import 'package:flutter/material.dart';

import '../tema/pluriwave_theme.dart';
import 'pluri_wave_scaffold.dart';

/// Design ADR-2: chrome is decided by route topology, not a parameter.
/// [PluriPushScaffold] is the ONE shape a second-level (pushed) screen may
/// take — root screens are plain body widgets living in `_PaginaPrincipal`
/// and never construct a Scaffold themselves.
///
/// The load-bearing part of this API is what it does NOT have: there is no
/// `bottomNavigationBar` parameter. That absence is what makes "second-level
/// screens have no tab bar" unrepresentable rather than a convention someone
/// can forget.
class PluriPushScaffold extends StatelessWidget {
  const PluriPushScaffold({
    super.key,
    required this.title,
    required this.body,
    this.titleOverride,
    this.leadingIcon = Icons.arrow_back_rounded,
    this.onBack,
    this.actions = const <Widget>[],
    this.bottom,
    this.floatingActionButton,
  });

  /// Styled once, here, with [PluriWaveTypography.screenTitle] — the reason
  /// this is a String and not a Widget, so screens stop copy-pasting the
  /// style. See [titleOverride] for the one documented exception.
  final String title;

  final Widget body;

  /// Single documented exception to [title]: the full player's centered
  /// "EN DIRECTO" pill (WU14). A second consumer means ADR-2 gets revisited,
  /// not that this parameter quietly becomes the general case.
  final Widget? titleOverride;

  /// Defaults to a back arrow; `pantalla_reproductor.dart` dismisses with
  /// `keyboard_arrow_down` instead — still one pushed route, one back
  /// affordance, only the glyph differs.
  final IconData leadingIcon;

  /// Defaults to [Navigator.maybePop].
  final VoidCallback? onBack;

  final List<Widget> actions;

  /// Optional persistent footer (e.g. a CTA).
  final PreferredSizeWidget? bottom;

  final Widget? floatingActionButton;

  static const double headerHeight = 56;

  /// Centralises route construction so the transition is uniform and a test
  /// can assert "pushed, not index-switched". Precedent:
  /// `PantallaReproductor.abrir`.
  static Future<T?> push<T>(BuildContext context, WidgetBuilder builder) {
    return Navigator.of(
      context,
    ).push<T>(MaterialPageRoute<T>(builder: builder));
  }

  @override
  Widget build(BuildContext context) {
    final type = context.pluriType;
    return PluriWaveScaffold(
      appBar: AppBar(
        toolbarHeight: headerHeight,
        automaticallyImplyLeading: false,
        leading: IconButton(
          icon: Icon(leadingIcon),
          onPressed: onBack ?? () => Navigator.maybePop(context),
        ),
        title: titleOverride ?? Text(title, style: type.screenTitle),
        actions: actions,
        bottom: bottom,
      ),
      body: body,
      floatingActionButton: floatingActionButton,
    );
  }
}