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

import '../../../../i18n/i18n.dart';
import '../../../../utils/config.dart';
import '../../../../widgets/component/component.dart';
import '../../../../widgets/import/progress_state.dart';
import '../../../../widgets/simple_skeleton.dart';
import '../../../import_csv/data/csv_deck.dart';
import 'progress_bloc.dart';
import 'progress_view_model.dart';

class ProgressComponent extends StatelessWidget {
  const ProgressComponent({
    required this.appBarTitle,
    required this.deck,
    required this.onOpenEmailAppTap,
    Key? key,
  }) : super(key: key);

  final CSVDeck deck;
  final String appBarTitle;
  final AsyncCallback onOpenEmailAppTap;

  @override
  Widget build(BuildContext context) {
    return Component<ProgressBloc>(
      createViewModel: (bloc) => bloc.createViewModel(
        deck: deck,
        onOpenEmailAppTap: onOpenEmailAppTap,
      ),
      builder: (context, bloc) {
        return StreamBuilder<ImportProgressViewModel>(
          stream: bloc.viewModel,
          builder: (context, snapshot) {
            if (!snapshot.hasData) {
              return SimpleSkeleton(appBarTitle: appBarTitle);
            }

            return _ProgressView(
              viewModel: snapshot.data!,
              appBarTitle: appBarTitle,
            );
          },
        );
      },
    );
  }
}

@immutable
class _ProgressView extends StatefulWidget {
  const _ProgressView({
    required this.viewModel,
    required this.appBarTitle,
    Key? key,
  }) : super(key: key);

  final ImportProgressViewModel viewModel;
  final String appBarTitle;

  @override
  _ProgressViewState createState() => _ProgressViewState();
}

class _ProgressViewState extends State<_ProgressView>
    with SingleTickerProviderStateMixin {
  late final AnimationController _fadeAnimationController;
  late final Animation<double> _fadeAnimation;

  @override
  void initState() {
    super.initState();

    _fadeAnimationController = AnimationController(
      duration: const Duration(seconds: 2),
      vsync: this,
    )..repeat(reverse: true);
    _fadeAnimation = _fadeAnimationController.drive(
      CurveTween(curve: Curves.easeInOutSine),
    );
  }

  @override
  Widget build(BuildContext context) {
    final isError =
        widget.viewModel.importState == ProgressState.isGeneralError ||
            widget.viewModel.importState == ProgressState.isInternetError;

    return WillPopScope(
      onWillPop: () async {
        widget.viewModel.onCloseTap();

        // Always return false because popping is handled by onCancelTap
        return false;
      },
      child: Scaffold(
        appBar: AppBar(
          leading: IconButton(
            icon: Icon(
              widget.viewModel.importState == ProgressState.isImporting
                  ? Icons.close_outlined
                  : Icons.arrow_back_ios_new_outlined,
            ),
            onPressed: widget.viewModel.onCloseTap,
          ),
          title: Text(widget.appBarTitle),
          elevation: 0,
        ),
        body: Column(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: <Widget>[
            const Spacer(flex: 6),
            Center(
              child: Padding(
                padding: const EdgeInsets.symmetric(horizontal: 32),
                child: _buildProgressIndicator(context),
              ),
            ),
            const Spacer(),

            if (!isError) const Spacer(flex: 2),
            if (isError)
              Flexible(
                flex: 2,
                fit: FlexFit.tight,
                child: Center(
                  child: Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 24),
                    child: Text(
                      widget.viewModel.importState ==
                              ProgressState.isInternetError
                          ? S.of(context).errorNoInternetText
                          : S
                              .of(context)
                              .pleaseSendUsAnEmailAtSupport(supportEmail),
                      textAlign: TextAlign.center,
                    ),
                  ),
                ),
              ),
            const Spacer(flex: 3),
            // Size of extended floating action button + padding
            const SizedBox(height: 48.0 + 16),
          ],
        ),
        floatingActionButton: _buildFAB(context),
        floatingActionButtonLocation: FloatingActionButtonLocation.centerFloat,
      ),
    );
  }

