import 'dart:async';
import 'package:bloc/bloc.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:get_it/get_it.dart';
import 'package:okane/database/sqlite.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) TransactionDto? activeTransaction,
    @Default([]) List<Account> accounts,
    @Default([]) List<RecurringTransactionDto> recurringTransactions,
    @Default([]) List<TransactionDto> transactions,
    @Default([]) List<TransactionTemplateDto> transactionTemplates,
    @Default([]) List<Beneficiary> beneficiaries,
    @Default([]) List<ExpenseCategory> expenseCategories,
    @Default([]) List<BudgetsDto> budgets,
    @Default([]) List<BudgetItemDto> budgetItems,
    @Default(null) BudgetsDto? activeBudget,
    @Default([]) List<LoanDto> loans,
    @Default(null) LoanDto? activeLoan,
    @Default(false) bool isDeletingAccount,
  }) = _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;
  StreamSubscription<void>? _budgetItemsStreamSubscription;
  StreamSubscription<void>? _loanStreamSubscription;

  void setupAccountStream() {
    _accountsStreamSubscription?.cancel();
    _accountsStreamSubscription = GetIt.I
        .get<OkaneDatabase>()
        .accountsDao
        .accountsStream()
        .listen((accounts) {
          emit(
            state.copyWith(
              accounts: accounts,
              activeAccountIndex:
                  accounts.isNotEmpty ? state.activeAccountIndex ?? 0 : null,
            ),
          );
        });
  }

  void setupStreams(Account account) {
    final db = GetIt.I.get<OkaneDatabase>();
    setupAccountStream();
    _recurringTransactionStreamSubscription?.cancel();
    _recurringTransactionStreamSubscription = db.recurringTransactionsDao
        .recurringTransactionsStream(account)
        .listen((recurring) async {
          emit(state.copyWith(recurringTransactions: recurring));
        });
    _transactionTemplatesStreamSubcription?.cancel();
    _transactionTemplatesStreamSubcription = db.transactionTemplatesDao
        .transactionTemplatesStream(account)
        .listen((templates) async {
          emit(state.copyWith(transactionTemplates: templates));
        });
    _transactionsStreamSubscription?.cancel();
    _transactionsStreamSubscription = db.transactionsDao
        .transactionsStream(activeAccount!)
        .listen((transactions) async {
          emit(state.copyWith(transactions: transactions));
        });
    _beneficiariesStreamSubscription?.cancel();
    _beneficiariesStreamSubscription = db.beneficiariesDao
        .beneficiariesStream()
        .listen((beneficiaries) async {
          emit(state.copyWith(beneficiaries: beneficiaries));
        });
    _expenseCategoryStreamSubscription?.cancel();
    _expenseCategoryStreamSubscription = db.expenseCategoriesDao
        .expenseCategoriesStream(account)
        .listen((expenseCategories) async {
          emit(state.copyWith(expenseCategories: expenseCategories));
        });
    _budgetsStreamSubscription?.cancel();
    _budgetsStreamSubscription = db.budgetsDao
        .budgetsStream(activeAccount!)
        .listen((budgets) async {
          print("BUDGETS: $budgets");
          emit(state.copyWith(budgets: budgets));
        });
    _loanStreamSubscription?.cancel();
    _loanStreamSubscription = db.loansDao.loansStream(account).listen((
      loans,
    ) async {
      emit(state.copyWith(loans: loans));
    });
  }

  void cancelStreams() {
    _recurringTransactionStreamSubscription?.cancel();
    _accountsStreamSubscription?.cancel();
    _beneficiariesStreamSubscription?.cancel();
    _budgetsStreamSubscription?.cancel();
    _expenseCategoryStreamSubscription?.cancel();
    _transactionsStreamSubscription?.cancel();
    _transactionTemplatesStreamSubcription?.cancel();
    _loanStreamSubscription?.cancel();
  }

  Future<void> init() async {
    final db = GetIt.I.get<OkaneDatabase>();
    final accounts = await db.accountsDao.getAccounts();
    final account = accounts.isEmpty ? null : accounts[0];
    emit(
      state.copyWith(
        accounts: accounts,
        activeAccountIndex: accounts.isEmpty ? null : 0,
        transactions: await db.transactionsDao.getTransactions(account),
        beneficiaries: await db.beneficiariesDao.getBeneficiaries(),
        transactionTemplates: await db.transactionTemplatesDao
            .getTransactionTemplates(account),
        recurringTransactions: await db.recurringTransactionsDao
            .getRecurringTransactions(account),
        expenseCategories: await db.expenseCategoriesDao.getExpenseCategories(
          account,
        ),
        //budgets: await db.budgetsDao.getBudgets(account),
        loans: await db.loansDao.getLoans(account),
      ),
    );

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

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

  Future<void> setActiveAccountIndex(int index) async {
    final db = GetIt.I.get<OkaneDatabase>();
    final account = state.accounts[index];
    emit(
      state.copyWith(
        activeAccountIndex: index,
        transactions: await db.transactionsDao.getTransactions(account),
        beneficiaries: await db.beneficiariesDao.getBeneficiaries(),
        transactionTemplates: await db.transactionTemplatesDao
            .getTransactionTemplates(account),
        recurringTransactions: await db.recurringTransactionsDao
            .getRecurringTransactions(account),
        budgets: await db.budgetsDao.getBudgets(account),
        activeBudget: null,
        activeTransaction: null,
        activeLoan: null,
      ),
    );
    setupStreams(account);
  }

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

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

  void setActiveBudget(BudgetsDto? budget) {
    emit(state.copyWith(activeBudget: budget, budgetItems: []));
    _budgetItemsStreamSubscription?.cancel();
    if (budget != null) {
      _budgetItemsStreamSubscription = GetIt.I
          .get<OkaneDatabase>()
          .budgetsDao
          .watchBudgetItems(budget.budget)
          .listen((items) {
            emit(state.copyWith(budgetItems: items));
          });
    }
  }

  Future<void> deleteAccount(Account account) async {
    final l = List.of(state.accounts);
    l.removeWhere((a) => a.id == account.id);
    final newIndex = l.isEmpty ? null : 0;
    emit(state.copyWith(activeAccountIndex: newIndex, isDeletingAccount: true));

    cancelStreams();
    try {
      // TODO
      //await db.deleteAccount(account);
    } finally {
      emit(state.copyWith(isDeletingAccount: false));
    }
    await init();
  }

  void setActiveLoan(LoanDto loan) {
    emit(state.copyWith(activeLoan: loan));
  }

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