using VoiceCat.Interop;

namespace VoiceCat.App.Forms;

/// <summary>
/// Post-auth main window. Owns the VoiceCatClient for its entire lifetime.
/// Phase E: channel tree, user list, chat. Phase F: voice controls, device pickers, PTT,
/// per-user tuning.
/// </summary>
public partial class MainForm : Form
{
    private readonly VoiceCatClient _client;
    private readonly uint _selfUserId;
    private readonly string _nickname;
    private readonly System.Windows.Forms.Timer _pumpTimer = new() { Interval = 30 };

    // Channel / user state
    private uint _currentChannelId;
    private List<ChannelInfo> _channels = [];
    private readonly Dictionary<uint, UserInfo> _users = [];
    private readonly HashSet<uint> _talkingUsers = [];

    // Voice state
    private uint _micStreamId; // 0 = not started
    private Keys _pttKey = Keys.F8;

    public MainForm(VoiceCatClient client, uint selfUserId, string nickname)
    {
        InitializeComponent();
        _client = client;
        _selfUserId = selfUserId;
        _nickname = nickname;

        Text = $"VoiceCat — {nickname}";

        _client.EventReceived += OnEvent;
        _client.LevelChanged += OnLevelChanged;
        _pumpTimer.Tick += (_, _) => _client.PumpEvents();
        _pumpTimer.Start();

        // Channel tree
        tvChannels.DoubleClick += TvChannels_DoubleClick;
        tvChannels.KeyDown += TvChannels_KeyDown;

        // User list — double-click or Enter for per-user tuning, right-click for context menu
        var ctxUsers = new ContextMenuStrip();
        var miTune = new ToolStripMenuItem("&Adjust volume and noise settings...");
        miTune.Click += (_, _) => OpenUserTuning();
        ctxUsers.Opening += (_, _) => miTune.Enabled = lstUsers.SelectedItem is UserListItem;
        ctxUsers.Items.Add(miTune);
        lstUsers.ContextMenuStrip = ctxUsers;
        lstUsers.DoubleClick += (_, _) => OpenUserTuning();
        lstUsers.KeyDown += (_, e) => { if (e.KeyCode == Keys.Enter) OpenUserTuning(); };

        // Compose
        txtCompose.KeyDown += TxtCompose_KeyDown;
        btnSend.Click += (_, _) => SendText();

        // Voice controls
        btnMicToggle.Click += BtnMicToggle_Click;
        chkMute.CheckedChanged += (_, _) => ApplySelfMute();
        chkDeafen.CheckedChanged += (_, _) => ApplySelfMute();
        radioVad.CheckedChanged += RadioVad_CheckedChanged;
        radioPtt.CheckedChanged += RadioPtt_CheckedChanged;
        radioAlwaysOn.CheckedChanged += RadioAlwaysOn_CheckedChanged;
        trkVadThreshold.Scroll += TrkVadThreshold_Scroll;
        btnChangePtt.Click += BtnChangePtt_Click;
        btnRefreshDevices.Click += (_, _) => LoadInputDevices();
        cboInputDevice.SelectedIndexChanged += CboInputDevice_SelectedIndexChanged;

        // PTT (focus-scoped — works only while this form has focus; documented limitation)
        KeyDown += MainForm_KeyDown;
        KeyUp += MainForm_KeyUp;
        Deactivate += (_, _) =>
        {
            if (_micStreamId != 0) _client.SetPushToTalk(false); // release PTT on focus loss
        };

        BootstrapFromServer();
    }

    // ── Startup ──────────────────────────────────────────────────────────────

    private void BootstrapFromServer()
    {
        _channels = _client.ListChannels();
        var users = _client.ListUsers();
        _users.Clear();
        foreach (var u in users)
        {
            _users[u.Id] = u;
            if (u.Id == _selfUserId) _currentChannelId = u.ChannelId;
        }
        RefreshChannelTree();
        RefreshUserList();
        RebuildScopeCombo();
        UpdateStatusLabel();
        AddActivity($"Connected to server as {_nickname}");
    }

