"use client";

import { useRef, useCallback, useEffect, useState } from "react";
import { useAudioPlayer } from "./audio-context";
import { AudioWaveAnimation } from "./audio-wave";
import { cn } from "@/lib/utils";
import Link from "next/link";
import Image from "next/image";
import { motion, AnimatePresence } from "framer-motion";
import {
  Play,
  Pause,
  SkipBack,
  SkipForward,
  Volume2,
  VolumeX,
  Volume1,
  X,
  ExternalLink,
  Loader2,
} from "lucide-react";

// ---------------------------------------------------------------------------
// Mobile auto-minimize hook
// ---------------------------------------------------------------------------

const MINIMIZE_DELAY = 8000;

function useIsMobile() {
  const [mobile, setMobile] = useState(false);
  useEffect(() => {
    const mq = window.matchMedia("(max-width: 767px)");
    setMobile(mq.matches);
    const handler = (e: MediaQueryListEvent) => setMobile(e.matches);
    mq.addEventListener("change", handler);
    return () => mq.removeEventListener("change", handler);
  }, []);
  return mobile;
}

/**
 * Returns [minimized, setMinimized, resetTimer].
 * Auto-minimizes after `MINIMIZE_DELAY` ms of inactivity on mobile.
 * Call `resetTimer()` on any user interaction to restart the countdown.
 */
function useAutoMinimize(hasTrack: boolean) {
  const [minimized, setMinimized] = useState(false);
  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);

  const clearTimer = useCallback(() => {
    if (timerRef.current) {
      clearTimeout(timerRef.current);
      timerRef.current = null;
    }
  }, []);

  const startTimer = useCallback(() => {
    clearTimer();
    timerRef.current = setTimeout(() => setMinimized(true), MINIMIZE_DELAY);
  }, [clearTimer]);

  const resetTimer = useCallback(() => {
    setMinimized(false);
    startTimer();
  }, [startTimer]);

  // Start timer when track begins
  useEffect(() => {
    if (hasTrack) {
      startTimer();
    } else {
      clearTimer();
      setMinimized(false);
    }
    return clearTimer;
  }, [hasTrack, startTimer, clearTimer]);

  return { minimized, setMinimized, resetTimer } as const;
}

// ---------------------------------------------------------------------------
// Constants
// ---------------------------------------------------------------------------

const FALLBACK_COVER = "/images/cover.png";

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

function formatTime(seconds: number): string {
  if (!isFinite(seconds) || seconds < 0) return "0:00";
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  const s = Math.floor(seconds % 60);
  if (h > 0)
    return `${h}:${String(m).padStart(2, "0")}:${String(s).padStart(2, "0")}`;
  return `${m}:${String(s).padStart(2, "0")}`;
}

function VolumeIcon({
  volume,
  isMuted,
  className,
}: {
  volume: number;
  isMuted: boolean;
  className?: string;
}) {
  if (isMuted || volume === 0) return <VolumeX className={className} />;
  if (volume < 0.5) return <Volume1 className={className} />;
  return <Volume2 className={className} />;
}

// ---------------------------------------------------------------------------
// Progress Bar
// ---------------------------------------------------------------------------

function ProgressBar({
  currentTime,
  duration,
  onSeek,
  thin = false,
}: {
  currentTime: number;
  duration: number;
  onSeek: (time: number) => void;
  thin?: boolean;
}) {
  const barRef = useRef<HTMLDivElement>(null);
  const draggingRef = useRef(false);

  const progress = duration > 0 ? (currentTime / duration) * 100 : 0;

  const calculateSeekTime = useCallback(
    (clientX: number) => {
      const bar = barRef.current;
      if (!bar || duration <= 0) return;
      const rect = bar.getBoundingClientRect();
      const fraction = Math.max(
        0,
        Math.min(1, (clientX - rect.left) / rect.width),
      );
      onSeek(fraction * duration);
    },
    [duration, onSeek],
  );

  const handlePointerDown = useCallback(
    (e: React.PointerEvent) => {
      e.preventDefault();
      draggingRef.current = true;
      (e.target as HTMLElement).setPointerCapture(e.pointerId);
      calculateSeekTime(e.clientX);
    },
    [calculateSeekTime],
  );

  const handlePointerMove = useCallback(
    (e: React.PointerEvent) => {
      if (!draggingRef.current) return;
      calculateSeekTime(e.clientX);
    },
    [calculateSeekTime],
  );

  const handlePointerUp = useCallback(() => {
    draggingRef.current = false;
  }, []);

