'use client'

import { useState, useEffect } from 'react'
import Link from 'next/link'

interface ComplianceTrigger {
  id: string
  regulation: string
  article: string
  title: string
  severity: 'high' | 'medium' | 'low'
  reason: string
  affected_hazard_count?: number
  module_path: string
  module_label: string
}

interface TriggersResponse {
  triggers: ComplianceTrigger[]
  total: number
}

const SEVERITY_CONFIG: Record<string, { border: string; bg: string; text: string; badge: string; icon: string }> = {
  high: {
    border: 'border-red-200 dark:border-red-800',
    bg: 'bg-red-50 dark:bg-red-900/20',
    text: 'text-red-700 dark:text-red-400',
    badge: 'bg-red-100 text-red-800 dark:bg-red-900/50 dark:text-red-300',
    icon: 'text-red-500',
  },
  medium: {
    border: 'border-yellow-200 dark:border-yellow-800',
    bg: 'bg-yellow-50 dark:bg-yellow-900/20',
    text: 'text-yellow-700 dark:text-yellow-400',
    badge: 'bg-yellow-100 text-yellow-800 dark:bg-yellow-900/50 dark:text-yellow-300',
    icon: 'text-yellow-500',
  },
  low: {
    border: 'border-blue-200 dark:border-blue-800',
    bg: 'bg-blue-50 dark:bg-blue-900/20',
    text: 'text-blue-700 dark:text-blue-400',
    badge: 'bg-blue-100 text-blue-800 dark:bg-blue-900/50 dark:text-blue-300',
    icon: 'text-blue-500',
  },
}

const SEVERITY_LABELS: Record<string, string> = {
  high: 'HOCH',
  medium: 'MITTEL',
  low: 'NIEDRIG',
}

const REGULATION_BADGES: { key: string; label: string; activeColor: string }[] = [
  { key: 'DSGVO', label: 'DSGVO', activeColor: 'bg-red-100 text-red-800 border-red-300' },
  { key: 'AI Act', label: 'AI Act', activeColor: 'bg-orange-100 text-orange-800 border-orange-300' },
  { key: 'CRA', label: 'CRA', activeColor: 'bg-yellow-100 text-yellow-800 border-yellow-300' },
  { key: 'NIS2', label: 'NIS2', activeColor: 'bg-indigo-100 text-indigo-800 border-indigo-300' },
  { key: 'Data Act', label: 'Data Act', activeColor: 'bg-amber-100 text-amber-800 border-amber-300' },
]

function WarningIcon({ className }: { className?: string }) {
  return (
    <svg className={className} fill="none" viewBox="0 0 24 24" stroke="currentColor">
      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2}
        d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4.5c-.77-.833-2.694-.833-3.464 0L3.34 16.5c-.77.833.192 2.5 1.732 2.5z" />
    </svg>
  )
}

function ChevronIcon({ open }: { open: boolean }) {
  return (
    <svg className={`w-4 h-4 text-gray-400 transition-transform ${open ? 'rotate-180' : ''}`}
      fill="none" viewBox="0 0 24 24" stroke="currentColor">
      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
    </svg>
  )
}

export function ComplianceAlerts({ projectId }: { projectId: string }) {
  const [data, setData] = useState<TriggersResponse | null>(null)
  const [loading, setLoading] = useState(true)
  const [collapsed, setCollapsed] = useState(false)
  const [expandedIds, setExpandedIds] = useState<Set<string>>(new Set())

  useEffect(() => {
    fetch(`/api/sdk/v1/iace/projects/${projectId}/compliance-triggers`)
      .then((r) => (r.ok ? r.json() : null))
      .then((json) => {
        if (json?.triggers) setData(json)
        else if (Array.isArray(json)) setData({ triggers: json, total: json.length })
      })
      .catch(() => {})
      .finally(() => setLoading(false))
  }, [projectId])

  if (loading) return null
  if (!data || data.triggers.length === 0) return null

  const triggers = data.triggers
  const activeRegulations = new Set(triggers.map((t) => t.regulation))

  function toggleExpanded(id: string) {
    setExpandedIds((prev) => {
      const next = new Set(prev)
      if (next.has(id)) next.delete(id)
      else next.add(id)
      return next
    })
  }

