package dev.cobblesurvival.selftest

import dev.cobblesurvival.CobbleSurvival
import dev.cobblesurvival.zone.ZoneSample
import dev.cobblesurvival.zone.Zones
import net.minecraft.core.registries.BuiltInRegistries
import net.minecraft.gametest.framework.GameTestAssertException
import net.minecraft.resources.ResourceLocation
import net.minecraft.server.level.ServerPlayer
import net.minecraft.world.effect.MobEffects
import net.minecraft.world.entity.EquipmentSlot
import net.minecraft.world.entity.LivingEntity
import net.minecraft.world.item.ItemStack
import net.minecraft.world.item.Items
import net.minecraft.world.level.levelgen.Heightmap

/**
 * Roadmap Phase 3, hazards as gates, on the island itself (real biomes, real altitude): in Frostpeak and Sunscorch
 * a player without the right gear freezes or overheats within a minute or two, while the fur (cold) or hide (heat)
 * set holds them off for many minutes; leather armour alone doesn't help. The zones without a hazard are livable
 * without gear by day and by night. The Mangrove Mire poisons anyone without Mire Waders.
 *
 * Cold Sweat's insulation doesn't change what counts as too cold or too hot; it slows how fast the body drifts
 * there. So the tests reset each player's core temperature to 0, wait, and turn the drift into minutes until the
 * body reaches ±100, where Cold Sweat starts to hurt. Each case changes the time of day, so it runs in a batch of
 * its own.
 */
object HazardTests {
    private val FUR = listOf("goat_fur_helmet", "goat_fur_chestplate", "goat_fur_leggings", "goat_fur_boots")
    private val HIDE = listOf("hoglin_helmet", "hoglin_chestplate", "hoglin_leggings", "hoglin_boots")
    private val LEATHER = listOf("leather_helmet", "leather_chestplate", "leather_leggings", "leather_boots")
    private const val NOON = 6000L
    private const val MIDNIGHT = 18000L
    private const val MEASURE_TICKS = 60
    /** Cold Sweat eases the felt temperature towards a new place; let it arrive before measuring. */
    private const val SETTLE_TICKS = 120

    /** Without gear the hazard must hurt within this many minutes... */
    private const val UNPROTECTED_MAX_MINUTES = 3.0
    /** ...and with the right set not before this many. */
    private const val PROTECTED_MIN_MINUTES = 10.0

    fun all() = listOf(
        SelfTestCase("cold_needs_fur", 600, ::cold, islandOnly = true, batch = "hazard_cold"),
        SelfTestCase("heat_needs_hide", 600, ::heat, islandOnly = true, batch = "hazard_heat"),
        SelfTestCase("lowlands_are_mild", 4000, ::lowlands, islandOnly = true, batch = "hazard_lowlands"),
        SelfTestCase("mire_poisons_without_waders", 400, ::mire),
    )

    /** Frostpeak at noon, its warmest hour. */
    private fun cold(s: Scenario) {
        val bare = s.player()
        val leather = s.player().also { dress(it, "minecraft", LEATHER) }
        val fur = s.player().also { dress(it, "cold_sweat", FUR) }
        val players = listOf(bare, leather, fur)
        s.helper.startSequence()
            .thenExecute { exposeAt(s, Zones.biomeSamples["frostpeak"], NOON, players) }
            .thenIdle(SETTLE_TICKS)
            .thenExecute { players.forEach { ColdSweat.setCore(it, 0.0) } }
            .thenIdle(MEASURE_TICKS)
            .thenExecute {
                val (bareMin, leatherMin, furMin) = players.map { ColdSweat.minutesToLimit(it) }
                report(s, "Frostpeak at noon (%s), minutes until the body freezes: none %.1f, leather %.1f, fur %.1f".format(ColdSweat.describe(bare), bareMin, leatherMin, furMin))
                s.check(bareMin <= UNPROTECTED_MAX_MINUTES) { "without gear Frostpeak takes %.1f min to freeze".format(bareMin) }
                s.check(leatherMin <= UNPROTECTED_MAX_MINUTES) { "in leather Frostpeak takes %.1f min to freeze".format(leatherMin) }
                s.check(furMin >= PROTECTED_MIN_MINUTES) { "in the fur set Frostpeak freezes in %.1f min".format(furMin) }
                // And it really hurts: a frozen body without the new-player grace takes damage.
                ColdSweat.endGrace(bare)
                ColdSweat.setCore(bare, -150.0)
            }
            .thenExecuteAfter(60) {
                s.check(bare.health < bare.maxHealth) { "a frozen player took no damage (health ${bare.health})" }
            }
            .thenSucceed()
    }

