using System.Collections.Concurrent;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using RadicadeServer.API.Storefront;
using RadicadeServer.DB;
using RadicadeServer.Extensions;
using RadicadeServer.RecNet.Avatar;
using RadicadeServer.RecNet.Enums.Store;
using RadicadeServer.RecNet.Moderation;
using RadicadeServer.RecNet.Progression;
using RadicadeServer.RecNet.Storefront;
using RadicadeServer.Utils;

namespace RadicadeServer.API.GameRewards.V1
{
	public class GameRewardRequestDTO
	{
		public RewardType RewardType { get; set; }
		public string Message { get; set; } = string.Empty;
		public GiftContext? GiftContext { get; set; }
	}

	public class GameRewardSelectDTO
	{
		public long RewardSelectionId { get; set; }
		public long GiftDropId { get; set; }
	}

	[Route("api/gamerewards/v1")]
	[Route("econ/api/gamerewards/v1")]
	public class GameRewardsAPI(RecDBContext db) : Controller
	{
		[HttpGet("pending")]
		public async Task<List<GameReward>> GetPendingGameRewards()
		{
			var userId = User.GetUserId();
			if (userId == null) return new List<GameReward>();

			var data = await db.Progression.FirstOrDefaultAsync(x => x.PlayerId == userId.Value);
			var progression = data?.GetProgressionJson();
			var pending = progression?.PendingGameRewards;
			if (pending == null) return new List<GameReward>();

			var changed = false;

			var forgotten = pending.RemoveAll(r => r.Consumed && r.ConsumedAt is { } at && at < DateTime.UtcNow.AddDays(-1));
			changed |= forgotten > 0;

			var outstanding = pending.Where(r => !r.Consumed).ToList();
			foreach (var reward in outstanding)
				changed |= ClampRewardIds(reward);
			if (changed && data != null)
			{
				data.Progress = progression!.ToJson();
				await db.SaveChangesAsync();
			}
			return outstanding;
		}

		private static bool ClampRewardIds(GameReward reward)
		{
			var changed = false;

			void Clamp(Gift? gift)
			{
				if (gift == null || (gift.GiftDropId >= int.MinValue && gift.GiftDropId <= int.MaxValue)) return;
				gift.GiftDropId = StorefrontShared.NewGiftDropId();
				changed = true;
			}

			if (reward.RewardSelectionId > int.MaxValue || reward.RewardSelectionId < int.MinValue)
			{
				_ = reward.RewardSelectionId;
			}
			Clamp(reward.GiftDrop1);
			Clamp(reward.GiftDrop2);
			Clamp(reward.GiftDrop3);
			return changed;
		}

		[HttpPost("request"), Authorize]
		public async Task<ActionResult<OkResponse>> RequestReward()
		{
			var userId = User.GetUserId();
			if (userId == null) return Unauthorized();

			var dto = await ReadRewardBodyAsync();
			if (dto == null) return BadRequest();

			if (dto.RewardType == RewardType.WeeklyCompleteButHaveSkin)
				return Ok(new OkResponse { Success = true });

			Trace(userId.Value, $"claimed rewardType={dto.RewardType} ({(int)dto.RewardType}) giftContext={dto.GiftContext?.ToString() ?? "none"} body={_rawBody}");

			var data = await db.Progression.FirstOrDefaultAsync(x => x.PlayerId == userId.Value);
			if (data == null)
			{
				data = new ProgressionData { PlayerId = userId.Value };
				db.Progression.Add(data);
			}
			var json = data.GetProgressionJson() ?? new ProgressionJson();
			json.PendingGameRewards ??= new List<GameReward>();

			var ledger = RewardDay.For(json, DateTime.UtcNow);

			var completion = IsCompletion(dto.RewardType);
			GameReward? reward = null;

			if (completion)
			{
				var rewardType = RewardDay.CompletionType(ledger, dto.RewardType);

				var paid = rewardType == RewardType.FirstActivityOfDay
					? RewardDay.TryTakeFirstActivity(ledger)
					: RewardDay.TryTakeActivityBox(ledger);