    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);
        splitMain.SplitterDistance = Math.Min(220, splitMain.Width - 304);
        splitLeft.SplitterDistance = Math.Min(260, splitLeft.Height - 84);
        LoadInputDevices();
    }

    // ── Event dispatch ────────────────────────────────────────────────────────

    private void OnEvent(VoiceCatEvent ev)
    {
        switch (ev.Type)
        {
            case VcEventType.ChannelList:
                HandleChannelList();
                break;
            case VcEventType.UserJoined:
                HandleUserJoined(ev);
                break;
            case VcEventType.UserLeft:
                HandleUserLeft(ev);
                break;
            case VcEventType.UserUpdated:
                HandleUserUpdated();
                break;
            case VcEventType.JoinResult:
                HandleJoinResult(ev);
                break;
            case VcEventType.TextMessage:
                HandleTextMessage(ev);
                break;
            case VcEventType.TalkState:
                HandleTalkState(ev);
                break;
            case VcEventType.StreamStarted:
                HandleStreamStarted(ev);
                break;
            case VcEventType.StreamStopped:
                if (_users.TryGetValue(ev.UserId, out var stUser) &&
                    stUser.ChannelId == _currentChannelId)
                    AddActivity($"{stUser.Nickname} stopped a stream");
                break;
            case VcEventType.Disconnected:
                HandleDisconnected(ev);
                break;
        }
    }

    // ── Event handlers ────────────────────────────────────────────────────────

    private void HandleChannelList()
    {
        _channels = _client.ListChannels();
        var users = _client.ListUsers();
        _users.Clear();
        foreach (var u in users)
        {
            _users[u.Id] = u;
            if (u.Id == _selfUserId) _currentChannelId = u.ChannelId;
        }
        RefreshChannelTree();
        RefreshUserList();
        RebuildScopeCombo();
    }

    private void HandleUserJoined(VoiceCatEvent ev)
    {
        var user = new UserInfo(ev.UserId, ev.Text ?? $"User#{ev.UserId}", false, ev.ChannelId);
        _users[ev.UserId] = user;
        RefreshUserList();
        RebuildScopeCombo();
        if (ev.ChannelId == _currentChannelId && ev.UserId != _selfUserId)
            AddActivity($"{user.Nickname} joined the channel");
    }

    private void HandleUserLeft(VoiceCatEvent ev)
    {
        if (!_users.TryGetValue(ev.UserId, out var user)) return;
        bool wasHere = user.ChannelId == _currentChannelId && ev.UserId != _selfUserId;
        _users.Remove(ev.UserId);
        _talkingUsers.Remove(ev.UserId);
        RefreshUserList();
        RebuildScopeCombo();
        if (wasHere) AddActivity($"{user.Nickname} left the channel");
    }

    private void HandleUserUpdated()
    {
        var users = _client.ListUsers();
        _users.Clear();
        foreach (var u in users)
        {
            _users[u.Id] = u;
            if (u.Id == _selfUserId) _currentChannelId = u.ChannelId;
        }
        RefreshChannelTree();
        RefreshUserList();
        RebuildScopeCombo();
    }

    private void HandleJoinResult(VoiceCatEvent ev)
    {
        if (ev.Result == VcResult.Ok)
        {
            _currentChannelId = ev.ChannelId;
            // Server doesn't echo UserJoined/UserUpdated back to the mover — patch our
            // own entry in _users so RefreshUserList shows us in the new channel.
            if (_users.TryGetValue(_selfUserId, out var self))
                _users[_selfUserId] = self with { ChannelId = ev.ChannelId };
            RefreshChannelTree();
            RefreshUserList();
            UpdateStatusLabel();
            string chanName = _channels.FirstOrDefault(c => c.Id == ev.ChannelId)?.Name
                              ?? $"Channel #{ev.ChannelId}";
            AddActivity($"Joined {chanName}");
        }
        else
        {
            AddActivity($"Could not join channel: {ev.Text ?? ev.Result.ToString()}");
        }
    }

