chain-studio/lib/pages/flows.dart

// FlowsPage — Studio's flow surface. Thin host wrapper around
// the swappable fai_studio_flow_editor package: loads the
// hub's installed capabilities, hands them + a Studio-side
// FlowRunDriver to the editor, and lets the editor own
// everything else (file list, three-tab body, properties
// panel, run progress, …).
//
// Pre-0.52 versions split file-listing and run-dialog state
// across this page. v0.52 moves all of that into the editor
// package so a swap is one pubspec change — Studio doesn't
// need to know what's inside the editor any more.

import 'package:fai_studio_flow_editor/fai_studio_flow_editor.dart';
import 'package:flutter/material.dart';

import '../data/flow_run_driver.dart';
import '../data/hub.dart';

class FlowsPage extends StatefulWidget {
  /// Pre-load this flow when the editor first builds. Studio
  /// keeps the parameter so the Cmd+K palette + welcome page
  /// can deep-link straight into a specific flow.
  final String? initialFlowName;

  const FlowsPage({super.key, this.initialFlowName});

  @override
  State<FlowsPage> createState() => _FlowsPageState();
}

class _FlowsPageState extends State<FlowsPage> {
  late Future<List<String>> _capabilities;
  late final StudioFlowRunDriver _driver;

  @override
  void initState() {
    super.initState();
    _driver = StudioFlowRunDriver();
    _capabilities = _loadCapabilities();
  }

  /// Pulls the capability identifiers the picker dialog
  /// offers when adding a step. `<capability>@<version>` so
  /// the operator can see exactly what they'll be wiring in,
  /// matching the format the `use:` field expects. Soft-fails
  /// to an empty list if the hub is unreachable — the editor
  /// falls back to a free-form text field in that case.
  Future<List<String>> _loadCapabilities() async {
    try {
      final caps = await HubService.instance.allCapabilities();
      final entries =
          caps.map((c) => '${c.capability}@${c.version}').toSet().toList()
            ..sort();
      return entries;
    } catch (_) {
      return const <String>[];
    }
  }

  /// Quick-fix handler — invoked when the operator clicks
  /// `Install <capability>` on an analyzer issue. Parses the
  /// editor-supplied `provider/name@version` spec into the
  /// Hub's install API and returns the refreshed capability
  /// list so the editor can re-analyze without waiting for the
  /// parent widget rebuild.
  Future<List<String>?> _onInstallCapability(String capability) async {
    try {
      // Editor passes the raw `use:` value (e.g.
      // `text.classify@^1`). HubService.installModule resolves
      // any version spec the hub's registry accepts.
      await HubService.instance.installModule(source: capability);
      final caps = await HubService.instance.allCapabilities();
      final updated = caps
          .map((c) => '${c.capability}@${c.version}')
          .toSet()
          .toList()
        ..sort();
      if (mounted) {
        // Refresh the cached capability future so subsequent
        // FutureBuilder rebuilds also see the new list.
        setState(() => _capabilities = Future.value(updated));
      }
      return updated;
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).removeCurrentSnackBar();
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Install failed: $e'),
            behavior: SnackBarBehavior.floating,
          ),
        );
      }
      return null;
    }
  }

  @override
  Widget build(BuildContext context) {
    final locale = Localizations.localeOf(context);
    final editorLocale = locale.languageCode == 'de'
        ? FlowEditorLocale.de
        : FlowEditorLocale.en;
    return FutureBuilder<List<String>>(
      future: _capabilities,
      builder: (context, snap) {
        final caps = snap.data ?? const <String>[];
        return FlowEditorPage(
          initialFlowName: widget.initialFlowName,
          locale: editorLocale,
          runDriver: _driver,
          availableCapabilities: caps,
          onInstallCapability: _onInstallCapability,
        );
      },
    );
  }
}