'use client'

import { useState } from 'react'
import { StepHeader, STEP_EXPLANATIONS } from '@/components/sdk/StepHeader'
import { DisplayRequirement, mapCriticalityToPriority, mapStatusToDisplayStatus, AddRequirementData } from './_types'
import { requirementTemplates } from './_data'
import { AddRequirementForm } from './_components/AddRequirementForm'
import { RequirementCard } from './_components/RequirementCard'
import { LoadingSkeleton } from './_components/LoadingSkeleton'
import { useRequirementsData } from './_hooks/useRequirementsData'

export default function RequirementsPage() {
  const {
    state,
    loading,
    error,
    setError,
    ragExtracting,
    ragResult,
    setRagResult,
    extractFromRAG,
    handleStatusChange,
    handleDeleteRequirement,
    handleAddRequirement,
  } = useRequirementsData()

  const [filter, setFilter] = useState<string>('all')
  const [searchQuery, setSearchQuery] = useState('')
  const [showAddForm, setShowAddForm] = useState(false)
  const [expandedId, setExpandedId] = useState<string | null>(null)

  const onSubmitAdd = async (data: AddRequirementData) => {
    const ok = await handleAddRequirement(data)
    if (ok) setShowAddForm(false)
  }

  // Convert SDK requirements to display requirements
  const displayRequirements: DisplayRequirement[] = state.requirements.map(req => {
    const template = requirementTemplates.find(t => t.id === req.id)
    const linkedControls = state.controls.filter(c => c.evidence.includes(req.id))
    const linkedEvidence = state.evidence.filter(e => e.controlId && linkedControls.some(c => c.id === e.controlId))

    return {
      ...req,
      code: template?.code || req.id,
      source: template?.source || `${req.regulation} ${req.article}`,
      category: template?.category || req.regulation,
      priority: mapCriticalityToPriority(req.criticality),
      displayStatus: mapStatusToDisplayStatus(req.status),
      controlsLinked: linkedControls.length,
      evidenceCount: linkedEvidence.length,
    }
  })

  const filteredRequirements = displayRequirements.filter(req => {
    const matchesFilter = filter === 'all' ||
      req.displayStatus === filter ||
      req.priority === filter
    const matchesSearch = searchQuery === '' ||
      req.title.toLowerCase().includes(searchQuery.toLowerCase()) ||
      req.code.toLowerCase().includes(searchQuery.toLowerCase())
    return matchesFilter && matchesSearch
  })

  const compliantCount = displayRequirements.filter(r => r.displayStatus === 'compliant').length
  const partialCount = displayRequirements.filter(r => r.displayStatus === 'partial').length
  const nonCompliantCount = displayRequirements.filter(r => r.displayStatus === 'non-compliant').length

  const stepInfo = STEP_EXPLANATIONS['requirements']

  return (
    <div className="space-y-6">
      {/* Step Header */}
      <StepHeader
        stepId="requirements"
        title={stepInfo.title}
        description={stepInfo.description}
        explanation={stepInfo.explanation}
        tips={stepInfo.tips}
      >
        <div className="flex items-center gap-2">
          <button
            onClick={extractFromRAG}
            disabled={ragExtracting}
            className="flex items-center gap-2 px-4 py-2 bg-indigo-600 text-white rounded-lg hover:bg-indigo-700 disabled:opacity-60 transition-colors"
          >
            {ragExtracting ? (
              <svg className="w-4 h-4 animate-spin" fill="none" viewBox="0 0 24 24">
                <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
                <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8v8H4z" />
              </svg>
            ) : (
              <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9.663 17h4.673M12 3v1m6.364 1.636l-.707.707M21 12h-1M4 12H3m3.343-5.657l-.707-.707m2.828 9.9a5 5 0 117.072 0l-.347.347a3.5 3.5 0 01-4.95 0l-.347-.347z" />
              </svg>
            )}
            Aus RAG extrahieren
          </button>
          <button
            onClick={() => setShowAddForm(true)}
            className="flex items-center gap-2 px-4 py-2 bg-purple-600 text-white rounded-lg hover:bg-purple-700 transition-colors"
          >
            <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 6v6m0 0v6m0-6h6m-6 0H6" />
            </svg>
            Anforderung hinzufuegen
          </button>
        </div>
      </StepHeader>

      {/* RAG Extraction Result Banner */}
      {ragResult && (
        <div className={`flex items-center justify-between p-3 rounded-lg border ${ragResult.created > 0 ? 'bg-green-50 border-green-200' : 'bg-blue-50 border-blue-200'}`}>
          <span className="text-sm">
            {ragResult.created > 0 ? '✅' : 'ℹ️'} {ragResult.message}
          </span>
          <button onClick={() => setRagResult(null)} className="text-gray-400 hover:text-gray-600 ml-4">&times;</button>
        </div>
      )}

