plezy/lib/screens/libraries/content_state_builder.dart

import 'package:flutter/material.dart';
import 'package:material_symbols_icons/symbols.dart';
import '../../i18n/strings.g.dart';
import 'state_messages.dart';

/// Sliver wrapper around [ErrorStateWidget] for use in `CustomScrollView.slivers`.
class SliverErrorState extends StatelessWidget {
  final String message;
  final VoidCallback? onRetry;
  final String? retryLabel;

  const SliverErrorState({super.key, required this.message, this.onRetry, this.retryLabel});

  @override
  Widget build(BuildContext context) => SliverFillRemaining(
    child: ErrorStateWidget(
      message: message,
      icon: Symbols.error_outline_rounded,
      onRetry: onRetry,
      retryLabel: retryLabel ?? t.common.retry,
    ),
  );
}

/// Sliver wrapper around [EmptyStateWidget] for use in `CustomScrollView.slivers`.
class SliverEmptyState extends StatelessWidget {
  final String message;
  final IconData? icon;
  final String? subtitle;
  final VoidCallback? onAction;
  final String? actionLabel;
  final IconData? actionIcon;

  const SliverEmptyState({
    super.key,
    required this.message,
    required this.icon,
    this.subtitle,
    this.onAction,
    this.actionLabel,
    this.actionIcon,
  });

  @override
  Widget build(BuildContext context) => SliverFillRemaining(
    child: EmptyStateWidget(
      message: message,
      icon: icon,
      subtitle: subtitle,
      onAction: onAction,
      actionLabel: actionLabel,
      actionIcon: actionIcon,
    ),
  );
}

/// A widget that handles loading, error, empty, and content states
/// Provides a consistent UI pattern across the app for data-driven screens
class ContentStateBuilder<T> extends StatelessWidget {
  /// Whether data is currently loading
  final bool isLoading;

  /// Error message to display (null if no error)
  final String? errorMessage;

  /// The list of items to display
  final List<T> items;

  /// Icon to display when the list is empty
  final IconData emptyIcon;

  /// Message to display when the list is empty
  final String emptyMessage;

  /// Callback when user taps retry button
  final VoidCallback onRetry;

  /// Builder for the content when items are available
  final Widget Function(List<T> items) builder;

  const ContentStateBuilder({
    super.key,
    required this.isLoading,
    required this.errorMessage,
    required this.items,
    required this.emptyIcon,
    required this.emptyMessage,
    required this.onRetry,
    required this.builder,
  });

  @override
  Widget build(BuildContext context) {
    // Loading state (only show loading indicator if items list is empty)
    if (isLoading && items.isEmpty) {
      return const Center(child: CircularProgressIndicator());
    }

    // Error state (only show error if items list is empty)
    if (errorMessage != null && items.isEmpty) {
      return ErrorStateWidget(
        message: errorMessage!,
        icon: Symbols.error_outline_rounded,
        onRetry: onRetry,
        retryLabel: t.common.retry,
      );
    }

    // Empty state
    if (items.isEmpty) {
      return EmptyStateWidget(message: emptyMessage, icon: emptyIcon);
    }

    // Content state - delegate to builder
    return builder(items);
  }
}