import React, { useState } from 'react';
import { useAudio } from '../../../context/AudioContext';
import { Card } from '../../ui/card';
import { Button } from '../../ui/button';
import { EmptyState } from '../../ui/empty-state';
import { SaveQueueAsPlaylistModal } from './SaveQueueAsPlaylistModal';
import {
  createPlaylist,
  addTrack,
} from '../../../features/playlists/services/playlistService';
import {
  Play,
  Pause,
  X,
  GripVertical,
  Trash2,
  Save,
  ListMusic,
} from 'lucide-react';
import { useToast } from '../../../components/feedback/ToastProvider';

export const QueueView: React.FC = () => {
  const {
    queue,
    currentTrack,
    reorderQueue,
    removeFromQueue,
    clearQueue,
    playTrack,
    isPlaying,
    togglePlay,
    autoplay,
    toggleAutoplay,
  } = useAudio();
  const { addToast } = useToast();
  const [showSaveModal, setShowSaveModal] = useState(false);
  const [draggedIndex, setDraggedIndex] = useState<number | null>(null);
  const [dragOverIndex, setDragOverIndex] = useState<number | null>(null);

  const handleDragStart = (e: React.DragEvent, index: number) => {
    setDraggedIndex(index);
    e.dataTransfer.effectAllowed = 'move';
    // Transparent ghost image
    const ghost = document.createElement('div');
    ghost.style.opacity = '0';
    document.body.appendChild(ghost);
    e.dataTransfer.setDragImage(ghost, 0, 0);
    setTimeout(() => document.body.removeChild(ghost), 0);
  };

  const handleDragOver = (e: React.DragEvent, index: number) => {
    e.preventDefault();
    setDragOverIndex(index);
    if (draggedIndex === null || draggedIndex === index) return;
    reorderQueue(draggedIndex, index);
    setDraggedIndex(index);
  };

  const handleDragEnd = () => {
    setDraggedIndex(null);
    setDragOverIndex(null);
  };

  const handleSavePlaylist = async (name: string, isPublic: boolean) => {
    const tracksToSave = [
      ...(currentTrack ? [currentTrack] : []),
      ...queue,
    ];
    if (tracksToSave.length === 0) {
      addToast('Queue is empty', 'error');
      throw new Error('Queue is empty');
    }
    const playlist = await createPlaylist({
      title: name,
      description: '',
      is_public: isPublic,
    });
    for (const track of tracksToSave) {
      await addTrack(playlist.id, String(track.id));
    }
    addToast(`Queue saved as "${name}"`, 'success');
  };

  return (
    <div className="max-w-4xl mx-auto space-y-6 animate-fadeIn pb-20">
      <div className="flex flex-col md:flex-row justify-between items-end border-b border-border/50 pb-6 gap-4">
        <div>
          <h1 className="text-3xl font-heading font-bold text-foreground mb-2">
            PLAY QUEUE
          </h1>
          <p className="text-muted-foreground font-mono text-sm">
            {queue.length} tracks upcoming
          </p>
        </div>
        <div className="flex gap-4">
          <Button
            variant="ghost"
            onClick={() => setShowSaveModal(true)}
            icon={<Save className="w-4 h-4" />}
          >
            Save Queue
          </Button>
          <Button
            variant="ghost"
            className="text-destructive hover:bg-destructive/10"
            onClick={clearQueue}
            icon={<Trash2 className="w-4 h-4" />}
          >
            Clear
          </Button>
        </div>
      </div>