  if (thin) {
    return (
      <div
        ref={barRef}
        className="w-full h-2 bg-white/15 cursor-pointer shrink-0 relative"
        onPointerDown={handlePointerDown}
        onPointerMove={handlePointerMove}
        onPointerUp={handlePointerUp}
        role="slider"
        aria-label="Playback progress"
        aria-valuemin={0}
        aria-valuemax={duration || 0}
        aria-valuenow={currentTime}
        tabIndex={0}
      >
        <div
          className="h-full bg-primary transition-[width] duration-100 ease-linear"
          style={{ width: `${progress}%` }}
        />
      </div>
    );
  }

  return (
    <div className="flex items-center gap-2 w-full">
      <span className="text-[10px] tabular-nums text-muted-foreground min-w-[32px] text-right select-none">
        {formatTime(currentTime)}
      </span>
      <div
        ref={barRef}
        className="relative flex-1 h-1 bg-muted rounded-full cursor-pointer group/progress"
        onPointerDown={handlePointerDown}
        onPointerMove={handlePointerMove}
        onPointerUp={handlePointerUp}
        role="slider"
        aria-label="Playback progress"
        aria-valuemin={0}
        aria-valuemax={duration || 0}
        aria-valuenow={currentTime}
        tabIndex={0}
      >
        <div
          className="h-full bg-primary rounded-full transition-[width] duration-100 ease-linear"
          style={{ width: `${progress}%` }}
        />
        <div
          className="absolute top-1/2 -translate-y-1/2 -translate-x-1/2 size-2.5 bg-primary rounded-full opacity-0 group-hover/progress:opacity-100 transition-opacity shadow-sm pointer-events-none"
          style={{ left: `${progress}%` }}
        />
      </div>
      <span className="text-[10px] tabular-nums text-muted-foreground min-w-[32px] select-none">
        {formatTime(duration)}
      </span>
    </div>
  );
}

// ---------------------------------------------------------------------------
// Transport Button
// ---------------------------------------------------------------------------

function TransportButton({
  onClick,
  disabled = false,
  label,
  size = "default",
  children,
  className,
}: {
  onClick: () => void;
  disabled?: boolean;
  label: string;
  size?: "default" | "large";
  children: React.ReactNode;
  className?: string;
}) {
  return (
    <button
      type="button"
      onClick={onClick}
      disabled={disabled}
      aria-label={label}
      className={cn(
        "inline-flex items-center justify-center rounded-full transition-colors outline-none",
        "focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-card",
        "disabled:opacity-30 disabled:pointer-events-none",
        size === "large"
          ? "size-9 bg-foreground text-background hover:bg-foreground/90"
          : "size-8 text-foreground hover:bg-muted",
        className,
      )}
    >
      {children}
    </button>
  );
}

// ---------------------------------------------------------------------------
// Floating Player
// ---------------------------------------------------------------------------

export function FloatingPlayer() {
  const {
    currentTrack,
    isPlaying,
    currentTime,
    duration,
    volume,
    isMuted,
    isLoading,
    playlist,
    currentIndex,
    togglePlayPause,
    stop,
    seekTo,
    setVolume,
    toggleMute,
    next,
    previous,
  } = useAudioPlayer();

  const playerRef = useRef<HTMLDivElement>(null);
  const [selectionToolbarVisible, setSelectionToolbarVisible] = useState(false);
  const isMobile = useIsMobile();
  const { minimized, setMinimized, resetTimer } =
    useAutoMinimize(!!currentTrack);

  // Watch for the selection toolbar appearing/disappearing in the DOM
  useEffect(() => {
    if (!currentTrack) return;

    const check = () => {
      const toolbar = document.querySelector("[data-selection-toolbar]");
      // The toolbar wrapper is always present; check if it has visible children
      setSelectionToolbarVisible(!!toolbar && toolbar.childElementCount > 0);
    };

    check();

    const observer = new MutationObserver(check);
    observer.observe(document.body, { childList: true, subtree: true });

    return () => observer.disconnect();
  }, [currentTrack]);

  // Add bottom padding to body when player is visible
  useEffect(() => {
    if (!currentTrack) return;
    document.body.style.paddingBottom = "96px";
    return () => {
      document.body.style.paddingBottom = "";
    };
  }, [currentTrack]);

  // Wrap interactions to reset the minimize timer
  const interact = useCallback(
    <T extends unknown[]>(fn: (...args: T) => void) =>
      (...args: T) => {
        resetTimer();
        fn(...args);
      },
    [resetTimer],
  );

  const iTogglePlayPause = interact(togglePlayPause);
  const iSeekTo = interact(seekTo);
  const iSetVolume = interact(setVolume);
  const iToggleMute = interact(toggleMute);
  const iNext = interact(next);
  const iPrevious = interact(previous);
  const iStop = interact(stop);

