import { useCallback, useRef, useState, type DragEvent, type ReactNode } from 'react';
import { useTranslation } from 'react-i18next';

import type { Channel } from '@/api/types';
import { Avatar } from '@/components/ui/Avatar';
import { Menu, MenuGroupLabel, MenuItem } from '@/components/ui/Menu';
import { Card, Button } from '@/components/ui/primitives';
import { RemoteAudio, RemoteVideo } from '@/components/voice/RemoteAudio';
import { VoiceFlags, VoiceQualityDot } from '@/components/voice/VoiceIndicators';
import { VoiceOccupantMenu } from '@/components/voice/VoiceOccupantMenu';
import { VoiceSoundboard } from '@/components/voice/VoiceSoundboard';
import { VoiceStatsButton } from '@/components/voice/VoiceStatsButton';
import { useVoiceEnabled } from '@/components/voice/useVoiceEnabled';
import { useGuildVoiceStates } from '@/components/voice/useGuildVoiceStates';
import {
  useCanUseSoundboard,
  useVoiceChannels,
  useVoiceModeration,
  useVoiceOccupants,
  type VoiceOccupant,
} from '@/components/voice/useVoiceOccupants';
import { VOICE_DRAG_MIME } from '@/components/voice/voiceDrag';
import { speakingRingClass } from '@/components/voice/voiceStyles';
import type { VoiceModerationPermissions } from '@/lib/identity';
import { SCREEN_SHARE_PRESET_IDS, type ScreenSharePresetId } from '@/lib/livekit';
import { useApiErrorMessage } from '@/lib/useApiErrorMessage';
import { useVoiceStore, type VoicePublishQuality } from '@/stores/voice';
import { useVoiceConnectionStore } from '@/stores/voiceConnection';

/** Плитка участника: видео или аватар, имя, флаги, качество связи. */
function VoiceTile({
  occupant,
  permissions,
  moveTargets,
  onMute,
  onDeafen,
  onMove,
  children,
}: {
  occupant: VoiceOccupant;
  permissions: VoiceModerationPermissions;
  moveTargets: Channel[];
  onMute: (userId: string, muted: boolean) => void;
  onDeafen: (userId: string, deafened: boolean) => void;
  onMove: (userId: string, targetId: string) => void;
  /** Кнопки управления — только на своей плитке. */
  children?: ReactNode;
}) {
  const { t } = useTranslation();
  const [menuOpen, setMenuOpen] = useState(false);
  const anchorRef = useRef<HTMLButtonElement | null>(null);
  const volume = useVoiceStore((state) => state.participantVolumes[occupant.userId] ?? 100);
  // Подписка именно на карту пингов: селектор-функция не вызывает перерисовку.
  const latencies = useVoiceConnectionStore((state) => state.latencies);
  // Общая громкость звука умножается на личную громкость участника.
  const outputVolume = useVoiceStore((state) => state.outputVolume);
  const deafened = useVoiceConnectionStore((state) => state.deafened);
  const media = occupant.participant;
  const video = media?.screen ?? media?.video;

  const onDragStart = (event: DragEvent<HTMLDivElement>): void => {
    if (occupant.isLocal || !permissions.move) {
      return;
    }
    event.dataTransfer.setData(VOICE_DRAG_MIME, occupant.userId);
    event.dataTransfer.effectAllowed = 'move';
  };

