using Catalogger.Backend.Cache;
using Catalogger.Backend.Cache.InMemoryCache;
using Catalogger.Backend.Database;
using Catalogger.Backend.Database.Queries;
using Catalogger.Backend.Extensions;
using Catalogger.Backend.Services;
using Remora.Discord.API.Abstractions.Gateway.Events;
using Remora.Discord.Extensions.Embeds;
using Remora.Discord.Gateway.Responders;
using Remora.Results;

namespace Catalogger.Backend.Bot.Responders.Guilds;

public class GuildMemberRemoveResponder(
    ILogger logger,
    DatabaseContext db,
    IMemberCache memberCache,
    RoleCache roleCache,
    WebhookExecutorService webhookExecutor,
    AuditLogEnrichedResponderService auditLogEnrichedResponderService) : IResponder<IGuildMemberRemove>
{
    private readonly ILogger _logger = logger.ForContext<GuildMemberAddResponder>();

    public async Task<Result> RespondAsync(IGuildMemberRemove evt, CancellationToken ct = default)
    {
        try
        {
            // spin events that Discord doesn't send us all the data for off to another responder
            _ = auditLogEnrichedResponderService.RespondAsync(evt);

            var embed = new EmbedBuilder()
                .WithTitle("Member left")
                .WithAuthor(evt.User.Tag(), iconUrl: evt.User.AvatarUrl())
                .WithColour(DiscordUtils.Orange)
                .WithDescription($"<@{evt.User.ID}>")
                .WithFooter($"ID: {evt.User.ID}")
                .WithCurrentTimestamp();

            var guildConfig = await db.GetGuildAsync(evt.GuildID, ct);

            var member = await memberCache.TryGetAsync(evt.GuildID, evt.User.ID);
            if (member == null)
            {
                _logger.Information(
                    "Guild member {UserId} in {GuildId} left but wasn't in the cache, sending limited embed",
                    evt.User.ID, evt.GuildID);
                webhookExecutor.QueueLog(guildConfig, LogChannelType.GuildMemberRemove, embed.Build().GetOrThrow());
                return Result.Success;
            }

            embed.Description +=
                $"\njoined <t:{member.JoinedAt.ToUnixTimeSeconds()}>\n({member.JoinedAt.Prettify()} ago)";

            // get the member's roles, sort them, and turn them into mentions
            var guildRoles = roleCache.GuildRoles(evt.GuildID);
            var roles = guildRoles.Sorted(member.Roles).ToList();

            var roleMentions = "";
            foreach (var (idx, role) in roles.Select((r, i) => (i, r)))
            {
                if (roleMentions.Length > 900)
                {
                    roleMentions += $"\n(too many roles to list, showing {idx}/{roles.Count})";
                    break;
                }

                roleMentions += $"<@&{role.ID}>";
                if (idx != roles.Count - 1) roleMentions += ", ";
            }

            embed.AddField("Roles", roleMentions, inline: false);

            webhookExecutor.QueueLog(guildConfig, LogChannelType.GuildMemberRemove, embed.Build().GetOrThrow());
            return Result.Success;
        }
        finally
        {
            await memberCache.RemoveAsync(evt.GuildID, evt.User.ID);
        }
    }
}