/*
 * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

package moe.nea.firmament.gui.entity

import com.google.gson.Gson
import com.google.gson.JsonArray
import com.google.gson.JsonObject
import org.apache.logging.log4j.LogManager
import org.joml.Quaternionf
import org.joml.Vector3f
import kotlin.math.atan
import net.minecraft.client.gui.DrawContext
import net.minecraft.client.gui.screen.ingame.InventoryScreen
import net.minecraft.entity.Entity
import net.minecraft.entity.EntityType
import net.minecraft.entity.LivingEntity
import net.minecraft.util.Identifier
import moe.nea.firmament.util.MC
import moe.nea.firmament.util.assertNotNullOr
import moe.nea.firmament.util.iterate
import moe.nea.firmament.util.openFirmamentResource
import moe.nea.firmament.util.render.enableScissorWithTranslation

object EntityRenderer {
    val fakeWorld = FakeWorld()
    private fun <T : Entity> t(entityType: EntityType<T>): () -> T {
        return { entityType.create(fakeWorld)!! }
    }

    val entityIds: Map<String, () -> LivingEntity> = mapOf(
        "Zombie" to t(EntityType.ZOMBIE),
        "Chicken" to t(EntityType.CHICKEN),
        "Slime" to t(EntityType.SLIME),
        "Wolf" to t(EntityType.WOLF),
        "Skeleton" to t(EntityType.SKELETON),
        "Creeper" to t(EntityType.CREEPER),
        "Ocelot" to t(EntityType.OCELOT),
        "Blaze" to t(EntityType.BLAZE),
        "Rabbit" to t(EntityType.RABBIT),
        "Sheep" to t(EntityType.SHEEP),
        "Horse" to t(EntityType.HORSE),
        "Eisengolem" to t(EntityType.IRON_GOLEM),
        "Silverfish" to t(EntityType.SILVERFISH),
        "Witch" to t(EntityType.WITCH),
        "Endermite" to t(EntityType.ENDERMITE),
        "Snowman" to t(EntityType.SNOW_GOLEM),
        "Villager" to t(EntityType.VILLAGER),
        "Guardian" to t(EntityType.GUARDIAN),
        "ArmorStand" to t(EntityType.ARMOR_STAND),
        "Squid" to t(EntityType.SQUID),
        "Bat" to t(EntityType.BAT),
        "Spider" to t(EntityType.SPIDER),
        "CaveSpider" to t(EntityType.CAVE_SPIDER),
        "Pigman" to t(EntityType.ZOMBIFIED_PIGLIN),
        "Ghast" to t(EntityType.GHAST),
        "MagmaCube" to t(EntityType.MAGMA_CUBE),
        "Wither" to t(EntityType.WITHER),
        "Enderman" to t(EntityType.ENDERMAN),
        "Mooshroom" to t(EntityType.MOOSHROOM),
        "WitherSkeleton" to t(EntityType.WITHER_SKELETON),
        "Cow" to t(EntityType.COW),
        "Dragon" to t(EntityType.ENDER_DRAGON),
        "Player" to { makeGuiPlayer(fakeWorld) },
        "Pig" to t(EntityType.PIG),
        "Giant" to t(EntityType.GIANT),
    )
    val entityModifiers: Map<String, EntityModifier> = mapOf(
        "playerdata" to ModifyPlayerSkin,
        "equipment" to ModifyEquipment,
        "riding" to ModifyRiding,
        "charged" to ModifyCharged,
        "witherdata" to ModifyWither,
        "invisible" to ModifyInvisible,
        "age" to ModifyAge,
        "horse" to ModifyHorse,
        "name" to ModifyName,
    )