    private void HandleTextMessage(VoiceCatEvent ev)
    {
        string time = ev.TimestampUnixMs > 0
            ? DateTimeOffset.FromUnixTimeMilliseconds((long)ev.TimestampUnixMs)
                           .LocalDateTime.ToString("HH:mm")
            : DateTime.Now.ToString("HH:mm");
        string sender = GetNickname(ev.UserId);
        string prefix = ev.TextScope == VcTextScope.Private ? "(private) " : "";
        rtbChat.AppendText($"[{time}] {prefix}{sender}: {ev.Text ?? ""}\n");
        rtbChat.ScrollToCaret();
        if (ev.TextScope == VcTextScope.Private && ev.UserId != _selfUserId)
            AddActivity($"Private message from {sender}");
    }

    private void HandleTalkState(VoiceCatEvent ev)
    {
        bool talking = ev.U32a == 1;
        if (talking) _talkingUsers.Add(ev.UserId);
        else _talkingUsers.Remove(ev.UserId);
        RefreshUserList();
        if (talking && ev.UserId != _selfUserId &&
            _users.TryGetValue(ev.UserId, out var tUser) &&
            tUser.ChannelId == _currentChannelId)
            AddActivity($"{tUser.Nickname} started talking");
    }

    private void HandleStreamStarted(VoiceCatEvent ev)
    {
        if (!_users.TryGetValue(ev.UserId, out var sUser) ||
            sUser.ChannelId != _currentChannelId) return;
        var streams = _client.ListUserStreams(ev.UserId);
        var stream = streams.FirstOrDefault(s => s.StreamId == ev.StreamId);
        string kind = stream?.Kind switch
        {
            VcStreamKind.ScreenAudio => "screen audio",
            VcStreamKind.AuxDevice => "aux device",
            _ => "microphone",
        };
        AddActivity($"{sUser.Nickname} started {kind} stream");
    }

    private void HandleDisconnected(VoiceCatEvent ev)
    {
        string msg = string.IsNullOrEmpty(ev.Text)
            ? "Disconnected from server."
            : $"Disconnected: {ev.Text}";
        lblStatus.Text = msg;
        AddActivity(msg);
        tvChannels.Nodes.Clear();
        lstUsers.Items.Clear();
        _users.Clear();
        _talkingUsers.Clear();
        _currentChannelId = 0;
        _micStreamId = 0;
        txtCompose.Enabled = false;
        btnSend.Enabled = false;
        btnMicToggle.Enabled = false;
    }

    // ── Level meter ───────────────────────────────────────────────────────────

    private void OnLevelChanged(uint streamId, float rms)
    {
        if (streamId == _micStreamId)
            pbLevel.Value = Math.Min(100, (int)(rms * 400));
    }

    // ── UI refresh helpers ────────────────────────────────────────────────────

    private void RefreshChannelTree()
    {
        uint toSelect = tvChannels.SelectedNode?.Tag is uint s ? s : _currentChannelId;
        tvChannels.BeginUpdate();
        tvChannels.Nodes.Clear();

        var byParent = _channels
            .GroupBy(c => c.ParentId)
            .ToDictionary(g => g.Key, g => g.ToList());

        void AddChildren(TreeNodeCollection nodes, uint parentId)
        {
            if (!byParent.TryGetValue(parentId, out var kids)) return;
            foreach (var ch in kids.OrderBy(c => c.Name))
            {
                var label = ch.Name;
                if (ch.PasswordProtected) label += " [password]";
                if (ch.Id == _currentChannelId) label += " ►";
                var node = new TreeNode(label) { Tag = ch.Id };
                nodes.Add(node);
                AddChildren(node.Nodes, ch.Id);
            }
        }
        AddChildren(tvChannels.Nodes, 0);
        tvChannels.ExpandAll();
        SeekAndSelect(tvChannels.Nodes, toSelect);
        tvChannels.EndUpdate();
    }

    private bool SeekAndSelect(TreeNodeCollection nodes, uint channelId)
    {
        if (channelId == 0) return false;
        foreach (TreeNode n in nodes)
        {
            if (n.Tag is uint id && id == channelId) { tvChannels.SelectedNode = n; return true; }
            if (SeekAndSelect(n.Nodes, channelId)) return true;
        }
        return false;
    }

