import { useEffect, useRef } from 'react';

import { CrownIcon, HeadphonesOffIcon, LockIcon, MicOffIcon } from './icons';

export type AvatarColorKey = 'violet' | 'amber' | 'rose' | 'teal';

const AVATAR_COLORS: Record<AvatarColorKey, { bg: string; fg: string }> = {
  // Tailwind classes tuned per spec: violet/amber/rose/teal swatches in both
  // light and dark modes. Dark pairs invert to keep contrast readable.
  violet: {
    bg: 'bg-violet-200 dark:bg-violet-900/60',
    fg: 'text-violet-800 dark:text-violet-200',
  },
  amber: {
    bg: 'bg-amber-200 dark:bg-amber-900/60',
    fg: 'text-amber-900 dark:text-amber-200',
  },
  rose: {
    bg: 'bg-rose-200 dark:bg-rose-900/60',
    fg: 'text-rose-900 dark:text-rose-200',
  },
  teal: {
    bg: 'bg-teal-200 dark:bg-teal-900/60',
    fg: 'text-teal-900 dark:text-teal-200',
  },
};

const COLOR_KEYS: AvatarColorKey[] = ['violet', 'amber', 'rose', 'teal'];

// Stable per-user color from identity string — keeps avatars visually
// consistent across re-mounts without needing a color field on the profile.
export function colorKeyFor(id: string): AvatarColorKey {
  let hash = 0;
  for (let i = 0; i < id.length; i++) {
    hash = (hash * 31 + id.charCodeAt(i)) >>> 0;
  }
  return COLOR_KEYS[hash % COLOR_KEYS.length]!;
}

export interface ParticipantTileProps {
  userId: string;
  displayName: string;
  avatarUrl: string | null;
  me: boolean;
  muted: boolean;
  /** Local-only: true when THIS user has muted everyone else via the deafen
   *  toggle. Remote deafen state is not propagated, so only the own tile
   *  ever carries a truthy value. */
  deafened: boolean;
  speaking: boolean;
  video: boolean;
  e2ee: boolean;
  /** MediaStreamTrack for the participant's active camera, when `video` is
   *  true. When null the tile falls back to the avatar placeholder. */
  videoTrack?: MediaStreamTrack | null;
  size?: 'default' | 'small';
  focused?: boolean;
  onClick?: () => void;
  onContextMenu?: (e: React.MouseEvent) => void;
}

export function CallParticipantTile(props: ParticipantTileProps) {
  const {
    displayName,
    me,
    muted,
    deafened,
    speaking,
    video,
    e2ee,
    size = 'default',
    focused = false,
    onClick,
    onContextMenu,
  } = props;

  const small = size === 'small';
  // Split the speaking indicator per-mode so we don't stack a tile border
  // + inset glow on top of the avatar pulse (visual double-chrome). Video
  // tiles get the border (the avatar is hidden behind the stream so the
  // pulse wouldn't be visible anyway); audio tiles rely on the avatar
  // pulse rendered inside AudioContent.
  const videoSpeaking = speaking && video;
  const borderClass = videoSpeaking
    ? 'border-emerald-500 shadow-[0_0_0_2px_rgba(22,163,74,0.25)] dark:border-emerald-400'
    : focused
      ? 'border-accent'
      : 'border-line hover:border-accent';

  return (
    <div
      onClick={onClick}
      onContextMenu={onContextMenu}
      className={
        'relative flex flex-col overflow-hidden rounded-[14px] border bg-surface-3 transition ' +
        (onClick ? 'cursor-pointer ' : '') +
        borderClass +
        (small ? ' min-w-[140px]' : '')
      }
    >
      {video ? (
        <VideoStub {...props} small={small} />
      ) : (
        <AudioContent {...props} small={small} />
      )}

      {/* Video-only speaking indicator. Audio tiles use the avatar pulse
          from AudioContent so we don't double-render chrome. z-10 keeps
          it above the video element. */}
      {videoSpeaking && (
        <span
          aria-hidden="true"
          className="pointer-events-none absolute inset-0 z-10 rounded-[14px] border-[3px] border-emerald-400 shadow-[inset_0_0_18px_rgba(34,197,94,0.55)]"
        />
      )}

