import 'dart:async';

import 'package:flutter/material.dart';

import 'package:pshared/provider/payout_verification.dart';

import 'package:pweb/models/flow_status.dart';


class PayoutVerificationController extends ChangeNotifier {
  PayoutVerificationProvider? _provider;

  FlowStatus _status = FlowStatus.idle;
  Object? _error;
  Timer? _cooldownTimer;
  int _cooldownRemainingSeconds = 0;
  DateTime? _cooldownUntil;

  FlowStatus get status => _status;
  bool get isSubmitting => _status == FlowStatus.submitting;
  bool get isResending => _status == FlowStatus.resending;
  bool get hasError => _status == FlowStatus.error;
  bool get verificationSuccess => _status == FlowStatus.success;
  Object? get error => _error;
  String get target => _provider?.target ?? '';
  int get cooldownRemainingSeconds => _cooldownRemainingSeconds;
  bool get isCooldownActive => _cooldownRemainingSeconds > 0;

  void update(PayoutVerificationProvider provider) {
    if (identical(_provider, provider)) return;
    _provider?.removeListener(_onProviderChanged);
    _provider = provider;
    _provider?.addListener(_onProviderChanged);
    _syncCooldown(provider.cooldownUntil);
  }

  Future<void> requestCode() async {
    final provider = _provider;
    if (provider == null) {
      throw StateError('Payout verification provider is not ready');
    }
    _error = null;
    _setStatus(FlowStatus.submitting);
    try {
      await provider.requestCode();
      _setStatus(FlowStatus.idle);
    } catch (e) {
      _error = e;
      _setStatus(FlowStatus.error);
      rethrow;
    }
  }

  Future<void> submitCode(String code) async {
    final provider = _provider;
    if (provider == null) {
      throw StateError('Payout verification provider is not ready');
    }

    _error = null;
    _setStatus(FlowStatus.submitting);

    try {
      await provider.confirmCode(code);
      _setStatus(FlowStatus.success);
    } catch (e) {
      _error = e;
      _setStatus(FlowStatus.error);
    }
  }

  Future<void> resendCode() async {
    final provider = _provider;
    if (provider == null) {
      throw StateError('Payout verification provider is not ready');
    }
    if (isResending || isCooldownActive) return;

    _error = null;
    _setStatus(FlowStatus.resending);

    try {
      await provider.resendCode();
      _setStatus(FlowStatus.idle);
    } catch (e) {
      _error = e;
      _setStatus(FlowStatus.error);
    }
  }

  void reset() {
    _error = null;
    _setStatus(FlowStatus.idle);
    _stopCooldown();
    _provider?.reset();
  }

  void resetStatus() {
    _error = null;
    _setStatus(FlowStatus.idle);
  }

  void _onProviderChanged() {
    _syncCooldown(_provider?.cooldownUntil);
    notifyListeners();
  }

  void _syncCooldown(DateTime? until) {
    if (until == null) {
      _stopCooldown(notify: _cooldownRemainingSeconds != 0);
      return;
    }

    if (!_isCooldownActive(until) && _cooldownRemainingSeconds != 0) {
      _stopCooldown(notify: true);
      return;
    }

    if (_cooldownUntil == null || _cooldownUntil != until) {
      _startCooldownUntil(until);
    }
  }

  void _startCooldownUntil(DateTime until) {
    _cooldownTimer?.cancel();
    _cooldownUntil = until;
    _cooldownRemainingSeconds = _cooldownRemaining();

    if (_cooldownRemainingSeconds <= 0) {
      _cooldownTimer = null;
      _cooldownUntil = null;
      notifyListeners();
      return;
    }

    _cooldownTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
      final remaining = _cooldownRemaining();
      if (remaining <= 0) {
        _stopCooldown(notify: true);
        return;
      }
      if (remaining != _cooldownRemainingSeconds) {
        _cooldownRemainingSeconds = remaining;
        notifyListeners();
      }
    });

    notifyListeners();
  }

  bool _isCooldownActive(DateTime until) => until.isAfter(DateTime.now());

  int _cooldownRemaining() {
    final until = _cooldownUntil;
    if (until == null) return 0;
    final remaining = until.difference(DateTime.now()).inSeconds;
    return remaining < 0 ? 0 : remaining;
  }

  void _stopCooldown({bool notify = false}) {
    _cooldownTimer?.cancel();
    _cooldownTimer = null;
    final hadCooldown = _cooldownRemainingSeconds != 0;
    _cooldownRemainingSeconds = 0;
    _cooldownUntil = null;

    if (notify && hadCooldown) {
      notifyListeners();
    }
  }

  void _setStatus(FlowStatus status) {
    if (_status == status) return;
    _status = status;
    notifyListeners();
  }

  @override
  void dispose() {
    _provider?.removeListener(_onProviderChanged);
    _stopCooldown();
    super.dispose();
  }
}