import { useEffect, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { useLocation, useNavigate } from 'react-router-dom';

import { useAuth } from '../context/AuthContext';
import { useCall } from '../context/CallContext';
import { useConversationsContext } from '../context/ConversationsContext';
import { useFriendshipsContext } from '../context/FriendshipsContext';
import { ringtone } from '../lib/ringtone';
import { useActiveSpeakers } from '../lib/useActiveSpeakers';
import { Avatar } from './Avatar';
import { AvatarColorKey, colorKeyFor } from './CallParticipantTile';
import { LockIcon, MonitorShareIcon, PhoneIcon, PhoneOffIcon } from './icons';

// Shell-level mount. Responsibilities:
//   - Start/stop ringtones by call-state transition.
//   - Toast-style incoming-call banner for conversations the user isn't in
//     (clicking the toast routes to the docked IncomingCallPanel).
//   - PiP widget when an active call is live but the user is looking at a
//     different route.
//   - Top-center pending-incoming toast for Discord-style second-call ringer.
export function CallUI() {
  const { state, pendingIncoming } = useCall();
  const { profile } = useAuth();
  const dnd = profile?.presenceState === 'dnd';

  useEffect(() => {
    // DND silences only the *incoming* ring — outgoing stays audible because
    // the user initiated that call themselves. The incoming-call panel still
    // appears visually; only the audible ring is suppressed. The pending
    // second-call ringer plays the same incoming sound at the same volume:
    // user explicitly asked for parity with the normal ring.
    if (state.kind === 'outgoing') ringtone.start('outgoing');
    else if (state.kind === 'incoming' && !dnd) ringtone.start('incoming');
    else if (pendingIncoming && !dnd) ringtone.start('incoming');
    else ringtone.stop();
  }, [state.kind, pendingIncoming, dnd]);

  useEffect(() => {
    return () => ringtone.stop();
  }, []);

  return (
    <>
      <IncomingCallToast />
      <PendingIncomingToast />
      <PipCall />
    </>
  );
}

// ---------------------------------------------------------------------------

const TOAST_AVATAR: Record<AvatarColorKey, string> = {
  violet: 'bg-violet-500/90 text-white',
  amber: 'bg-amber-500/90 text-white',
  rose: 'bg-rose-500/90 text-white',
  teal: 'bg-teal-500/90 text-white',
};

function IncomingCallToast() {
  const { t } = useTranslation(['app']);
  const { state, acceptIncoming, rejectIncoming } = useCall();
  const { friendships } = useFriendshipsContext();
  const { conversations } = useConversationsContext();
  const navigate = useNavigate();
  const location = useLocation();

  if (state.kind !== 'incoming') return null;

  // When the user is already looking at the target conversation, the docked
  // IncomingCallPanel handles the UI; hide the toast to avoid double chrome.
  if (location.pathname === '/chats/' + state.conversationId) return null;

  const conv = conversations.find((c) => c.id === state.conversationId) ?? null;
  const callerName =
    conv?.members.find((m) => m.userId === state.fromUserId)?.profile?.displayName ??
    friendships.find((f) => f.peer.userId === state.fromUserId)?.peer.displayName ??
    '?';
  const isGroup = conv?.type === 'group';
  const groupName = isGroup ? (conv?.name ?? t('app:chats.new_group')) : null;
  const title = isGroup ? groupName ?? callerName : callerName;
  const letter = title.trim().charAt(0).toUpperCase() || '?';
  const color = colorKeyFor(state.fromUserId);

