m3_lightmeter/lib/screens/lightmeter_pro/screen_lightmeter_pro.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:lightmeter/data/models/app_feature.dart';
import 'package:lightmeter/generated/l10n.dart';
import 'package:lightmeter/res/dimens.dart';
import 'package:lightmeter/screens/lightmeter_pro/components/offering/widget_offering_lightmeter_pro.dart';
import 'package:lightmeter/screens/shared/sliver_screen/screen_sliver.dart';
import 'package:lightmeter/utils/text_height.dart';
import 'package:m3_lightmeter_iap/m3_lightmeter_iap.dart';

typedef PurchasesState = ({bool isPurchasingProduct, bool isRestoringPurchases});

class LightmeterProScreen extends StatefulWidget {
  const LightmeterProScreen({super.key});

  @override
  State<LightmeterProScreen> createState() => _LightmeterProScreenState();
}

class _LightmeterProScreenState extends State<LightmeterProScreen> {
  final features =
      defaultTargetPlatform == TargetPlatform.android ? AppFeature.androidFeatures : AppFeature.iosFeatures;

  final _purchasesNotifier = ValueNotifier<PurchasesState>(
    (
      isPurchasingProduct: false,
      isRestoringPurchases: false,
    ),
  );

  @override
  Widget build(BuildContext context) {
    return SliverScreen(
      title: Text(S.of(context).proFeaturesTitle),
      appBarActions: [
        ValueListenableBuilder(
          valueListenable: _purchasesNotifier,
          builder: (context, value, _) {
            if (value.isRestoringPurchases) {
              return const SizedBox.square(
                dimension: Dimens.grid24 - Dimens.grid4,
                child: CircularProgressIndicator(),
              );
            } else {
              return IconButton(
                onPressed: value.isPurchasingProduct ? null : _restorePurchases,
                icon: const Icon(Icons.restore),
                tooltip: S.of(context).restorePurchases,
              );
            }
          },
        ),
      ],
      slivers: [
        SliverToBoxAdapter(
          child: Padding(
            padding: const EdgeInsets.all(Dimens.paddingM),
            child: Text(
              S.of(context).proFeaturesPromoText,
              style: Theme.of(context).textTheme.bodyLarge,
            ),
          ),
        ),
        SliverToBoxAdapter(
          child: Padding(
            padding: const EdgeInsets.fromLTRB(
              Dimens.paddingM,
              0,
              Dimens.paddingM,
              Dimens.paddingS,
            ),
            child: Text(
              S.of(context).proFeaturesWhatsIncluded,
              style: Theme.of(context).textTheme.headlineSmall,
            ),
          ),
        ),
        const SliverToBoxAdapter(child: _FeaturesHeader()),
        SliverList.separated(
          itemCount: features.length,
          itemBuilder: (_, index) => _FeatureItem(feature: features[index]),
          separatorBuilder: (_, __) => const Padding(
            padding: EdgeInsets.symmetric(horizontal: Dimens.paddingM),
            child: Divider(),
          ),
        ),
        SliverToBoxAdapter(
          child: Padding(
            padding: const EdgeInsets.all(Dimens.paddingM),
            child: Text(S.of(context).proFeaturesSupportText),
          ),
        ),
      ],
      bottomNavigationBar: ValueListenableBuilder(
        valueListenable: _purchasesNotifier,
        builder: (context, value, _) {
          return LightmeterProOffering(
            isEnabled: !value.isRestoringPurchases && !value.isPurchasingProduct,
            onBuyProduct: _buyPro,
          );
        },
      ),
    );
  }

  @override
  void dispose() {
    _purchasesNotifier.dispose();
    super.dispose();
  }

  Future<void> _restorePurchases() async {
    _purchasesNotifier.isRestoringPurchases = true;
    try {
      final isPro = await IAPProductsProvider.of(context).restorePurchases();
      if (mounted && isPro) {
        Navigator.of(context).pop(true);
      }
    } on PlatformException catch (e) {
      _showSnackbar(e.message ?? '');
    } catch (e) {
      _showSnackbar(e.toString());
    } finally {
      _purchasesNotifier.isRestoringPurchases = false;
    }
  }

