@namespace Sandbox
@using Sandbox;
@using Sandbox.UI;
@using System;
@using System.Linq;
@using System.Collections.Generic;
@inherits Panel
@attribute [StyleSheet("LoadoutPanel.razor.scss")]

<root>
	<div class="hide_button" onclick=@(() => Close())></div>
	<div class="title_label">Loadout</div>

	<div class="tabs">
		@for(int t = 0; t < TabNames.Length; t++)
		{
			var tabIndex = t;
			<div class="tab @(_selectedTab == tabIndex ? "active" : "")" onclick=@(() => SelectTab(tabIndex))>
				@TabNames[tabIndex]
			</div>
		}
	</div>

	<div class="panel_body">
		@if(_selectedTab == 2)
		{
			var equippedGems = ProgressManager.GetEquippedGems();
			var ownedGems = ProgressManager.GetOwnedItemsByCategory(ShopItemCategory.Gem);
			var maxGemSlots = ProgressManager.GetSelectedGunSocketCount();
			var gemsFull = equippedGems.Count >= maxGemSlots;

			@if(ownedGems.Count > 0)
			{
				<div class="items_grid">
					@foreach(var gem in ownedGems)
					{
						var isEquipped = equippedGems.Contains(gem.Id);
						var gemCapture = gem;
						<LoadoutItemPanel Item=@gem IsSelected=@isEquipped IsSlotFull=@(!isEquipped && gemsFull) OnClick=@(() => OnSelectGem(gemCapture)) />
					}
				</div>
			}
			else
			{
				<div class="coming_soon">Buy gems in the Shop to equip them here.</div>
			}
		}
		else
		{
			var items = GetItemsForTab(_selectedTab);

			@if(_selectedTab == 1)
			{
				var selectedCharmIds = ProgressManager.GetSelectedCharmIds();
				var maxCharmSlots = ProgressManager.GetSelectedGunCharmSlotCount();
				var charmsFull = selectedCharmIds.Count >= maxCharmSlots;

				<div class="items_grid">
					@foreach(var item in items)
					{
						var isSelected = selectedCharmIds.Contains(item.Id);
						var itemCapture = item;
						<LoadoutItemPanel Item=@item IsSelected=@isSelected IsSlotFull=@(!isSelected && charmsFull && maxCharmSlots > 1) OnClick=@(() => OnSelectItem(itemCapture)) />
					}
				</div>
			}
			else
			{
				var selectedGunId = ProgressManager.GetSelectedGunId();

				<div class="items_grid">
					@foreach(var item in items)
					{
						var isSelected = item.Id == selectedGunId;
						var itemCapture = item;
						<LoadoutItemPanel Item=@item IsSelected=@isSelected OnClick=@(() => OnSelectItem(itemCapture)) />
					}
				</div>
			}
		}
	</div>
</root>

@code
{
	static readonly string[] TabNames = { "Guns", "Charms", "Gems" };
	static readonly ShopItemCategory[] TabCategories = { ShopItemCategory.Gun, ShopItemCategory.Charm, ShopItemCategory.Gem };

	static int _selectedTab = 0;
	static bool _initialTabSet = false;

	protected override void OnAfterTreeRender(bool firstTime)
	{
		base.OnAfterTreeRender(firstTime);
		if(firstTime)
		{
			GunPreviewController.Show();
			if(!_initialTabSet)
			{
				_selectedTab = BestStartingTab();
				_initialTabSet = true;
			}
		}
	}

	int BestStartingTab()
	{
		for(int i = 0; i < TabCategories.Length; i++)
			if(GetItemsForTab(i).Count > 0)
				return i;
		return 0;
	}

	List<ShopItemDef> GetItemsForTab(int tab)
	{
		if(tab < 0 || tab >= TabCategories.Length)
			return new List<ShopItemDef>();
		return ProgressManager.GetOwnedItemsByCategory(TabCategories[tab]);
	}

	void OnSelectItem(ShopItemDef item)
	{
		if(_selectedTab == 0)
		{
			var currentGunId = ProgressManager.GetSelectedGunId();
			var deselecting = currentGunId == item.Id;
			var targetDef = deselecting ? ProgressManager.DefaultGun : item;

			// Unequip gems that exceed the target gun's socket count
			var newSocketCount = targetDef.GemSocketCount > 0 ? targetDef.GemSocketCount : 3;
			var equippedGems = ProgressManager.GetEquippedGems();
			while(equippedGems.Count > newSocketCount)
			{
				ProgressManager.UnequipGem(equippedGems[equippedGems.Count - 1]);
				equippedGems = ProgressManager.GetEquippedGems();
			}

