package net.aiterp.git.ykonsole2.domain.models

import net.aiterp.git.ykonsole2.domain.runtime.*

fun MutableMap<Value, List<Value>>.tryMilestone(event: ValuesReceived): MilestoneReached? = tryMilestone(event.values)

fun List<WorkoutState>.makeMilestoneReachedEvents(): List<MilestoneReached> {
  val cache = mutableMapOf<Value, List<Value>>()

  return mapNotNull { cache.tryMilestone(it) }
}

private fun MutableMap<Value, List<Value>>.tryMilestone(state: WorkoutState): MilestoneReached? =
  tryMilestone(state.asValueList())

private fun MutableMap<Value, List<Value>>.tryMilestone(newValues: List<Value>): MilestoneReached? {
  val time = newValues.find<Time>() ?: return null
  val calories = newValues.find<Calories>() ?: return null
  val distance = newValues.find<Distance>() ?: return null

  var next: MilestoneReached? = null

  val roundDistance = distance.roundedDown
  if (roundDistance.isMilestone && !containsKey(roundDistance)) {
    val last = getOrDefault(distance.lastMilestone, default)

    this[roundDistance] = listOf(time, calories)
    next = MilestoneReached(
      roundDistance, listOf(time, calories), listOf(
        Time(time.seconds - last.findInt<Time>()),
        Calories(calories.kcal - last.findInt<Calories>()),
      )
    )
  }

  val roundedCals = calories.roundedDown
  if (roundedCals.isMilestone && !containsKey(roundedCals)) {
    val last = getOrDefault(roundedCals.lastMilestone, default)

    this[roundedCals] = listOf(time, distance)
    next = MilestoneReached(
      roundedCals, listOf(time, distance), listOf(
        Time(time.seconds - last.findInt<Time>()),
        Distance(distance.meters - last.findInt<Distance>()),
      )
    )
  }

  val roundedTime = time.roundedDown
  if (roundedTime.isMilestone && !containsKey(roundedTime)) {
    val last = this.getOrDefault(time.lastMilestone, default)

    this[roundedTime] = listOf(calories, distance)
    next = MilestoneReached(
      roundedTime, listOf(calories, distance), listOf(
        Calories(calories.kcal - last.findInt<Calories>()),
        Distance(distance.meters - last.findInt<Distance>()),
      )
    )
  }

  return next
}

private val default = listOf(Time(0), Calories(0), Distance(0))

private val Value.roundedDown
  get() = when (this) {
    is Time -> Time(seconds - (seconds % 2))
    is Calories -> Calories(kcal - (kcal % 4))
    is Distance -> Distance(meters - (meters % 10))
    else -> error("Not milestone-able")
  }

private val Value.isMilestone
  get() = when (this) {
    is Time -> seconds > 0 && seconds % 60 == 0
    is Calories -> kcal > 0 && kcal % 100 == 0
    is Distance -> meters > 0 && meters % 1000 == 0
    else -> error("Not milestone-able")
  }

private val Value.lastMilestone
  get() = when (this) {
    is Time -> Time(maxOf(0, (seconds - 1) - ((seconds - 1) % 60)))
    is Calories -> Calories(maxOf(0, (kcal - 1) - ((kcal - 1) % 100)))
    is Distance -> Distance(maxOf(0, (meters - 1) - ((meters - 1) % 1000)))
    else -> error("Not milestone-able")
  }