    private void RefreshUserList()
    {
        lstUsers.BeginUpdate();
        lstUsers.Items.Clear();
        foreach (var user in _users.Values
            .Where(u => u.ChannelId == _currentChannelId)
            .OrderBy(u => u.Nickname))
        {
            string label = user.Nickname;
            if (user.Id == _selfUserId) label += " (you)";
            if (_talkingUsers.Contains(user.Id)) label += " (talking)";
            lstUsers.Items.Add(new UserListItem(user.Id, label));
        }
        lstUsers.EndUpdate();
    }

    private void RebuildScopeCombo()
    {
        uint prevTarget = (cboScope.SelectedItem is ScopeItem prev &&
                           prev.Scope == VcTextScope.Private)
            ? prev.TargetId : 0u;

        cboScope.Items.Clear();
        cboScope.Items.Add(new ScopeItem("Channel", VcTextScope.Channel, 0));
        foreach (var u in _users.Values.OrderBy(u => u.Nickname))
        {
            if (u.Id == _selfUserId) continue;
            cboScope.Items.Add(new ScopeItem($"Private: {u.Nickname}", VcTextScope.Private, u.Id));
        }

        if (prevTarget != 0)
        {
            for (int i = 1; i < cboScope.Items.Count; i++)
            {
                if (cboScope.Items[i] is ScopeItem si && si.TargetId == prevTarget)
                {
                    cboScope.SelectedIndex = i;
                    return;
                }
            }
        }
        if (cboScope.Items.Count > 0) cboScope.SelectedIndex = 0;
    }

    private void UpdateStatusLabel()
    {
        if (_currentChannelId == 0)
        {
            lblStatus.Text = $"Connected as {_nickname} — not in a channel.";
            return;
        }
        string chanName = _channels.FirstOrDefault(c => c.Id == _currentChannelId)?.Name
                          ?? $"Channel #{_currentChannelId}";
        int count = _users.Values.Count(u => u.ChannelId == _currentChannelId);
        lblStatus.Text = $"Connected as {_nickname} — {chanName} ({count} user{(count == 1 ? "" : "s")})";
    }

    // ── Device management ─────────────────────────────────────────────────────

    private void LoadInputDevices()
    {
        var devices = _client.ListDevices(VcDeviceKind.Input);
        DeviceInfo? prevDevice = cboInputDevice.SelectedItem as DeviceInfo;

        cboInputDevice.Items.Clear();
        foreach (var d in devices) cboInputDevice.Items.Add(d);

        // Restore selection or pick default
        if (prevDevice is not null)
        {
            for (int i = 0; i < cboInputDevice.Items.Count; i++)
            {
                if (cboInputDevice.Items[i] is DeviceInfo d && d.Id == prevDevice.Id)
                {
                    cboInputDevice.SelectedIndex = i;
                    return;
                }
            }
        }
        // Select default device
        for (int i = 0; i < cboInputDevice.Items.Count; i++)
        {
            if (cboInputDevice.Items[i] is DeviceInfo d && d.IsDefault)
            {
                cboInputDevice.SelectedIndex = i;
                return;
            }
        }
        if (cboInputDevice.Items.Count > 0) cboInputDevice.SelectedIndex = 0;
    }

    // ── Voice controls ────────────────────────────────────────────────────────

    private void BtnMicToggle_Click(object? sender, EventArgs e)
    {
        if (_micStreamId == 0)
        {
            var (result, streamId) = _client.StartStream(VcStreamKind.Mic, "Microphone");
            if (result == VcResult.Ok)
            {
                _micStreamId = streamId;
                // Apply selected device if not default
                if (cboInputDevice.SelectedItem is DeviceInfo { IsDefault: false } dev)
                    _client.SetInputDevice(streamId, dev.Id);
                // Apply current mode
                _client.SetInputMode(CurrentInputMode());
                if (radioVad.Checked) _client.SetVadThreshold(VadThresholdFromSlider());
                btnMicToggle.Text = "Leave &Voice";
                chkMute.Enabled = true;
                chkDeafen.Enabled = true;
                radioVad.Enabled = true;
                radioPtt.Enabled = true;
                radioAlwaysOn.Enabled = true;
                AddActivity("Joined voice — microphone active");
            }
            else
            {
                AddActivity($"Failed to start microphone: {result}");
            }
        }
        else
        {
            _client.SetPushToTalk(false); // release PTT if held
            _client.StopStream(_micStreamId);
            _micStreamId = 0;
            pbLevel.Value = 0;
            btnMicToggle.Text = "&Join Voice";
            chkMute.Enabled = false;
            chkDeafen.Enabled = false;
            radioVad.Enabled = false;
            radioPtt.Enabled = false;
            radioAlwaysOn.Enabled = false;
            AddActivity("Left voice");
        }
    }