				if (paid)
				{
					dto.Message = CompletionMessage(rewardType, dto.Message);
					reward = await BuildRewardAsync(userId.Value, dto, rewardType);
				}
			}
			else if (dto.RewardType == RewardType.DailyChallengesComplete)
			{
				if (RewardDay.TryTakeDailyChallengeBox(ledger))
				{
					dto.Message = string.IsNullOrWhiteSpace(dto.Message) ? "Daily Challenge Reward" : dto.Message;
					reward = await BuildDailyChallengeRewardAsync(userId.Value, dto);
				}
			}
			else
			{
				reward = BuildReward(dto.RewardType, dto.Message,
					BonusContext(dto.RewardType) ?? dto.GiftContext ?? GiftContext.GameRewards_Tokens);
			}

			if (reward != null)
				json.PendingGameRewards.Add(reward);

			data.Progress = json.ToJson();
			await db.SaveChangesAsync();

			if (completion)
			{
				await ProgressionAwardService.AwardXpAsync(db, userId.Value,
					ProgressionAwardService.XpPerGameCompleted, "game completed");
			}

			if (reward == null) return Ok(new OkResponse { Success = true });

			if (RroRewardPools.IsQuestContext(reward.GiftContext))
			{
				await DeliverQuestRewardAsync(userId.Value, reward);
				data.Progress = json.ToJson();
				await db.SaveChangesAsync();
				return Ok(new OkResponse { Success = true });
			}

			await PushRewardSelectionAsync(userId.Value, reward);

			return Ok(new OkResponse { Success = true });
		}

		private async Task DeliverQuestRewardAsync(long playerId, GameReward reward)
		{
			var box = reward.GiftDrop1;
			if (box == null) return;
			if (box.GiftDropId == 0) box.GiftDropId = StorefrontShared.NewGiftDropId();

			var already = await GameRewardRedemption.TakeRecentlyHandedOverAsync(
				db, playerId, reward.GiftContext, TimeSpan.FromMinutes(10));

			if (already == null)
				await StorefrontShared.PersistGiftBoxAsync(db, playerId, box, notify: true);
			reward.Consumed = true;
			reward.ConsumedGiftDropId = already?.GiftDropId ?? box.GiftDropId;
			reward.ConsumedAt = DateTime.UtcNow;
			RewardTrace.Log(playerId, $"stage=DeliveredAsQuestBox context={RewardTrace.Context(reward.GiftContext)} " +
				$"selectionId={reward.RewardSelectionId} alreadyHandedOver={already != null} box={RewardTrace.Box(box)} " +
				"a quest's reward is the box its run generated, not a selection.");
		}

		private static string CompletionMessage(RewardType rewardType, string? claimed) => rewardType switch
		{
			RewardType.FirstActivityOfDay => "First Game of the Day",
			RewardType.PostQuestActivity => string.IsNullOrWhiteSpace(claimed) ? "Quest Complete" : claimed,
			_ => "Game Reward"
		};

		private async Task<GameReward> BuildDailyChallengeRewardAsync(long playerId, GameRewardRequestDTO dto)
		{
			var owned = await LevelUpGiftService.CollectOwnedKeysAsync(db, playerId, GiftContext.Daily_Challenge_Complete);
			var drops = RroRewardPools.BuildDailyChallengeSelection(owned: owned);

			if (drops.Count == 0)
			{
				return BuildReward(dto.RewardType, dto.Message, GiftContext.Daily_Challenge_Complete);
			}

			foreach (var drop in drops)
				drop.GiftDropId = StorefrontShared.NewGiftDropId();

			return new GameReward
			{
				RewardSelectionId = StorefrontShared.NewGiftDropId(),
				Message = string.IsNullOrWhiteSpace(dto.Message) ? "Daily Challenge Reward" : dto.Message,
				GiftContext = GiftContext.Daily_Challenge_Complete,
				RewardType = dto.RewardType,
				GiftDrop1 = drops[0],
				GiftDrop2 = drops.Count > 1 ? drops[1] : drops[0],
				GiftDrop3 = drops.Count > 2 ? drops[2] : drops[0],
				CreatedAt = DateTime.UtcNow
			};
		}

