// HubLoadErrorView — the one way a page presents "my content
// could not be loaded". Pages used to open-code a "hub not
// reachable" empty state for ANY failure, contradicting the
// sidebar's green connected dot whenever the hub answered but the
// RPC failed (an older hub without the RPC, a feature gate, a real
// bug). This widget routes the failure through the shared
// classification instead:
//
//   * unreachable  -> the honest "hub not reachable" state
//   * unsupported  -> "this view needs a newer hub version"
//   * other        -> "could not load" + the friendly error in a
//                     copyable detail box (hard rule: errors are
//                     always copyable)
//
// The state-matrix suite pins the behaviour across every page.

import 'package:flutter/material.dart';

import '../data/friendly_error.dart';
import '../l10n/app_localizations.dart';
import 'chain_empty_state.dart';
import 'chain_error_box.dart';

class HubLoadErrorView extends StatelessWidget {
  final Object error;

  /// Re-runs the page's load. Rendered on the unreachable and
  /// load-failed states when provided.
  final VoidCallback? onRetry;

  const HubLoadErrorView({super.key, required this.error, this.onRetry});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final l = AppLocalizations.of(context)!;
    final retry = onRetry == null
        ? null
        : FilledButton.tonal(
            onPressed: onRetry,
            child: Text(l.buttonRetry),
          );
    switch (classifyHubLoadError(error)) {
      case HubLoadIssue.unreachable:
        return ChainEmptyState(
          icon: Icons.cloud_off_outlined,
          iconColor: theme.colorScheme.error,
          title: l.hubUnreachable,
          hint: l.hubUnreachableHint,
          action: retry,
        );
      case HubLoadIssue.unsupported:
        return ChainEmptyState(
          icon: Icons.system_update_alt_outlined,
          title: l.hubViewTooOldTitle,
          hint: l.hubViewTooOldHint,
          action: retry,
        );
      case HubLoadIssue.other:
        return ChainEmptyState(
          icon: Icons.error_outline,
          iconColor: theme.colorScheme.error,
          title: l.hubViewLoadFailedTitle,
          action: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 420),
                child: ChainErrorBox(error: error, isError: true),
              ),
              if (retry != null) ...[
                const SizedBox(height: 12),
                retry,
              ],
            ],
          ),
        );
    }
  }
}