hrynco-notification-service/HrynCo.NotificationService.Worker.Services/EmailProcessing/EmailTemplateService.cs

namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;

using HrynCo.NotificationService.DAL.Abstract.Repositories;
using HrynCo.NotificationService.DAL.Abstract.Templates;

internal sealed class EmailTemplateService : IEmailTemplateService
{
    private readonly IEmailTemplateRepository _templateRepository;

    public EmailTemplateService(IEmailTemplateRepository templateRepository)
    {
        _templateRepository = templateRepository;
    }

    public async Task<EmailTemplate> GetAsync(
        string serviceName,
        string templateKey,
        string? languageCode,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(languageCode))
            throw new InvalidDataException("LanguageCode is required.");

        string lang = languageCode.Trim().ToLowerInvariant();
        EmailTemplate? template = await _templateRepository.GetAsync(
            serviceName,
            templateKey,
            lang,
            cancellationToken);

        return template
            ?? throw new InvalidOperationException(
                $"Template not found: service='{serviceName}' key='{templateKey}' language='{lang}'.");
    }
}