  return (
    <div className="bg-white dark:bg-gray-800 rounded-xl border border-red-200 dark:border-red-800">
      {/* Header */}
      <button
        onClick={() => setCollapsed(!collapsed)}
        className="w-full flex items-center justify-between p-6 text-left"
      >
        <div className="flex items-center gap-3">
          <div className="w-10 h-10 bg-red-50 dark:bg-red-900/30 rounded-lg flex items-center justify-center">
            <WarningIcon className="w-5 h-5 text-red-600" />
          </div>
          <div>
            <h2 className="text-sm font-semibold text-gray-900 dark:text-white">
              {triggers.length} Compliance-Hinweise erkannt
            </h2>
            <p className="text-xs text-gray-500">
              Basierend auf den identifizierten Gefaehrdungen bestehen rechtliche Implikationen
            </p>
          </div>
        </div>
        <div className="w-8 h-8 flex items-center justify-center rounded-full hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors flex-shrink-0">
          <ChevronIcon open={!collapsed} />
        </div>
      </button>

      {!collapsed && (
        <div className="px-6 pb-6 space-y-4">
          {/* Regulation summary badges */}
          <div className="flex flex-wrap gap-2">
            {REGULATION_BADGES.map((reg) => {
              const active = activeRegulations.has(reg.key)
              return (
                <span
                  key={reg.key}
                  className={`px-2.5 py-1 text-xs font-medium rounded-full border ${
                    active
                      ? reg.activeColor
                      : 'bg-gray-50 text-gray-400 border-gray-200 dark:bg-gray-700 dark:text-gray-500 dark:border-gray-600'
                  }`}
                >
                  {reg.label}
                </span>
              )
            })}
          </div>

          {/* Trigger list */}
          <div className="space-y-2">
            {triggers.map((trigger) => {
              const sev = SEVERITY_CONFIG[trigger.severity] || SEVERITY_CONFIG.low
              const isOpen = expandedIds.has(trigger.id)

              return (
                <div key={trigger.id} className={`rounded-lg border ${sev.border} ${sev.bg} overflow-hidden`}>
                  {/* Trigger header row */}
                  <button
                    onClick={() => toggleExpanded(trigger.id)}
                    className="w-full flex items-center gap-3 px-4 py-3 text-left"
                  >
                    <ChevronIcon open={isOpen} />
                    <div className="flex-1 min-w-0">
                      <span className="text-sm font-medium text-gray-900 dark:text-white">
                        {trigger.regulation} {trigger.article} — {trigger.title}
                      </span>
                    </div>
                    <span className={`px-2 py-0.5 text-xs font-bold rounded ${sev.badge}`}>
                      {SEVERITY_LABELS[trigger.severity] || trigger.severity}
                    </span>
                  </button>

                  {/* Expanded detail */}
                  {isOpen && (
                    <div className="px-4 pb-4 pt-0 ml-7 space-y-2">
                      <p className="text-xs text-gray-700 dark:text-gray-300">
                        <span className="font-medium">Grund:</span> {trigger.reason}
                      </p>
                      {trigger.affected_hazard_count != null && trigger.affected_hazard_count > 0 && (
                        <p className="text-xs text-gray-500">
                          Betroffene Gefaehrdungen: {trigger.affected_hazard_count}
                        </p>
                      )}
                      <Link
                        href={trigger.module_path}
                        className={`inline-flex items-center gap-1.5 text-xs font-medium ${sev.text} hover:underline`}
                      >
                        {trigger.module_label} oeffnen
                        <svg className="w-3.5 h-3.5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M13 7l5 5m0 0l-5 5m5-5H6" />
                        </svg>
                      </Link>
                    </div>
                  )}
                </div>
              )
            })}
          </div>

          {/* Disclaimer */}
          <div className="p-3 rounded-lg bg-amber-50 dark:bg-amber-900/20 border border-amber-200 dark:border-amber-800 text-xs text-amber-800 dark:text-amber-300">
            <strong>Hinweis:</strong> Diese Compliance-Hinweise werden automatisch aus den
            Gefaehrdungen und Klassifikationen abgeleitet. Der CE-Fachmann muss die
            regulatorischen Anforderungen im jeweiligen Modul verifizieren.
          </div>
        </div>
      )}
    </div>
  )
}
