books/backend/Books.Api/Domain/Companies/CompanyAggregate.cs

using Books.Api.Domain.Companies.Events;
using EventFlow.Aggregates;

namespace Books.Api.Domain.Companies;

public class CompanyAggregate(CompanyId id) : AggregateRoot<CompanyAggregate, CompanyId>(id),
    IEmit<CompanyCreatedEvent>,
    IEmit<CompanyUpdatedEvent>,
    IEmit<CompanyBankDetailsUpdatedEvent>
{
    private bool _isCreated;

    public void Apply(CompanyCreatedEvent e) => _isCreated = true;

    public void Apply(CompanyUpdatedEvent e) { }

    public void Apply(CompanyBankDetailsUpdatedEvent e) { }

    public void Create(
        string name,
        string? cvr,
        string? address,
        string? postalCode,
        string? city,
        string country,
        int fiscalYearStartMonth,
        string currency,
        bool vatRegistered,
        string? vatPeriodFrequency)
    {
        if (_isCreated)
            throw new DomainException("Company already exists");

        if (string.IsNullOrWhiteSpace(name))
            throw new DomainException("Company name is required");

        if (fiscalYearStartMonth < 1 || fiscalYearStartMonth > 12)
            throw new DomainException("Fiscal year start month must be between 1 and 12");

        // Validate CVR number if provided
        if (!string.IsNullOrWhiteSpace(cvr) && !CvrValidator.IsValid(cvr.Trim()))
            throw new DomainException(
                "INVALID_CVR",
                $"CVR number '{cvr}' is not valid. Must be 8 digits with valid checksum.",
                $"CVR-nummer '{cvr}' er ugyldigt. Skal være 8 cifre med gyldig kontrolsum.");

        Emit(new CompanyCreatedEvent(
            name.Trim(),
            cvr?.Trim(),
            address?.Trim(),
            postalCode?.Trim(),
            city?.Trim(),
            country,
            fiscalYearStartMonth,
            currency,
            vatRegistered,
            vatPeriodFrequency));
    }

    public void Update(
        string name,
        string? cvr,
        string? address,
        string? postalCode,
        string? city,
        string country,
        int fiscalYearStartMonth,
        string currency,
        bool vatRegistered,
        string? vatPeriodFrequency)
    {
        if (!_isCreated)
            throw new DomainException("Company does not exist");

        if (string.IsNullOrWhiteSpace(name))
            throw new DomainException("Company name is required");

        if (fiscalYearStartMonth < 1 || fiscalYearStartMonth > 12)
            throw new DomainException("Fiscal year start month must be between 1 and 12");

        // Validate CVR number if provided
        if (!string.IsNullOrWhiteSpace(cvr) && !CvrValidator.IsValid(cvr.Trim()))
            throw new DomainException(
                "INVALID_CVR",
                $"CVR number '{cvr}' is not valid. Must be 8 digits with valid checksum.",
                $"CVR-nummer '{cvr}' er ugyldigt. Skal være 8 cifre med gyldig kontrolsum.");

        Emit(new CompanyUpdatedEvent(
            name.Trim(),
            cvr?.Trim(),
            address?.Trim(),
            postalCode?.Trim(),
            city?.Trim(),
            country,
            fiscalYearStartMonth,
            currency,
            vatRegistered,
            vatPeriodFrequency));
    }
}