    private void ApplySelfMute() =>
        _client.SetSelfMute(chkMute.Checked, chkDeafen.Checked);

    private void RadioVad_CheckedChanged(object? sender, EventArgs e)
    {
        if (!radioVad.Checked) return;
        lblPttKey.Visible = false;
        btnChangePtt.Visible = false;
        lblVadThreshold.Visible = true;
        trkVadThreshold.Visible = true;
        if (_micStreamId != 0)
        {
            _client.SetInputMode(VcInputMode.VoiceActivation);
            _client.SetVadThreshold(VadThresholdFromSlider());
        }
    }

    private void RadioPtt_CheckedChanged(object? sender, EventArgs e)
    {
        if (!radioPtt.Checked) return;
        lblPttKey.Text = $"({_pttKey})";
        lblPttKey.Visible = true;
        btnChangePtt.Visible = true;
        lblVadThreshold.Visible = false;
        trkVadThreshold.Visible = false;
        if (_micStreamId != 0)
        {
            _client.SetInputMode(VcInputMode.PushToTalk);
            _client.SetPushToTalk(false); // start released
        }
    }

    private void RadioAlwaysOn_CheckedChanged(object? sender, EventArgs e)
    {
        if (!radioAlwaysOn.Checked) return;
        lblPttKey.Visible = false;
        btnChangePtt.Visible = false;
        lblVadThreshold.Visible = false;
        trkVadThreshold.Visible = false;
        if (_micStreamId != 0) _client.SetInputMode(VcInputMode.AlwaysOn);
    }

    private void TrkVadThreshold_Scroll(object? sender, EventArgs e)
    {
        if (_micStreamId != 0 && radioVad.Checked)
            _client.SetVadThreshold(VadThresholdFromSlider());
    }

    // threshold = 0.1 × (1 − (value−1) / 99): slider=1→0.1 (least sensitive), slider=100→0.001
    private float VadThresholdFromSlider() =>
        0.1f * (1f - (trkVadThreshold.Value - 1f) / 99f);

    private VcInputMode CurrentInputMode() =>
        radioPtt.Checked ? VcInputMode.PushToTalk :
        radioAlwaysOn.Checked ? VcInputMode.AlwaysOn :
        VcInputMode.VoiceActivation;

    private void BtnChangePtt_Click(object? sender, EventArgs e)
    {
        using var dlg = new PttKeyCaptureDialog(_pttKey);
        if (dlg.ShowDialog(this) == DialogResult.OK)
        {
            _pttKey = dlg.CapturedKey;
            lblPttKey.Text = $"({_pttKey})";
        }
    }

    private void CboInputDevice_SelectedIndexChanged(object? sender, EventArgs e)
    {
        if (_micStreamId == 0) return;
        string? deviceId = (cboInputDevice.SelectedItem as DeviceInfo)?.Id;
        _client.SetInputDevice(_micStreamId, deviceId);
    }

    // ── PTT key handling (focus-scoped) ───────────────────────────────────────

    private void MainForm_KeyDown(object? sender, KeyEventArgs e)
    {
        if (!radioPtt.Checked || e.KeyCode != _pttKey || _micStreamId == 0) return;
        // Don't intercept PTT key while user is typing in a text control
        if (ActiveControl is TextBox or RichTextBox) return;
        _client.SetPushToTalk(true);
        lblPttKey.Text = $"({_pttKey} ▶)";
        e.Handled = true;
    }

    private void MainForm_KeyUp(object? sender, KeyEventArgs e)
    {
        if (!radioPtt.Checked || e.KeyCode != _pttKey || _micStreamId == 0) return;
        _client.SetPushToTalk(false);
        lblPttKey.Text = $"({_pttKey})";
        e.Handled = true;
    }

