server/MareSynchronosServer/MareSynchronosServer/Hubs/MareHub.Functions.cs

using MareSynchronosShared.Models;
using Microsoft.EntityFrameworkCore;
using MareSynchronosServer.Utils;
using MareSynchronosShared.Utils;
using Microsoft.IdentityModel.Tokens;

namespace MareSynchronosServer.Hubs;

public partial class MareHub
{
    private async Task UpdateUserOnRedis()
    {
        await _redis.AddAsync("UID:" + UserUID, UserCharaIdent, TimeSpan.FromSeconds(60), StackExchange.Redis.When.Always, StackExchange.Redis.CommandFlags.FireAndForget).ConfigureAwait(false);
    }

    private async Task RemoveUserFromRedis()
    {
        await _redis.RemoveAsync("UID:" + UserUID, StackExchange.Redis.CommandFlags.FireAndForget).ConfigureAwait(false);
    }

    private async Task<string> GetUserIdent(string uid)
    {
        if (uid.IsNullOrEmpty()) return string.Empty;
        return await _redis.GetAsync<string>("UID:" + uid).ConfigureAwait(false);
    }

    private async Task<Dictionary<string, string>> GetOnlineUsers(List<string> uids)
    {
        var result = await _redis.GetAllAsync<string>(uids.Select(u => "UID:" + u).ToArray()).ConfigureAwait(false);
        return uids.Where(u => result.TryGetValue("UID:" + u, out var ident) && !string.IsNullOrEmpty(ident)).ToDictionary(u => u, u => result["UID:" + u], StringComparer.Ordinal);
    }

    private async Task<List<PausedEntry>> GetAllPairedClientsWithPauseState(string? uid = null)
    {
        uid ??= UserUID;

        var query = await (from userPair in _dbContext.ClientPairs
                           join otherUserPair in _dbContext.ClientPairs on userPair.OtherUserUID equals otherUserPair.UserUID
                           where otherUserPair.OtherUserUID == uid && userPair.UserUID == uid
                           select new
                           {
                               UID = Convert.ToString(userPair.OtherUserUID),
                               GID = "DIRECT",
                               PauseStateSelf = userPair.IsPaused,
                               PauseStateOther = otherUserPair.IsPaused,
                           })
                            .Union(
                                (from userGroupPair in _dbContext.GroupPairs
                                 join otherGroupPair in _dbContext.GroupPairs on userGroupPair.GroupGID equals otherGroupPair.GroupGID
                                 where
                                     userGroupPair.GroupUserUID == uid
                                     && otherGroupPair.GroupUserUID != uid
                                 select new
                                 {
                                     UID = Convert.ToString(otherGroupPair.GroupUserUID),
                                     GID = Convert.ToString(otherGroupPair.GroupGID),
                                     PauseStateSelf = userGroupPair.IsPaused,
                                     PauseStateOther = otherGroupPair.IsPaused,
                                 })
                            ).AsNoTracking().ToListAsync().ConfigureAwait(false);

        return query.GroupBy(g => g.UID, g => (g.GID, g.PauseStateSelf, g.PauseStateOther),
            (key, g) => new PausedEntry
            {
                UID = key,
                PauseStates = g.Select(p => new PauseState() { GID = string.Equals(p.GID, "DIRECT", StringComparison.Ordinal) ? null : p.GID, IsSelfPaused = p.PauseStateSelf, IsOtherPaused = p.PauseStateOther })
                .ToList(),
            }, StringComparer.Ordinal).ToList();
    }

    private async Task<List<string>> GetAllPairedUnpausedUsers(string? uid = null)
    {
        uid ??= UserUID;
        var ret = await GetAllPairedClientsWithPauseState(uid).ConfigureAwait(false);
        return ret.Where(k => !k.IsPaused).Select(k => k.UID).ToList();
    }

    private async Task<List<string>> SendOnlineToAllPairedUsers()
    {
        var usersToSendDataTo = await GetAllPairedUnpausedUsers().ConfigureAwait(false);
        var self = await _dbContext.Users.AsNoTracking().SingleAsync(u => u.UID == UserUID).ConfigureAwait(false);
        await Clients.Users(usersToSendDataTo).Client_UserSendOnline(new(self.ToUserData(), UserCharaIdent)).ConfigureAwait(false);

