import { useEffect, useRef, useState } from 'react'
import { Search, X } from 'lucide-react'
import { API_URL, conAuth, manejar401 } from '../services/auth'

/** Elemento de resultado de búsqueda global */
interface BuscadoItem {
  tipo: 'lead' | 'oportunidad' | 'contacto' | 'unidad'
  id: string
  nombre: string
  detalle: string
  url: string
}

const ETIQUETA_TIPO: Record<BuscadoItem['tipo'], string> = {
  lead: 'Lead',
  oportunidad: 'Oportunidad',
  contacto: 'Contacto',
  unidad: 'Unidad',
}

const COLOR_TIPO: Record<BuscadoItem['tipo'], string> = {
  lead: 'bg-gray-100 text-gray-700',
  oportunidad: 'bg-blue-100 text-blue-700',
  contacto: 'bg-green-100 text-green-700',
  unidad: 'bg-purple-100 text-purple-700',
}

export function CommandPalette() {
  const [abierto, setAbierto] = useState(false)
  const [query, setQuery] = useState('')
  const [resultados, setResultados] = useState<BuscadoItem[]>([])
  const [cargando, setCargando] = useState(false)
  const [indiceSeleccionado, setIndiceSeleccionado] = useState(0)
  const inputRef = useRef<HTMLInputElement>(null)
  const debounceRef = useRef<ReturnType<typeof setTimeout> | null>(null)

  // Atajo de teclado Ctrl+K / Cmd+K
  useEffect(() => {
    const handler = (e: KeyboardEvent) => {
      if ((e.ctrlKey || e.metaKey) && e.key === 'k') {
        e.preventDefault()
        setAbierto((v) => !v)
      }
      if (e.key === 'Escape' && abierto) {
        setAbierto(false)
      }
    }
    window.addEventListener('keydown', handler)
    return () => window.removeEventListener('keydown', handler)
  }, [abierto])

  // Focus en input al abrir
  useEffect(() => {
    if (abierto) {
      setTimeout(() => inputRef.current?.focus(), 50)
    } else {
      setQuery('')
      setResultados([])
      setIndiceSeleccionado(0)
    }
  }, [abierto])

  // Búsqueda con debounce
  useEffect(() => {
    if (debounceRef.current) clearTimeout(debounceRef.current)
    if (query.trim().length < 2) {
      setResultados([])
      return
    }
    setCargando(true)
    debounceRef.current = setTimeout(async () => {
      try {
        const resp = await fetch(`${API_URL}/buscar?q=${encodeURIComponent(query.trim())}&limite=20`, conAuth())
        manejar401(resp)
        if (resp.ok) {
          setResultados(await resp.json())
        }
      } catch {
        setResultados([])
      } finally {
        setCargando(false)
      }
    }, 300)
    return () => {
      if (debounceRef.current) clearTimeout(debounceRef.current)
    }
  }, [query])

  // Navegación con teclado
  const onKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === 'ArrowDown') {
      e.preventDefault()
      setIndiceSeleccionado((i) => Math.min(i + 1, resultados.length - 1))
    } else if (e.key === 'ArrowUp') {
      e.preventDefault()
      setIndiceSeleccionado((i) => Math.max(i - 1, 0))
    } else if (e.key === 'Enter' && resultados[indiceSeleccionado]) {
      window.location.href = resultados[indiceSeleccionado].url
    }
  }

  // Agrupar por tipo
  const agrupados = resultados.reduce<Record<string, BuscadoItem[]>>((acc, item) => {
    const key = item.tipo
    if (!acc[key]) acc[key] = []
    acc[key].push(item)
    return acc
  }, {})

  return (
    <>
      {/* Botón trigger */}
      <button
        type="button"
        onClick={() => setAbierto(true)}
        className="flex h-8 w-8 items-center justify-center rounded-lg text-[#64748B] dark:text-[#94A3B8] transition-colors hover:bg-[#F1F5F9] hover:text-accent"
        aria-label="Buscar (Ctrl+K)"
        title="Buscar (Ctrl+K)"
      >
        <Search size={16} />
      </button>