  return (
    <div
      data-testid={`voice-tile-${occupant.userId}`}
      data-speaking={occupant.isSpeaking}
      draggable={permissions.move && !occupant.isLocal}
      onDragStart={onDragStart}
      onContextMenu={(event) => {
        // ПКМ по плитке открывает меню участника (AGENT.md 7.14).
        if (occupant.isLocal) {
          return;
        }
        event.preventDefault();
        setMenuOpen(true);
      }}
      className={`flex flex-col gap-2 rounded-[var(--radius-lg)] border bg-surface-1 p-3 transition-colors duration-[var(--duration-fast)] ${
        occupant.isSpeaking ? 'border-success/70' : 'border-border/60'
      }`}
    >
      <div className="relative flex min-h-28 items-center justify-center overflow-hidden rounded-[var(--radius-md)] bg-surface-2">
        {video === undefined ? (
          <span className={`rounded-full ${speakingRingClass(occupant.isSpeaking)}`}>
            <Avatar
              name={occupant.name}
              seed={occupant.userId}
              fileId={occupant.avatarFileId}
              size="lg"
            />
          </span>
        ) : (
          <RemoteVideo track={video} muted={occupant.isLocal} />
        )}
        {media?.audio === undefined ? null : (
          <RemoteAudio
            track={media.audio}
            volume={(volume * outputVolume) / 100}
            muted={deafened}
          />
        )}
      </div>

      <div className="flex items-center gap-2">
        <span className="min-w-0 flex-1 truncate text-sm font-medium" title={occupant.name}>
          {occupant.name}
        </span>
        <VoiceQualityDot quality={occupant.quality} latencyMs={latencies[occupant.userId]} />
        {occupant.isLocal ? (
          <>
            {/* Статистика своей публикации: разрешение, fps, кодек, канал (7.14). */}
            <VoiceStatsButton />
            <span className="text-xs text-fg-muted">{t('voice.you')}</span>
          </>
        ) : (
          <button
            ref={anchorRef}
            type="button"
            aria-haspopup="menu"
            aria-expanded={menuOpen}
            aria-label={t('voice.menu.label', { name: occupant.name })}
            title={t('voice.menu.label', { name: occupant.name })}
            onClick={() => setMenuOpen((value) => !value)}
            className="rounded-[var(--radius-sm)] px-1 text-fg-muted transition-colors duration-[var(--duration-fast)] hover:bg-surface-3 hover:text-fg"
          >
            <span aria-hidden="true">⋯</span>
          </button>
        )}
      </div>

      <VoiceFlags
        selfMute={occupant.selfMute}
        selfDeaf={occupant.selfDeaf}
        serverMute={occupant.serverMute}
        serverDeaf={occupant.serverDeaf}
        camera={occupant.camera}
        screen={occupant.screen}
      />

      {occupant.isSpeaking ? <p className="sr-only">{t('voice.speaking')}</p> : null}
      {children}

      <VoiceOccupantMenu
        open={menuOpen}
        occupant={occupant}
        anchorRef={anchorRef}
        onClose={() => setMenuOpen(false)}
        permissions={permissions}
        moveTargets={moveTargets}
        onMute={onMute}
        onDeafen={onDeafen}
        onMove={onMove}
      />
    </div>
  );
}

/** Кнопки управления своей сессией: микрофон, звук, камера, экран, выход. */
function VoiceControlsRow({
  micEnabled,
  deafened,
  cameraEnabled,
  screenEnabled,
  serverMuted,
  serverDeafened,
  screenPreset,
  videoQuality,
  soundboard,
  onMic,
  onSound,
  onCamera,
  onScreen,
  onVideoQuality,
  onLeave,
}: {
  micEnabled: boolean;
  deafened: boolean;
  cameraEnabled: boolean;
  screenEnabled: boolean;
  serverMuted: boolean;
  serverDeafened: boolean;
  /** Выбранный пресет шаринга: показывается в меню демонстрации экрана. */
  screenPreset: ScreenSharePresetId;
  /** Качество публикации видео. */
  videoQuality: VoicePublishQuality;
  /** Кнопка саундборда: рисуется, когда есть право `USE_SOUNDBOARD`. */
  soundboard: ReactNode;
  onMic: () => void;
  onSound: () => void;
  onCamera: () => void;
  /** `null` — остановить демонстрацию, иначе — начать с этим пресетом. */
  onScreen: (preset: ScreenSharePresetId | null) => void;
  onVideoQuality: (quality: VoicePublishQuality) => void;
  onLeave: () => void;
}) {
  const { t } = useTranslation();
  const [screenMenuOpen, setScreenMenuOpen] = useState(false);
  const [qualityMenuOpen, setQualityMenuOpen] = useState(false);
  const screenAnchorRef = useRef<HTMLButtonElement | null>(null);
  const qualityAnchorRef = useRef<HTMLButtonElement | null>(null);