		[HttpPost("select"), Authorize]
		public async Task<ActionResult<OkResponse>> SelectReward()
		{
			var userId = User.GetUserId();
			if (userId == null) return Unauthorized();

			var dto = await ReadSelectBodyAsync();
			if (dto == null || dto.RewardSelectionId <= 0 || dto.GiftDropId <= 0) return BadRequest();

			var data = await db.Progression.FirstOrDefaultAsync(x => x.PlayerId == userId.Value);
			if (data == null) return NotFound();

			var json = data.GetProgressionJson();
			var reward = json?.PendingGameRewards?.FirstOrDefault(r => r.RewardSelectionId == dto.RewardSelectionId);
			if (reward == null) return NotFound();

			var drops = new[] { reward.GiftDrop1, reward.GiftDrop2, reward.GiftDrop3 }
				.Where(g => g != null)
				.ToList();

			if (reward.Consumed)
			{
				return Ok(new OkResponse { Success = true });
			}

			var gift = drops.FirstOrDefault(g => g.GiftDropId == dto.GiftDropId);

			if (gift == null)
			{
				var available = string.Join(", ", drops.Select(d => d.GiftDropId));
				gift = drops.FirstOrDefault();
				if (gift == null) return NotFound();
			}

			await StorefrontShared.PersistGiftBoxAsync(db, userId.Value, gift, notify: true);

			reward.Consumed = true;
			reward.ConsumedGiftDropId = gift.GiftDropId;
			reward.ConsumedAt = DateTime.UtcNow;
			data.Progress = json!.ToJson();
			await db.SaveChangesAsync();
			return Ok(new OkResponse { Success = true });
		}

		private async Task<GameRewardRequestDTO?> ReadRewardBodyAsync()
		{
			var fields = await ReadBodyFieldsAsync();
			if (fields.Count == 0) return null;

			var dto = new GameRewardRequestDTO();
			if (fields.TryGetValue("rewardType", out var rewardTypeRaw))
			{
				if (int.TryParse(rewardTypeRaw, out var rewardTypeInt) && Enum.IsDefined(typeof(RewardType), rewardTypeInt))
					dto.RewardType = (RewardType)rewardTypeInt;
				else if (Enum.TryParse<RewardType>(rewardTypeRaw, true, out var rewardTypeEnum))
					dto.RewardType = rewardTypeEnum;
			}
			if (fields.TryGetValue("Message", out var message))
				dto.Message = message;
			dto.GiftContext = ReadClaimedContext(fields);

			return dto;
		}

		private static GiftContext? ReadClaimedContext(IReadOnlyDictionary<string, string> fields)
		{
			if (!fields.TryGetValue("giftContext", out var raw) || string.IsNullOrWhiteSpace(raw)) return null;

			if (int.TryParse(raw, out var numeric) && Enum.IsDefined(typeof(GiftContext), numeric))
				return (GiftContext)numeric;

			return Enum.TryParse<GiftContext>(raw.Trim(), true, out var named) ? named : null;
		}

		private async Task<GameRewardSelectDTO?> ReadSelectBodyAsync()
		{
			var fields = await ReadBodyFieldsAsync();
			if (fields.Count == 0) return null;

			var dto = new GameRewardSelectDTO();
			if (fields.TryGetValue("rewardSelectionId", out var selectionRaw) && long.TryParse(selectionRaw, out var selectionId))
				dto.RewardSelectionId = selectionId;
			if (fields.TryGetValue("giftDropId", out var dropRaw) && long.TryParse(dropRaw, out var dropId))
				dto.GiftDropId = dropId;

			return dto;
		}

		private async Task<Dictionary<string, string>> ReadBodyFieldsAsync()
		{
			var fields = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
			try
			{
				Request.EnableBuffering();
				using var reader = new StreamReader(Request.Body, leaveOpen: true);
				var raw = (await reader.ReadToEndAsync()).Trim();
				Request.Body.Position = 0;
				_rawBody = raw;
				if (raw.Length == 0) return fields;