    /** Sunscorch at noon, its hottest hour. */
    private fun heat(s: Scenario) {
        val bare = s.player()
        val hide = s.player().also { dress(it, "cold_sweat", HIDE) }
        val players = listOf(bare, hide)
        s.helper.startSequence()
            .thenExecute { exposeAt(s, Zones.biomeSamples["sunscorch"], NOON, players) }
            .thenIdle(SETTLE_TICKS)
            .thenExecute { players.forEach { ColdSweat.setCore(it, 0.0) } }
            .thenIdle(MEASURE_TICKS)
            .thenExecute {
                val (bareMin, hideMin) = players.map { ColdSweat.minutesToLimit(it) }
                report(s, "Sunscorch at noon (%s), minutes until the body overheats: none %.1f, hide %.1f".format(ColdSweat.describe(bare), bareMin, hideMin))
                s.check(bareMin <= UNPROTECTED_MAX_MINUTES) { "without gear Sunscorch takes %.1f min to overheat".format(bareMin) }
                s.check(hideMin >= PROTECTED_MIN_MINUTES) { "in the hide set Sunscorch overheats in %.1f min".format(hideMin) }
            }
            .thenSucceed()
    }

    /** Every zone without a hazard, at noon and at midnight, without gear. */
    private fun lowlands(s: Scenario) {
        val player = s.player()
        val problems = mutableListOf<String>()
        val readings = mutableListOf<String>()
        var sequence = s.helper.startSequence()
        // Nights are the cold risk everywhere; the warm zones are checked at noon too.
        val checks = listOf("button_isle", "southwold", "westmarch", "jungle", "highlands", "mire").map { it to MIDNIGHT } +
            listOf("jungle" to NOON, "mire" to NOON)
        for ((zone, time) in checks) {
            run {
                val label = "$zone at ${if (time == NOON) "noon" else "midnight"}"
                sequence = sequence
                    .thenExecute { exposeAt(s, Zones.samples[zone], time, listOf(player)) }
                    .thenIdle(SETTLE_TICKS)
                    .thenExecute { ColdSweat.setCore(player, 0.0) }
                    .thenIdle(MEASURE_TICKS)
                    .thenExecute {
                        val minutes = ColdSweat.minutesToLimit(player)
                        readings += "$label %.0f (world %.2f)".format(minutes, ColdSweat.get(player, "WORLD"))
                        if (minutes < PROTECTED_MIN_MINUTES) problems += "$label: limit in %.1f min (%s)".format(minutes, ColdSweat.describe(player))
                    }
            }
        }
        sequence.thenExecute {
            report(s, "minutes until too hot or cold without gear: ${readings.joinToString()}")
            s.check(problems.isEmpty()) { problems.joinToString("; ") }
        }.thenSucceed()
    }