  Widget _buildProgressIndicator(BuildContext context) {
    var currentStep = 0;
    if (widget.viewModel.importProgress != null &&
        widget.viewModel.importProgress!.toPercent().isFinite) {
      // Multiply by 10 to show a progress by 0.1 percent
      currentStep =
          (widget.viewModel.importProgress!.toPercent(1) * 10).toInt();
    }

    return CircularStepProgressIndicator(
      totalSteps: 1000,
      stepSize: 1,
      currentStep: currentStep,
      selectedColor:
          widget.viewModel.importState == ProgressState.isImporting ||
                  widget.viewModel.importState == ProgressState.isDone
              ? Theme.of(context).colorScheme.primary
              : Theme.of(context).colorScheme.error,
      unselectedColor: Colors.grey[200],
      padding: 0,
      width: 200,
      height: 200,
      selectedStepSize: 10,
      unselectedStepSize: 5,
      roundedCap: (_, __) => true,
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: _buildInnerProgressWidget(context),
      ),
    );
  }

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

  Widget _buildInnerProgressWidget(BuildContext context) {
    var subtitleText = '';
    switch (widget.viewModel.importState) {
      case ProgressState.isImporting:
        if (widget.viewModel.remainingTime == null) {
          subtitleText = S.of(context).calculatingRemainingTime;
        } else if (widget.viewModel.remainingTime!.inMinutes > 120) {
          subtitleText = S
              .of(context)
              .hoursRemaining(widget.viewModel.remainingTime!.inHours);
        } else if (widget.viewModel.remainingTime!.inSeconds > 180) {
          subtitleText = S
              .of(context)
              .minutesRemaining(widget.viewModel.remainingTime!.inMinutes);
        } else {
          subtitleText = S
              .of(context)
              .secondsRemaining(widget.viewModel.remainingTime!.inSeconds);
        }
        break;
      case ProgressState.isDone:
        subtitleText = S.of(context).importFinished;
        break;
      case ProgressState.isGeneralError:
      case ProgressState.isInternetError:
        subtitleText = S.of(context).anErrorOccured;
    }

    final isError =
        widget.viewModel.importState == ProgressState.isGeneralError ||
            widget.viewModel.importState == ProgressState.isInternetError;

    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        Text.rich(
          TextSpan(
            children: [
              TextSpan(
                text: widget.viewModel.importProgress
                        ?.toPercent()
                        .toInt()
                        .toString() ??
                    '0',
                style: Theme.of(context)
                    .textTheme
                    .bodyText1!
                    .copyWith(fontSize: 32),
              ),
              TextSpan(
                text: '%',
                style: Theme.of(context).textTheme.bodyText1!,
              ),
            ],
          ),
        ),
        const SizedBox(height: 8),
        FadeTransition(
          opacity: widget.viewModel.remainingTime != null || isError
              ? const AlwaysStoppedAnimation(1)
              : _fadeAnimation,
          child: Text(
            subtitleText,
            textAlign: TextAlign.center,
            style: Theme.of(context).textTheme.subtitle1,
          ),
        ),
      ],
    );
  }

  Widget _buildFAB(BuildContext context) {
    switch (widget.viewModel.importState) {
      case ProgressState.isImporting:
        return FloatingActionButton.extended(
          label: Text(S.of(context).abortImport.toUpperCase()),
          onPressed: widget.viewModel.onCloseTap,
          backgroundColor: Theme.of(context).colorScheme.error,
        );
      case ProgressState.isGeneralError:
        return FloatingActionButton.extended(
          label: Text(S.of(context).openEmailApp.toUpperCase()),
          onPressed: widget.viewModel.onOpenEmailAppTap,
          foregroundColor: Theme.of(context).colorScheme.onPrimary,
          backgroundColor: Theme.of(context).colorScheme.primary,
        );
      case ProgressState.isDone:
      case ProgressState.isInternetError:
        return FloatingActionButton.extended(
          label: Text(S.of(context).goToHomePage.toUpperCase()),
          onPressed: widget.viewModel.onCloseTap,
        );
    }
  }
}