      <div className="pointer-events-none absolute inset-x-2 bottom-2 flex items-center justify-between gap-2 rounded-lg glass-chip px-2.5 py-1.5">
        <div className="flex min-w-0 items-center gap-1.5 text-xs font-semibold">
          {me && <CrownIcon className="h-3 w-3 shrink-0 text-amber-300" />}
          <span className="truncate">
            {displayName}
            {me ? ' (du)' : ''}
          </span>
          {e2ee && (
            <span
              aria-label="E2E verschlüsselt"
              title="E2E verschlüsselt"
              className="flex opacity-70"
            >
              <LockIcon className="h-3 w-3" />
            </span>
          )}
        </div>
        <div className="flex shrink-0 items-center gap-1">
          {muted && (
            <span
              aria-label="Mikro stumm"
              title="Mikro stumm"
              className="flex h-5 w-5 items-center justify-center rounded-md bg-rose-500/80 text-white"
            >
              <MicOffIcon className="h-3 w-3" />
            </span>
          )}
          {deafened && (
            <span
              aria-label="Ton aus"
              title="Ton aus"
              className="flex h-5 w-5 items-center justify-center rounded-md bg-rose-500/80 text-white"
            >
              <HeadphonesOffIcon className="h-3 w-3" />
            </span>
          )}
        </div>
      </div>
    </div>
  );
}

function AudioContent({
  userId,
  displayName,
  avatarUrl,
  speaking,
  small,
}: ParticipantTileProps & { small: boolean }) {
  const key = colorKeyFor(userId);
  const colors = AVATAR_COLORS[key];
  const letter = displayName.trim().charAt(0).toUpperCase() || '?';
  return (
    <div className="flex min-h-0 flex-1 items-center justify-center p-4">
      <div
        className={
          'relative flex items-center justify-center rounded-full ' +
          (small ? 'h-11 w-11' : 'h-[72px] w-[72px]')
        }
      >
        {speaking && (
          <span
            aria-hidden="true"
            className="absolute -inset-1.5 animate-audio-pulse rounded-full border-2 border-emerald-500 dark:border-emerald-400"
          />
        )}
        {avatarUrl ? (
          <img
            src={avatarUrl}
            alt=""
            className="relative h-full w-full rounded-full object-cover"
          />
        ) : (
          <span
            className={
              'relative flex h-full w-full items-center justify-center rounded-full font-bold ' +
              colors.bg + ' ' + colors.fg + ' ' +
              (small ? 'text-lg' : 'text-2xl')
            }
          >
            {letter}
          </span>
        )}
      </div>
    </div>
  );
}

function VideoStub({
  userId,
  displayName,
  avatarUrl,
  videoTrack,
  me,
  small,
}: ParticipantTileProps & { small: boolean }) {
  const videoRef = useRef<HTMLVideoElement | null>(null);
  useEffect(() => {
    const el = videoRef.current;
    if (!el || !videoTrack) return;
    el.srcObject = new MediaStream([videoTrack]);
    return () => {
      if (el.srcObject) {
        (el.srcObject as MediaStream).getTracks().forEach((t) => {
          // Don't stop the live track — other consumers may still need it.
          // Just detach from this element.
          void t;
        });
        el.srcObject = null;
      }
    };
  }, [videoTrack]);

  if (videoTrack) {
    return (
      <div className="relative flex min-h-0 flex-1 items-center justify-center bg-black">
        <video
          ref={videoRef}
          autoPlay
          playsInline
          muted
          className={
            'h-full w-full object-cover ' +
            (me ? 'scale-x-[-1]' : '') /* mirror local preview */
          }
        />
      </div>
    );
  }

  // Camera flag true but no track yet (publishing / subscribing race).
  const key = colorKeyFor(userId);
  const colors = AVATAR_COLORS[key];
  const letter = displayName.trim().charAt(0).toUpperCase() || '?';
  return (
    <div className="flex min-h-0 flex-1 items-center justify-center bg-gradient-to-br from-accent/20 to-surface-2 p-4">
      <div
        className={
          'flex items-center justify-center rounded-full font-bold ' +
          colors.bg + ' ' + colors.fg + ' ' +
          (small ? 'h-11 w-11 text-lg' : 'h-[72px] w-[72px] text-2xl')
        }
      >
        {avatarUrl ? (
          <img src={avatarUrl} alt="" className="h-full w-full rounded-full object-cover" />
        ) : (
          letter
        )}
      </div>
    </div>
  );
}