// Copyright (c) 2023 Timothy Schenk. Subject to the GNU AGPL Version 3 License.

using Continuity.AuthServer.DB;
using Continuity.AuthServer.DB.Documents;
using Continuity.AuthServer.Services;
using Microsoft.EntityFrameworkCore;
using NetCoreServer;
using Wonderking.Game.Data.Character;
using Wonderking.Game.Mapping;
using Wonderking.Packets.Incoming;
using Wonderking.Packets.Outgoing;
using Wonderking.Packets.Outgoing.Data;

namespace Continuity.AuthServer.PacketHandlers;

public class CharacterCreationHandler : IPacketHandler<CharacterCreationPacket>
{
    private readonly CharacterStatsMappingConfiguration _characterStatsMapping;
    private readonly ItemObjectPoolService _itemObjectPoolService;
    private readonly WonderkingContext _wonderkingContext;

    public CharacterCreationHandler(WonderkingContext wonderkingContext, ItemObjectPoolService itemObjectPoolService,
        CharacterStatsMappingConfiguration characterStatsMappingConfiguration)
    {
        _wonderkingContext = wonderkingContext;
        _itemObjectPoolService = itemObjectPoolService;
        _characterStatsMapping = characterStatsMappingConfiguration;
    }

    public async Task HandleAsync(CharacterCreationPacket packet, TcpSession session)
    {
        if (session is not AuthSession authSession)
        {
            return;
        }

        var account = await _wonderkingContext.Accounts.FirstOrDefaultAsync(a => a.Id == authSession.AccountId);

        if (account is null)
        {
            return;
        }

        var firstJobConfig = SelectFirstJobConfig(packet.FirstJob);
        var items = CreateDefaultItems(packet, firstJobConfig);

        var toBeAddedCharacter = CreateDefaultCharacter(packet, account, items, firstJobConfig);
        account.Characters.Add(toBeAddedCharacter);
        await _wonderkingContext.SaveChangesAsync();

        var character =
            new CharacterData
            {
                Name = toBeAddedCharacter.Name,
                Job = toBeAddedCharacter.JobData,
                Gender = toBeAddedCharacter.Gender,
                Level = toBeAddedCharacter.Level,
                Experience = toBeAddedCharacter.Experience,
                Stats = toBeAddedCharacter.BaseStats,
                Health = toBeAddedCharacter.Health,
                Mana = toBeAddedCharacter.Mana,
                EquippedItems =
                    GetItemIDsByInventoryTab(toBeAddedCharacter.InventoryItems
                        .Where(item => item.InventoryTab == InventoryTab.WornEquipment)
                        .Select(item => new Tuple<ushort, byte>(item.ItemId, item.Slot)).AsEnumerable()),
                EquippedCashItems = GetItemIDsByInventoryTab(toBeAddedCharacter.InventoryItems
                    .Where(item => item.InventoryTab == InventoryTab.WornCashEquipment)
                    .Select(item => new Tuple<ushort, byte>(item.ItemId, item.Slot)).AsEnumerable())
            };

        await authSession.SendAsync(new CharacterCreationResponsePacket
        {
            Character = character,
            Slot = packet.Slot,
            isDuplicate = false
        });
    }

    private InventoryItem[] CreateDefaultItems(CharacterCreationPacket packet, JobSpecificMapping firstJobConfig)
    {
        var mappedDefaultItems = _characterStatsMapping.DefaultCharacterMapping.Items
            .Select(i => _itemObjectPoolService.GetBaseInventoryItem(i.Id, i.Quantity)).ToArray();

        var mappedJobItems = firstJobConfig.Items
            .Select(i => _itemObjectPoolService.GetBaseInventoryItem(i.Id, i.Quantity)).ToArray();
        var defaultItems = CreateChosenItems(packet);
        InventoryItem[] items =
        [
            .. mappedDefaultItems,
            .. mappedJobItems,
            .. defaultItems
        ];
        return items;
    }

    private static Character CreateDefaultCharacter(CharacterCreationPacket packet, Account account,
        InventoryItem[] items, JobSpecificMapping firstJobConfig)
    {
        return new Character()
        {
            Account = account,
            MapId = 300,
            Name = packet.Name,
            LastXCoordinate = 113,
            LastYCoordinate = 0,
            PvPLevel = PvPLevel.None,
            Gender = packet.Gender,
            Experience = 0,
            Level = 1,
            InventoryItems = items,
            BaseStats = firstJobConfig.BaseStats,
            JobData = new JobData { FirstJob = packet.FirstJob, SecondJob = 0, ThirdJob = 0, FourthJob = 0 },
            Health = CalculateCurrentHealth(1, firstJobConfig),
            Mana = CalculateCurrentMana(1, firstJobConfig)
        };
    }

    private JobSpecificMapping SelectFirstJobConfig(byte firstJob)
    {
        return firstJob switch
        {
            1 => _characterStatsMapping.Swordsman,
            2 => _characterStatsMapping.Mage,
            3 => _characterStatsMapping.Thief,
            4 => _characterStatsMapping.Scout,
            _ => _characterStatsMapping.Swordsman
        };
    }

    private InventoryItem[] CreateChosenItems(CharacterCreationPacket packet)
    {
        return new[]
        {
            _itemObjectPoolService.GetBaseInventoryItem((ushort)((packet.FirstJob - 1) * 6 +
                                                                 ((byte)packet.Gender - 1) * 3 +
                                                                 packet.Hair + 1)),
            _itemObjectPoolService.GetBaseInventoryItem((ushort)((packet.FirstJob - 1) * 6 +
                                                                 ((byte)packet.Gender - 1) * 3 +
                                                                 packet.Eyes + 25)),
            _itemObjectPoolService.GetBaseInventoryItem((ushort)(((byte)packet.Gender - 1) * 3 +
                                                                 packet.Shirt + 49)),
            _itemObjectPoolService.GetBaseInventoryItem((ushort)(((byte)packet.Gender - 1) * 3 +
                                                                 packet.Pants + 58))
        };
    }

    private static int CalculateCurrentHealth(ushort level, JobSpecificMapping firstJobConfig)
    {
        return (int)((level - 1) * firstJobConfig.DynamicStats.HealthPerLevel +
                     firstJobConfig.BaseStats.Vitality * firstJobConfig.DynamicStats.HealthPerVitality);
    }

    private static int CalculateCurrentMana(ushort level, JobSpecificMapping firstJobConfig)
    {
        return (int)((level - 1) * firstJobConfig.DynamicStats.ManaPerLevel +
                     firstJobConfig.BaseStats.Wisdom * firstJobConfig.DynamicStats.ManaPerWisdom);
    }

    private static ushort[] GetItemIDsByInventoryTab(IEnumerable<Tuple<ushort, byte>> items)
    {
        Span<ushort> ids = stackalloc ushort[20];
        ids.Clear();

        foreach (var item in items)
        {
            if (item.Item2 > 20)
            {
                continue;
            }

            ids[item.Item2] = item.Item1;
        }

        return ids.ToArray();
    }
}