  // Minimize when clicking/tapping outside the player
  useEffect(() => {
    if (!currentTrack || minimized) return;

    function handleOutsideClick(e: PointerEvent) {
      const player = playerRef.current;
      if (!player) return;
      if (player.contains(e.target as Node)) return;
      setMinimized(true);
    }

    document.addEventListener("pointerdown", handleOutsideClick);
    return () =>
      document.removeEventListener("pointerdown", handleOutsideClick);
  }, [currentTrack, minimized, setMinimized]);

  // Keyboard shortcuts when player is focused
  const handleKeyDown = useCallback(
    (e: React.KeyboardEvent) => {
      switch (e.key) {
        case " ":
          e.preventDefault();
          iTogglePlayPause();
          break;
        case "ArrowLeft":
          e.preventDefault();
          iSeekTo(Math.max(0, currentTime - 10));
          break;
        case "ArrowRight":
          e.preventDefault();
          iSeekTo(Math.min(duration, currentTime + 10));
          break;
        case "ArrowUp":
          e.preventDefault();
          iSetVolume(Math.min(1, volume + 0.05));
          break;
        case "ArrowDown":
          e.preventDefault();
          iSetVolume(Math.max(0, volume - 0.05));
          break;
        case "m":
        case "M":
          e.preventDefault();
          iToggleMute();
          break;
        case "Escape":
          e.preventDefault();
          iStop();
          break;
      }
    },
    [
      iTogglePlayPause,
      iSeekTo,
      iSetVolume,
      iToggleMute,
      iStop,
      currentTime,
      duration,
      volume,
    ],
  );

  if (!currentTrack) return null;

  const hasNext = currentIndex >= 0 && currentIndex < playlist.length - 1;
  const hasPrev = currentIndex > 0;
  const coverSrc = currentTrack.coverImage || FALLBACK_COVER;
  const progress = duration > 0 ? (currentTime / duration) * 100 : 0;

  // ── Hide entirely when selection toolbar is active ──
  if (selectionToolbarVisible) return null;

  // ── Render ──
  return (
    <AnimatePresence mode="popLayout">
      {minimized ? (
        <motion.button
          key="mini-pill"
          data-audio-player
          type="button"
          onClick={() => {
            setMinimized(false);
            resetTimer();
          }}
          aria-label="Expand audio player"
          initial={{ opacity: 0, scale: 0.5, bottom: -60 }}
          animate={{
            opacity: 1,
            scale: 1,
            bottom: selectionToolbarVisible ? 90 : 24,
          }}
          exit={{ opacity: 0, scale: 0.5, bottom: -60 }}
          transition={{ type: "spring", damping: 20, stiffness: 400 }}
          className={cn(
            "fixed z-40 right-4",
            "size-14 rounded-full",
            "shadow-2xl shadow-black/30",
            "overflow-hidden",
            "ring-2 ring-white/20",
          )}
        >
          {/* Cover image */}
          <Image
            src={coverSrc}
            alt=""
            fill
            className="object-cover"
            unoptimized
          />
          {/* Dark overlay */}
          <div className="absolute inset-0 bg-black/40" />
          {/* Circular progress ring */}
          <svg
            className="absolute inset-0 size-full -rotate-90"
            viewBox="0 0 56 56"
          >
            <circle
              cx="28"
              cy="28"
              r="26"
              fill="none"
              stroke="white"
              strokeOpacity={0.15}
              strokeWidth="2"
            />
            <circle
              cx="28"
              cy="28"
              r="26"
              fill="none"
              stroke="white"
              strokeOpacity={0.8}
              strokeWidth="2"
              strokeDasharray={2 * Math.PI * 26}
              strokeDashoffset={2 * Math.PI * 26 * (1 - progress / 100)}
              strokeLinecap="round"
              className="transition-[stroke-dashoffset] duration-300"
            />
          </svg>
          {/* Audio wave indicator */}
          <div className="absolute inset-0 flex items-center justify-center">
            <AudioWaveAnimation
              paused={!isPlaying}
              colorClassName="bg-white/90"
            />
          </div>
        </motion.button>
      ) : (
        <motion.div
          key="full-player"
          ref={playerRef}
          data-audio-player
          role="region"
          aria-label="Audio player"
          tabIndex={0}
          onKeyDown={handleKeyDown}
          initial={{ opacity: 0, bottom: -80 }}
          animate={{
            opacity: 1,
            bottom: selectionToolbarVisible ? 64 : 20,
          }}
          exit={{ opacity: 0, bottom: -80 }}
          transition={{ type: "spring", damping: 25, stiffness: 300 }}
          className={cn(
            // Centered floating bar
            "fixed z-40 left-1/2 -translate-x-1/2",
            // Narrower width
            "w-[calc(100%-2rem)] max-w-[680px]",
            // Forced dark surface for contrast regardless of theme
            "bg-[#1c1c1e] text-white",
            "border border-white/10",
            "rounded-2xl",
            "shadow-2xl shadow-black/25",
            // Clip seeker to rounded top corners
            "overflow-hidden",
          )}
        >
          {/* Thin progress bar — absolutely positioned at top edge */}
          <ProgressBar
            currentTime={currentTime}
            duration={duration}
            onSeek={iSeekTo}
            thin
          />