				if (raw.StartsWith('{'))
				{
					using var doc = System.Text.Json.JsonDocument.Parse(raw);
					if (doc.RootElement.ValueKind == System.Text.Json.JsonValueKind.Object)
					{
						foreach (var prop in doc.RootElement.EnumerateObject())
						{
							fields[prop.Name] = prop.Value.ValueKind == System.Text.Json.JsonValueKind.String
								? prop.Value.GetString() ?? ""
								: prop.Value.ToString();
						}
					}
				}
				else
				{
					foreach (var pair in raw.Split('&'))
					{
						var kv = pair.Split('=', 2);
						if (kv.Length < 2) continue;
						fields[Uri.UnescapeDataString(kv[0])] = Uri.UnescapeDataString(kv[1]);
					}
				}
			}
			catch (Exception)
			{
			}
			return fields;
		}

		private async Task<GameReward> BuildRewardAsync(long playerId, GameRewardRequestDTO dto, RewardType rewardType)
		{
			var lastRoom = await MatchmakingUtils.GetLastVisitedRoomNameAsync(db, playerId);
			var roomName = lastRoom;
			var claimedContext = dto.GiftContext;
			if (claimedContext.HasValue
				&& RroRewardPools.RoomForContext(claimedContext.Value) is { } claimedRoom
				&& !RroRewardPools.ContextsForRoom(roomName).Values.Contains(claimedContext.Value))
			{
				roomName = claimedRoom;
			}

			if (!RroRewardPools.IsRewardActivity(roomName)
				&& await MatchmakingUtils.GetLastRewardActivityRoomNameAsync(db, playerId, ActivityVisitWindow) is { } activityRoom)
			{
				Trace(playerId, $"lastRoom={lastRoom} is not an activity this server pays; {activityRoom} is the newest activity they were placed into, so that is the activity this completion is answered from.");
				roomName = activityRoom;
			}

			var paidByRoom = RroRewardPools.ContextsForRoom(roomName);
			var paidList = string.Join(", ", paidByRoom.Select(x => x.Key + "=" + (int)x.Value));
			Trace(playerId, "rewardType=" + rewardType
				+ " claimedContext=" + dto.GiftContext + " lastRoom=" + lastRoom
				+ " activity=" + roomName
				+ " isRewardActivity=" + RroRewardPools.IsRewardActivity(roomName) + " roomPays=[" + paidList + "]");

			if (!RroRewardPools.IsRewardActivity(roomName))
			{
				Trace(playerId, "room=" + roomName + " is not an activity this server pays rewards for; paying the token package.");
				return BuildReward(rewardType, dto.Message, dto.GiftContext ?? GiftContext.GameRewards_Tokens);
			}

			var paid = RroRewardPools.ContextsForRoom(roomName);
			var claimed = dto.GiftContext;
			GiftContext context;
			if (claimed.HasValue && paid.Values.Contains(claimed.Value))
			{
				context = claimed.Value;
			}
			else if (RroRewardPools.TryFloorContext(roomName, out var floor))
			{
				context = floor;
			}
			else
			{
				return BuildReward(rewardType, dto.Message, GiftContext.GameRewards_Tokens);
			}

			if (RroRewardPools.PaysTickets(roomName))
			{
				var games = LaserTagGamesToday.AddOrUpdate((playerId, DateOnly.FromDateTime(DateTime.UtcNow)), 1, (_, count) => count + 1);
				var tickets = RroRewardPools.LaserTagTicketsPerGame
					+ (games <= RroRewardPools.LaserTagBonusGamesPerDay ? RroRewardPools.LaserTagFirstGamesBonus : 0);
				return TicketReward(rewardType, dto.Message, GiftContext.Lasertag, tickets);
			}

			var selection = RroRewardPools.OffersSelection(roomName);
			var owned = await LevelUpGiftService.CollectOwnedKeysAsync(db, playerId, context);

			var fromOwnPool = !RroRewardPools.PaysNoItemReward(roomName)
				&& Random.Shared.NextDouble() <= RroRewardPools.DropChanceFor(context);
			var drops = fromOwnPool
				? RroRewardPools.BuildDrops(context, selection, owned)
				: new List<Gift>();

			var source = context;

