'use client'

import React, { useMemo, useState, useRef, useEffect } from 'react'
import { SearchInput, FilterDropdown, Pagination, ExpandableRow } from './LibraryTable'

export interface HazardPattern {
  id: string
  name_de: string
  name_en: string
  priority: number
  required_component_tags: string[]
  generated_hazard_categories: string[]
  scenario_de: string
  trigger_de: string
  harm_de: string
  affected_de?: string
  zone_de?: string
}

const PER_PAGE = 50
const PRIORITY_OPTIONS = [
  { value: '', label: 'Alle Prioritaeten' },
  { value: '90', label: 'Prioritaet > 90' },
  { value: '70', label: 'Prioritaet > 70' },
  { value: '50', label: 'Prioritaet > 50' },
]

function priorityColor(p: number): string {
  if (p >= 90) return 'bg-red-100 text-red-800'
  if (p >= 70) return 'bg-orange-100 text-orange-800'
  if (p >= 50) return 'bg-yellow-100 text-yellow-800'
  return 'bg-gray-100 text-gray-700'
}

interface Props { patterns: HazardPattern[] }

export default function PatternsTab({ patterns }: Props) {
  const [search, setSearch] = useState('')
  const [debounced, setDebounced] = useState('')
  const [catFilter, setCatFilter] = useState('')
  const [prioFilter, setPrioFilter] = useState('')
  const [page, setPage] = useState(1)
  const timer = useRef<ReturnType<typeof setTimeout> | null>(null)

  useEffect(() => {
    timer.current = setTimeout(() => setDebounced(search), 300)
    return () => { if (timer.current) clearTimeout(timer.current) }
  }, [search])

  useEffect(() => { setPage(1) }, [debounced, catFilter, prioFilter])

  const categories = useMemo(() => {
    const set = new Set<string>()
    patterns.forEach((p) => p.generated_hazard_categories.forEach((c) => set.add(c)))
    return Array.from(set).sort()
  }, [patterns])

  const catOptions = useMemo(() => [
    { value: '', label: 'Alle Kategorien' },
    ...categories.map((c) => ({ value: c, label: c.replace(/_/g, ' ') })),
  ], [categories])

  const filtered = useMemo(() => {
    const q = debounced.toLowerCase()
    const prioMin = prioFilter ? parseInt(prioFilter) : 0
    return patterns.filter((p) => {
      if (q && !p.name_de.toLowerCase().includes(q) && !p.scenario_de.toLowerCase().includes(q) && !p.harm_de.toLowerCase().includes(q)) return false
      if (catFilter && !p.generated_hazard_categories.includes(catFilter)) return false
      if (prioMin && p.priority <= prioMin) return false
      return true
    })
  }, [patterns, debounced, catFilter, prioFilter])

  const totalPages = Math.ceil(filtered.length / PER_PAGE)
  const pageItems = filtered.slice((page - 1) * PER_PAGE, page * PER_PAGE)

  return (
    <div className="space-y-4">
      <div className="flex flex-wrap items-center gap-3">
        <div className="flex-1 min-w-[200px]">
          <SearchInput value={search} onChange={setSearch} placeholder="Name, Szenario oder Schaden suchen..." />
        </div>
        <FilterDropdown label="Kategorie" value={catFilter} options={catOptions} onChange={setCatFilter} />
        <FilterDropdown label="Prioritaet" value={prioFilter} options={PRIORITY_OPTIONS} onChange={setPrioFilter} />
        <span className="text-sm text-gray-500 dark:text-gray-400 ml-auto">
          {patterns.length} Patterns{filtered.length !== patterns.length && ` (${filtered.length} gefiltert)`}
        </span>
      </div>

      <div className="overflow-x-auto rounded-lg border border-gray-200 dark:border-gray-700">
        <table className="w-full text-left">
          <thead className="bg-gray-100 dark:bg-gray-800">
            <tr>
              {['ID', 'Name', 'Kategorie', 'Prioritaet', 'Schaden', 'Tags'].map((h) => (
                <th key={h} className="px-4 py-2.5 text-xs font-semibold text-gray-600 dark:text-gray-400 uppercase tracking-wider">{h}</th>
              ))}
              <th className="w-8" />
            </tr>
          </thead>
          <tbody>
            {pageItems.map((p) => (
              <ExpandableRow
                key={p.id}
                colSpan={6}
                cells={[
                  <span key="id" className="font-mono text-xs text-gray-500">{p.id.slice(0, 8)}</span>,
                  <span key="name" className="max-w-xs truncate block">{p.name_de}</span>,
                  <span key="cat" className="text-xs">{p.generated_hazard_categories[0]?.replace(/_/g, ' ') || '-'}</span>,
                  <span key="prio" className={`inline-flex items-center px-2 py-0.5 rounded text-xs font-medium ${priorityColor(p.priority)}`}>{p.priority}</span>,
                  <span key="harm" className="max-w-[160px] truncate block text-xs">{p.harm_de || '-'}</span>,
                  <span key="tags" className="text-xs text-gray-500">{p.required_component_tags.length > 0 ? p.required_component_tags.slice(0, 2).join(', ') : '-'}{p.required_component_tags.length > 2 ? ` +${p.required_component_tags.length - 2}` : ''}</span>,
                ]}
                expandedContent={
                  <div className="space-y-2">
                    {p.scenario_de && <div><span className="font-medium text-gray-700 dark:text-gray-300">Szenario:</span> {p.scenario_de}</div>}
                    {p.trigger_de && <div><span className="font-medium text-gray-700 dark:text-gray-300">Ausloeser:</span> {p.trigger_de}</div>}
                    {p.harm_de && <div><span className="font-medium text-gray-700 dark:text-gray-300">Schaden:</span> {p.harm_de}</div>}
                    {p.affected_de && <div><span className="font-medium text-gray-700 dark:text-gray-300">Betroffene:</span> {p.affected_de}</div>}
                    {p.zone_de && <div><span className="font-medium text-gray-700 dark:text-gray-300">Zone:</span> {p.zone_de}</div>}
                    {p.generated_hazard_categories.length > 0 && (
                      <div className="flex flex-wrap gap-1">
                        {p.generated_hazard_categories.map((c) => (
                          <span key={c} className="px-1.5 py-0.5 rounded text-xs bg-orange-100 dark:bg-orange-900/30 text-orange-700 dark:text-orange-300">{c.replace(/_/g, ' ')}</span>
                        ))}
                      </div>
                    )}
                  </div>
                }
              />
            ))}
            {pageItems.length === 0 && (
              <tr><td colSpan={7} className="px-4 py-8 text-center text-sm text-gray-400">Keine Patterns gefunden</td></tr>
            )}
          </tbody>
        </table>
      </div>

      <Pagination page={page} totalPages={totalPages} onPageChange={setPage} />
    </div>
  )
}