// ignore_for_file: annotate_overrides

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:markettakers/markettakers.dart';
import 'package:markettakers/src/loaders/loader.dart';
import 'package:percent_indicator/circular_percent_indicator.dart';

part 'bootstrapper.freezed.dart';

abstract class StageFactory {
  String get title;

  Future<bool> get isAlreadyCompleted async => false;

  Future<void> start(StageController controller);
  void dispose() {}
}

@freezed
sealed class Progress with _$Progress {
  const factory Progress.definite(double value) = PercentageProgress;
  const factory Progress.indefinite() = IndefiniteProgress;
}

@freezed
class StageState with _$StageState {
  final String title;
  final Progress progress;

  StageState({required this.title, required this.progress});
}

class StageController extends Cubit<StageState> {
  StageController({required String title})
    : super(StageState(title: title, progress: const Progress.indefinite()));

  void setDefiniteProgress(double value) {
    emit(state.copyWith(progress: Progress.definite(value)));
  }

  void setIndefiniteProgress() {
    emit(state.copyWith(progress: const Progress.indefinite()));
  }

  void updateTitle(String title) {
    emit(state.copyWith(title: title));
  }
}

typedef Stages = List<StageFactory>;

@freezed
class BootstrapState with _$BootstrapState {
  final Stages stages;
  final int currentStageIndex;
  final StageController? controller;

  StageFactory get currentStage => stages[currentStageIndex];
  bool get areStagesCompleted => currentStageIndex >= stages.length;

  BootstrapState(this.stages, {this.currentStageIndex = 0, this.controller});
}

@freezed
sealed class _BootstrapEvent with _$BootstrapEvent {
  const factory _BootstrapEvent.start() = StartEvent;
  const factory _BootstrapEvent.stageCompleted() = StageCompletedEvent;
}

class _BootstrapController extends Bloc<_BootstrapEvent, BootstrapState> {
  final Completer<void> completer;
  _BootstrapController(super.initialState, this.completer) {
    assert(state.stages.isNotEmpty, "Stages list cannot be empty");

    on<StartEvent>((event, emit) {
      talker.info("BootstrapController: Starting bootstrap process");
      final controller = launchCurrentStage(
        state.stages,
        state.currentStageIndex,
      );
      emit(state.copyWith(controller: controller));
    });
    on<StageCompletedEvent>((event, emit) async {
      talker.info("BootstrapController: ${state.currentStage.title} completed");
      state.currentStage.dispose();

      final nextIndex = state.currentStageIndex + 1;
      final newState = state.copyWith(currentStageIndex: nextIndex);

      // all stages completed
      if (newState.areStagesCompleted) {
        talker.info("BootstrapController: All stages completed");
        completer.complete();

        // skip already completed stages
      } else if (await newState.currentStage.isAlreadyCompleted) {
        talker.info(
          "BootstrapController: Stage ${newState.currentStage.title} already completed, skipping",
        );
        add(const _BootstrapEvent.stageCompleted());

        // move to next stage
      } else {
        final nextStage = newState.currentStage;
        talker.info("BootstrapController: Starting stage ${nextStage.title}");
        launchCurrentStage(state.stages, nextIndex);
        emit(newState);
      }
    });
  }

  StageController launchCurrentStage(Stages stages, int index) {
    final currentStage = stages[index];
    final controller = StageController(title: currentStage.title);

    currentStage
        .start(controller)
        .then((_) {
          add(_BootstrapEvent.stageCompleted());
        })
        .catchError((error) {
          talker.handle(
            error,
            null,
            "BootstrapController: Error in  ${currentStage.title}",
          );
          addError(error);
        });

    return controller;
  }
}

class _DefiniteIndicator extends StatelessWidget {
  final double progress; // 0.0 to 1.0

  const _DefiniteIndicator({required this.progress});

  @override
  Widget build(BuildContext context) {
    final formattedProgress = "${(progress * 100).toStringAsFixed(0)}%";
    return CircularPercentIndicator(
      radius: 40.0,
      lineWidth: 5.0,
      percent: progress.clamp(0.0, 1.0),
      center: Text(formattedProgress),
      progressColor: Theme.of(context).colorScheme.secondary,
    );
  }
}

class _BootstrapFooter extends StatelessWidget {
  const _BootstrapFooter();

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<_BootstrapController, BootstrapState>(
      builder: (context, state) {
        if (state.areStagesCompleted) {
          return Text(
            "All stages completed",
            style: Theme.of(context).textTheme.titleMedium,
          );
        } else if (state.controller != null) {
          return BlocBuilder<StageController, StageState>(
            bloc: state.controller,
            builder: (context, state) {
              final progressIndicator = state.progress.when(
                definite: (definite) => _DefiniteIndicator(progress: definite),
                indefinite: () => const CircularProgressIndicator(),
              );

              return Column(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                mainAxisSize: MainAxisSize.max,
                children: [
                  Flexible(
                    flex: 1,
                    child: Text(
                      state.title,
                      style: Theme.of(context).textTheme.titleLarge,
                    ),
                  ),
                  Flexible(flex: 1, child: progressIndicator),
                ],
              );
            },
          );
        } else {
          return const SizedBox.shrink();
        }
      },
    );
  }
}

class Bootstrapper extends StatelessWidget {
  final Stages stages;
  final Completer onCompleted;

  const Bootstrapper({
    super.key,
    required this.stages,
    required this.onCompleted,
  });

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) {
        final controller = _BootstrapController(
          BootstrapState(stages),
          onCompleted,
        );
        controller.add(const _BootstrapEvent.start());
        return controller;
      },
      child: BlocListener<_BootstrapController, BootstrapState>(
        listener: (context, state) {
          if (state.areStagesCompleted) {
            onCompleted.complete();
          }
        },
        child: Column(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            Flexible(
              flex: 2,
              child: Center(child: Loader.playing(flavour: LoaderFlavour.big)),
            ),
            Flexible(flex: 1, child: Container()),
            Flexible(flex: 1, child: _BootstrapFooter()),
            Flexible(flex: 1, child: Container()),
          ],
        ),
      ),
    );
  }
}