			// Trim selected charms to the target gun's charm slot count
			var newCharmSlots = targetDef.CharmSlotCount > 0 ? targetDef.CharmSlotCount : 1;
			var selectedCharms = ProgressManager.GetSelectedCharmIds();
			if(selectedCharms.Count > newCharmSlots)
				ProgressManager.SetSelectedCharmIds(selectedCharms.Take(newCharmSlots).ToList());

			ProgressManager.SetSelectedGunId(deselecting ? ProgressManager.DefaultGun.Id : item.Id);

			// Broadcast gun swap so all clients see the new model
			var player = Manager.Instance.LocalPlayer;
			if(player.IsValid())
			{
				var gunPrefab = ProgressManager.GetPrefabPath(targetDef.Id) ?? "prefabs/guns/gun_default.prefab";
				var charmIds = ProgressManager.GetSelectedCharmIds();
				var charm0 = charmIds.Count > 0 ? ProgressManager.GetPrefabPath(charmIds[0]) ?? "" : "";
				var charm1 = charmIds.Count > 1 ? ProgressManager.GetPrefabPath(charmIds[1]) ?? "" : "";
				var (g0, g1, g2, g3) = GetEquippedGemPrefabs();
				player.SwapGunRpc(gunPrefab, charm0, g0, g1, g2, g3, charm1);
			}
			GunPreviewController.Refresh();
		}
		else if(_selectedTab == 1)
		{
			var selectedIds = ProgressManager.GetSelectedCharmIds();
			var maxSlots = ProgressManager.GetSelectedGunCharmSlotCount();

			if(selectedIds.Contains(item.Id))
			{
				// Deselect
				ProgressManager.SetSelectedCharmIds(selectedIds.Where(id => id != item.Id).ToList());
			}
			else if(maxSlots == 1)
			{
				// Single-slot gun: replace
				ProgressManager.SetSelectedCharmIds(new List<string> { item.Id });
			}
			else if(selectedIds.Count < maxSlots)
			{
				// Multi-slot gun with a free slot: add
				ProgressManager.SetSelectedCharmIds(selectedIds.Concat(new[] { item.Id }).ToList());
			}
			else
			{
				// All slots full: do nothing, player must deselect first
				return;
			}

			// Broadcast charm swap so all clients see the new model
			var player = Manager.Instance.LocalPlayer;
			if(player.IsValid())
			{
				var ids = ProgressManager.GetSelectedCharmIds();
				var charm0 = ids.Count > 0 ? ProgressManager.GetPrefabPath(ids[0]) ?? "" : "";
				var charm1 = ids.Count > 1 ? ProgressManager.GetPrefabPath(ids[1]) ?? "" : "";
				player.SwapCharmRpc(charm0, charm1);
			}
			GunPreviewController.Refresh();
		}
		StateHasChanged();
	}

	void OnSelectGem(ShopItemDef gem)
	{
		var equipped = ProgressManager.GetEquippedGems();
		var maxSlots = ProgressManager.GetSelectedGunSocketCount();
		if(equipped.Contains(gem.Id))
			ProgressManager.UnequipGem(gem.Id);
		else if(equipped.Count < maxSlots)
			ProgressManager.EquipGem(gem.Id, maxSlots);

		BroadcastGemSwap();
		GunPreviewController.Refresh();
		StateHasChanged();
	}


	void BroadcastGemSwap()
	{
		var player = Manager.Instance.LocalPlayer;
		if(!player.IsValid()) return;
		var (g0, g1, g2, g3) = GetEquippedGemPrefabs();
		player.SwapGemsRpc(g0, g1, g2, g3);
	}

	static (string, string, string, string) GetEquippedGemPrefabs()
	{
		var equipped = ProgressManager.GetEquippedGems();
		string Get(int i) => i < equipped.Count ? (ProgressManager.GetPrefabPath(equipped[i]) ?? "") : "";
		return (Get(0), Get(1), Get(2), Get(3));
	}

	void SelectTab(int tabIndex)
	{
		if(_selectedTab == tabIndex) return;
		_selectedTab = tabIndex;
		StateHasChanged();
	}

	void Close()
	{
		GunPreviewController.Hide();
		Manager.Instance.ShowLoadoutPanel = false;
	}

	protected override int BuildHash()
	{
		return System.HashCode.Combine(
			Manager.Instance.ShowLoadoutPanel,
			_selectedTab,
			ProgressManager.StateVersion
		);
	}
}