/**
 * Admin 后台 - 键盘快捷键: Cmd+K 命令面板
 *
 * 提供全局快捷键:
 *   Cmd/Ctrl+K — 打开命令面板(页面跳转)
 *   / — 聚焦搜索(日志页)
 *   r — 刷新当前页面数据(通用)
 */

import { useEffect, useState, useCallback } from 'react'
import { useNavigate } from 'react-router-dom'

interface CommandItem {
  id: string
  label: string
  group: string
  action: () => void
}

export function useCommandPalette(pages: Array<{ to: string; label: string; group: string }>) {
  const [open, setOpen] = useState(false)
  const [query, setQuery] = useState('')
  const navigate = useNavigate()

  const items: CommandItem[] = pages.map(p => ({
    id: p.to,
    label: p.label,
    group: p.group,
    action: () => { navigate(p.to); setOpen(false) },
  }))

  const filtered = query
    ? items.filter(i => i.label.toLowerCase().includes(query.toLowerCase()) || i.id.includes(query.toLowerCase()))
    : items

  useEffect(() => {
    const handler = (e: KeyboardEvent) => {
      // Cmd/Ctrl+K → 命令面板
      if ((e.metaKey || e.ctrlKey) && e.key === 'k') {
        e.preventDefault()
        setOpen(o => !o)
        setQuery('')
      }
      // Escape → 关闭
      if (e.key === 'Escape' && open) {
        setOpen(false)
        setQuery('')
      }
    }
    document.addEventListener('keydown', handler)
    return () => document.removeEventListener('keydown', handler)
  }, [open])

  return { open, setOpen, query, setQuery, items: filtered }
}

/** 命令面板弹窗 */
export function CommandPalette({
  open,
  query,
  setQuery,
  items,
  onClose,
}: {
  open: boolean
  query: string
  setQuery: (q: string) => void
  items: CommandItem[]
  onClose: () => void
}) {
  const [selected, setSelected] = useState(0)

  // 重置选中项当列表变化
  useEffect(() => { setSelected(0) }, [items.length])

  useEffect(() => {
    if (!open) return
    const handler = (e: KeyboardEvent) => {
      if (e.key === 'ArrowDown') { e.preventDefault(); setSelected(s => Math.min(s + 1, items.length - 1)) }
      if (e.key === 'ArrowUp') { e.preventDefault(); setSelected(s => Math.max(s - 1, 0)) }
      if (e.key === 'Enter' && items[selected]) { items[selected].action(); onClose() }
    }
    document.addEventListener('keydown', handler)
    return () => document.removeEventListener('keydown', handler)
  }, [open, items, selected, onClose])

  if (!open) return null

  // 按分组聚合
  const grouped: Record<string, CommandItem[]> = {}
  for (const item of items) {
    grouped[item.group] = grouped[item.group] || []
    grouped[item.group].push(item)
  }

  return (
    <div
      className="fixed inset-0 z-[60] flex items-start justify-center bg-ink-900/50 p-4 pt-[15vh]"
      onClick={onClose}
      role="dialog"
      aria-modal="true"
      aria-label="命令面板"
    >
      <div
        className="w-full max-w-lg border border-ink-900 bg-paper-50 shadow-2xl"
        onClick={e => e.stopPropagation()}
      >
        {/* 搜索框 */}
        <div className="flex items-center gap-2 border-b border-ink-200 px-3 py-2.5">
          <span className="text-ink-400">⌘</span>
          <input
            value={query}
            onChange={e => setQuery(e.target.value)}
            placeholder="输入页面名或路径…"
            autoFocus
            className="flex-1 bg-transparent text-sm outline-none placeholder:text-ink-400"
          />
          <kbd className="border border-ink-200 px-1.5 py-0.5 text-2xs text-ink-400">ESC</kbd>
        </div>

        {/* 结果列表 */}
        <div className="max-h-[50vh] overflow-y-auto py-2">
          {items.length === 0 ? (
            <p className="py-6 text-center text-xs text-ink-400">无匹配页面</p>
          ) : (
            Object.entries(grouped).map(([group, groupItems]) => (
              <div key={group}>
                <p className="px-3 py-1 text-2xs font-medium uppercase tracking-widest text-ink-400">{group}</p>
                {groupItems.map((item, i) => (
                  <button
                    key={item.id}
                    onClick={() => { item.action(); onClose() }}
                    className={`flex w-full items-center gap-2 px-3 py-2 text-left text-sm transition-colors ${
                      selected === items.indexOf(item) ? 'bg-paper-100 text-press' : 'text-ink-700 hover:bg-paper-100'
                    }`}
                  >
                    <span className="truncate">{item.label}</span>
                    <span className="ml-auto text-2xs text-ink-400">{item.id}</span>
                  </button>
                ))}
              </div>
            ))
          )}
        </div>

        {/* 底部提示 */}
        <div className="flex items-center gap-3 border-t border-ink-200 px-3 py-1.5 text-2xs text-ink-400">
          <span>↑↓ 导航</span>
          <span>↵ 跳转</span>
          <span>ESC 关闭</span>
        </div>
      </div>
    </div>
  )
}