jmonkey-test/src/main/scala/wow/doge/mygame/game/entities/player/PlayerMovementReducer.scala

package wow.doge.mygame.game.entities.player

import scala.concurrent.duration._

import akka.util.Timeout
import cats.syntax.eq._
import monix.eval.Fiber
import monix.eval.Task
import monix.reactive.Observable
import monix.{eval => me}
import wow.doge.mygame.EnumActionEvent
import wow.doge.mygame.game.entities.CharacterStats
import wow.doge.mygame.game.subsystems.input.PlayerMovementInput
import wow.doge.mygame.game.subsystems.input.PlayerMovementInput.Jump
import wow.doge.mygame.game.subsystems.input.PlayerMovementInput.WalkBackward
import wow.doge.mygame.game.subsystems.input.PlayerMovementInput.WalkForward
import wow.doge.mygame.game.subsystems.input.PlayerMovementInput.WalkLeft
import wow.doge.mygame.game.subsystems.input.PlayerMovementInput.WalkRight
import wow.doge.mygame.implicits._
import wow.doge.mygame.types.AkkaScheduler
import wow.doge.mygame.utils.MovementDirection
import io.odin.Logger

class PlayerMovementReducer(
    val playerActor: PlayerActor.Ref,
    logger: Logger[monix.bio.Task]
)(implicit
    akkaSched: AkkaScheduler
) {
  import PlayerMovementReducer._
  import com.softwaremill.quicklens._

  implicit val timeout = Timeout(1.second)
  implicit val sched = akkaSched.value

  def staminaTimer(multiplier: Int) =
    Task.deferAction(implicit s =>
      Observable
        .interval(250.millis)
        .doOnNextF(_ => logger.trace("Sending Stamina Consume Item"))
        .mapEvalF(_ =>
          playerActor
            .askL(
              PlayerActor
                .ConsumeStamina(CharacterStats.DamageStamina(1 * multiplier), _)
            )
        )
        .doOnNext(stats =>
          if (stats.stamina.toInt === 0)
            Task(playerActor ! PlayerActor.StopMoving)
          else Task.unit
        )
        .takeWhile(_.stamina.toInt >= 0)
        .completedL
    )

  def staminaRegenTimer(multiplier: Int) =
    Task.deferAction(implicit s =>
      Observable
        .interval(500.millis)
        .doOnNextF(_ => logger.trace("Sending Stamina Regen Item"))
        .mapEvalF(_ =>
          playerActor.askL(
            PlayerActor
              .HealStamina(CharacterStats.HealStamina(1 * multiplier), _)
          )
        )
        .takeWhile(_.stamina.toInt =!= 100)
        .delayExecution(1.second)
        .completedL
    )

  def handleStamina(
      state: State,
      pressed: Boolean,
      consumptionMultiplier: Int,
      regenMultiplier: Int
  ): Task[State] =
    state.staminaRegenTimer.cancel >>
      (if (pressed) {
         val nextState1 =
           if (state.keysPressed === 0)
             staminaTimer(consumptionMultiplier).start.map(
               state.modify(_.staminaTimer).setTo
             )
           else Task.pure(state)
         val nextState2 =
           nextState1.map(_.modify(_.keysPressed).using(_ + 1))

         nextState2
       } else {
         val nextState1 = state
           .modify(_.keysPressed)
           .using(_ - 1)
         if (nextState1.keysPressed === 0)
           nextState1.staminaTimer.cancel >>
             staminaRegenTimer(regenMultiplier).start.map(
               nextState1.modify(_.staminaRegenTimer).setTo
             )
         else
           Task.pure(nextState1)
       })

  def value(
      state: State,
      action: EnumActionEvent[PlayerMovementInput]
  ): Task[State] =
    action match {
      case EnumActionEvent(WalkForward, pressed, tpf) =>
        playerActor ! PlayerActor.Walk(pressed, MovementDirection.Forward)
        handleStamina(state, pressed, 1, 1)
      case EnumActionEvent(WalkRight, pressed, tpf) =>
        playerActor ! PlayerActor.Walk(pressed, MovementDirection.Right)
        handleStamina(state, pressed, 1, 1)
      case EnumActionEvent(WalkLeft, pressed, tpf) =>
        playerActor ! PlayerActor.Walk(pressed, MovementDirection.Left)
        handleStamina(state, pressed, 1, 1)
      case EnumActionEvent(WalkBackward, pressed, tpf) =>
        playerActor ! PlayerActor.Walk(pressed, MovementDirection.Backward)
        handleStamina(state, pressed, 1, 1)
      case EnumActionEvent(Jump, pressed, tpf) =>
        if (pressed) playerActor ! PlayerActor.Jump else ()
        handleStamina(state, pressed, 10, 1)
    }
}
object PlayerMovementReducer {
  final case class State(
      keysPressed: Int,
      staminaTimer: Fiber[Unit],
      staminaRegenTimer: Fiber[Unit]
  )
  object State {
    val empty = State(
      0,
      me.Fiber(me.Task.unit, me.Task.unit),
      me.Fiber(me.Task.unit, me.Task.unit)
    )
  }
}