    val logger = LogManager.getLogger("Firmament.Entity")
    fun applyModifiers(entityId: String, modifiers: List<JsonObject>): LivingEntity? {
        val entityType = assertNotNullOr(entityIds[entityId]) {
            logger.error("Could not create entity with id $entityId")
            return null
        }
        var entity = entityType()
        for (modifierJson in modifiers) {
            val modifier = assertNotNullOr(modifierJson["type"]?.asString?.let(entityModifiers::get)) {
                logger.error("Unknown modifier $modifierJson")
                return null
            }
            entity = modifier.apply(entity, modifierJson)
        }
        return entity
    }

    fun constructEntity(info: JsonObject): LivingEntity? {
        val modifiers = (info["modifiers"] as JsonArray?)?.map { it.asJsonObject } ?: emptyList()
        val entityType = assertNotNullOr(info["entity"]?.asString) {
            logger.error("Missing entity type on entity object")
            return null
        }
        return applyModifiers(entityType, modifiers)
    }

    private val gson = Gson()
    fun constructEntity(location: Identifier): LivingEntity? {
        return constructEntity(
            gson.fromJson(
                location.openFirmamentResource().bufferedReader(), JsonObject::class.java
            )
        )
    }

    fun renderEntity(
        entity: LivingEntity,
        renderContext: DrawContext,
        posX: Int,
        posY: Int,
        mouseX: Float,
        mouseY: Float
    ) {
        var bottomOffset = 0.0F
        var currentEntity = entity
        val maxSize = entity.iterate { it.firstPassenger as? LivingEntity }
            .map { it.height }
            .sum()
        while (true) {
            currentEntity.age = MC.player?.age ?: 0
            drawEntity(
                renderContext,
                posX,
                posY,
                posX + 50,
                posY + 80,
                (minOf(2F / maxSize, 1F) * 30).toInt(),
                -bottomOffset,
                mouseX,
                mouseY,
                currentEntity
            )
            val next = currentEntity.firstPassenger as? LivingEntity ?: break
            bottomOffset += currentEntity.getPassengerRidingPos(next).y.toFloat() * 0.75F
            currentEntity = next
        }
    }


    fun drawEntity(
        context: DrawContext,
        x1: Int,
        y1: Int,
        x2: Int,
        y2: Int,
        size: Int,
        bottomOffset: Float,
        mouseX: Float,
        mouseY: Float,
        entity: LivingEntity
    ) {
        context.enableScissorWithTranslation(x1.toFloat(), y1.toFloat(), x2.toFloat(), y2.toFloat())
        val centerX = (x1 + x2) / 2f
        val centerY = (y1 + y2) / 2f
        val targetYaw = atan(((centerX - mouseX) / 40.0f).toDouble()).toFloat()
        val targetPitch = atan(((centerY - mouseY) / 40.0f).toDouble()).toFloat()
        val rotateToFaceTheFront = Quaternionf().rotateZ(Math.PI.toFloat())
        val rotateToFaceTheCamera = Quaternionf().rotateX(targetPitch * 20.0f * (Math.PI.toFloat() / 180))
        rotateToFaceTheFront.mul(rotateToFaceTheCamera)
        val oldBodyYaw = entity.bodyYaw
        val oldYaw = entity.yaw
        val oldPitch = entity.pitch
        val oldPrevHeadYaw = entity.prevHeadYaw
        val oldHeadYaw = entity.headYaw
        entity.bodyYaw = 180.0f + targetYaw * 20.0f
        entity.yaw = 180.0f + targetYaw * 40.0f
        entity.pitch = -targetPitch * 20.0f
        entity.headYaw = entity.yaw
        entity.prevHeadYaw = entity.yaw
        val vector3f = Vector3f(0.0f, entity.height / 2.0f + bottomOffset, 0.0f)
        InventoryScreen.drawEntity(
            context,
            centerX,
            centerY,
            size,
            vector3f,
            rotateToFaceTheFront,
            rotateToFaceTheCamera,
            entity
        )
        entity.bodyYaw = oldBodyYaw
        entity.yaw = oldYaw
        entity.pitch = oldPitch
        entity.prevHeadYaw = oldPrevHeadYaw
        entity.headYaw = oldHeadYaw
        context.disableScissor()
    }


}