  return (
    <div
      className="flex flex-wrap items-center gap-1"
      role="group"
      aria-label={t('voice.controls')}
    >
      <VoiceControlButton
        glyph="🎤"
        label={t(micEnabled ? 'voice.mic.off' : 'voice.mic.on')}
        active={micEnabled}
        disabled={serverMuted}
        {...(serverMuted ? { disabledReason: t('voice.serverMuted') } : {})}
        onClick={onMic}
      />
      <VoiceControlButton
        glyph="🎧"
        label={t(deafened ? 'voice.sound.on' : 'voice.sound.off')}
        active={!deafened}
        disabled={serverDeafened}
        {...(serverDeafened ? { disabledReason: t('voice.serverDeafened') } : {})}
        onClick={onSound}
      />
      <VoiceControlButton
        glyph="🎥"
        label={t(cameraEnabled ? 'voice.camera.off' : 'voice.camera.on')}
        active={cameraEnabled}
        onClick={onCamera}
      />
      {/* Демонстрация экрана: перед публикацией выбираем разрешение и fps. */}
      <button
        ref={screenAnchorRef}
        type="button"
        aria-pressed={screenEnabled}
        aria-haspopup="menu"
        aria-expanded={screenMenuOpen}
        aria-label={t(screenEnabled ? 'voice.screen.off' : 'voice.screen.on')}
        title={t(screenEnabled ? 'voice.screen.off' : 'voice.screen.on')}
        data-testid="voice-screen-button"
        onClick={() => {
          if (screenEnabled) {
            onScreen(null);
            return;
          }
          setScreenMenuOpen((value) => !value);
        }}
        className={`rounded-[var(--radius-md)] border px-3 py-1.5 text-base leading-none transition-[color,background-color,transform] duration-[var(--duration-fast)] active:scale-95 ${
          screenEnabled
            ? 'border-border/60 bg-surface-2 text-fg'
            : 'border-danger/60 bg-danger/10 text-danger'
        }`}
      >
        <span aria-hidden="true">🖥</span>
      </button>
      <Menu
        open={screenMenuOpen}
        label={t('voice.screen.quality')}
        onClose={() => setScreenMenuOpen(false)}
        anchorRef={screenAnchorRef}
        placement="bottom"
      >
        <MenuGroupLabel>{t('voice.screen.quality')}</MenuGroupLabel>
        {SCREEN_SHARE_PRESET_IDS.map((preset) => (
          <MenuItem
            key={preset}
            role="menuitemradio"
            selected={screenPreset === preset}
            data-testid={`voice-screen-preset-${preset}`}
            onClick={() => {
              setScreenMenuOpen(false);
              onScreen(preset);
            }}
          >
            {t(`voice.screen.presets.${preset}`)}
          </MenuItem>
        ))}
      </Menu>

      {/* Качество публикации видео: low/medium/high (`setPublishingQuality`). */}
      <button
        ref={qualityAnchorRef}
        type="button"
        aria-haspopup="menu"
        aria-expanded={qualityMenuOpen}
        aria-label={t('voice.publishQuality.label')}
        title={t('voice.publishQuality.label')}
        data-testid="voice-quality-button"
        onClick={() => setQualityMenuOpen((value) => !value)}
        className="rounded-[var(--radius-md)] border border-border/60 bg-surface-2 px-2 py-1.5 text-xs leading-none text-fg transition-colors duration-[var(--duration-fast)]"
      >
        {t(`voice.publishQuality.short.${videoQuality}`)}
      </button>
      <Menu
        open={qualityMenuOpen}
        label={t('voice.publishQuality.label')}
        onClose={() => setQualityMenuOpen(false)}
        anchorRef={qualityAnchorRef}
        placement="bottom"
      >
        <MenuGroupLabel>{t('voice.publishQuality.label')}</MenuGroupLabel>
        {(['low', 'medium', 'high'] as VoicePublishQuality[]).map((quality) => (
          <MenuItem
            key={quality}
            role="menuitemradio"
            selected={videoQuality === quality}
            data-testid={`voice-publish-quality-${quality}`}
            onClick={() => {
              setQualityMenuOpen(false);
              onVideoQuality(quality);
            }}
          >
            {t(`voice.publishQuality.level.${quality}`)}
          </MenuItem>
        ))}
      </Menu>

