import 'dart:async';

import 'package:drift/drift.dart';
import 'package:drift_flutter/drift_flutter.dart';
import 'package:okane/ui/utils.dart';
import 'package:path_provider/path_provider.dart';

part 'sqlite.g.dart';

class Accounts extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get name => text()();
}

enum BeneficiaryType { account, other }

class Beneficiaries extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get name => text().unique()();
  TextColumn get type => textEnum<BeneficiaryType>()();
  IntColumn get accountId => integer().nullable().references(Accounts, #id)();
  TextColumn get imagePath => text().nullable()();
}

class ExpenseCategories extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get name => text()();
}

enum BudgetPeriod { month }

class BudgetItems extends Table {
  IntColumn get id => integer().autoIncrement()();
  RealColumn get amount => real()();
  IntColumn get expenseCategoryId =>
      integer().references(ExpenseCategories, #id)();
  IntColumn get budgetId => integer().references(Budgets, #id)();
}

class BudgetItemDto {
  final BudgetItem item;
  final ExpenseCategory expenseCategory;

  BudgetItemDto({required this.item, required this.expenseCategory});
}

class Budgets extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get period => textEnum<BudgetPeriod>()();
  TextColumn get name => text()();
  RealColumn get income => real()();
  BoolColumn get includeOtherSpendings => boolean()();

  IntColumn get accountId => integer().references(Accounts, #id)();
}

class BudgetsDto {
  final Budget budget;

  BudgetsDto({required this.budget});
}

class Loans extends Table {
  IntColumn get id => integer().autoIncrement()();
  IntColumn get beneficiaryId => integer().references(Beneficiaries, #id)();
}

class LoanChanges extends Table {
  IntColumn get id => integer().autoIncrement()();
  IntColumn get loanId => integer().references(Loans, #id)();
  RealColumn get amount => real()();
  DateTimeColumn get date => dateTime()();
}

class LoanDto {
  final Loan loan;
  final Beneficiary beneficiary;

  LoanDto({required this.loan, required this.beneficiary});
}

class RecurringTransactions extends Table {
  IntColumn get id => integer().autoIncrement()();
  IntColumn get days => integer()();
  DateTimeColumn get lastExecution => dateTime().nullable()();

  IntColumn get templateId => integer().references(TransactionTemplates, #id)();

  IntColumn get accountId => integer().references(Accounts, #id)();
}

typedef RecurringTransactionDto =
    ({
      RecurringTransaction recurring,
      Beneficiary beneficiary,
      TransactionTemplate template,
    });

class TransactionTemplates extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get name => text()();
  RealColumn get amount => real()();
  BoolColumn get recurring => boolean()();

  IntColumn get expenseCategoryId =>
      integer().nullable().references(ExpenseCategories, #id)();
  IntColumn get beneficiaryId => integer().references(Beneficiaries, #id)();
  IntColumn get accountId => integer().references(Accounts, #id)();
}

typedef TransactionTemplateDto =
    ({
      TransactionTemplate template,
      Beneficiary beneficiary,
      ExpenseCategory? expenseCategory,
    });

class Transactions extends Table {
  IntColumn get id => integer().autoIncrement()();

  RealColumn get amount => real()();
  // TODO: tags
  DateTimeColumn get date => dateTime()();
  IntColumn get expenseCategoryId =>
      integer().nullable().references(ExpenseCategories, #id)();
  IntColumn get accountId => integer().references(Accounts, #id)();
  IntColumn get beneficiaryId => integer().references(Beneficiaries, #id)();
}

class TransactionDto {
  final Transaction transaction;
  final Beneficiary beneficiary;
  final ExpenseCategory? expenseCategory;

  TransactionDto({
    required this.transaction,
    required this.beneficiary,
    required this.expenseCategory,
  });
}

@DriftDatabase(
  tables: [
    Accounts,
    Beneficiaries,
    Budgets,
    BudgetItems,
    ExpenseCategories,
    Loans,
    LoanChanges,
    RecurringTransactions,
    TransactionTemplates,
    Transactions,
  ],
  daos: [
    AccountsDao,
    BeneficiariesDao,
    BudgetsDao,
    ExpenseCategoriesDao,
    LoansDao,
    RecurringTransactionsDao,
    TransactionTemplatesDao,
    TransactionsDao,
  ],
)
class OkaneDatabase extends _$OkaneDatabase {
  OkaneDatabase() : super(_openConnection());

  @override
  int get schemaVersion => 1;

  static QueryExecutor _openConnection() {
    return driftDatabase(
      name: "okane",
      native: const DriftNativeOptions(
        databaseDirectory: getApplicationSupportDirectory,
      ),
    );
  }
}