  return (
    <div
      role="dialog"
      aria-modal="false"
      aria-label={t('app:call.incoming_title')}
      className="fixed bottom-6 right-6 z-50 w-80 animate-slide-up overflow-hidden rounded-2xl border border-line bg-surface-3 shadow-call-card-dark"
    >
      <button
        type="button"
        onClick={() => navigate('/chats/' + state.conversationId)}
        className="group block w-full cursor-pointer p-5 text-left transition hover:bg-surface-2 focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
      >
        <p className="text-[10px] font-semibold uppercase tracking-[0.12em] text-fg-muted">
          {t('app:call.incoming_title')}
        </p>
        <div className="mt-2 flex items-center gap-3">
          <div
            className={
              'flex h-11 w-11 shrink-0 items-center justify-center rounded-full font-semibold ' +
              TOAST_AVATAR[color]
            }
          >
            {letter}
          </div>
          <div className="min-w-0 flex-1">
            <p className="truncate font-display text-base font-semibold text-fg">{title}</p>
            <p className="flex items-center gap-1.5 truncate text-xs text-fg-muted">
              <LockIcon className="h-3 w-3" />
              <span>
                {isGroup
                  ? t('app:call.incoming_group_from', {
                      name: callerName,
                      defaultValue: callerName + ' ruft Gruppe',
                    })
                  : t('app:call.incoming_from', { name: callerName })}
              </span>
            </p>
          </div>
        </div>
      </button>
      <div className="flex gap-2 px-5 pb-5">
        <button
          type="button"
          onClick={rejectIncoming}
          className="inline-flex flex-1 cursor-pointer items-center justify-center gap-2 rounded-lg border border-rose-500/40 bg-transparent px-3 py-2 text-sm font-semibold text-rose-600 transition hover:bg-rose-500/10 focus:outline-none focus-visible:ring-2 focus-visible:ring-rose-500/40 dark:text-rose-400"
        >
          <PhoneOffIcon className="h-4 w-4" />
          <span>{t('app:call.decline')}</span>
        </button>
        <button
          type="button"
          onClick={() => void acceptIncoming()}
          className="inline-flex flex-1 cursor-pointer items-center justify-center gap-2 rounded-lg bg-emerald-600 px-3 py-2 text-sm font-semibold text-white transition hover:bg-emerald-500 focus:outline-none focus-visible:ring-2 focus-visible:ring-emerald-500/50"
        >
          <PhoneIcon className="h-4 w-4" />
          <span>{t('app:call.accept')}</span>
        </button>
      </div>
    </div>
  );
}

// ---------------------------------------------------------------------------
// Discord-style "second-call" ringer — pops at the top centre while we're
// already in another call. Accepting hangs up the active call (handled in
// CallContext.acceptPendingIncoming) then routes to the new conversation.
// ---------------------------------------------------------------------------

function PendingIncomingToast() {
  const { t } = useTranslation(['app']);
  const { pendingIncoming, acceptPendingIncoming, rejectPendingIncoming } = useCall();
  const { friendships } = useFriendshipsContext();
  const { conversations } = useConversationsContext();
  const navigate = useNavigate();

  if (!pendingIncoming) return null;

  const conv = conversations.find((c) => c.id === pendingIncoming.conversationId) ?? null;
  const callerName =
    conv?.members.find((m) => m.userId === pendingIncoming.fromUserId)?.profile?.displayName ??
    friendships.find((f) => f.peer.userId === pendingIncoming.fromUserId)?.peer.displayName ??
    '?';
  const isGroup = conv?.type === 'group';
  const groupName = isGroup ? (conv?.name ?? t('app:chats.new_group')) : null;
  const title = isGroup ? groupName ?? callerName : callerName;
  const letter = title.trim().charAt(0).toUpperCase() || '?';
  const color = colorKeyFor(pendingIncoming.fromUserId);
  const targetConversationId = pendingIncoming.conversationId;

