'use client'

/**
 * DraftEditor - Split-Pane Editor fuer Compliance-Dokument-Entwuerfe
 *
 * Links (2/3): Gerenderter Draft mit Section-Headern
 * Rechts (1/3): Chat-Panel fuer iterative Verfeinerung
 * Oben: Document-Type Label, Depth-Level Badge, Constraint-Compliance
 */

import { useState, useRef, useCallback } from 'react'
import { DOCUMENT_TYPE_LABELS } from '@/lib/sdk/compliance-scope-types'
import type { ScopeDocumentType } from '@/lib/sdk/compliance-scope-types'
import type {
  DraftRevision,
  ConstraintCheckResult,
  ValidationResult,
} from '@/lib/sdk/drafting-engine/types'

interface DraftEditorProps {
  draft: DraftRevision
  documentType: ScopeDocumentType | null
  constraintCheck: ConstraintCheckResult | null
  validationResult: ValidationResult | null
  isTyping: boolean
  onAccept: () => void
  onValidate: () => void
  onClose: () => void
  onRefine: (instruction: string) => void
}

export function DraftEditor({
  draft,
  documentType,
  constraintCheck,
  validationResult,
  isTyping,
  onAccept,
  onValidate,
  onClose,
  onRefine,
}: DraftEditorProps) {
  const [refineInput, setRefineInput] = useState('')
  const [activeSection, setActiveSection] = useState<string | null>(null)
  const contentRef = useRef<HTMLDivElement>(null)

  const handleRefine = useCallback(() => {
    if (!refineInput.trim() || isTyping) return
    onRefine(refineInput.trim())
    setRefineInput('')
  }, [refineInput, isTyping, onRefine])

  const handleRefineKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === 'Enter' && !e.shiftKey) {
      e.preventDefault()
      handleRefine()
    }
  }

  const docLabel = documentType
    ? DOCUMENT_TYPE_LABELS[documentType]?.split(' (')[0] || documentType
    : 'Dokument'

  return (
    <div className="fixed inset-0 bg-gray-900/50 z-50 flex items-center justify-center p-4">
      <div className="bg-white rounded-2xl shadow-2xl w-full max-w-6xl h-[85vh] flex flex-col overflow-hidden">
        {/* Header */}
        <div className="bg-gradient-to-r from-blue-600 to-indigo-600 text-white px-6 py-3 flex items-center justify-between shrink-0">
          <div className="flex items-center gap-3">
            <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11 5H6a2 2 0 00-2 2v11a2 2 0 002 2h11a2 2 0 002-2v-5m-1.414-9.414a2 2 0 112.828 2.828L11.828 15H9v-2.828l8.586-8.586z" />
            </svg>
            <div>
              <div className="font-semibold text-sm">{docLabel} - Entwurf</div>
              <div className="text-xs text-white/70">
                {draft.sections.length} Sections | Erstellt {new Date(draft.createdAt).toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit' })}
              </div>
            </div>
          </div>

          <div className="flex items-center gap-2">
            {/* Constraint Badge */}
            {constraintCheck && (
              <span className={`px-2 py-0.5 rounded-full text-xs font-medium ${
                constraintCheck.allowed
                  ? 'bg-green-500/20 text-green-100'
                  : 'bg-red-500/20 text-red-100'
              }`}>
                {constraintCheck.allowed ? 'Constraints OK' : 'Constraint-Verletzung'}
              </span>
            )}

            {/* Validation Badge */}
            {validationResult && (
              <span className={`px-2 py-0.5 rounded-full text-xs font-medium ${
                validationResult.passed
                  ? 'bg-green-500/20 text-green-100'
                  : 'bg-amber-500/20 text-amber-100'
              }`}>
                {validationResult.passed ? 'Validiert' : `${validationResult.errors.length} Fehler`}
              </span>
            )}

            <button
              onClick={onClose}
              className="text-white/80 hover:text-white transition-colors p-1"
              aria-label="Editor schliessen"
            >
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
              </svg>
            </button>
          </div>
        </div>

        {/* Adjustment Warnings */}
        {constraintCheck && constraintCheck.adjustments.length > 0 && (
          <div className="px-6 py-2 bg-amber-50 border-b border-amber-200 shrink-0">
            {constraintCheck.adjustments.map((adj, i) => (
              <p key={i} className="text-xs text-amber-700 flex items-start gap-1">
                <svg className="w-3.5 h-3.5 mt-0.5 shrink-0" 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 1.732-2.5L13.732 4c-.77-.833-1.964-.833-2.732 0L3.732 16.5c-.77.833.192 2.5 1.732 2.5z" />
                </svg>
                {adj}
              </p>
            ))}
          </div>
        )}

        {/* Main Content: 2/3 Editor + 1/3 Chat */}
        <div className="flex-1 flex overflow-hidden">
          {/* Left: Draft Content (2/3) */}
          <div className="w-2/3 border-r border-gray-200 overflow-y-auto" ref={contentRef}>
            {/* Section Navigation */}
            <div className="sticky top-0 bg-white border-b border-gray-100 px-4 py-2 flex items-center gap-1 overflow-x-auto z-10">
              {draft.sections.map((section) => (
                <button
                  key={section.id}
                  onClick={() => {
                    setActiveSection(section.id)
                    document.getElementById(`section-${section.id}`)?.scrollIntoView({ behavior: 'smooth' })
                  }}
                  className={`px-2.5 py-1 rounded-md text-xs font-medium whitespace-nowrap transition-colors ${
                    activeSection === section.id
                      ? 'bg-blue-100 text-blue-700'
                      : 'text-gray-500 hover:bg-gray-100'
                  }`}
                >
                  {section.title}
                </button>
              ))}
            </div>