    /** The Mire's fumes (companion mod zone hazard) poison a player without Mire Waders, and nobody outside it. */
    private fun mire(s: Scenario) {
        val level = s.level
        val mire = Zones.samples["mire"] ?: throw GameTestAssertException("no sample point for the Mire")
        val elsewhere = Zones.samples["button_isle"] ?: throw GameTestAssertException("no sample point for Button Isle")
        val waders = BuiltInRegistries.ITEM.get(ResourceLocation.fromNamespaceAndPath("cobblesurvival", "mire_waders"))
        s.check(waders != Items.AIR) { "the Mire Waders item does not exist" }
        val bare = s.player()
        val wading = s.player().also { it.setItemSlot(EquipmentSlot.FEET, ItemStack(waders)) }
        val outside = s.player()
        fun surface(sample: ZoneSample): Double {
            level.getChunk(sample.x shr 4, sample.z shr 4)
            return level.getHeight(Heightmap.Types.MOTION_BLOCKING_NO_LEAVES, sample.x, sample.z).toDouble()
        }
        s.helper.startSequence()
            .thenExecute {
                for (player in listOf(bare, wading)) s.moveTo(player, mire.x + 0.5, surface(mire), mire.z + 0.5)
                s.moveTo(outside, elsewhere.x + 0.5, surface(elsewhere), elsewhere.z + 0.5)
            }
            .thenIdle(220)
            .thenExecute {
                val poison = MobEffects.POISON
                s.check(bare.hasEffect(poison)) { "a player without waders in the Mire isn't poisoned" }
                s.check(!wading.hasEffect(poison)) { "a player in Mire Waders got poisoned" }
                s.check(!outside.hasEffect(poison)) { "a player on Button Isle got poisoned" }
            }
            .thenSucceed()
    }

    private fun dress(player: ServerPlayer, namespace: String, pieces: List<String>) {
        val slots = listOf(EquipmentSlot.HEAD, EquipmentSlot.CHEST, EquipmentSlot.LEGS, EquipmentSlot.FEET)
        for ((slot, piece) in slots.zip(pieces)) {
            player.setItemSlot(slot, ItemStack(BuiltInRegistries.ITEM.get(ResourceLocation.fromNamespaceAndPath(namespace, piece))))
        }
    }

    /** Stands the players on the surface at the sample point at that time of day. */
    private fun exposeAt(s: Scenario, sample: ZoneSample?, time: Long, players: List<ServerPlayer>) {
        if (sample == null) throw GameTestAssertException("no sample point (run tools/zone_layout.py)")
        val level = s.level
        for (dx in -2..2) for (dz in -2..2) level.getChunk((sample.x shr 4) + dx, (sample.z shr 4) + dz)
        val y = level.getHeight(Heightmap.Types.MOTION_BLOCKING_NO_LEAVES, sample.x, sample.z)
        level.dayTime = time
        for (player in players) {
            s.moveTo(player, sample.x + 0.5, y.toDouble(), sample.z + 0.5)
        }
    }

    private fun report(s: Scenario, text: String) = CobbleSurvival.LOGGER.info("selftest {}: {}", s.case.name, text)

    /** Cold Sweat's temperature API, by reflection: the companion mod doesn't compile against Cold Sweat. */
    private object ColdSweat {
        private val api = Class.forName("com.momosoftworks.coldsweat.api.util.Temperature")
        private val traits = Class.forName("com.momosoftworks.coldsweat.api.util.Temperature\$Trait")
        private val get = api.getMethod("get", LivingEntity::class.java, traits)
        private val set = api.getMethod("set", LivingEntity::class.java, traits, Double::class.javaPrimitiveType)

        private fun trait(name: String) = traits.getField(name).get(null)
        fun get(entity: LivingEntity, name: String) = get.invoke(null, entity, trait(name)) as Double
        fun setCore(player: ServerPlayer, value: Double) { set.invoke(null, player, trait("CORE"), value) }

        /** Minutes from now until the core reaches ±100 at the drift since it was reset to 0. */
        fun minutesToLimit(player: ServerPlayer): Double {
            val perTick = kotlin.math.abs(get(player, "CORE")) / MEASURE_TICKS
            return if (perTick == 0.0) Double.POSITIVE_INFINITY else 100.0 / perTick / 20.0 / 60.0
        }

        fun endGrace(player: ServerPlayer) {
            BuiltInRegistries.MOB_EFFECT.getHolder(ResourceLocation.fromNamespaceAndPath("cold_sweat", "grace"))
                .ifPresent { player.removeEffect(it) }
        }

        fun describe(player: ServerPlayer) = "world %.2f, comfortable %.2f..%.2f, core %.1f".format(
            get(player, "WORLD"), get(player, "FREEZING_POINT"), get(player, "BURNING_POINT"), get(player, "CORE"),
        )
    }
}