@DriftAccessor(tables: [Accounts])
class AccountsDao extends DatabaseAccessor<OkaneDatabase>
    with _$AccountsDaoMixin {
  AccountsDao(OkaneDatabase db) : super(db);

  Stream<List<Account>> accountsStream() {
    return select(accounts).watch();
  }

  Future<List<Account>> getAccounts() {
    return select(accounts).get();
  }

  Future<int> upsertAccount(AccountsCompanion account) {
    return into(accounts).insertOnConflictUpdate(account);
  }
}

enum TransactionQueryDateOption { thisMonth }

@DriftAccessor(tables: [Transactions, Beneficiaries, ExpenseCategories])
class TransactionsDao extends DatabaseAccessor<OkaneDatabase>
    with _$TransactionsDaoMixin {
  TransactionsDao(OkaneDatabase db) : super(db);

  JoinedSelectStatement _transactionQuery(Account account) {
    return (select(transactions)
      ..where((t) => t.accountId.equals(account.id))).join([
      leftOuterJoin(
        beneficiaries,
        beneficiaries.id.equalsExp(transactions.beneficiaryId),
      ),
      leftOuterJoin(
        expenseCategories,
        expenseCategories.id.equalsExp(transactions.expenseCategoryId),
      ),
    ]);
  }

  TransactionDto _mapToDto(TypedResult row) {
    return TransactionDto(
      transaction: row.readTable(transactions),
      beneficiary: row.readTable(beneficiaries),
      expenseCategory: row.readTableOrNull(expenseCategories),
    );
  }

  Stream<List<TransactionDto>> transactionsStream(Account account) {
    return _transactionQuery(account).watch().map((rows) {
      return rows.map(_mapToDto).toList();
    });
  }

  Future<List<TransactionDto>> getTransactions(Account? account) {
    if (account == null) {
      return Future.value(List.empty());
    }

    return _transactionQuery(
      account,
    ).get().then((rows) => rows.map(_mapToDto).toList());
  }

  Future<List<TransactionDto>> getLastTransactions(
    Account account,
    DateTime today,
    int days,
  ) async {
    return (select(transactions)..where(
          (t) =>
              t.accountId.equals(account.id) &
              t.date.isBiggerThanValue(
                toMidnight(today.subtract(Duration(days: days))),
              ),
        ))
        .join([
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(transactions.beneficiaryId),
          ),
          leftOuterJoin(
            expenseCategories,
            expenseCategories.id.equalsExp(transactions.expenseCategoryId),
          ),
        ])
        .get()
        .then((rows) => rows.map(_mapToDto).toList());
  }

  Future<double> getTotalBalance(Iterable<int> accountIds) async {
    final sum = transactions.amount.sum();
    final query =
        selectOnly(transactions)
          ..where(transactions.accountId.isIn(accountIds))
          ..addColumns([sum]);
    return query
        .map((row) => row.read(sum))
        .getSingleOrNull()
        .then((v) => v ?? 0);
  }

  Future<List<TransactionDto>> getTransactionsInTimeframe(
    Account account,
    DateTime today,
    TransactionQueryDateOption option,
  ) {
    final lower = switch (option) {
      TransactionQueryDateOption.thisMonth => DateTime(
        today.year,
        today.month,
        0,
      ),
    };
    final upper = switch (option) {
      TransactionQueryDateOption.thisMonth => monthEnding(today),
    };

    return (select(transactions)..where(
          (t) =>
              t.accountId.equals(account.id) &
              t.date.isBetweenValues(lower, upper),
        ))
        .join([
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(transactions.beneficiaryId),
          ),
          leftOuterJoin(
            expenseCategories,
            expenseCategories.id.equalsExp(transactions.expenseCategoryId),
          ),
        ])
        .get()
        .then((rows) => rows.map(_mapToDto).toList());
  }

  Future<Transaction> upsertTransaction(TransactionsCompanion t) {
    return into(
      transactions,
    ).insertReturning(t, mode: InsertMode.insertOrReplace);
  }
}

@DriftAccessor(tables: [Beneficiaries])
class BeneficiariesDao extends DatabaseAccessor<OkaneDatabase>
    with _$BeneficiariesDaoMixin {
  BeneficiariesDao(OkaneDatabase db) : super(db);

  Stream<List<Beneficiary>> beneficiariesStream() {
    return select(beneficiaries).watch();
  }

  Future<List<Beneficiary>> getBeneficiaries() {
    return select(beneficiaries).get();
  }

  Future<Beneficiary> upsertBeneficiary(BeneficiariesCompanion beneficiary) {
    return into(
      beneficiaries,
    ).insertReturning(beneficiary, mode: InsertMode.insertOrReplace);
  }

