using System;
using System.Collections.Generic;
using Dalamud.Plugin.Services;
using FFXIVClientStructs.FFXIV.Client.Game;
using LLib.GameData;
using Lumina.Excel;
using Lumina.Excel.Sheets;

namespace LLib.Gear;

public sealed class BestItemFinder
{
	public static readonly IReadOnlyList<InventoryType> ArmoryAndEquipped = new global::_003C_003Ez__ReadOnlyArray<InventoryType>(new InventoryType[12]
	{
		InventoryType.EquippedItems,
		InventoryType.ArmoryMainHand,
		InventoryType.ArmoryOffHand,
		InventoryType.ArmoryHead,
		InventoryType.ArmoryBody,
		InventoryType.ArmoryHands,
		InventoryType.ArmoryLegs,
		InventoryType.ArmoryFeets,
		InventoryType.ArmoryEar,
		InventoryType.ArmoryNeck,
		InventoryType.ArmoryWrist,
		InventoryType.ArmoryRings
	});

	public static readonly IReadOnlyList<InventoryType> ArmoryEquippedAndBags = new global::_003C_003Ez__ReadOnlyArray<InventoryType>(new InventoryType[16]
	{
		InventoryType.EquippedItems,
		InventoryType.ArmoryMainHand,
		InventoryType.ArmoryOffHand,
		InventoryType.ArmoryHead,
		InventoryType.ArmoryBody,
		InventoryType.ArmoryHands,
		InventoryType.ArmoryLegs,
		InventoryType.ArmoryFeets,
		InventoryType.ArmoryEar,
		InventoryType.ArmoryNeck,
		InventoryType.ArmoryWrist,
		InventoryType.ArmoryRings,
		InventoryType.Inventory1,
		InventoryType.Inventory2,
		InventoryType.Inventory3,
		InventoryType.Inventory4
	});

	private readonly GearStatsCalculator _calculator;

	private readonly ExcelSheet<Item> _itemSheet;

	private readonly ExcelSheet<ClassJobCategory> _classJobCategorySheet;

	public BestItemFinder(GearStatsCalculator calculator, IDataManager dataManager)
	{
		ArgumentNullException.ThrowIfNull(calculator, "calculator");
		ArgumentNullException.ThrowIfNull(dataManager, "dataManager");
		_calculator = calculator;
		_itemSheet = dataManager.GetExcelSheet<Item>();
		_classJobCategorySheet = dataManager.GetExcelSheet<ClassJobCategory>();
	}

	public unsafe BestItemRef? FindBest(EClassJob job, IReadOnlyList<uint> acceptedSlotCategories, StatPriority priority, IReadOnlyList<InventoryType> containers, byte playerLevel, EItemRankingMode rankingMode, BestItemRef? excludeContainerSlot = null)
	{
		BestItemRef? result = null;
		ItemRankingKey best = ItemRankingKey.None;
		EBaseParam param = (job.DealsMagicDamage() ? EBaseParam.DamageMag : EBaseParam.DamagePhys);
		InventoryManager* ptr = InventoryManager.Instance();
		if (ptr == null)
		{
			return null;
		}
		foreach (InventoryType container in containers)
		{
			InventoryContainer* inventoryContainer = ptr->GetInventoryContainer(container);
			if (inventoryContainer == null)
			{
				continue;
			}
			for (int i = 0; i < inventoryContainer->Size; i++)
			{
				InventoryItem* inventorySlot = inventoryContainer->GetInventorySlot(i);
				if (inventorySlot == null || inventorySlot->ItemId == 0)
				{
					continue;
				}
				if (excludeContainerSlot.HasValue)
				{
					BestItemRef valueOrDefault = excludeContainerSlot.GetValueOrDefault();
					if (valueOrDefault.Container == container && valueOrDefault.Slot == i)
					{
						continue;
					}
				}
				Item? rowOrDefault = _itemSheet.GetRowOrDefault(inventorySlot->ItemId);
				if (!rowOrDefault.HasValue)
				{
					continue;
				}
				Item value = rowOrDefault.Value;
				if (IsAcceptedSlot(value.EquipSlotCategory.RowId, acceptedSlotCategories) && value.LevelEquip <= playerLevel && IsItemForJob(value, job))
				{
					EquipmentStats equipmentStats = _calculator.CalculateGearStats(inventorySlot);
					ItemRankingKey itemRankingKey = new ItemRankingKey(value.LevelItem.RowId, priority.Score(equipmentStats), equipmentStats.Get(param));
					if (IsUpgrade(rankingMode, itemRankingKey, best))
					{
						result = new BestItemRef(container, i, inventorySlot->ItemId, itemRankingKey.ItemLevel, itemRankingKey.Score);
						best = itemRankingKey;
					}
				}
			}
		}
		return result;
	}

	public static bool IsUpgrade(EItemRankingMode mode, ItemRankingKey candidate, ItemRankingKey best)
	{
		if (mode == EItemRankingMode.DamageFirst && candidate.Damage != best.Damage)
		{
			return candidate.Damage > best.Damage;
		}
		if (mode == EItemRankingMode.ItemLevelFirst)
		{
			if (candidate.ItemLevel != best.ItemLevel)
			{
				return candidate.ItemLevel > best.ItemLevel;
			}
			return candidate.Score > best.Score;
		}
		if (candidate.Score != best.Score)
		{
			return candidate.Score > best.Score;
		}
		return candidate.ItemLevel > best.ItemLevel;
	}

	public bool IsItemForJob(Item item, EClassJob job)
	{
		uint rowId = item.ClassJobCategory.RowId;
		if (rowId == 0)
		{
			return true;
		}
		ClassJobCategory? rowOrDefault = _classJobCategorySheet.GetRowOrDefault(rowId);
		if (!rowOrDefault.HasValue)
		{
			return false;
		}
		return job.IsInCategory(rowOrDefault.Value);
	}

	private static bool IsAcceptedSlot(uint itemSlotCategory, IReadOnlyList<uint> accepted)
	{
		foreach (uint item in accepted)
		{
			if (item == itemSlotCategory)
			{
				return true;
			}
		}
		return false;
	}
}