/**
 * GraphicalEditorPage
 *
 * Layout: [UDB sidebar (collapsible)] [FlowEditor (flex)] [Chat/Tracing (inside FlowEditor)]
 * UDB provides access to Files & Sources while configuring nodes.
 * AI Chat and Tracing panels are managed by the FlowEditor's CanvasHeader.
 *
 * File/Source attachment UX mirrors the Workspace:
 *   - Files: click in UDB FilesTab → added as pendingFile chip in chat input
 *   - Data Sources: 🔗 picker button in chat input (loaded from UDB API)
 */
import React, { useState, useMemo, useRef, useCallback, useEffect } from 'react';
import { useSearchParams } from 'react-router-dom';
import { FaDatabase, FaChevronLeft } from 'react-icons/fa';
import { useInstanceId, useMandateId } from '../../../hooks/useCurrentInstance';
import { useLanguage } from '../../../providers/language/LanguageContext';
import { Automation2FlowEditor as FlowEditor } from '../../../components/FlowEditor';
import type { PendingFile, EditorDataSource, EditorFeatureDataSource } from '../../../components/FlowEditor';
import { UnifiedDataBar } from '../../../components/UnifiedDataBar';
import type { UdbContext, UdbTab } from '../../../components/UnifiedDataBar';
import api from '../../../api';
import styles from '../../FeatureView.module.css';

interface GraphicalEditorPageProps {
  persistentInstanceId?: string;
  persistentMandateId?: string;
}

export const GraphicalEditorPage: React.FC<GraphicalEditorPageProps> = ({
  persistentInstanceId,
  persistentMandateId,
}) => {
  const urlInstanceId = useInstanceId();
  const urlMandateId = useMandateId();
  const instanceId = persistentInstanceId || urlInstanceId;
  const mandateId = persistentMandateId || urlMandateId;
  const [searchParams] = useSearchParams();
  const initialWorkflowIdRef = useRef(searchParams.get('workflowId'));
  const { currentLanguage } = useLanguage();
  const language = (currentLanguage?.slice(0, 2) || 'de') as string;
  const [udbTab, setUdbTab] = useState<UdbTab>('files');
  const [udbOpen, setUdbOpen] = useState(true);

  const [pendingFiles, setPendingFiles] = useState<PendingFile[]>([]);
  const [dataSources, setDataSources] = useState<EditorDataSource[]>([]);
  const [featureDataSources, setFeatureDataSources] = useState<EditorFeatureDataSource[]>([]);

  const udbContext: UdbContext = useMemo(() => ({
    instanceId: instanceId || '',
    mandateId: mandateId || '',
    featureInstanceId: instanceId || '',
  }), [instanceId, mandateId]);

  useEffect(() => {
    if (!instanceId) return;
    api.get(`/api/workspace/${instanceId}/datasources`)
      .then(res => {
        const list = (res.data.dataSources || res.data || []).map((d: any) => ({
          id: d.id, label: d.label || d.path || d.id, path: d.path, sourceType: d.sourceType,
        }));
        setDataSources(list);
      })
      .catch(() => setDataSources([]));
  }, [instanceId]);

  useEffect(() => {
    if (!instanceId) return;
    api.get(`/api/workspace/${instanceId}/feature-datasources`)
      .then(res => {
        const list = (res.data.featureDataSources || res.data || []).map((d: any) => ({
          id: d.id, featureInstanceId: d.featureInstanceId, featureCode: d.featureCode,
          tableName: d.tableName, label: d.label || d.tableName,
        }));
        setFeatureDataSources(list);
      })
      .catch(() => setFeatureDataSources([]));
  }, [instanceId]);

  const _handleFileSelect = useCallback((fileId: string, fileName?: string) => {
    setPendingFiles(prev => {
      if (prev.some(f => f.fileId === fileId)) return prev;
      return [...prev, { fileId, fileName: fileName || fileId.slice(0, 12) }];
    });
  }, []);