        return usersToSendDataTo;
    }

    private async Task<List<string>> SendOfflineToAllPairedUsers()
    {
        var usersToSendDataTo = await GetAllPairedUnpausedUsers().ConfigureAwait(false);
        var self = await _dbContext.Users.AsNoTracking().SingleAsync(u => u.UID == UserUID).ConfigureAwait(false);
        await Clients.Users(usersToSendDataTo).Client_UserSendOffline(new(self.ToUserData())).ConfigureAwait(false);

        return usersToSendDataTo;
    }

    public string UserUID => Context.User?.Claims?.SingleOrDefault(c => string.Equals(c.Type, MareClaimTypes.Uid, StringComparison.Ordinal))?.Value ?? throw new Exception("No UID in Claims");
    public string UserCharaIdent => Context.User?.Claims?.SingleOrDefault(c => string.Equals(c.Type, MareClaimTypes.CharaIdent, StringComparison.Ordinal))?.Value ?? throw new Exception("No Chara Ident in Claims");

    private async Task UserGroupLeave(GroupPair groupUserPair, List<PausedEntry> allUserPairs, string userIdent, string? uid = null)
    {
        uid ??= UserUID;
        var userPair = allUserPairs.SingleOrDefault(p => string.Equals(p.UID, groupUserPair.GroupUserUID, StringComparison.Ordinal));
        if (userPair != null)
        {
            if (userPair.IsDirectlyPaused != PauseInfo.NoConnection) return;
            if (userPair.IsPausedPerGroup is PauseInfo.Unpaused) return;
        }

        var groupUserIdent = await GetUserIdent(groupUserPair.GroupUserUID).ConfigureAwait(false);
        if (!string.IsNullOrEmpty(groupUserIdent))
        {
            await Clients.User(uid).Client_UserSendOffline(new(new(groupUserPair.GroupUserUID))).ConfigureAwait(false);
            await Clients.User(groupUserPair.GroupUserUID).Client_UserSendOffline(new(new(uid))).ConfigureAwait(false);
        }
    }

    private async Task SendGroupDeletedToAll(List<GroupPair> groupUsers)
    {
        foreach (var pair in groupUsers)
        {
            var pairIdent = await GetUserIdent(pair.GroupUserUID).ConfigureAwait(false);
            if (string.IsNullOrEmpty(pairIdent)) continue;

            var pairs = await GetAllPairedClientsWithPauseState(pair.GroupUserUID).ConfigureAwait(false);

            foreach (var groupUserPair in groupUsers.Where(g => !string.Equals(g.GroupUserUID, pair.GroupUserUID, StringComparison.Ordinal)))
            {
                await UserGroupLeave(groupUserPair, pairs, pairIdent, pair.GroupUserUID).ConfigureAwait(false);
            }
        }
    }

    private async Task<(bool IsValid, GroupPair ReferredPair)> TryValidateUserInGroup(string gid, string? uid = null)
    {
        uid ??= UserUID;

        var groupPair = await _dbContext.GroupPairs.Include(c => c.GroupUser)
            .SingleOrDefaultAsync(g => g.GroupGID == gid && (g.GroupUserUID == uid || g.GroupUser.Alias == uid)).ConfigureAwait(false);
        if (groupPair == null) return (false, null);

        return (true, groupPair);
    }

    private async Task<(bool IsValid, Group ReferredGroup)> TryValidateGroupModeratorOrOwner(string gid)
    {
        var isOwnerResult = await TryValidateOwner(gid).ConfigureAwait(false);
        if (isOwnerResult.isValid) return (true, isOwnerResult.ReferredGroup);

        if (isOwnerResult.ReferredGroup == null) return (false, null);

        var groupPairSelf = await _dbContext.GroupPairs.SingleOrDefaultAsync(g => g.GroupGID == gid && g.GroupUserUID == UserUID).ConfigureAwait(false);
        if (groupPairSelf == null || !groupPairSelf.IsModerator) return (false, null);

        return (true, isOwnerResult.ReferredGroup);
    }

    private async Task<(bool isValid, Group ReferredGroup)> TryValidateOwner(string gid)
    {
        var group = await _dbContext.Groups.SingleOrDefaultAsync(g => g.GID == gid).ConfigureAwait(false);
        if (group == null) return (false, null);

        return (string.Equals(group.OwnerUID, UserUID, StringComparison.Ordinal), group);
    }
}