/**
 * RbacExportImport
 * 
 * Component for exporting and importing RBAC configurations.
 * Supports mandate-level and global exports with different import modes.
 */

import React, { useState, useRef, useCallback, useEffect } from 'react';
import {
  FaDownload,
  FaUpload,
  FaFileExport,
  FaFileImport,
  FaSpinner,
  FaCheckCircle,
  FaExclamationTriangle,
  FaInfoCircle,
  FaTrash,
  FaEye,
} from 'react-icons/fa';
import {
  useRbacExportImport,
  type RbacExport,
  type ImportMode,
  type RbacImportResult,
} from '../../hooks/useRbacExportImport';
import styles from './RbacExportImport.module.css';

// =============================================================================
// TYPES
// =============================================================================

interface RbacExportImportProps {
  mandateId?: string;
  mandateName?: string;
  isGlobal?: boolean;
  featureCode?: string;
}

// =============================================================================
// IMPORT MODE OPTIONS
// =============================================================================

const IMPORT_MODES: { value: ImportMode; label: string; description: string; icon: React.ReactNode }[] = [
  {
    value: 'merge',
    label: 'Zusammenführen',
    description: 'Bestehende Regeln aktualisieren, neue hinzufügen',
    icon: <FaCheckCircle style={{ color: '#38a169' }} />,
  },
  {
    value: 'add_only',
    label: 'Nur hinzufügen',
    description: 'Nur neue Regeln hinzufügen, bestehende nicht ändern',
    icon: <FaInfoCircle style={{ color: '#3182ce' }} />,
  },
  {
    value: 'replace',
    label: 'Ersetzen',
    description: 'Alle bestehenden Regeln löschen und ersetzen',
    icon: <FaExclamationTriangle style={{ color: '#d69e2e' }} />,
  },
];

// =============================================================================
// PREVIEW COMPONENT
// =============================================================================

interface PreviewProps {
  data: RbacExport;
  onClose: () => void;
}

const ExportPreview: React.FC<PreviewProps> = ({ data, onClose }) => {
  return (
    <div className={styles.preview}>
      <div className={styles.previewHeader}>
        <h4 className={styles.previewTitle}>Export-Vorschau</h4>
        <button className={styles.closeButton} onClick={onClose}>✕</button>
      </div>
      <div className={styles.previewContent}>
        <div className={styles.previewSection}>
          <h5>Scope</h5>
          <ul className={styles.previewList}>
            <li><strong>Typ:</strong> {data.scope.type}</li>
            {data.scope.mandateName && <li><strong>Mandant:</strong> {data.scope.mandateName}</li>}
            {data.scope.featureCode && <li><strong>Feature:</strong> {data.scope.featureCode}</li>}
          </ul>
        </div>
        <div className={styles.previewSection}>
          <h5>Rollen ({data.roles.length})</h5>
          <ul className={styles.previewList}>
            {data.roles.slice(0, 5).map((role, i) => (
              <li key={i}>
                <code>{role.roleLabel}</code>
                {role.featureCode && <span className={styles.featureBadge}>{role.featureCode}</span>}
              </li>
            ))}
            {data.roles.length > 5 && (
              <li className={styles.moreItems}>... und {data.roles.length - 5} weitere</li>
            )}
          </ul>
        </div>
        <div className={styles.previewSection}>
          <h5>Regeln ({data.accessRules.length})</h5>
          <ul className={styles.previewList}>
            {data.accessRules.slice(0, 5).map((rule, i) => (
              <li key={i}>
                <span className={styles.contextBadge}>{rule.context}</span>
                <code>{rule.item || '(global)'}</code>
              </li>
            ))}
            {data.accessRules.length > 5 && (
              <li className={styles.moreItems}>... und {data.accessRules.length - 5} weitere</li>
            )}
          </ul>
        </div>
      </div>
    </div>
  );
};