  return (
    <div
      role="dialog"
      aria-modal="false"
      aria-label={t('app:call.incoming_title')}
      className="pointer-events-none fixed inset-x-0 top-5 z-[70] flex justify-center px-4"
    >
      <div className="pointer-events-auto w-full max-w-[420px] animate-slide-down overflow-hidden rounded-2xl border border-emerald-500/50 bg-surface-3/95 shadow-call-card-dark backdrop-blur-md">
        <div className="flex items-center gap-3 px-5 pt-4">
          <div
            className={
              'flex h-10 w-10 shrink-0 items-center justify-center rounded-full font-semibold ' +
              TOAST_AVATAR[color]
            }
          >
            {letter}
          </div>
          <div className="min-w-0 flex-1">
            <p className="text-[10px] font-semibold uppercase tracking-[0.12em] text-emerald-500 dark:text-emerald-400">
              {t('app:call.incoming_while_busy', {
                defaultValue: 'Anderer Anruf eingehend',
              })}
            </p>
            <p className="mt-0.5 truncate font-display text-base font-semibold text-fg">
              {title}
            </p>
            <p className="truncate text-xs text-fg-muted">
              {isGroup
                ? t('app:call.incoming_group_from', {
                    name: callerName,
                    defaultValue: callerName + ' ruft Gruppe',
                  })
                : t('app:call.incoming_from', { name: callerName })}
            </p>
          </div>
        </div>
        <div className="flex gap-2 px-5 pb-4 pt-3">
          <button
            type="button"
            onClick={rejectPendingIncoming}
            className="inline-flex flex-1 cursor-pointer items-center justify-center gap-2 rounded-lg border border-rose-500/40 bg-transparent px-3 py-2 text-sm font-semibold text-rose-600 transition hover:bg-rose-500/10 focus:outline-none focus-visible:ring-2 focus-visible:ring-rose-500/40 dark:text-rose-400"
          >
            <PhoneOffIcon className="h-4 w-4" />
            <span>{t('app:call.decline')}</span>
          </button>
          <button
            type="button"
            onClick={() => {
              // Route first so the user lands on the new conversation
              // before the connecting state resolves — feels snappier than
              // waiting for the join to complete. acceptPendingIncoming
              // tears down the old call internally.
              navigate('/chats/' + targetConversationId);
              void acceptPendingIncoming();
            }}
            className="inline-flex flex-1 cursor-pointer items-center justify-center gap-2 rounded-lg bg-emerald-600 px-3 py-2 text-sm font-semibold text-white transition hover:bg-emerald-500 focus:outline-none focus-visible:ring-2 focus-visible:ring-emerald-500/50"
          >
            <PhoneIcon className="h-4 w-4" />
            <span>{t('app:call.accept_and_switch', { defaultValue: 'Wechseln & Annehmen' })}</span>
          </button>
        </div>
      </div>
    </div>
  );
}

// ---------------------------------------------------------------------------
// PiP widget — shown when the user has an active call but is browsing
// somewhere else. Clicking expands back to the call's conversation.
// ---------------------------------------------------------------------------

function PipCall() {
  const { t } = useTranslation(['app']);
  const {
    state,
    room,
    remoteParticipants,
    remoteScreenShares,
    hangup,
  } = useCall();
  const navigate = useNavigate();
  const location = useLocation();
  const { conversations } = useConversationsContext();
  const { profile } = useAuth();
  // Active-speakers hook drives the green ring on mini-avatars so the user
  // can spot who's talking from the PiP without expanding back to the call.
  const activeSpeakers = useActiveSpeakers(room);

  const active =
    state.kind === 'connected' ||
    state.kind === 'connecting' ||
    state.kind === 'reconnecting' ||
    state.kind === 'outgoing';
  if (!active) return null;

  // Only render when the user is NOT currently viewing the call's
  // conversation. Inside that conversation the full dock is visible already.
  if (location.pathname === '/chats/' + state.conversationId) return null;

  const conv = conversations.find((c) => c.id === state.conversationId) ?? null;
  const title =
    conv?.type === 'group'
      ? conv?.name ?? t('app:chats.new_group')
      : conv?.peer?.displayName ?? '—';
  const someoneSharing = remoteScreenShares.length > 0;
  // Discord-style mini-grid: collect actual present participants (self +
  // joined remotes), match with profile data from the conversation roster
  // for avatars/displayName. Show up to MAX, plus a "+N" overflow chip.
  const MAX_TILES = 4;
  const myId = profile?.userId ?? null;
  const presentIds: string[] = [];
  if (myId) presentIds.push(myId);
  for (const rp of remoteParticipants) {
    if (rp.identity && !presentIds.includes(rp.identity)) presentIds.push(rp.identity);
  }
  const tileIds = presentIds.slice(0, MAX_TILES);
  const overflow = Math.max(0, presentIds.length - MAX_TILES);
  // Duration ticks while connected or reconnecting (LiveKit holds the room
  // across reconnects, so the timer shouldn't reset on a wobble). Absent
  // on outgoing/connecting where the call hasn't started yet.
  const startedAt =
    state.kind === 'connected' || state.kind === 'reconnecting'
      ? state.startedAt
      : null;

