply(_, _, _)(Position(pos._1, pos._2))
  }
}