// =============================================================================
// IMPORT RESULT COMPONENT
// =============================================================================

interface ImportResultProps {
  result: RbacImportResult;
  onClose: () => void;
}

const ImportResult: React.FC<ImportResultProps> = ({ result, onClose }) => {
  const isSuccess = result.status === 'success';
  
  return (
    <div className={`${styles.importResult} ${isSuccess ? styles.success : styles.error}`}>
      <div className={styles.resultHeader}>
        {isSuccess ? (
          <FaCheckCircle className={styles.resultIcon} />
        ) : (
          <FaExclamationTriangle className={styles.resultIcon} />
        )}
        <h4 className={styles.resultTitle}>
          {isSuccess ? 'Import erfolgreich' : 'Import fehlgeschlagen'}
        </h4>
        <button className={styles.closeButton} onClick={onClose}>✕</button>
      </div>
      <div className={styles.resultContent}>
        <ul className={styles.resultStats}>
          <li><strong>Modus:</strong> {IMPORT_MODES.find(m => m.value === result.mode)?.label}</li>
          <li><strong>Rollen erstellt:</strong> {result.rolesCreated}</li>
          <li><strong>Rollen aktualisiert:</strong> {result.rolesUpdated}</li>
          <li><strong>Regeln erstellt:</strong> {result.rulesCreated}</li>
          <li><strong>Regeln aktualisiert:</strong> {result.rulesUpdated}</li>
        </ul>
        {result.errors && result.errors.length > 0 && (
          <div className={styles.resultErrors}>
            <h5>Fehler:</h5>
            <ul>
              {result.errors.map((err, i) => (
                <li key={i}>{err}</li>
              ))}
            </ul>
          </div>
        )}
      </div>
    </div>
  );
};

// =============================================================================
// MAIN COMPONENT
// =============================================================================

export const RbacExportImport: React.FC<RbacExportImportProps> = ({
  mandateId,
  mandateName,
  isGlobal = false,
  featureCode,
}) => {
  const {
    exporting,
    importing,
    error,
    lastExport,
    lastImportResult,
    exportMandateRbac,
    exportGlobalRbac,
    importMandateRbac,
    importGlobalRbac,
    downloadExport,
    parseImportFile,
    reset,
  } = useRbacExportImport();

  const [importMode, setImportMode] = useState<ImportMode>('merge');
  const [importFile, setImportFile] = useState<File | null>(null);
  const [importData, setImportData] = useState<RbacExport | null>(null);
  const [parseError, setParseError] = useState<string | null>(null);
  const [showPreview, setShowPreview] = useState(false);
  const [showResult, setShowResult] = useState(false);
  
  const fileInputRef = useRef<HTMLInputElement>(null);

  // Handle export
  const handleExport = async () => {
    let result;
    if (isGlobal) {
      result = await exportGlobalRbac(featureCode);
    } else if (mandateId) {
      result = await exportMandateRbac(mandateId, featureCode);
    } else {
      return;
    }
    
    if (result.success && result.data) {
      downloadExport(result.data);
    }
  };

  // Handle file selection
  const handleFileSelect = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file) return;
    
    setImportFile(file);
    setParseError(null);
    
    const result = await parseImportFile(file);
    if (result.success && result.data) {
      setImportData(result.data);
    } else {
      setParseError(result.error || 'Fehler beim Parsen');
      setImportData(null);
    }
  };

  // Handle import
  const handleImport = async () => {
    if (!importData) return;
    
    let result;
    if (isGlobal) {
      result = await importGlobalRbac(importData, importMode);
    } else if (mandateId) {
      result = await importMandateRbac(mandateId, importData, importMode);
    } else {
      return;
    }
    
    if (result.success) {
      setShowResult(true);
      // Clear import state
      setImportFile(null);
      setImportData(null);
      if (fileInputRef.current) {
        fileInputRef.current.value = '';
      }
    }
  };

  // Clear import state
  const handleClearImport = () => {
    setImportFile(null);
    setImportData(null);
    setParseError(null);
    if (fileInputRef.current) {
      fileInputRef.current.value = '';
    }
  };

  // Handle close result
  const handleCloseResult = () => {
    setShowResult(false);
    reset();
  };

  return (
    <div className={styles.rbacExportImport}>
      {/* Export Section */}
      <div className={styles.section}>
        <div className={styles.sectionHeader}>
          <FaFileExport className={styles.sectionIcon} />
          <h3 className={styles.sectionTitle}>Export</h3>
        </div>
        <div className={styles.sectionContent}>
          <p className={styles.sectionDescription}>
            Exportiert alle Rollen und Berechtigungen 
            {isGlobal ? ' der globalen Templates' : ` des Mandanten "${mandateName || mandateId}"`}
            {featureCode ? ` für Feature "${featureCode}"` : ''} als JSON-Datei.
          </p>
          <button
            className={styles.primaryButton}
            onClick={handleExport}
            disabled={exporting || (!isGlobal && !mandateId)}
          >
            {exporting ? (
              <>
                <FaSpinner className="spinning" /> Exportieren...
              </>
            ) : (
              <>
                <FaDownload /> RBAC exportieren
              </>
            )}
          </button>
        </div>
      </div>

