using Microsoft.Extensions.Caching.Memory;
using NetCord;
using NetCord.Gateway;
using NetCord.Hosting.Gateway;
using NetCord.Rest;
using SquadBot.Providers;

namespace SquadBot.StateMangers;

public class VoiceStateManager
{
    // Key: GuildId Value: List of UserId for users in voice channel
    // TODO: We probably want to persist this somewhere else (Redis/Valkey)
    private Dictionary<ulong, ISet<ulong>> _guildVoiceStates;
    private IMemoryCache _yapperNotificationTimeoutCache;
    private RestClient _restClient;
    private ILogger<VoiceStateManager> _logger;
    
    public VoiceStateManager(ILogger<VoiceStateManager> logger, RestClient restClient, IMemoryCache yapperNotificationTimeoutCache)
    {
        _guildVoiceStates = new Dictionary<ulong, ISet<ulong>>();
        _yapperNotificationTimeoutCache = yapperNotificationTimeoutCache;
        _restClient = restClient ?? throw new System.ArgumentNullException(nameof(restClient));
        _logger = logger ?? throw new System.ArgumentNullException(nameof(logger));
    }

    public async Task HandleVoiceStateChange(VoiceState voice_state)
    {
        if (voice_state.ChannelId is not null)
        {
            // Joining channel
            _logger.LogInformation($"New yapper detected: {voice_state.User.Username}");
            if (!_guildVoiceStates.TryGetValue(voice_state.GuildId, out var yappers) || yappers.Count == 0)
            {
                yappers ??= new HashSet<ulong>();
                var channels = await _restClient.GetGuildChannelsAsync(voice_state.GuildId);
                var alertChannelId = channels.FirstOrDefault(channel => channel.Name == "bot-tinkering")?.Id;
                var guildRoles = await _restClient.GetGuildRolesAsync(voice_state.GuildId,
                    new RestRequestProperties() { AuditLogReason = "Role lookup" });
                var yapperRoleId = guildRoles.FirstOrDefault(role => role.Name.ToLower() == "yapper")?.Id;
                if (alertChannelId is null || yapperRoleId is null)
                {
                    _logger.LogError($"Found incorrect state, alert channel or yapper role does not exist.");
                    return;
                }
                
                if (!CheckIfTimeoutExpired(voice_state.GuildId)) return;

                // Notify that new yapper has arrived
                await SendYapperNotification(yapperRoleId.GetValueOrDefault(), alertChannelId.GetValueOrDefault());
            }
            
            yappers.Add(voice_state.UserId);
            _guildVoiceStates[voice_state.GuildId] = yappers;
        }
        else
        {
            // Leaving channel
            _logger.LogInformation($"Yapper leaving: {voice_state.User.Username}");
            if (_guildVoiceStates.TryGetValue(voice_state.GuildId, out var yappers))
            {
                yappers.Remove(voice_state.UserId);
                _guildVoiceStates[voice_state.GuildId] = yappers;
                if (yappers.Count == 0) SetGuildTimeout(voice_state.GuildId);
            }
        }

        return;
    }

    private void SetGuildTimeout(ulong guild_id)
    {
        #if DEBUG
        var expiration = DateTimeOffset.UtcNow.AddMinutes(1);
        #else
        var expiration = DateTimeOffset.UtcNow.AddHours(2);
        #endif
        
        _yapperNotificationTimeoutCache.Set(guild_id, expiration, expiration);
    }

    private bool CheckIfTimeoutExpired(ulong guild_id)
    {
        var timeOutCached =
            _yapperNotificationTimeoutCache.TryGetValue(guild_id, out DateTimeOffset timeout);
        if (timeOutCached == false) return true;
        if (timeout < DateTimeOffset.UtcNow) return true;
        return false;
    }

    private async Task SendYapperNotification(ulong yapperRoleId, ulong alertChannelId)
    {
        await _restClient.SendMessageAsync(
            alertChannelId,
            new MessageProperties()
            {
                AllowedMentions = new AllowedMentionsProperties() {AllowedRoles = [yapperRoleId]},
                Content = $"<@&{yapperRoleId}> " + PhraseProvider.GetYapperPhrase()
            });
    }
}