      {soundboard}
      <VoiceControlButton glyph="⏻" label={t('voice.disconnect')} active onClick={onLeave} />
    </div>
  );
}

/** Кнопка управления голосом: иконка с состоянием и подписью. */
function VoiceControlButton({
  glyph,
  label,
  active,
  disabled = false,
  disabledReason,
  onClick,
}: {
  glyph: string;
  label: string;
  active: boolean;
  disabled?: boolean;
  disabledReason?: string;
  onClick: () => void;
}) {
  const title = disabled && disabledReason !== undefined ? disabledReason : label;
  return (
    <button
      type="button"
      aria-pressed={active}
      aria-label={title}
      title={title}
      disabled={disabled}
      onClick={onClick}
      className={`rounded-[var(--radius-md)] border px-3 py-1.5 text-base leading-none transition-[color,background-color,transform] duration-[var(--duration-fast)] active:scale-95 disabled:cursor-not-allowed disabled:opacity-50 ${
        active
          ? 'border-border/60 bg-surface-2 text-fg'
          : 'border-danger/60 bg-danger/10 text-danger'
      }`}
    >
      <span aria-hidden="true">{glyph}</span>
    </button>
  );
}

/**
 * Панель голосовой комнаты в области контента: крупные плитки участников,
 * управление своей сессией и модерация при наличии прав (AGENT.md 7.14).
 */
export function VoiceRoomPanel({ guildId, channel }: { guildId: string; channel: Channel }) {
  const { t } = useTranslation();
  const voiceEnabled = useVoiceEnabled();
  const describeError = useApiErrorMessage();
  useGuildVoiceStates(guildId);

  const occupants = useVoiceOccupants(guildId, channel.id);
  const permissions = useVoiceModeration(guildId);
  const canUseSoundboard = useCanUseSoundboard(guildId);
  const moveTargets = useVoiceChannels(guildId).filter((item) => item.id !== channel.id);
  const screenPreset = useVoiceStore((state) => state.screenSharePreset);
  const setScreenSharePreset = useVoiceStore((state) => state.setScreenSharePreset);
  const videoQuality = useVoiceStore((state) => state.videoQuality);
  const status = useVoiceConnectionStore((state) => state.status);
  const activeChannelId = useVoiceConnectionStore((state) => state.channelId);
  const error = useVoiceConnectionStore((state) => state.error);
  const micEnabled = useVoiceConnectionStore((state) => state.micEnabled);
  const cameraEnabled = useVoiceConnectionStore((state) => state.cameraEnabled);
  const screenEnabled = useVoiceConnectionStore((state) => state.screenEnabled);
  const deafened = useVoiceConnectionStore((state) => state.deafened);
  const serverMuted = useVoiceConnectionStore((state) => state.serverMuted);
  const serverDeafened = useVoiceConnectionStore((state) => state.serverDeafened);
  const refreshing = useVoiceConnectionStore((state) => state.refreshing);
  const join = useVoiceConnectionStore((state) => state.join);
  const leave = useVoiceConnectionStore((state) => state.leave);
  const setMicEnabled = useVoiceConnectionStore((state) => state.setMicEnabled);
  const setDeafened = useVoiceConnectionStore((state) => state.setDeafened);
  const setCameraEnabled = useVoiceConnectionStore((state) => state.setCameraEnabled);
  const setScreenShareEnabled = useVoiceConnectionStore((state) => state.setScreenShareEnabled);
  const setVideoQuality = useVoiceConnectionStore((state) => state.setVideoQuality);
  const setParticipantMuted = useVoiceConnectionStore((state) => state.setParticipantMuted);
  const setParticipantDeafened = useVoiceConnectionStore((state) => state.setParticipantDeafened);
  const moveParticipant = useVoiceConnectionStore((state) => state.moveParticipant);