      {/* Modal */}
      {abierto && (
        <div className="fixed inset-0 z-50 flex items-start justify-center px-4 pt-[15vh]" role="dialog" aria-modal="true">
          {/* Backdrop */}
          <div className="fixed inset-0 bg-black/40" onClick={() => setAbierto(false)} />

          {/* Panel */}
          <div className="relative w-full max-w-lg rounded-2xl border border-[#E5E7EB] bg-white dark:border-[#1E293B] dark:bg-[#1E293B] shadow-2xl overflow-hidden">
            {/* Input */}
            <div className="flex items-center gap-3 border-b border-[#E5E7EB] dark:border-[#334155] px-4 py-3">
              <Search size={18} className="shrink-0 text-[#94A3B8]" />
              <input
                ref={inputRef}
                type="text"
                placeholder="Buscar leads, contactos, cotizaciones, unidades…"
                value={query}
                onChange={(e) => { setQuery(e.target.value); setIndiceSeleccionado(0) }}
                onKeyDown={onKeyDown}
                className="flex-1 bg-transparent text-sm text-[#111827] dark:text-[#E2E8F0] placeholder-[#94A3B8] focus:outline-none"
              />
              <button
                type="button"
                onClick={() => setAbierto(false)}
                className="rounded-md p-1 text-[#94A3B8] transition-colors hover:bg-[#F1F5F9] hover:text-[#64748B] dark:hover:bg-[#334155] dark:hover:text-[#CBD5E1]"
              >
                <X size={16} />
              </button>
            </div>

            {/* Resultados */}
            <div className="max-h-80 overflow-y-auto p-2">
              {query.trim().length < 2 ? (
                <p className="px-4 py-6 text-center text-xs text-[#94A3B8]">
                  Escribe al menos 2 caracteres para buscar
                </p>
              ) : cargando ? (
                <p className="px-4 py-6 text-center text-xs text-[#94A3B8]">Buscando…</p>
              ) : resultados.length === 0 ? (
                <p className="px-4 py-6 text-center text-xs text-[#94A3B8]">Sin resultados para "{query}"</p>
              ) : (
                Object.entries(agrupados).map(([tipo, items]) => (
                  <div key={tipo} className="mb-2">
                    <p className="px-3 py-1 text-[10px] font-semibold uppercase tracking-wider text-[#94A3B8]">
                      {ETIQUETA_TIPO[tipo as BuscadoItem['tipo']]}
                    </p>
                    {items.map((item) => {
                      const idxGlobal = resultados.indexOf(item)
                      return (
                        <a
                          key={`${item.tipo}-${item.id}`}
                          href={item.url}
                          className={`flex items-center gap-3 rounded-lg px-3 py-2 transition-colors ${
                            idxGlobal === indiceSeleccionado
                              ? 'bg-blue-50 dark:bg-blue-900/30'
                              : 'hover:bg-[#F8FAFC] dark:hover:bg-[#0F172A]'
                          }`}
                        >
                          <span className={`inline-flex shrink-0 items-center rounded-full px-2 py-0.5 text-[10px] font-medium ${COLOR_TIPO[item.tipo]}`}>
                            {ETIQUETA_TIPO[item.tipo]}
                          </span>
                          <span className="min-w-0 flex-1">
                            <span className="block truncate text-sm font-medium text-[#111827] dark:text-[#E2E8F0]">{item.nombre}</span>
                            {item.detalle && (
                              <span className="block truncate text-[11px] text-[#94A3B8]">{item.detalle}</span>
                            )}
                          </span>
                        </a>
                      )
                    })}
                  </div>
                ))
              )}
            </div>

            {/* Footer */}
            <div className="flex items-center gap-4 border-t border-[#E5E7EB] dark:border-[#334155] px-4 py-2 text-[10px] text-[#94A3B8]">
              <span>↑↓ navegar</span>
              <span>↵ abrir</span>
              <span>esc cerrar</span>
            </div>
          </div>
        </div>
      )}
    </>
  )
}