			var reacquired = drops.Count == 0;
			if (reacquired)
			{
				foreach (var weaker in RroRewardPools.LowerRanksOf(context))
				{
					drops = RroRewardPools.BuildDrops(weaker, selection, owned);
					if (drops.Count == 0) continue;
					break;
				}
			}

			if (drops.Count == 0)
			{
				if (selection)
				{
					drops = RroRewardPools.BuildFallbackSelection(owned: owned, message: dto.Message);
				}
				else
				{
					drops = RroRewardPools.BuildFallbackDrops(selection: false, owned: owned);
				}
			}

			if (drops.Count == 0)
			{
				RewardTrace.Error(playerId, $"stage=Fallback activity={roomName} rank={RewardRankOf(context, roomName)} " +
					$"context={RewardTrace.Context(context)} pool={DescribeSets(context)} " +
					$"EligibleItems={RroRewardPools.Resolve(context).Count} UnownedItems=0 " +
					"Reason=neither the activity's pool nor the reacquisition pool has anything left to give; " +
					"paying the token package as the last resort.");
				return BuildReward(rewardType, dto.Message, context);
			}

			foreach (var drop in drops)
				drop.GiftDropId = StorefrontShared.NewGiftDropId();

			var reward = new GameReward
			{
				RewardSelectionId = StorefrontShared.NewGiftDropId(),
				Message = string.IsNullOrWhiteSpace(dto.Message) ? "Game Reward" : dto.Message,
				GiftContext = source,
				RewardType = rewardType,
				GiftDrop1 = drops[0],
				GiftDrop2 = drops.Count > 1 ? drops[1] : drops[0],
				GiftDrop3 = drops.Count > 2 ? drops[2] : drops[0],
				CreatedAt = DateTime.UtcNow
			};

			var eligible = RroRewardPools.Resolve(context);
			var unowned = eligible
				.Where(item => !owned.Contains(LevelUpRewardPool.OwnershipKey(item.AvatarItemDesc)))
				.ToList();
			var boxKind = IsTokenBox(drops[0]) ? "Tokens" : "AvatarItem";

			RewardTrace.Log(playerId, $"stage=Quest activity={roomName} rank={RewardRankOf(context, roomName)} " +
				$"context={RewardTrace.Context(context)} source={RewardTrace.Context(source)} rewardType={rewardType}");
			RewardTrace.Log(playerId, $"stage=RewardPool context={RewardTrace.Context(context)} " +
				$"pool={DescribeSets(context)} EligibleItems={eligible.Count} {RewardTrace.Items(eligible)}");
			RewardTrace.Log(playerId, $"stage=UnownedItems context={RewardTrace.Context(context)} UnownedItems={unowned.Count} {RewardTrace.Items(unowned)}");
			RewardTrace.Log(playerId, $"stage=SelectedItem {RewardTrace.Boxes(drops)}");
			RewardTrace.Log(playerId, $"stage=BoxCreated selectionId={reward.RewardSelectionId} " +
				$"boxType={boxKind} BoxRewardItem=\"{drops[0].AvatarItemDesc}\"");
			RewardTrace.Log(playerId, $"stage=GrantReward giftDropId={drops[0].GiftDropId} " +
				$"name=\"{drops[0].FriendlyName}\" item=\"{drops[0].AvatarItemDesc}\" " +
				$"consumable=\"{drops[0].ConsumableItemDesc}\" currency={drops[0].CurrencyType} {drops[0].Currency}");
			RewardTrace.Log(playerId, $"stage=FinalReward rewardType={rewardType} context={RewardTrace.Context(source)} " +
				$"boxType={boxKind} firstTime={!reacquired}");

			return reward;
		}

		private static readonly ConcurrentDictionary<(long PlayerId, DateOnly Day), int> LaserTagGamesToday = new();

		private static GameReward TicketReward(RewardType type, string message, GiftContext context, int tickets)
		{
			var box = new Gift
			{
				GiftDropId = StorefrontShared.NewGiftDropId(),
				FriendlyName = "Laser Tag Tickets",
				Tooltip = string.IsNullOrWhiteSpace(message) ? "Tickets for playing!" : message,
				CurrencyType = CurrencyType.LaserTagTickets,
				Currency = tickets,
				Context = context,
				Rarity = Rarity.Common
			};