  Future<void> _buyPro(IAPProduct product) async {
    _purchasesNotifier.isPurchasingProduct = true;
    try {
      final isPro = await IAPProductsProvider.of(context).buyPro(product);
      if (mounted && isPro) {
        Navigator.of(context).pop(true);
      }
    } on PlatformException catch (e) {
      _showSnackbar(e.message ?? '');
    } catch (e) {
      _showSnackbar(e.toString());
    } finally {
      _purchasesNotifier.isPurchasingProduct = false;
    }
  }

  void _showSnackbar(String message) {
    if (mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(message),
          behavior: SnackBarBehavior.floating,
        ),
      );
    }
  }
}

class _FeaturesHeader extends StatelessWidget {
  const _FeaturesHeader();

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: Dimens.paddingM),
      child: Row(
        children: [
          const Spacer(),
          _FeatureHighlight(child: Text(S.of(context).featuresFree)),
          _FeatureHighlight(
            roundedTop: true,
            highlight: true,
            child: Text(
              S.of(context).featuresPro,
              style: Theme.of(context)
                  .textTheme
                  .bodyMedium!
                  .copyWith(color: Theme.of(context).colorScheme.onSecondaryContainer),
            ),
          ),
        ],
      ),
    );
  }
}

class _FeatureItem extends StatelessWidget {
  final AppFeature feature;

  const _FeatureItem({
    required this.feature,
  });

  @override
  Widget build(BuildContext context) {
    return ConstrainedBox(
      constraints: const BoxConstraints(minHeight: Dimens.grid48),
      child: IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          mainAxisSize: MainAxisSize.min,
          children: [
            Expanded(
              child: Align(
                alignment: Alignment.centerLeft,
                child: Padding(
                  padding: const EdgeInsets.symmetric(
                    horizontal: Dimens.paddingM,
                    vertical: Dimens.paddingS,
                  ),
                  child: Text(
                    feature.name(context),
                    style: Theme.of(context).textTheme.bodyLarge,
                  ),
                ),
              ),
            ),
            Opacity(
              opacity: feature.isFree ? 1 : 0,
              child: const _FeatureHighlight(
                child: _CheckBox(highlight: false),
              ),
            ),
            _FeatureHighlight(
              highlight: true,
              roundedBottom: feature == AppFeature.values.last,
              child: const _CheckBox(highlight: true),
            ),
            const SizedBox(width: Dimens.grid16),
          ],
        ),
      ),
    );
  }
}

class _FeatureHighlight extends StatelessWidget {
  final bool highlight;
  final bool roundedTop;
  final bool roundedBottom;
  final Widget child;

  const _FeatureHighlight({
    this.highlight = false,
    this.roundedTop = false,
    this.roundedBottom = false,
    required this.child,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      constraints: BoxConstraints(
        minWidth: textSize(
              highlight ? S.of(context).featuresPro : S.of(context).featuresFree,
              Theme.of(context).textTheme.bodyMedium,
              MediaQuery.sizeOf(context).width,
            ).width +
            Dimens.paddingM * 2,
      ),
      padding: const EdgeInsets.symmetric(vertical: Dimens.paddingS),
      decoration: BoxDecoration(
        color: highlight ? Theme.of(context).colorScheme.secondaryContainer : null,
        borderRadius: roundedTop
            ? const BorderRadius.only(
                topLeft: Radius.circular(Dimens.borderRadiusM),
                topRight: Radius.circular(Dimens.borderRadiusM),
              )
            : roundedBottom
                ? const BorderRadius.only(
                    bottomLeft: Radius.circular(Dimens.borderRadiusM),
                    bottomRight: Radius.circular(Dimens.borderRadiusM),
                  )
                : null,
      ),
      child: Center(child: child),
    );
  }
}

class _CheckBox extends StatelessWidget {
  final bool highlight;

  const _CheckBox({required this.highlight});

  @override
  Widget build(BuildContext context) {
    return Icon(
      Icons.check_outlined,
      color: highlight ? Theme.of(context).colorScheme.onSecondaryContainer : null,
    );
  }
}

extension on ValueNotifier<PurchasesState> {
  set isPurchasingProduct(bool isPurchasingProduct) {
    value = (isPurchasingProduct: isPurchasingProduct, isRestoringPurchases: value.isRestoringPurchases);
  }

  set isRestoringPurchases(bool isRestoringPurchases) {
    value = (isPurchasingProduct: value.isPurchasingProduct, isRestoringPurchases: isRestoringPurchases);
  }
}