package database

import (
	"context"
	"fmt"
	"log/slog"

	"bunker/client/internal/services/core"

	"github.com/jmoiron/sqlx"
)

type transaction struct {
	transaction *sqlx.Tx
	logger      *slog.Logger
}

func (d *database) Transaction(ctx context.Context) (core.DatabaseTransaction, error) {
	txn, err := d.db.BeginTxx(ctx, nil)
	if err != nil {
		return nil, fmt.Errorf("%w: starting transaction: %w", core.ErrDatabase, err)
	}

	txHandler := &transaction{
		transaction: txn,
		logger:      d.logger.With("module", "transactioner"),
	}

	return txHandler, nil
}

func (t *transaction) Apply(steps ...core.TransactionFunc) error {
	for stepNumber, stepFunc := range steps {
		if err := stepFunc(t.transaction); err != nil {
			t.logger.Error(
				"Error occurred.",
				"step", stepNumber,
				"error", err.Error(),
				"module", "core/database",
				"subsystem", "transaction",
			)

			if rollbackErr := t.transaction.Rollback(); rollbackErr != nil {
				t.logger.Error(
					"Transaction rollback failed.",
					"error", err.Error(),
					"module", "core/database",
					"subsystem", "transaction",
				)

				return fmt.Errorf("%w: transaction rollback: %w", core.ErrDatabase, rollbackErr)
			}

			return err
		}
	}

	if err := t.transaction.Commit(); err != nil {
		t.logger.Error(
			"Transaction commit failed.",
			"error", err.Error(),
			"module", "core/database",
			"subsystem", "transaction",
		)

		if rollbackErr := t.transaction.Rollback(); rollbackErr != nil {
			t.logger.Error(
				"Transaction rollback failed.",
				"error", err.Error(),
				"module", "core/database",
				"subsystem", "transaction",
			)

			return fmt.Errorf("%w: transaction rollback: %w", core.ErrDatabase, rollbackErr)
		}

		return fmt.Errorf("%w: transaction commit: %w", core.ErrDatabase, err)
	}

	return nil
}