      {/* Add Form */}
      {showAddForm && (
        <AddRequirementForm
          onSubmit={onSubmitAdd}
          onCancel={() => setShowAddForm(false)}
        />
      )}

      {/* Error Banner */}
      {error && (
        <div className="p-4 bg-red-50 border border-red-200 rounded-lg text-red-700 flex items-center justify-between">
          <span>{error}</span>
          <button onClick={() => setError(null)} className="text-red-500 hover:text-red-700">&times;</button>
        </div>
      )}

      {/* Module Alert */}
      {state.modules.length === 0 && !loading && (
        <div className="bg-amber-50 border border-amber-200 rounded-xl p-4">
          <div className="flex items-start gap-3">
            <svg className="w-5 h-5 text-amber-600 mt-0.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z" />
            </svg>
            <div>
              <h4 className="font-medium text-amber-800">Keine Module aktiviert</h4>
              <p className="text-sm text-amber-700 mt-1">
                Bitte aktivieren Sie zuerst Compliance-Module, um die zugehoerigen Anforderungen zu laden.
              </p>
            </div>
          </div>
        </div>
      )}

      {/* Stats */}
      <div className="grid grid-cols-1 md:grid-cols-4 gap-4">
        <div className="bg-white rounded-xl border border-gray-200 p-6">
          <div className="text-sm text-gray-500">Gesamt</div>
          <div className="text-3xl font-bold text-gray-900">{displayRequirements.length}</div>
        </div>
        <div className="bg-white rounded-xl border border-green-200 p-6">
          <div className="text-sm text-green-600">Konform</div>
          <div className="text-3xl font-bold text-green-600">{compliantCount}</div>
        </div>
        <div className="bg-white rounded-xl border border-yellow-200 p-6">
          <div className="text-sm text-yellow-600">In Bearbeitung</div>
          <div className="text-3xl font-bold text-yellow-600">{partialCount}</div>
        </div>
        <div className="bg-white rounded-xl border border-red-200 p-6">
          <div className="text-sm text-red-600">Offen</div>
          <div className="text-3xl font-bold text-red-600">{nonCompliantCount}</div>
        </div>
      </div>

      {/* Search and Filter */}
      <div className="flex items-center gap-4">
        <div className="flex-1 relative">
          <svg className="w-5 h-5 text-gray-400 absolute left-3 top-1/2 -translate-y-1/2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z" />
          </svg>
          <input
            type="text"
            value={searchQuery}
            onChange={(e) => setSearchQuery(e.target.value)}
            placeholder="Anforderungen durchsuchen..."
            className="w-full pl-10 pr-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
          />
        </div>
        <div className="flex items-center gap-2">
          {['all', 'compliant', 'partial', 'non-compliant', 'critical'].map(f => (
            <button
              key={f}
              onClick={() => setFilter(f)}
              className={`px-3 py-1 text-sm rounded-full transition-colors ${
                filter === f
                  ? 'bg-purple-600 text-white'
                  : 'bg-gray-100 text-gray-600 hover:bg-gray-200'
              }`}
            >
              {f === 'all' ? 'Alle' :
               f === 'compliant' ? 'Konform' :
               f === 'partial' ? 'Teilweise' :
               f === 'non-compliant' ? 'Offen' : 'Kritisch'}
            </button>
          ))}
        </div>
      </div>

      {/* Loading State */}
      {loading && <LoadingSkeleton />}

      {/* Requirements List */}
      {!loading && (
        <div className="space-y-4">
          {filteredRequirements.map(requirement => {
            const linkedControls = state.controls
              .filter(c => c.evidence.includes(requirement.id))
              .map(c => ({ id: c.id, name: c.name }))
            return (
              <RequirementCard
                key={requirement.id}
                requirement={requirement}
                onStatusChange={(status) => handleStatusChange(requirement.id, status)}
                onDelete={() => handleDeleteRequirement(requirement.id)}
                expanded={expandedId === requirement.id}
                onToggleDetails={() => setExpandedId(expandedId === requirement.id ? null : requirement.id)}
                linkedControls={linkedControls}
              />
            )
          })}
        </div>
      )}

      {!loading && filteredRequirements.length === 0 && state.modules.length > 0 && (
        <div className="bg-white rounded-xl border border-gray-200 p-12 text-center">
          <div className="w-16 h-16 mx-auto bg-gray-100 rounded-full flex items-center justify-center mb-4">
            <svg className="w-8 h-8 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2" />
            </svg>
          </div>
          <h3 className="text-lg font-semibold text-gray-900">Keine Anforderungen gefunden</h3>
          <p className="mt-2 text-gray-500">Passen Sie die Suche oder den Filter an.</p>
        </div>
      )}
    </div>
  )
}