          {/* Time row — desktop (hidden on mobile, mobile has its own) */}
          <div className="hidden md:flex items-center justify-between px-5 pt-1.5">
            <span className="text-[10px] tabular-nums text-white/40 select-none">
              {formatTime(currentTime)}
            </span>
            <span className="text-[10px] tabular-nums text-white/40 select-none">
              {formatTime(duration)}
            </span>
          </div>

          {/* ── Desktop layout ── */}
          <div className="hidden md:flex items-center h-[64px] px-5 gap-5">
            {/* Left: Cover + Track info */}
            <div className="flex items-center gap-3 min-w-0 flex-1">
              {/* Cover image */}
              <div className="size-12 rounded-lg overflow-hidden bg-muted shrink-0 relative">
                <Image
                  src={coverSrc}
                  alt=""
                  fill
                  className="object-cover"
                  unoptimized
                />
              </div>
              <div className="min-w-0">
                <p className="text-sm font-medium text-white truncate leading-tight">
                  {currentTrack.title}
                </p>
                {currentTrack.subtitle && (
                  <p className="text-[11px] text-white/50 truncate leading-tight mt-0.5">
                    {currentTrack.subtitle}
                  </p>
                )}
              </div>
            </div>

            {/* Center: Transport controls */}
            <div className="flex items-center gap-1.5">
              <TransportButton
                onClick={iPrevious}
                disabled={!hasPrev && currentTime <= 3}
                label="Previous track"
                className="text-white/60 hover:text-white hover:bg-white/10"
              >
                <SkipBack className="size-4" />
              </TransportButton>

              <TransportButton
                onClick={iTogglePlayPause}
                label={isPlaying ? "Pause" : "Play"}
                size="large"
                className="bg-white text-black hover:bg-white/90"
              >
                {isLoading ? (
                  <Loader2 className="size-4 animate-spin" />
                ) : isPlaying ? (
                  <Pause className="size-4" />
                ) : (
                  <Play className="size-4 ml-0.5" />
                )}
              </TransportButton>

              <TransportButton
                onClick={iNext}
                disabled={!hasNext}
                label="Next track"
                className="text-white/60 hover:text-white hover:bg-white/10"
              >
                <SkipForward className="size-4" />
              </TransportButton>
            </div>

            {/* Right: Volume + Source link + Close */}
            <div className="flex items-center gap-1.5 shrink-0">
              {/* Volume control */}
              <div className="flex items-center gap-1">
                <button
                  type="button"
                  onClick={iToggleMute}
                  aria-label={isMuted ? "Unmute" : "Mute"}
                  className="size-7 inline-flex items-center justify-center rounded-md text-white/50 hover:text-white hover:bg-white/10 transition-colors outline-none focus-visible:ring-2 focus-visible:ring-ring"
                >
                  <VolumeIcon
                    volume={volume}
                    isMuted={isMuted}
                    className="size-4"
                  />
                </button>
                <input
                  type="range"
                  min={0}
                  max={100}
                  step={1}
                  value={isMuted ? 0 : Math.round(volume * 100)}
                  onChange={(e) => iSetVolume(Number(e.target.value) / 100)}
                  aria-label="Volume"
                  className={cn(
                    "w-16 h-1 appearance-none bg-white/15 rounded-full cursor-pointer",
                    "[&::-webkit-slider-thumb]:appearance-none",
                    "[&::-webkit-slider-thumb]:size-3",
                    "[&::-webkit-slider-thumb]:rounded-full",
                    "[&::-webkit-slider-thumb]:bg-white",
                    "[&::-webkit-slider-thumb]:cursor-pointer",
                    "[&::-moz-range-thumb]:size-3",
                    "[&::-moz-range-thumb]:rounded-full",
                    "[&::-moz-range-thumb]:bg-white",
                    "[&::-moz-range-thumb]:border-0",
                    "[&::-moz-range-thumb]:cursor-pointer",
                  )}
                />
              </div>