      {/* Current Track */}
      {currentTrack && (
        <div>
          <h3 className="text-xs font-bold text-muted-foreground uppercase tracking-widest mb-3">
            Now Playing
          </h3>
          <Card
            variant="glass"
            className="flex items-center gap-4 p-4 border-l-4 border-l-primary"
          >
            <div
              className="relative w-16 h-16 rounded overflow-hidden flex-shrink-0 group cursor-pointer"
              onClick={togglePlay}
            >
              <img
                src={currentTrack.coverUrl}
                className="w-full h-full object-cover"
              />
              <div className="absolute inset-0 bg-background/40 flex items-center justify-center opacity-0 group-hover:opacity-100 transition-opacity">
                {isPlaying ? (
                  <Pause className="w-6 h-6 text-foreground" />
                ) : (
                  <Play className="w-6 h-6 text-foreground fill-current ml-1" />
                )}
              </div>
              {isPlaying && (
                <div className="absolute bottom-1 right-1 flex gap-0.5 items-end h-3">
                  <div className="w-1 bg-primary animate-[bounce_1s_infinite] h-full"></div>
                  <div className="w-1 bg-primary animate-[bounce_1.2s_infinite] h-2/3"></div>
                  <div className="w-1 bg-primary animate-[bounce_0.8s_infinite] h-full"></div>
                </div>
              )}
            </div>
            <div className="flex-1">
              <h2 className="text-xl font-bold text-foreground">
                {currentTrack.title}
              </h2>
              <p className="text-muted-foreground">{currentTrack.artist}</p>
            </div>
            <div className="text-muted-foreground font-mono text-sm hidden md:block">
              {currentTrack.duration}
            </div>
          </Card>
        </div>
      )}

      {/* Up Next */}
      <div>
        <div className="flex justify-between items-center mb-3">
          <h3 className="text-xs font-bold text-muted-foreground uppercase tracking-widest">
            Up Next
          </h3>
          <div
            className="flex items-center gap-2 cursor-pointer group"
            onClick={toggleAutoplay}
          >
            <span
              className={`text-xs font-bold ${autoplay ? 'text-success' : 'text-muted-foreground'}`}
            >
              Autoplay
            </span>
            <div
              className={`w-8 h-4 rounded-full relative transition-colors ${autoplay ? 'bg-success' : 'bg-muted'}`}
            >
              <div
                className={`absolute top-0.5 w-3 h-3 bg-background rounded-full transition-all ${autoplay ? 'left-4.5' : 'left-0.5'}`}
              ></div>
            </div>
          </div>
        </div>

        <div className="space-y-2">
          {queue.length === 0 ? (
            <EmptyState
              variant="card"
              icon={<ListMusic className="w-full h-full" />}
              title="Nothing in your queue"
              description={
                autoplay
                  ? 'Autoplay is on — we\u2019ll pick something for you.'
                  : 'Start playing music and add tracks to build your queue.'
              }
              size="md"
            />
          ) : (
            queue.map((track, i) => (
              <div
                key={`${track.id}-${i}`}
                draggable
                onDragStart={(e) => handleDragStart(e, i)}
                onDragOver={(e) => handleDragOver(e, i)}
                onDragEnd={handleDragEnd}
                className={`flex items-center gap-4 p-4 bg-card rounded-lg border border-transparent hover:border-border transition-all group ${draggedIndex === i ? 'opacity-50 border-primary shadow-lg scale-[1.02] cursor-grabbing' : ''} ${dragOverIndex === i && draggedIndex !== null && draggedIndex !== i ? 'border-t-2 border-t-primary bg-primary/5' : ''}`}
              >
                <div className="text-muted-foreground cursor-grab active:cursor-grabbing hover:text-foreground p-1">
                  <GripVertical className="w-5 h-5" />
                </div>
                <div className="w-10 h-10 rounded overflow-hidden flex-shrink-0 relative">
                  <img
                    src={track.coverUrl}
                    className="w-full h-full object-cover"
                  />
                  <div
                    className="absolute inset-0 bg-background/50 hidden group-hover:flex items-center justify-center cursor-pointer"
                    onClick={() => playTrack(track)}
                  >
                    <Play className="w-4 h-4 text-foreground fill-current" />
                  </div>
                </div>
                <div className="flex-1 min-w-0">
                  <div className="text-sm font-bold text-foreground truncate">
                    {track.title}
                  </div>
                  <div className="text-xs text-muted-foreground truncate">
                    {track.artist}
                  </div>
                </div>
                <div className="text-muted-foreground font-mono text-xs hidden sm:block">
                  {track.duration}
                </div>
                <button
                  className="p-2 text-muted-foreground hover:text-destructive opacity-0 group-hover:opacity-100 transition-opacity"
                  onClick={() => removeFromQueue(track.id)}
                >
                  <X className="w-4 h-4" />
                </button>
              </div>
            ))
          )}
        </div>
      </div>

      {showSaveModal && (
        <SaveQueueAsPlaylistModal
          onClose={() => setShowSaveModal(false)}
          onSave={handleSavePlaylist}
        />
      )}
    </div>
  );
};