  Future<Beneficiary> getAccountBeneficiary(Account account) {
    return (select(beneficiaries)
      ..where((b) => b.accountId.equals(account.id))).getSingle();
  }

  Stream<Beneficiary> watchBeneficiary(int id) {
    return (select(beneficiaries)..where((b) => b.id.equals(id))).watchSingle();
  }
}

@DriftAccessor(tables: [ExpenseCategories])
class ExpenseCategoriesDao extends DatabaseAccessor<OkaneDatabase>
    with _$ExpenseCategoriesDaoMixin {
  ExpenseCategoriesDao(OkaneDatabase db) : super(db);

  Stream<List<ExpenseCategory>> expenseCategoriesStream(Account account) {
    return select(expenseCategories).watch();
  }

  Future<List<ExpenseCategory>> getExpenseCategories(Account? account) {
    if (account == null) {
      return Future.value(List.empty());
    }

    return select(expenseCategories).get();
  }

  Future<ExpenseCategory> upsertCategory(ExpenseCategoriesCompanion category) {
    return into(
      expenseCategories,
    ).insertReturning(category, mode: InsertMode.insertOrReplace);
  }
}

@DriftAccessor(tables: [Budgets, BudgetItems])
class BudgetsDao extends DatabaseAccessor<OkaneDatabase>
    with _$BudgetsDaoMixin {
  BudgetsDao(OkaneDatabase db) : super(db);

  Stream<List<BudgetsDto>> budgetsStream(Account account) {
    return (select(budgets)
      ..where((b) => b.accountId.equals(account.id))).watch().map((rows) {
      return rows.map((row) {
        return BudgetsDto(budget: row);
      }).toList();
    });
  }

  Future<List<BudgetsDto>> getBudgets(Account? account) {
    if (account == null) {
      return Future.value(List.empty());
    }

    return (select(budgets)
      ..where((b) => b.accountId.equals(account.id))).get().then((rows) {
      return rows.map((row) {
        return BudgetsDto(budget: row);
      }).toList();
    });
  }

  Stream<List<BudgetItemDto>> watchBudgetItems(Budget budget) {
    return (select(budgetItems)..where((b) => b.budgetId.equals(budget.id)))
        .join([
          leftOuterJoin(
            expenseCategories,
            expenseCategories.id.equalsExp(budgetItems.expenseCategoryId),
          ),
        ])
        .watch()
        .map((rows) {
          return rows.map((row) {
            return BudgetItemDto(
              expenseCategory: row.readTable(expenseCategories),
              item: row.readTable(budgetItems),
            );
          }).toList();
        });
  }

  Future<Budget> upsertBudget(BudgetsCompanion budget) {
    return into(
      budgets,
    ).insertReturning(budget, mode: InsertMode.insertOrReplace);
  }

  Future<BudgetItem> upsertBudgetItem(BudgetItemsCompanion item) {
    return into(
      budgetItems,
    ).insertReturning(item, mode: InsertMode.insertOrReplace);
  }
}

@DriftAccessor(tables: [Loans, LoanChanges, Beneficiaries])
class LoansDao extends DatabaseAccessor<OkaneDatabase> with _$LoansDaoMixin {
  LoansDao(OkaneDatabase db) : super(db);

  Stream<List<LoanDto>> loansStream(Account account) {
    return select(loans)
        .join([
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(loans.beneficiaryId),
          ),
        ])
        .watch()
        .map((rows) {
          return rows.map((row) {
            return LoanDto(
              loan: row.readTable(loans),
              beneficiary: row.readTable(beneficiaries),
            );
          }).toList();
        });
  }

  Future<List<LoanDto>> getLoans(Account? account) {
    if (account == null) {
      return Future.value(List.empty());
    }

    return select(loans)
        .join([
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(loans.beneficiaryId),
          ),
        ])
        .get()
        .then((rows) {
          return rows.map((row) {
            return LoanDto(
              loan: row.readTable(loans),
              beneficiary: row.readTable(beneficiaries),
            );
          }).toList();
        });
  }

  Future<double> getTotalLoanSum() async {
    final count = loanChanges.amount.sum();
    final query = selectOnly(loanChanges)..addColumns([count]);
    return query
        .map((row) => row.read(count))
        .getSingleOrNull()
        .then((v) => v ?? 0);
  }

  Future<Loan> upsertLoan(LoansCompanion loan) {
    return into(loans).insertReturning(loan, mode: InsertMode.insertOrReplace);
  }

  Future<LoanChange> upsertLoanChange(LoanChangesCompanion loanChange) {
    return into(
      loanChanges,
    ).insertReturning(loanChange, mode: InsertMode.insertOrReplace);
  }