            {/* Sections */}
            <div className="p-6 space-y-6">
              {draft.sections.map((section) => (
                <div
                  key={section.id}
                  id={`section-${section.id}`}
                  className={`rounded-lg border transition-colors ${
                    activeSection === section.id
                      ? 'border-blue-300 bg-blue-50/30'
                      : 'border-gray-200 bg-white'
                  }`}
                >
                  <div className="px-4 py-2.5 border-b border-gray-100 flex items-center justify-between">
                    <h3 className="text-sm font-semibold text-gray-900">{section.title}</h3>
                    {section.schemaField && (
                      <span className="text-xs text-gray-400 font-mono">{section.schemaField}</span>
                    )}
                  </div>
                  <div className="px-4 py-3">
                    <div className="text-sm text-gray-700 whitespace-pre-wrap leading-relaxed">
                      {section.content}
                    </div>
                  </div>
                </div>
              ))}
            </div>
          </div>

          {/* Right: Refinement Chat (1/3) */}
          <div className="w-1/3 flex flex-col bg-gray-50">
            <div className="px-4 py-3 border-b border-gray-200 bg-white">
              <h3 className="text-sm font-semibold text-gray-900">Verfeinerung</h3>
              <p className="text-xs text-gray-500">Geben Sie Anweisungen zur Verbesserung</p>
            </div>

            {/* Validation Summary (if present) */}
            {validationResult && (
              <div className="px-4 py-3 border-b border-gray-100">
                <div className="space-y-1.5">
                  {validationResult.errors.length > 0 && (
                    <div className="flex items-center gap-1.5 text-xs text-red-600">
                      <span className="w-2 h-2 rounded-full bg-red-500" />
                      {validationResult.errors.length} Fehler
                    </div>
                  )}
                  {validationResult.warnings.length > 0 && (
                    <div className="flex items-center gap-1.5 text-xs text-amber-600">
                      <span className="w-2 h-2 rounded-full bg-amber-500" />
                      {validationResult.warnings.length} Warnungen
                    </div>
                  )}
                  {validationResult.suggestions.length > 0 && (
                    <div className="flex items-center gap-1.5 text-xs text-blue-600">
                      <span className="w-2 h-2 rounded-full bg-blue-500" />
                      {validationResult.suggestions.length} Vorschlaege
                    </div>
                  )}
                </div>
              </div>
            )}

            {/* Refinement Area */}
            <div className="flex-1 p-4 overflow-y-auto">
              <div className="space-y-3">
                <p className="text-xs text-gray-500">
                  Beschreiben Sie, was geaendert werden soll. Der Agent erstellt eine ueberarbeitete Version unter Beachtung der Scope-Constraints.
                </p>

                {/* Quick Refinement Buttons */}
                <div className="space-y-1.5">
                  {[
                    'Mehr Details hinzufuegen',
                    'Platzhalter ausfuellen',
                    'Rechtliche Referenzen ergaenzen',
                    'Sprache vereinfachen',
                  ].map((suggestion) => (
                    <button
                      key={suggestion}
                      onClick={() => onRefine(suggestion)}
                      disabled={isTyping}
                      className="w-full text-left px-3 py-1.5 text-xs bg-white hover:bg-blue-50 border border-gray-200 rounded-md transition-colors text-gray-600 disabled:opacity-50"
                    >
                      {suggestion}
                    </button>
                  ))}
                </div>
              </div>
            </div>

            {/* Refinement Input */}
            <div className="border-t border-gray-200 p-3 bg-white">
              <div className="flex gap-2">
                <input
                  type="text"
                  value={refineInput}
                  onChange={(e) => setRefineInput(e.target.value)}
                  onKeyDown={handleRefineKeyDown}
                  placeholder="Anweisung eingeben..."
                  disabled={isTyping}
                  className="flex-1 px-3 py-2 text-sm border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent disabled:opacity-50"
                />
                <button
                  onClick={handleRefine}
                  disabled={!refineInput.trim() || isTyping}
                  className="px-3 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
                >
                  <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 19l9 2-9-18-9 18 9-2zm0 0v-8" />
                  </svg>
                </button>
              </div>
            </div>
          </div>
        </div>

        {/* Footer Actions */}
        <div className="border-t border-gray-200 px-6 py-3 bg-white flex items-center justify-between shrink-0">
          <div className="flex items-center gap-2">
            <button
              onClick={onValidate}
              disabled={isTyping}
              className="px-4 py-2 text-sm font-medium text-green-700 bg-green-50 border border-green-200 rounded-lg hover:bg-green-100 disabled:opacity-50 transition-colors"
            >
              Validieren
            </button>
          </div>

          <div className="flex items-center gap-2">
            <button
              onClick={onClose}
              className="px-4 py-2 text-sm font-medium text-gray-600 bg-gray-50 border border-gray-200 rounded-lg hover:bg-gray-100 transition-colors"
            >
              Abbrechen
            </button>
            <button
              onClick={onAccept}
              disabled={isTyping}
              className="px-4 py-2 text-sm font-medium text-white bg-blue-600 rounded-lg hover:bg-blue-700 disabled:opacity-50 transition-colors"
            >
              Draft akzeptieren
            </button>
          </div>
        </div>
      </div>
    </div>
  )
}