  const _handleRemovePendingFile = useCallback((fileId: string) => {
    setPendingFiles(prev => prev.filter(f => f.fileId !== fileId));
  }, []);

  const _handleSourcesChanged = useCallback(() => {
    if (!instanceId) return;
    api.get(`/api/workspace/${instanceId}/datasources`)
      .then(res => {
        setDataSources((res.data.dataSources || res.data || []).map((d: any) => ({
          id: d.id, label: d.label || d.path || d.id, path: d.path, sourceType: d.sourceType,
        })));
      })
      .catch(() => {});
    api.get(`/api/workspace/${instanceId}/feature-datasources`)
      .then(res => {
        setFeatureDataSources((res.data.featureDataSources || res.data || []).map((d: any) => ({
          id: d.id, featureInstanceId: d.featureInstanceId, featureCode: d.featureCode,
          tableName: d.tableName, label: d.label || d.tableName,
        })));
      })
      .catch(() => {});
  }, [instanceId]);

  if (!instanceId) {
    return (
      <div className={styles.placeholder}>
        <h2>Graphical Editor</h2>
        <p>Keine Feature-Instanz gefunden.</p>
      </div>
    );
  }

  return (
    <div style={{ flex: 1, minHeight: 0, display: 'flex', position: 'relative' }}>
      {/* UDB Sidebar */}
      {udbOpen ? (
        <div style={{
          width: 280, minWidth: 280,
          borderRight: '1px solid var(--border-color, #e0e0e0)',
          display: 'flex', flexDirection: 'column', overflow: 'hidden',
          background: 'var(--bg-primary, #fff)',
        }}>
          <div style={{
            display: 'flex', justifyContent: 'space-between', alignItems: 'center',
            padding: '6px 12px',
            borderBottom: '1px solid var(--border-color, #e0e0e0)',
            background: 'var(--bg-secondary, #f8f9fa)',
          }}>
            <span style={{ fontWeight: 600, fontSize: '13px', display: 'flex', alignItems: 'center', gap: 6 }}>
              <FaDatabase style={{ fontSize: 12, opacity: 0.6 }} /> Daten
            </span>
            <button
              onClick={() => setUdbOpen(false)}
              title="Sidebar schliessen"
              style={{
                border: 'none', background: 'transparent', cursor: 'pointer',
                fontSize: '14px', padding: '2px 4px', borderRadius: 4,
                display: 'flex', alignItems: 'center',
              }}
            >
              <FaChevronLeft style={{ fontSize: 12 }} />
            </button>
          </div>
          <UnifiedDataBar
            context={udbContext}
            activeTab={udbTab}
            onTabChange={setUdbTab}
            hideTabs={['chats']}
            onFileSelect={_handleFileSelect}
            onSourcesChanged={_handleSourcesChanged}
          />
        </div>
      ) : (
        <button
          onClick={() => setUdbOpen(true)}
          title="Daten-Sidebar öffnen"
          style={{
            position: 'absolute', left: 0, top: '50%', transform: 'translateY(-50%)',
            zIndex: 20, width: 28, height: 80,
            border: '1px solid var(--border-color, #ddd)', borderLeft: 'none',
            borderRadius: '0 8px 8px 0',
            background: 'var(--bg-primary, #fff)', cursor: 'pointer',
            display: 'flex', alignItems: 'center', justifyContent: 'center',
            boxShadow: '2px 0 6px rgba(0,0,0,0.06)',
          }}
        >
          <FaDatabase style={{ fontSize: 13, opacity: 0.5 }} />
        </button>
      )}

      {/* FlowEditor */}
      <div style={{ flex: 1, minWidth: 0, display: 'flex', flexDirection: 'column' }}>
        <FlowEditor
          instanceId={instanceId}
          language={language}
          initialWorkflowId={initialWorkflowIdRef.current}
          pendingFiles={pendingFiles}
          onRemovePendingFile={_handleRemovePendingFile}
          dataSources={dataSources}
          featureDataSources={featureDataSources}
        />
      </div>
    </div>
  );
};