  Stream<List<LoanChange>> watchLoanChanges(Loan loan) {
    return (select(loanChanges)
      ..where((c) => c.loanId.equals(loan.id))).watch();
  }

  Future<void> deleteLoanChange(int id) {
    return (delete(loanChanges)..where((c) => c.id.equals(id))).go();
  }
}

@DriftAccessor(tables: [TransactionTemplates, ExpenseCategories, Beneficiaries])
class TransactionTemplatesDao extends DatabaseAccessor<OkaneDatabase>
    with _$TransactionTemplatesDaoMixin {
  TransactionTemplatesDao(OkaneDatabase db) : super(db);

  Stream<List<TransactionTemplateDto>> transactionTemplatesStream(
    Account account,
  ) {
    return (select(transactionTemplates)
          ..where((b) => b.accountId.equals(account.id)))
        .join([
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(transactionTemplates.beneficiaryId),
          ),
          leftOuterJoin(
            expenseCategories,
            expenseCategories.id.equalsExp(
              transactionTemplates.expenseCategoryId,
            ),
          ),
        ])
        .watch()
        .map((rows) {
          return rows.map((row) {
            return (
              template: row.readTable(transactionTemplates),
              beneficiary: row.readTable(beneficiaries),
              expenseCategory: row.readTable(expenseCategories),
            );
          }).toList();
        });
  }

  Future<List<TransactionTemplateDto>> getTransactionTemplates(
    Account? account,
  ) {
    if (account == null) {
      return Future.value(List.empty());
    }

    return (select(transactionTemplates)
          ..where((b) => b.accountId.equals(account.id)))
        .join([
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(transactionTemplates.beneficiaryId),
          ),
          leftOuterJoin(
            expenseCategories,
            expenseCategories.id.equalsExp(
              transactionTemplates.expenseCategoryId,
            ),
          ),
        ])
        .get()
        .then((rows) {
          return rows.map((row) {
            return (
              template: row.readTable(transactionTemplates),
              beneficiary: row.readTable(beneficiaries),
              expenseCategory: row.readTable(expenseCategories),
            );
          }).toList();
        });
  }

  Future<TransactionTemplate> upsertTemplate(
    TransactionTemplatesCompanion template,
  ) {
    return into(
      transactionTemplates,
    ).insertReturning(template, mode: InsertMode.insertOrReplace);
  }

  Future<void> deleteTemplate(TransactionTemplate template) {
    return (delete(transactionTemplates)
      ..where((t) => t.id.equals(template.id))).go();
  }
}

@DriftAccessor(tables: [TransactionTemplates, RecurringTransactions])
class RecurringTransactionsDao extends DatabaseAccessor<OkaneDatabase>
    with _$RecurringTransactionsDaoMixin {
  RecurringTransactionsDao(OkaneDatabase db) : super(db);

  Stream<List<RecurringTransactionDto>> recurringTransactionsStream(
    Account account,
  ) {
    return (select(recurringTransactions)
          ..where((b) => b.accountId.equals(account.id)))
        .join([
          leftOuterJoin(
            transactionTemplates,
            transactionTemplates.id.equalsExp(recurringTransactions.templateId),
          ),
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(transactionTemplates.beneficiaryId),
          ),
        ])
        .watch()
        .map((rows) {
          return rows.map((row) {
            return (
              recurring: row.readTable(recurringTransactions),
              beneficiary: row.readTable(beneficiaries),
              template: row.readTable(transactionTemplates),
            );
          }).toList();
        });
  }

  Future<List<RecurringTransactionDto>> getRecurringTransactions(
    Account? account,
  ) {
    if (account == null) {
      return Future.value(List.empty());
    }

    return (select(recurringTransactions)
          ..where((b) => b.accountId.equals(account.id)))
        .join([
          leftOuterJoin(
            transactionTemplates,
            transactionTemplates.id.equalsExp(recurringTransactions.templateId),
          ),
          leftOuterJoin(
            beneficiaries,
            beneficiaries.id.equalsExp(transactionTemplates.beneficiaryId),
          ),
        ])
        .get()
        .then((rows) {
          return rows.map((row) {
            return (
              recurring: row.readTable(recurringTransactions),
              beneficiary: row.readTable(beneficiaries),
              template: row.readTable(transactionTemplates),
            );
          }).toList();
        });
  }

  Future<int> upsertRecurringTransaction(RecurringTransactionsCompanion r) {
    return into(recurringTransactions).insertOnConflictUpdate(r);
  }

  Future<void> deleteTemplate(RecurringTransactionDto dto) async {
    await db.transactionTemplatesDao.deleteTemplate(dto.template);
    await (delete(recurringTransactions)
      ..where((t) => t.id.equals(dto.recurring.id))).go();
  }
}