    // ── Channel navigation ────────────────────────────────────────────────────

    private void TvChannels_DoubleClick(object? sender, EventArgs e)
    {
        if (tvChannels.SelectedNode?.Tag is uint channelId)
            JoinChannelRequest(channelId);
    }

    private void TvChannels_KeyDown(object? sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Enter && tvChannels.SelectedNode?.Tag is uint channelId)
        {
            JoinChannelRequest(channelId);
            e.Handled = e.SuppressKeyPress = true;
        }
    }

    private void JoinChannelRequest(uint channelId)
    {
        if (channelId == _currentChannelId) return;
        var channel = _channels.FirstOrDefault(c => c.Id == channelId);
        string? password = null;
        if (channel?.PasswordProtected == true)
        {
            using var dlg = new PasswordPromptDialog($"Password for channel \"{channel.Name}\":");
            if (dlg.ShowDialog(this) != DialogResult.OK) return;
            password = dlg.Password;
        }
        _client.JoinChannel(channelId, password);
    }

    // ── Per-user tuning ───────────────────────────────────────────────────────

    private void OpenUserTuning()
    {
        if (lstUsers.SelectedItem is not UserListItem item) return;
        if (!_users.TryGetValue(item.UserId, out var user)) return;
        using var dlg = new PerUserTuningDialog(_client, item.UserId, user.Nickname);
        dlg.ShowDialog(this);
    }

    // ── Text chat ─────────────────────────────────────────────────────────────

    private void TxtCompose_KeyDown(object? sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Enter)
        {
            SendText();
            e.Handled = e.SuppressKeyPress = true;
        }
    }

    private void SendText()
    {
        string msg = txtCompose.Text.Trim();
        if (string.IsNullOrEmpty(msg)) return;

        var scope = VcTextScope.Channel;
        uint targetId = _currentChannelId;
        if (cboScope.SelectedItem is ScopeItem { Scope: VcTextScope.Private } si)
        {
            scope = VcTextScope.Private;
            targetId = si.TargetId;
        }

        if (scope == VcTextScope.Channel && _currentChannelId == 0) return;

        _client.SendText(scope, targetId, msg);
        txtCompose.Clear();

        // Server excludes sender from channel fan-out — echo our own message locally.
        string time = DateTime.Now.ToString("HH:mm");
        string prefix = scope == VcTextScope.Private
            ? $"(private to {GetNickname(targetId)}) "
            : "";
        rtbChat.AppendText($"[{time}] {prefix}{_nickname}: {msg}\n");
        rtbChat.ScrollToCaret();
    }

    // ── Utility ───────────────────────────────────────────────────────────────

    private void AddActivity(string text)
    {
        string entry = $"[{DateTime.Now:HH:mm}] {text}";
        lstActivity.Items.Add(entry);
        if (lstActivity.Items.Count > 200) lstActivity.Items.RemoveAt(0);
        lstActivity.TopIndex = lstActivity.Items.Count - 1;
    }

    private string GetNickname(uint userId)
    {
        if (userId == _selfUserId) return _nickname;
        return _users.TryGetValue(userId, out var u) ? u.Nickname : $"User#{userId}";
    }

    // ── Lifetime ──────────────────────────────────────────────────────────────

    protected override void OnFormClosed(FormClosedEventArgs e)
    {
        _pumpTimer.Stop();
        _client.LevelChanged -= OnLevelChanged;
        _client.EventReceived -= OnEvent;
        _client.Disconnect();
        _client.Dispose();
        base.OnFormClosed(e);
    }

    // ── Private types ─────────────────────────────────────────────────────────

    private sealed class ScopeItem(string display, VcTextScope scope, uint targetId)
    {
        public VcTextScope Scope { get; } = scope;
        public uint TargetId { get; } = targetId;
        public override string ToString() => display;
    }

    private sealed class UserListItem(uint userId, string display)
    {
        public uint UserId { get; } = userId;
        public override string ToString() => display;
    }
}