			return new GameReward
			{
				RewardSelectionId = StorefrontShared.NewGiftDropId(),
				Message = string.IsNullOrWhiteSpace(message) ? "Laser Tag Tickets" : message,
				GiftContext = context,
				RewardType = type,
				GiftDrop1 = box,
				GiftDrop2 = box,
				GiftDrop3 = box,
				CreatedAt = DateTime.UtcNow
			};
		}

		private static bool IsCompletion(RewardType type) =>
			type is RewardType.FirstActivityOfDay or RewardType.PostGameActivity or RewardType.PostQuestActivity;

		private static GiftContext? BonusContext(RewardType type) => type switch
		{
			RewardType.DailyChallengesComplete => GiftContext.All_Daily_Challenges_Complete,
			RewardType.WeeklyCompleteButHaveSkin => GiftContext.All_Weekly_Challenge_Complete,
			RewardType.Levelup => GiftContext.LevelUp,
			_ => null
		};

		private static GameReward BuildReward(RewardType type, string message, GiftContext context)
		{
			int baseTokens = type switch
			{
				RewardType.DailyChallengesComplete => 150,
				RewardType.WeeklyCompleteButHaveSkin => 300,
				RewardType.Levelup => 100,
				_ => RroRewardPools.CompletionTokenAmount
			};

			return new GameReward
			{
				RewardSelectionId = StorefrontShared.NewGiftDropId(),
				Message = string.IsNullOrWhiteSpace(message) ? "Tokens" : message,
				GiftContext = context,
				RewardType = type,
				GiftDrop1 = RroRewardPools.TokenGift(context, baseTokens, message),
				GiftDrop2 = RroRewardPools.TokenGift(context, baseTokens * 2, message),
				GiftDrop3 = RroRewardPools.TokenGift(context, baseTokens * 3, message),
				CreatedAt = DateTime.UtcNow
			};
		}

		private static async Task PushRewardSelectionAsync(long playerId, GameReward reward)
		{
			var number = Convert.ToInt64(
				RadicadeServer.RecNet.Enums.Messages.NotificationType.GiftPackageRewardSelectionReceived,
				System.Globalization.CultureInfo.InvariantCulture)
				.ToString(System.Globalization.CultureInfo.InvariantCulture);

			foreach (var id in new[] { RewardSelectionNotificationName, number })
			{
				try
				{
					await RadicadeServer.API.Notifications.Notify.SendNotify(playerId, new RadicadeServer.RecNet.Notifications.Notification
					{
						Id = id,
						Msg = reward
					});
				}
				catch (Exception)
				{
				}
			}
		}

		private static readonly TimeSpan ActivityVisitWindow = TimeSpan.FromHours(6);

		private string? _rawBody;

		private static void Trace(long playerId, string line) => RewardTrace.Log(playerId, line);

		private static string RewardRankOf(GiftContext context, string? roomName)
		{
			foreach (var (rank, paid) in RroRewardPools.ContextsForRoom(roomName))
			{
				if (paid != context) continue;
				return string.IsNullOrEmpty(rank) ? "unranked" : rank;
			}

			return RroRewardPools.IsDeprecated(context) ? "deprecated" : "not paid by this room";
		}

		private static string DescribeSets(GiftContext context)
		{
			var sets = RroRewardPools.SetsFor(context);
			if (sets.Count == 0) return "<none configured>";

			return string.Join(", ", sets.Select(set =>
				string.IsNullOrEmpty(set.Colour) ? set.Family : $"{set.Family} {set.Colour}"));
		}

		private static bool IsTokenBox(Gift box) =>
			string.IsNullOrWhiteSpace(box.AvatarItemDesc)
			&& string.IsNullOrWhiteSpace(box.ConsumableItemDesc)
			&& box.CurrencyType != CurrencyType.Invalid
			&& box.Currency != 0;

		private const string RewardSelectionNotificationName = "RewardSelectionReceived";
	}
}