using System.Diagnostics;
using Catalogger.Backend.Cache;
using Catalogger.Backend.Database;
using Catalogger.Backend.Database.Models;
using Catalogger.Backend.Extensions;
using Catalogger.Backend.Services;
using Remora.Discord.API.Abstractions.Gateway.Events;
using Remora.Discord.API.Gateway.Events;
using Remora.Discord.Extensions.Embeds;
using Remora.Discord.Gateway.Responders;
using Remora.Results;

namespace Catalogger.Backend.Bot.Responders;

public class GuildCreateResponder(
    Config config,
    ILogger logger,
    DatabaseContext db,
    GuildCacheService guildCache,
    RoleCacheService roleCache,
    ChannelCacheService channelCache,
    WebhookExecutorService webhookExecutor)
    : IResponder<IGuildCreate>, IResponder<GuildDelete>
{
    private readonly ILogger _logger = logger.ForContext<GuildCreateResponder>();

    public async Task<Result> RespondAsync(IGuildCreate evt, CancellationToken ct = default)
    {
        ulong guildId;
        string? guildName = null;
        if (evt.Guild.TryPickT0(out var guild, out var unavailableGuild))
        {
            _logger.Verbose("Received guild create for available guild {GuildName} / {GuildId})", guild.Name, guild.ID);
            guildId = guild.ID.ToUlong();
            guildName = guild.Name;

            guildCache.Set(guild);
            foreach (var c in guild.Channels) channelCache.Set(c, guild.ID);
            foreach (var r in guild.Roles) roleCache.Set(r, guild.ID);
        }
        else
        {
            _logger.Verbose("Received guild create for unavailable guild {GuildId}", unavailableGuild.ID);
            guildId = unavailableGuild.ID.ToUlong();
        }

        var tx = await db.Database.BeginTransactionAsync(ct);
        if (await db.Guilds.FindAsync([guildId], ct) != null) return Result.Success;

        db.Add(new Guild
        {
            Id = guildId
        });
        await db.SaveChangesAsync(ct);
        await tx.CommitAsync(ct);

        _logger.Information("Joined new guild {GuildName} / {GuildId}", guildName, guildId);

        if (config.Discord.GuildLogId != null && evt.Guild.IsT0)
            await webhookExecutor.QueueLogAsync(config.Discord.GuildLogId.Value, new EmbedBuilder()
                .WithTitle("Joined new guild")
                .WithDescription($"Joined new guild **{guild.Name}**")
                .WithFooter($"ID: {guild.ID}")
                .WithCurrentTimestamp()
#pragma warning disable CS8604 // Possible null reference argument.
                .WithThumbnailUrl(guild.IconUrl())
#pragma warning restore CS8604 // Possible null reference argument.
                .Build()
                .GetOrThrow());

        return Result.Success;
    }

    public async Task<Result> RespondAsync(GuildDelete evt, CancellationToken ct = default)
    {
        if (evt.IsUnavailable.OrDefault(false))
        {
            _logger.Debug("Guild {GuildId} became unavailable", evt.ID);
            return Result.Success;
        }

        if (!guildCache.TryGet(evt.ID, out var guild))
        {
            _logger.Information("Left uncached guild {GuildId}", evt.ID);
            return Result.Success;
        }

        _logger.Information("Left guild {GuildName} / {GuildId}", guild.Name, guild.ID);

        if (config.Discord.GuildLogId != null)
            await webhookExecutor.QueueLogAsync(config.Discord.GuildLogId.Value, new EmbedBuilder()
                .WithTitle("Left guild")
                .WithDescription($"Left guild **{guild.Name}**")
                .WithFooter($"ID: {guild.ID}")
                .WithCurrentTimestamp()
#pragma warning disable CS8604 // Possible null reference argument.
                .WithThumbnailUrl(guild.IconUrl())
#pragma warning restore CS8604 // Possible null reference argument.
                .Build()
                .GetOrThrow());

        return Result.Success;
    }
}