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

using DotNext.Collections.Generic;
using NetCoreServer;
using Server.DB;
using Server.DB.Documents;
using Wonderking.Packets.Incoming;
using Wonderking.Packets.Outgoing;
using Wonderking.Packets.Outgoing.Data;

namespace Server.PacketHandlers;

public partial class ChannelSelectionHandler : IPacketHandler<ChannelSelectionPacket>
{
    private readonly WonderkingContext _wonderkingContext;

    public ChannelSelectionHandler(WonderkingContext wonderkingContext)
    {
        _wonderkingContext = wonderkingContext;
    }

    public async Task HandleAsync(ChannelSelectionPacket packet, TcpSession session)
    {
        var authSession = (AuthSession)session;
        ChannelSelectionResponsePacket responsePacket;
        var guildNameResponsePacket = new CharacterSelectionSetGuildNamePacket { GuildNames = Array.Empty<string>() };

        var accountExists = await _accountExists(_wonderkingContext, authSession.AccountId);

        var amountOfCharacter = await _getAmountOfCharacters(_wonderkingContext, authSession.AccountId);

        if (!accountExists)
        {
            return;
        }

        if (amountOfCharacter > 0)
        {
            responsePacket = new ChannelSelectionResponsePacket
            {
                ChannelIsFullFlag = 0,
                Endpoint = "127.0.0.1",
                Port = 2000,
                Characters = await GetCharacterDataAsync(authSession.AccountId).ToArrayAsync()
            };

            guildNameResponsePacket.GuildNames =
                await _getGuildNames(_wonderkingContext, authSession.AccountId).ToArrayAsync();
        }
        else
        {
            responsePacket = new ChannelSelectionResponsePacket
            {
                ChannelIsFullFlag = 0,
                Endpoint = "127.0.0.1",
                Port = 2000,
                Characters = Array.Empty<CharacterData>()
            };
        }

        await authSession.SendAsync(responsePacket);
        if (guildNameResponsePacket.GuildNames.Length > 0 &&
            guildNameResponsePacket.GuildNames.Select(n => n != string.Empty).Any())
        {
            await authSession.SendAsync(guildNameResponsePacket);
        }
    }

    private static ushort[] GetItemIDsByInventoryTab(IEnumerable<InventoryItemProjection> items)
    {
        var ids = new ushort[20];
        ids.AsSpan().Clear();

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

            ids[item.Slot] = item.ItemId;
        }

        return ids;
    }

    private async IAsyncEnumerable<CharacterData> GetCharacterDataAsync(Guid accountId)
    {
        await foreach (var c in _getCharacters(_wonderkingContext, accountId))
        {
            yield return new CharacterData
            {
                Name = c.Name,
                Job = c.JobData,
                Gender = c.Gender,
                Level = c.Level,
                // TODO: Calculate instead of clamping based on max experience for level
                Experience = Math.Clamp(c.Experience, 0, 100),
                Stats = c.BaseStats,
                Health = c.Health,
                Mana = c.Mana,
                EquippedItems =
                    GetItemIDsByInventoryTab(c.InventoryItems.Where(i =>
                        i.InventoryTab == InventoryTab.WornEquipment)),
                EquippedCashItems = GetItemIDsByInventoryTab(c.InventoryItems.Where(i =>
                    i.InventoryTab == InventoryTab.WornCashEquipment))
            };
        }
    }

}