  const here = activeChannelId === channel.id;
  const connecting = here && status === 'connecting';
  const inRoom = here && (status === 'connected' || status === 'reconnecting');
  const failed = here && status === 'error';

  const onMute = useCallback(
    (userId: string, muted: boolean) => void setParticipantMuted(guildId, userId, muted),
    [guildId, setParticipantMuted],
  );
  const onDeafen = useCallback(
    (userId: string, deafenedNext: boolean) =>
      void setParticipantDeafened(guildId, userId, deafenedNext),
    [guildId, setParticipantDeafened],
  );
  const onMove = useCallback(
    (userId: string, targetId: string) => void moveParticipant(guildId, userId, targetId),
    [guildId, moveParticipant],
  );

  if (!voiceEnabled) {
    return (
      <div className="flex flex-1 items-center justify-center p-6">
        <Card className="max-w-md text-center" data-testid="voice-disabled">
          <h3 className="text-lg font-semibold">{t('voice.title')}</h3>
          <p className="mt-2 text-sm text-fg-muted">{t('voice.disabled')}</p>
        </Card>
      </div>
    );
  }

  return (
    <div className="flex flex-1 flex-col gap-4 overflow-y-auto p-4">
      <div className="flex flex-wrap items-center gap-2">
        {inRoom ? (
          <p role="status" className="text-xs text-fg-muted">
            {t(refreshing ? 'voice.refreshing' : 'voice.connected')}
          </p>
        ) : (
          <>
            <Button
              disabled={connecting}
              onClick={() => void join(guildId, channel.id)}
              data-testid="voice-join"
            >
              {t(connecting ? 'voice.joining' : 'voice.join')}
            </Button>
            {connecting ? (
              <p role="status" className="text-xs text-fg-muted">
                {t('voice.joining')}
              </p>
            ) : null}
          </>
        )}
      </div>

      {failed ? (
        <p role="alert" className="text-sm text-danger">
          {describeError(error)}
        </p>
      ) : null}

      {occupants.length === 0 ? (
        <p className="text-sm text-fg-muted">{t('voice.empty')}</p>
      ) : (
        <div className="grid grid-cols-[repeat(auto-fill,minmax(11rem,1fr))] gap-3">
          {occupants.map((occupant) => (
            <VoiceTile
              key={occupant.userId}
              occupant={occupant}
              permissions={permissions}
              moveTargets={moveTargets}
              onMute={onMute}
              onDeafen={onDeafen}
              onMove={onMove}
            >
              {occupant.isLocal && inRoom ? (
                <VoiceControlsRow
                  micEnabled={micEnabled}
                  deafened={deafened}
                  cameraEnabled={cameraEnabled}
                  screenEnabled={screenEnabled}
                  serverMuted={serverMuted}
                  serverDeafened={serverDeafened}
                  screenPreset={screenPreset}
                  videoQuality={videoQuality}
                  soundboard={
                    canUseSoundboard ? <VoiceSoundboard guildId={guildId} disabled={false} /> : null
                  }
                  onMic={() => void setMicEnabled(!micEnabled)}
                  onSound={() => void setDeafened(!deafened)}
                  onCamera={() => void setCameraEnabled(!cameraEnabled)}
                  onScreen={(preset) => {
                    if (preset === null) {
                      void setScreenShareEnabled(false);
                      return;
                    }
                    // Пресет сохраняем до публикации: стор читает его при старте.
                    setScreenSharePreset(preset);
                    void setScreenShareEnabled(true);
                  }}
                  onVideoQuality={(quality) => void setVideoQuality(quality)}
                  onLeave={() => void leave()}
                />
              ) : null}
            </VoiceTile>
          ))}
        </div>
      )}
    </div>
  );
}