package com.simpletombstone;

import net.fabricmc.api.ModInitializer;
import net.fabricmc.loader.api.FabricLoader;
import net.fabricmc.api.EnvType;
import net.minecraft.block.*;
import net.minecraft.server.network.ServerPlayerEntity;
import net.minecraft.text.Text;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.World;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import net.minecraft.item.ItemStack;
import net.fabricmc.fabric.api.entity.event.v1.ServerLivingEntityEvents;
import net.fabricmc.fabric.api.event.lifecycle.v1.ServerTickEvents;
import net.fabricmc.fabric.api.entity.event.v1.ServerPlayerEvents;
import java.util.*;

public class SimpleTombstone implements ModInitializer {
    public static final String MOD_ID = "simple-tombstone";
    public static final Logger LOGGER = LoggerFactory.getLogger(MOD_ID);
    private static final Map<BlockPos, PlayerTombstoneData> TOMBSTONE_CHESTS = new HashMap<>();
    private static final Set<UUID> DEAD_PLAYERS = new HashSet<>();
    private static final Set<UUID> RESURRECTED_PLAYERS = new HashSet<>();

    @Override
    public void onInitialize() {
        if (FabricLoader.getInstance().getEnvironmentType() == EnvType.SERVER) {
            LOGGER.info("[SimpleTombstone] 服务器端初始化中...");
            ServerLivingEntityEvents.ALLOW_DEATH.register((entity, damageSource, damageAmount) -> {
                if (entity instanceof ServerPlayerEntity player) {
                    LOGGER.info("[SimpleTombstone] 检测到玩家 {} 死亡，创建墓碑...", player.getName().getString());
                    createTombstoneForMixin(player);
                    DEAD_PLAYERS.add(player.getUuid());
                    return false;
                }
                return true;
            });

            ServerPlayerEvents.AFTER_RESPAWN.register((oldPlayer, newPlayer, alive) -> {
                UUID playerId = newPlayer.getUuid();
                if (DEAD_PLAYERS.contains(playerId)) {
                    LOGGER.info("[SimpleTombstone] 玩家 {} 已重生，物品归还功能已启用。", newPlayer.getName().getString());
                    DEAD_PLAYERS.remove(playerId);
                    RESURRECTED_PLAYERS.add(playerId);
                }
            });

            LOGGER.info("[SimpleTombstone] 服务器端初始化完成");
        }

        ServerTickEvents.END_SERVER_TICK.register(server -> {
            for (ServerPlayerEntity player : server.getPlayerManager().getPlayerList()) {
                if (RESURRECTED_PLAYERS.contains(player.getUuid())) {
                    checkPlayerNearTombstone(player);
                }
            }
        });
    }

    public static void createTombstoneForMixin(ServerPlayerEntity player) {
        BlockPos deathPos = player.getBlockPos();
        World world = player.getWorld();

        while (world.isAir(deathPos.down())) {
            deathPos = deathPos.down();
        }

        if (!world.getBlockState(deathPos).isSolid()) {
            LOGGER.warn("[SimpleTombstone] 位置 {} 处为液体，替换为玻璃。", deathPos.toShortString());
            world.setBlockState(deathPos, Blocks.GLASS.getDefaultState());
        }

        BlockPos tombstonePos = deathPos.up();
        List<ItemStack> items = new ArrayList<>();
        for (int i = 0; i < player.getInventory().size(); i++) {
            ItemStack stack = player.getInventory().removeStack(i, Integer.MAX_VALUE);
            if (!stack.isEmpty()) {
                items.add(stack);
            }
        }
        TOMBSTONE_CHESTS.put(tombstonePos, new PlayerTombstoneData(player.getUuid(), items));

        Random random = new Random();
        List<Block> flowerPots = Arrays.asList(
                Blocks.POTTED_OAK_SAPLING,
                Blocks.POTTED_DANDELION,
                Blocks.POTTED_POPPY,
                Blocks.POTTED_BLUE_ORCHID
        );
        Block chosenFlowerPot = flowerPots.get(random.nextInt(flowerPots.size()));
        world.setBlockState(tombstonePos, chosenFlowerPot.getDefaultState());

        player.sendMessage(Text.of("A loot chest has been placed at " + deathPos.toShortString()), false);
        LOGGER.info("[SimpleTombstone] 为玩家 {} 在 {} 创建了墓碑。", player.getName().getString(), deathPos.toShortString());
    }

    private void checkPlayerNearTombstone(ServerPlayerEntity player) {
        World world = player.getWorld();
        BlockPos playerPos = player.getBlockPos();

        for (BlockPos pos : BlockPos.iterate(
                playerPos.getX() - 4, playerPos.getY() - 4, playerPos.getZ() - 4,
                playerPos.getX() + 4, playerPos.getY() + 4, playerPos.getZ() + 4
        )) {
            PlayerTombstoneData data = TOMBSTONE_CHESTS.get(pos);
            if (data != null && data.getPlayerId().equals(player.getUuid())) {
                Block block = world.getBlockState(pos).getBlock();
                if (block instanceof FlowerPotBlock) {
                    LOGGER.info("[SimpleTombstone] 玩家 {} 靠近墓碑，恢复物品。", player.getName().getString());
                    for (ItemStack stack : data.getItems()) {
                        player.getInventory().offerOrDrop(stack);
                    }
                    world.removeBlock(pos, false);
                    TOMBSTONE_CHESTS.remove(pos);
                    RESURRECTED_PLAYERS.remove(player.getUuid());
                    LOGGER.info("[SimpleTombstone] 移除墓碑 {} 并归还物品。", pos.toShortString());
                    break;
                }
            }
        }
    }

    private static class PlayerTombstoneData {
        private final UUID playerId;
        private final List<ItemStack> items;

        public PlayerTombstoneData(UUID playerId, List<ItemStack> items) {
            this.playerId = playerId;
            this.items = items;
        }

        public UUID getPlayerId() { return playerId; }
        public List<ItemStack> getItems() { return items; }
    }
}