import 'dart:io' show Platform;
import 'dart:math' as math;
import 'dart:ui' show ImageFilter;

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../../providers/appearance_provider.dart';
import '../../../shared/theme/app_theme.dart';
import '../../../shared/widgets/top_drag_area.dart';
import '../../../shared/widgets/window_chrome.dart';
import '../../../shared/widgets/window_controls.dart';

const double _kDesktopTitleBarHeight = 38.0;

class DetailNavBar extends ConsumerWidget {
  final ValueListenable<double> scrollProgress;
  final String title;
  final VoidCallback onBack;
  final Color chromeColor;

  const DetailNavBar({
    super.key,
    required this.scrollProgress,
    required this.title,
    required this.onBack,
    this.chromeColor = const Color(0xFF08090c),
  });

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final isDesktop = WindowChrome.isDesktop;
    final topPadding = isDesktop
        ? _kDesktopTitleBarHeight
        : math.max(MediaQuery.paddingOf(context).top, _kDesktopTitleBarHeight);
    final tokens = context.appTokens;

    final headerMode =
        ref.watch(appearanceProvider).value?.headerMode ?? HeaderMode.frosted;
    final isFrosted = headerMode == HeaderMode.frosted;

    final navHeight = topPadding + 30;

    return Stack(
      children: [
        SizedBox(
          height: navHeight,
          width: double.infinity,
          child: ValueListenableBuilder<double>(
            valueListenable: scrollProgress,
            builder: (_, raw, _) {
              final p = raw.clamp(0.0, 1.0);
              if (isFrosted) {
                if (Platform.isAndroid && p < 0.05) {
                  return const SizedBox.expand();
                }
                final maxSigma = Platform.isAndroid ? 10.0 : 18.0;
                return ClipRect(
                  child: BackdropFilter(
                    filter: ImageFilter.blur(
                      sigmaX: p * maxSigma,
                      sigmaY: p * maxSigma,
                    ),
                    child: DecoratedBox(
                      decoration: BoxDecoration(
                        color: chromeColor.withValues(alpha: p * 0.7),
                        border: Border(
                          bottom: BorderSide(
                            color: const Color(
                              0xFFFFFFFF,
                            ).withValues(alpha: p * 0.08),
                            width: 1,
                          ),
                        ),
                      ),
                    ),
                  ),
                );
              }
              return ColoredBox(color: chromeColor.withValues(alpha: p));
            },
          ),
        ),
        const Positioned.fill(child: TopDragArea(child: SizedBox.expand())),
        Positioned(
          top: isDesktop
              ? tokens.chromeInset
              : MediaQuery.paddingOf(context).top,
          left: 0,
          right: 0,
          child: Row(
            children: [
              SizedBox(width: tokens.chromeInset),
              IconButton(
                icon: const Icon(
                  Icons.arrow_back,
                  color: Colors.white,
                  size: 18,
                ),
                onPressed: onBack,
                tooltip: '返回',
                constraints: const BoxConstraints(minWidth: 30, minHeight: 30),
                padding: const EdgeInsets.all(6),
              ),
              const SizedBox(width: 4),
              Expanded(
                child: IgnorePointer(
                  child: ValueListenableBuilder<double>(
                    valueListenable: scrollProgress,
                    builder: (_, p, child) {
                      return Opacity(opacity: p.clamp(0.0, 1.0), child: child);
                    },
                    child: Text(
                      title,
                      style: const TextStyle(
                        color: Colors.white,
                        fontSize: 16,
                        fontWeight: FontWeight.w600,
                      ),
                      overflow: TextOverflow.ellipsis,
                    ),
                  ),
                ),
              ),
              const SizedBox(width: 4),
              if (isDesktop) const WindowControls.forDarkSurface(),
              SizedBox(width: tokens.chromeInset),
            ],
          ),
        ),
      ],
    );
  }
}