      {/* Import Section */}
      <div className={styles.section}>
        <div className={styles.sectionHeader}>
          <FaFileImport className={styles.sectionIcon} />
          <h3 className={styles.sectionTitle}>Import</h3>
        </div>
        <div className={styles.sectionContent}>
          {/* File Upload */}
          <div className={styles.fileUpload}>
            <input
              type="file"
              ref={fileInputRef}
              accept=".json"
              onChange={handleFileSelect}
              className={styles.fileInput}
              id="rbac-import-file"
            />
            <label htmlFor="rbac-import-file" className={styles.fileLabel}>
              {importFile ? (
                <>
                  <FaCheckCircle className={styles.fileIcon} style={{ color: '#38a169' }} />
                  <span>{importFile.name}</span>
                </>
              ) : (
                <>
                  <FaUpload className={styles.fileIcon} />
                  <span>JSON-Datei auswählen oder hier ablegen</span>
                </>
              )}
            </label>
            {importFile && (
              <button
                className={styles.clearButton}
                onClick={handleClearImport}
                title="Datei entfernen"
              >
                <FaTrash />
              </button>
            )}
          </div>

          {/* Parse Error */}
          {parseError && (
            <div className={styles.errorMessage}>
              <FaExclamationTriangle /> {parseError}
            </div>
          )}

          {/* Import Data Info */}
          {importData && (
            <div className={styles.importInfo}>
              <div className={styles.importStats}>
                <span><strong>Rollen:</strong> {importData.roles.length}</span>
                <span><strong>Regeln:</strong> {importData.accessRules.length}</span>
                <span><strong>Quelle:</strong> {importData.scope.type}</span>
              </div>
              <button
                className={styles.previewButton}
                onClick={() => setShowPreview(true)}
              >
                <FaEye /> Vorschau
              </button>
            </div>
          )}

          {/* Import Mode Selection */}
          {importData && (
            <div className={styles.importModeSection}>
              <h4 className={styles.importModeTitle}>Import-Modus</h4>
              <div className={styles.importModes}>
                {IMPORT_MODES.map(mode => (
                  <label
                    key={mode.value}
                    className={`${styles.importModeOption} ${importMode === mode.value ? styles.selected : ''}`}
                  >
                    <input
                      type="radio"
                      name="importMode"
                      value={mode.value}
                      checked={importMode === mode.value}
                      onChange={(e) => setImportMode(e.target.value as ImportMode)}
                      className={styles.radioInput}
                    />
                    <span className={styles.modeIcon}>{mode.icon}</span>
                    <span className={styles.modeLabel}>{mode.label}</span>
                    <span className={styles.modeDescription}>{mode.description}</span>
                  </label>
                ))}
              </div>
            </div>
          )}

          {/* Import Button */}
          {importData && (
            <button
              className={`${styles.primaryButton} ${importMode === 'replace' ? styles.danger : ''}`}
              onClick={handleImport}
              disabled={importing || (!isGlobal && !mandateId)}
            >
              {importing ? (
                <>
                  <FaSpinner className="spinning" /> Importieren...
                </>
              ) : (
                <>
                  <FaUpload /> RBAC importieren
                </>
              )}
            </button>
          )}

          {/* Warning for replace mode */}
          {importMode === 'replace' && importData && (
            <div className={styles.warningMessage}>
              <FaExclamationTriangle /> 
              <strong>Achtung:</strong> Im Modus "Ersetzen" werden alle bestehenden Rollen und Regeln gelöscht!
            </div>
          )}
        </div>
      </div>

      {/* Error Message */}
      {error && (
        <div className={styles.errorMessage}>
          <FaExclamationTriangle /> {error}
        </div>
      )}

      {/* Preview Modal */}
      {showPreview && importData && (
        <div className={styles.modalOverlay} onClick={() => setShowPreview(false)}>
          <div className={styles.modal} onClick={e => e.stopPropagation()}>
            <ExportPreview data={importData} onClose={() => setShowPreview(false)} />
          </div>
        </div>
      )}

      {/* Result Modal */}
      {showResult && lastImportResult && (
        <div className={styles.modalOverlay} onClick={handleCloseResult}>
          <div className={styles.modal} onClick={e => e.stopPropagation()}>
            <ImportResult result={lastImportResult} onClose={handleCloseResult} />
          </div>
        </div>
      )}
    </div>
  );
};

export default RbacExportImport;