'use client'

import { useState, useRef, useCallback } from 'react'
import { usePartyStore } from '@/store/partyStore'

export default function QueueCard() {
  const { queue, curIdx, setCurIdx, generateMix, reorderQueue } = usePartyStore()
  const [open, setOpen] = useState(false)
  const dragSrcIdx = useRef<number | null>(null)

  const handleQueueClick = (e: React.MouseEvent, idx: number) => {
    if ((e.target as HTMLElement).closest('.drag-handle')) return
    setCurIdx(idx)
  }

  const onDragStart = useCallback((idx: number, el: HTMLElement) => {
    dragSrcIdx.current = idx
    el.classList.add('dragging')
  }, [])

  const onDragEnd = useCallback((el: HTMLElement) => {
    el.classList.remove('dragging')
    document.querySelectorAll('.q-item').forEach((i) => i.classList.remove('drag-over'))
  }, [])

  const onDragOver = useCallback((e: React.DragEvent, el: HTMLElement) => {
    e.preventDefault()
    document.querySelectorAll('.q-item').forEach((i) => i.classList.remove('drag-over'))
    el.classList.add('drag-over')
  }, [])

  const onDrop = useCallback(
    (e: React.DragEvent, tgtIdx: number, el: HTMLElement) => {
      e.preventDefault()
      el.classList.remove('drag-over')
      if (dragSrcIdx.current === null || dragSrcIdx.current === tgtIdx) return
      reorderQueue(dragSrcIdx.current, tgtIdx)
      dragSrcIdx.current = null
    },
    [reorderQueue],
  )

  if (!queue.length) return null

  return (
    <div className="bg-surface border border-white/[0.07] rounded-app overflow-hidden mb-4">
      <div
        onClick={() => setOpen((o) => !o)}
        className="flex items-center justify-between px-4 py-3 cursor-pointer hover:bg-surface2 transition-colors duration-100 select-none sm:px-3"
      >
        <div className="flex items-center gap-2">
          <span className="font-display text-[11px] font-bold tracking-[1.2px] uppercase text-muted">
            Очередь · {queue.length} треков
          </span>
          <button
            onClick={(e) => { e.stopPropagation(); generateMix() }}
            className="px-2.5 py-0.5 text-[11px] border border-white/[0.07] rounded-lg bg-transparent text-muted hover:bg-surface2 hover:text-app-text transition-all duration-150 cursor-pointer"
          >
            ↺
          </button>
        </div>
        <span className={`text-muted text-[11px] transition-transform duration-200 ${open ? 'rotate-180' : ''}`}>▼</span>
      </div>

      <div
        className="overflow-hidden transition-all duration-300"
        style={{ maxHeight: open ? '500px' : '0' }}
      >
        <div className="flex flex-col max-h-[500px] overflow-y-auto">
          {queue.map((item, i) => {
            const active = i === curIdx
            return (
              <div
                key={i}
                data-idx={i}
                draggable
                className="q-item flex items-center gap-2 px-4 py-2 border-b border-white/[0.07] last:border-b-0 cursor-pointer hover:bg-surface2 transition-colors duration-100 select-none relative sm:px-3"
                style={{ background: active ? 'rgba(var(--accent-rgb),0.04)' : undefined }}
                onClick={(e) => handleQueueClick(e, i)}
                onDragStart={(e) => onDragStart(i, e.currentTarget)}
                onDragEnd={(e) => onDragEnd(e.currentTarget)}
                onDragOver={(e) => onDragOver(e, e.currentTarget)}
                onDrop={(e) => onDrop(e, i, e.currentTarget)}
              >
                <div
                  className="drag-handle text-muted cursor-grab shrink-0 p-1 opacity-40 hover:opacity-80 transition-opacity duration-150 flex items-center touch-none"
                  title="Перетащить"
                >
                  <svg width="12" height="12" viewBox="0 0 24 24" fill="currentColor">
                    <circle cx="9" cy="5" r="1.5" />
                    <circle cx="9" cy="12" r="1.5" />
                    <circle cx="9" cy="19" r="1.5" />
                    <circle cx="15" cy="5" r="1.5" />
                    <circle cx="15" cy="12" r="1.5" />
                    <circle cx="15" cy="19" r="1.5" />
                  </svg>
                </div>

                {active ? (
                  <div className="flex items-end gap-[1.5px] w-3 h-3 shrink-0">
                    <div className="queue-bar" />
                    <div className="queue-bar" />
                    <div className="queue-bar" />
                  </div>
                ) : (
                  <span className="text-[11px] text-muted w-[18px] text-right shrink-0 font-display">{i + 1}</span>
                )}

                {item.img ? (
                  <img
                    src={item.img}
                    alt=""
                    className="w-7 h-7 rounded-[5px] object-cover shrink-0 bg-surface2"
                    onError={(e) => ((e.target as HTMLImageElement).style.display = 'none')}
                  />
                ) : (
                  <div className="w-7 h-7 rounded-[5px] bg-surface2 shrink-0" />
                )}

                <span className="flex-1 text-[13px] text-app-text whitespace-nowrap overflow-hidden text-ellipsis">
                  {item.title}
                </span>
                <span
                  className="text-[10px] px-1.5 py-0.5 rounded-[5px] shrink-0 font-medium"
                  style={{ background: item.color.bg, color: item.color.text }}
                >
                  {item.owner}
                </span>
              </div>
            )
          })}
        </div>
      </div>
    </div>
  )
}