import 'dart:async';

import 'package:bloc/bloc.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:okane/database/collections/account.dart';
import 'package:okane/database/collections/beneficiary.dart';
import 'package:okane/database/collections/budget.dart';
import 'package:okane/database/collections/expense_category.dart';
import 'package:okane/database/collections/recurrent.dart';
import 'package:okane/database/collections/template.dart';
import 'package:okane/database/collections/transaction.dart';
import 'package:okane/database/database.dart';
import 'package:okane/ui/navigation.dart';

part 'core.freezed.dart';

@freezed
abstract class CoreState with _$CoreState {
  const factory CoreState({
    @Default(OkanePage.accounts) OkanePage activePage,
    int? activeAccountIndex,
    @Default(null) Transaction? activeTransaction,
    @Default([]) List<Account> accounts,
    @Default([]) List<RecurringTransaction> recurringTransactions,
    @Default([]) List<Transaction> transactions,
    @Default([]) List<TransactionTemplate> transactionTemplates,
    @Default([]) List<Beneficiary> beneficiaries,
    @Default([]) List<ExpenseCategory> expenseCategories,
    @Default([]) List<Budget> budgets,
    @Default(null) Budget? activeBudget,
  }) = _CoreState;
}

class CoreCubit extends Cubit<CoreState> {
  CoreCubit() : super(CoreState());

  StreamSubscription<void>? _recurringTransactionStreamSubscription;
  StreamSubscription<void>? _transactionTemplatesStreamSubcription;
  StreamSubscription<void>? _accountsStreamSubscription;
  StreamSubscription<void>? _transactionsStreamSubscription;
  StreamSubscription<void>? _beneficiariesStreamSubscription;
  StreamSubscription<void>? _expenseCategoryStreamSubscription;
  StreamSubscription<void>? _budgetsStreamSubscription;

  void setupAccountStream() {
    _accountsStreamSubscription?.cancel();
    _accountsStreamSubscription = watchAccounts().listen((_) async {
      final resetStreams = state.activeAccountIndex == null;
      final accounts = await getAccounts();
      emit(
        state.copyWith(
          accounts: accounts,
          activeAccountIndex: state.activeAccountIndex ?? 0,
        ),
      );

      if (resetStreams) {
        setupStreams(accounts[0]);
      }
    });
  }

  void setupStreams(Account account) {
    setupAccountStream();
    _recurringTransactionStreamSubscription?.cancel();
    _recurringTransactionStreamSubscription = watchRecurringTransactions(
      activeAccount!,
    ).listen((_) async {
      emit(
        state.copyWith(
          recurringTransactions: await getRecurringTransactions(activeAccount!),
        ),
      );
    });
    _transactionTemplatesStreamSubcription?.cancel();
    _transactionTemplatesStreamSubcription = watchTransactionTemplates(
      activeAccount!,
    ).listen((_) async {
      emit(
        state.copyWith(
          transactionTemplates: await getTransactionTemplates(activeAccount!),
        ),
      );
    });
    _transactionsStreamSubscription?.cancel();
    _transactionsStreamSubscription = watchTransactions(activeAccount!).listen((
      _,
    ) async {
      emit(state.copyWith(transactions: await getTransactions(activeAccount!)));
    });
    _beneficiariesStreamSubscription?.cancel();
    _beneficiariesStreamSubscription = watchBeneficiaries().listen((_) async {
      emit(state.copyWith(beneficiaries: await getBeneficiaries()));
    });
    _expenseCategoryStreamSubscription?.cancel();
    _expenseCategoryStreamSubscription = watchExpenseCategory().listen((
      _,
    ) async {
      emit(state.copyWith(expenseCategories: await getExpenseCategories()));
    });
    _budgetsStreamSubscription?.cancel();
    _budgetsStreamSubscription = watchBudgets(activeAccount!).listen((_) async {
      emit(state.copyWith(budgets: await getBudgets(activeAccount!)));
    });
  }

  Future<void> init() async {
    final accounts = await getAccounts();
    final account = accounts.isEmpty ? null : accounts[0];
    emit(
      state.copyWith(
        accounts: accounts,
        activeAccountIndex: accounts.isEmpty ? null : 0,
        transactions: await getTransactions(account),
        beneficiaries: await getBeneficiaries(),
        transactionTemplates: await getTransactionTemplates(account),
        recurringTransactions: await getRecurringTransactions(account),
        expenseCategories: await getExpenseCategories(),
        budgets: await getBudgets(account),
      ),
    );

    if (account != null) {
      setupStreams(account);
    } else {
      setupAccountStream();
    }
    print("Core init done");
  }

  void setPage(OkanePage page) {
    emit(state.copyWith(activePage: page));
  }

  Future<void> setActiveAccountIndex(int index) async {
    final account = state.accounts[index];
    emit(
      state.copyWith(
        activeAccountIndex: index,
        transactions: await getTransactions(account),
        beneficiaries: await getBeneficiaries(),
        transactionTemplates: await getTransactionTemplates(account),
        recurringTransactions: await getRecurringTransactions(account),
        budgets: await getBudgets(account),
        activeBudget: null,
        activeTransaction: null,
      ),
    );
    setupStreams(account);
  }

  void setActiveTransaction(Transaction? item) {
    emit(state.copyWith(activeTransaction: item));
  }

  void setAccounts(List<Account> accounts) {
    emit(state.copyWith(accounts: accounts));
  }

  void setActiveBudget(Budget? budget) {
    emit(state.copyWith(activeBudget: budget));
  }

  Account? get activeAccount =>
      state.activeAccountIndex == null
          ? null
          : state.accounts[state.activeAccountIndex!];
}