  return (
    <div
      role="dialog"
      aria-label={t('app:call.active_in_conv', { defaultValue: 'Aktiver Anruf' })}
      onClick={() => navigate('/chats/' + state.conversationId)}
      className="fixed bottom-5 right-5 z-40 flex w-[300px] motion-safe:animate-slide-in-call cursor-pointer flex-col gap-2 rounded-[14px] border border-accent bg-surface-3 p-2.5 shadow-pip-call transition hover:-translate-y-0.5"
    >
      <div className="flex items-center gap-2">
        <div className="flex h-7 w-7 shrink-0 items-center justify-center rounded-md bg-surface-2">
          {someoneSharing ? (
            <MonitorShareIcon className="h-4 w-4 text-accent" />
          ) : (
            <PhoneIcon className="h-4 w-4 text-accent" />
          )}
        </div>
        <div className="min-w-0 flex-1">
          <p className="truncate text-[13px] font-semibold text-fg">{title}</p>
          <p className="flex items-center gap-1.5 text-[11px] text-fg-muted">
            <span
              aria-hidden="true"
              className="h-1.5 w-1.5 rounded-full bg-rose-500 motion-safe:animate-live-dot"
            />
            <span className="tabular-nums">
              {startedAt
                ? <PipDuration startedAt={startedAt} />
                : t('app:call.tap_to_open', { defaultValue: 'tippe zum Öffnen' })}
            </span>
          </p>
        </div>
        <button
          type="button"
          onClick={(e) => {
            e.stopPropagation();
            void hangup();
          }}
          aria-label={t('app:call.hangup')}
          className="flex h-8 w-8 shrink-0 cursor-pointer items-center justify-center rounded-full bg-rose-600 text-white transition hover:bg-rose-500 focus:outline-none focus-visible:ring-2 focus-visible:ring-rose-400/60"
        >
          <PhoneOffIcon className="h-4 w-4" />
        </button>
      </div>
      <div className="flex items-center gap-1.5">
        {tileIds.map((id) => {
          const member = conv?.members.find((m) => m.userId === id);
          const isMe = id === myId;
          const name = isMe
            ? profile?.displayName ?? '?'
            : member?.profile?.displayName ?? '?';
          const avatarUrl = isMe
            ? profile?.avatarUrl ?? null
            : member?.profile?.avatarUrl ?? null;
          const speaking = activeSpeakers.has(id);
          return (
            <div
              key={id}
              title={name + (isMe ? ' (du)' : '')}
              className={
                'relative h-8 w-8 shrink-0 overflow-hidden rounded-full ring-2 transition-shadow ' +
                (speaking
                  ? 'ring-emerald-500 shadow-[0_0_0_2px_rgba(34,197,94,0.35)]'
                  : 'ring-line')
              }
            >
              <Avatar url={avatarUrl} displayName={name} className="h-full w-full text-xs" />
            </div>
          );
        })}
        {overflow > 0 && (
          <span className="ml-0.5 inline-flex h-8 min-w-[2rem] items-center justify-center rounded-full bg-surface-2 px-2 text-[11px] font-semibold text-fg-muted">
            +{overflow}
          </span>
        )}
      </div>
    </div>
  );
}

// Live-ticking `mm:ss` / `hh:mm:ss` for the PiP. Duplicated from InCallPanel
// deliberately — the two widgets have different typography + tabular
// contexts, and extracting a shared component would be heavier than the
// 8-line countup it replaces.
function PipDuration({ startedAt }: { startedAt: string }) {
  const [, tick] = useState(0);
  useEffect(() => {
    const id = window.setInterval(() => tick((v) => v + 1), 1000);
    return () => window.clearInterval(id);
  }, []);
  const total = Math.max(
    0,
    Math.floor((Date.now() - new Date(startedAt).getTime()) / 1000),
  );
  const hh = Math.floor(total / 3600);
  const mm = Math.floor((total % 3600) / 60);
  const ss = total % 60;
  const pad = (n: number) => n.toString().padStart(2, '0');
  return <>{hh > 0 ? `${hh}:${pad(mm)}:${pad(ss)}` : `${pad(mm)}:${pad(ss)}`}</>;
}