              {/* Source link */}
              {currentTrack.sourceUrl && (
                <Link
                  href={currentTrack.sourceUrl}
                  aria-label="Go to source page"
                  className="size-7 inline-flex items-center justify-center rounded-md text-white/50 hover:text-white hover:bg-white/10 transition-colors"
                >
                  <ExternalLink className="size-3.5" />
                </Link>
              )}

              {/* Minimize (playing) or Close (paused) */}
              <button
                type="button"
                onClick={isPlaying ? () => setMinimized(true) : iStop}
                aria-label={isPlaying ? "Minimize player" : "Close player"}
                className="size-7 inline-flex items-center justify-center rounded-md text-white/50 hover:text-white hover:bg-white/10 transition-colors outline-none focus-visible:ring-2 focus-visible:ring-ring"
              >
                <X className="size-4" />
              </button>
            </div>
          </div>

          {/* ── Mobile layout ── */}
          <div
            className="flex md:hidden flex-col px-4 py-3 gap-2.5"
            onPointerDown={resetTimer}
          >
            {/* Time row — right below seeker */}
            <div className="flex items-center justify-between px-0.5">
              <span className="text-[10px] tabular-nums text-white/40 select-none">
                {formatTime(currentTime)}
              </span>
              <span className="text-[10px] tabular-nums text-white/40 select-none">
                {formatTime(duration)}
              </span>
            </div>

            {/* Row 1: Cover + Title + Source + Close */}
            <div className="flex items-center gap-3">
              {/* Cover image */}
              <div className="size-10 rounded-lg overflow-hidden bg-muted shrink-0 relative">
                <Image
                  src={coverSrc}
                  alt=""
                  fill
                  className="object-cover"
                  unoptimized
                />
              </div>

              {/* Track info */}
              <div className="flex-1 min-w-0">
                <p className="text-sm font-medium text-white truncate leading-tight">
                  {currentTrack.title}
                </p>
                {currentTrack.subtitle && (
                  <p className="text-[11px] text-white/50 truncate leading-tight mt-0.5">
                    {currentTrack.subtitle}
                  </p>
                )}
              </div>

              {/* Source link */}
              {currentTrack.sourceUrl && (
                <Link
                  href={currentTrack.sourceUrl}
                  aria-label="Go to source page"
                  className="size-8 inline-flex items-center justify-center rounded-full text-white/50 hover:text-white hover:bg-white/10 transition-colors shrink-0"
                >
                  <ExternalLink className="size-4" />
                </Link>
              )}

              {/* Minimize (playing) or Close (paused) */}
              <button
                type="button"
                onClick={isPlaying ? () => setMinimized(true) : iStop}
                aria-label={isPlaying ? "Minimize player" : "Close player"}
                className="size-8 inline-flex items-center justify-center rounded-full text-white/50 hover:text-white hover:bg-white/10 transition-colors outline-none focus-visible:ring-2 focus-visible:ring-ring shrink-0"
              >
                <X className="size-4" />
              </button>
            </div>

            {/* Row 2: Prev + Play/Pause + Next — centered */}
            <div className="flex items-center justify-center gap-4 py-1">
              <TransportButton
                onClick={iPrevious}
                disabled={!hasPrev && currentTime <= 3}
                label="Previous track"
                className="text-white/60 hover:text-white hover:bg-white/10 !size-10"
              >
                <SkipBack className="size-5" />
              </TransportButton>

              <TransportButton
                onClick={iTogglePlayPause}
                label={isPlaying ? "Pause" : "Play"}
                size="large"
                className="bg-white text-black hover:bg-white/90 !size-12"
              >
                {isLoading ? (
                  <Loader2 className="size-5 animate-spin" />
                ) : isPlaying ? (
                  <Pause className="size-5" />
                ) : (
                  <Play className="size-5 ml-0.5" />
                )}
              </TransportButton>

              <TransportButton
                onClick={iNext}
                disabled={!hasNext}
                label="Next track"
                className="text-white/60 hover:text-white hover:bg-white/10 !size-10"
              >
                <SkipForward className="size-5" />
              </TransportButton>
            </div>
          </div>
        </motion.div>
      )}
    </AnimatePresence>
  );
}