@page "/KnownHomeserverList"
@using System.Text.Json
@using MatrixRoomUtils.Core.Extensions
@using System.Diagnostics
<h3>Known Homeserver List</h3>
<hr/>

@if (!IsFinished) {
    <p>Loading... Please wait...</p>
    <progress value="@QueryProgress.ProcessedRooms" max="@QueryProgress.TotalRooms"></progress>
    <p>@QueryProgress.ProcessedRooms / @QueryProgress.TotalRooms</p>
    @foreach (var (room, state) in QueryProgress.ProcessedUsers.Where(x => !x.Value.IsFinished).OrderByDescending(x => x.Value.Total).ToList()) {
        @if (state.Blocked) {
            <p>🔒 @room.RoomId - @state.Processed / @state.Total, @state.Timing.Elapsed elapsed...</p>
        }
        else if (state.Slowmode) {
            <p>🐢 @room.RoomId - @state.Processed / @state.Total, @state.Timing.Elapsed elapsed...</p>
        }
        else {
            <p>@room.RoomId - @state.Processed / @state.Total, @state.Timing.Elapsed elapsed...</p>
        }
        <progress value="@state.Processed" max="@state.Total"></progress>
    }
}
else {
    @foreach (var server in HomeServers.OrderByDescending(x => x.KnownUserCount).ThenBy(x => x.Server).ToList()) {
        <p>@server.Server - @server.KnownUserCount</p>
    }
}
<hr/>

@code {
    List<HomeServerInfo> HomeServers = new();
    bool IsFinished { get; set; }
    HomeServerInfoQueryProgress QueryProgress { get; set; } = new();

    protected override async Task OnInitializedAsync() {
        await LocalStorageWrapper.LoadFromLocalStorage(LocalStorage);

        var sw = Stopwatch.StartNew();
        HomeServers = await GetHomeservers(progressCallback: async progress => {
            if (sw.ElapsedMilliseconds > 1000) {
                Console.WriteLine("Progress updated...");
                QueryProgress = progress;
                StateHasChanged();
                Console.WriteLine("Progress rendered!");
                sw.Restart();
                await Task.Delay(100);
                return true;
            }
            Console.WriteLine($"Progress updated, but not rendering because only {sw.ElapsedMilliseconds}ms elapsed since last call...");
            return false;
        });

        IsFinished = true;
        StateHasChanged();
        Console.WriteLine("Rerendered!");
        await base.OnInitializedAsync();
    }

    private async Task<List<HomeServerInfo>> GetHomeservers(int memberLimit = 1000, Func<HomeServerInfoQueryProgress, Task<bool>>? progressCallback = null) {
        HomeServerInfoQueryProgress progress = new();
        List<HomeServerInfo> homeServers = new();
        var rooms = await RuntimeCache.CurrentHomeServer.GetJoinedRooms();
        progress.TotalRooms = rooms.Count;

        var semaphore = new SemaphoreSlim(4);
        var semLock = new SemaphoreSlim(1);
        var tasks = rooms.Select(async room => {
            await semaphore.WaitAsync();
            progress.ProcessedUsers.Add(room, new HomeServerInfoQueryProgress.State());
            Console.WriteLine($"Fetching states for room ({rooms.IndexOf(room)}/{rooms.Count}) ({room.RoomId})");
            var states = (await room.GetStateAsync("")).Value.Deserialize<List<StateEventResponse>>();
            states.RemoveAll(x => x.Type != "m.room.member" || x.Content.GetProperty("membership").GetString() != "join");
            Console.WriteLine($"Room {room.RoomId} has {states.Count} members");
            if (states.Count > memberLimit) {
                Console.WriteLine("Skipping!");
                semaphore.Release();
                progress.ProcessedUsers.Remove(room);
                progress.TotalRooms--;
                return;
            }
            progress.ProcessedUsers[room].Total = states.Count;
            var updateInterval = progress.ProcessedUsers[room].Total >= 1000 ? 1000 : 100;
            while (progress.ProcessedUsers.Any(x => x.Value.Total == 0) && progress.ProcessedUsers[room].Total >= 1000) {
                progress.ProcessedUsers[room].Blocked = true;
                await Task.Delay(1000);
    // if(progressCallback != null)
    //     await progressCallback.Invoke(progress);
            }
            progress.ProcessedUsers[room].Blocked = false;
            var processedStates = 0;
            foreach (var state in states) {
                await semLock.WaitAsync();
                semLock.Release();
                if (progress.ProcessedUsers.Count(x => x.Value.Total == 0) > 5 && progress.ProcessedUsers[room].Total >= 200) {
                    progress.ProcessedUsers[room].Slowmode = true;
                    await Task.Delay(progress.ProcessedUsers[room].Total >= 500 ? 1000 : 100);
                }
                else {
                    progress.ProcessedUsers[room].Slowmode = false;
                }
                if (!homeServers.Any(x => x.Server == state.StateKey.Split(':')[1])) {
                    homeServers.Add(new HomeServerInfo { Server = state.StateKey.Split(':')[1] });
                }
                var hs = homeServers.First(x => x.Server == state.StateKey.Split(':')[1]);
                if (!hs.KnownUsers.Contains(state.StateKey.Split(':')[0]))
                    hs.KnownUsers.Add(state.StateKey.Split(':')[0]);
                if (++progress.ProcessedUsers[room].Processed % updateInterval == 0 && progressCallback != null) {
                    await semLock.WaitAsync();
                    var _ = await progressCallback.Invoke(progress);
                    semLock.Release();
                }
            }
            Console.WriteLine("Collected states!");
            progress.ProcessedRooms++;
            progress.ProcessedUsers[room].IsFinished = true;
            progressCallback?.Invoke(progress);
            semaphore.Release();
        });
        await Task.WhenAll(tasks);

        Console.WriteLine("Calculating member counts...");
        homeServers.ForEach(x => x.KnownUserCount = x.KnownUsers.Count);
        Console.WriteLine(homeServers.First(x => x.Server == "rory.gay").ToJson());
        Console.WriteLine("Recalculated!");
        return homeServers;
    }

    class HomeServerInfo {
        public string Server { get; set; }
        public int? KnownUserCount { get; set; }
        public List<string> KnownUsers { get; } = new();
    }

    class HomeServerInfoQueryProgress {
        public int ProcessedRooms { get; set; }
        public int TotalRooms { get; set; }
        public Dictionary<Room, State> ProcessedUsers { get; } = new();
        public List<HomeServerInfo> CurrentState { get; set; } = new();

        public class State {
            public int Processed { get; set; }
            public int Total { get; set; }
            public bool Blocked { get; set; }
            public bool Slowmode { get; set; }
            public float Progress => (float)Processed / Total;
            public bool IsFinished { get; set; }
            public Stopwatch Timing { get; } = Stopwatch.StartNew();
        }
    }

}