refactor: rename domain types and introduce TransactionBehavior pattern

- Rename Template -> EmailTemplate, Provider -> EmailChannel,
  ProviderSettings -> EmailChannelSettings, ProviderType -> EmailChannelType,
  ProviderUsage -> EmailChannelUsage throughout all layers
- Add Undefined = 0 to EmailChannelType enum for safe default handling
- Remove SaveChangesAsync from EfRepository methods — repositories now only stage changes
- Add SaveChangesAsync to IUnitOfWork and EfUnitOfWork
- Add TransactionBehavior MediatR pipeline: wraps every handler in a transaction,
  saves and commits on success, rolls back on exception
- Add MediatR package reference to Services project

Ref: IT-628

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

HrynCo.NotificationService.DAL.Abstract/IUnitOfWork.cs

@@ -2,6 +2,7 @@ namespace HrynCo.NotificationService.DAL.Abstract;
 
 public interface IUnitOfWork
 {
+    Task SaveChangesAsync(CancellationToken cancellationToken = default);
     Task<ITransaction> BeginTransactionAsync(CancellationToken cancellationToken = default);
     ITransaction? GetCurrentTransaction();
 

HrynCo.NotificationService.DAL.Abstract/Providers/EmailChannel.cs

@@ -2,14 +2,14 @@ using HrynCo.NotificationService.DAL.Abstract.Entities;
 
 namespace HrynCo.NotificationService.DAL.Abstract.Providers;
 
-public class Provider : Entity
+public class EmailChannel : Entity
 {
     public required string ServiceName { get; set; }
     public int Priority { get; set; }
-    public ProviderType ProviderType { get; set; }
+    public EmailChannelType EmailChannelType { get; set; }
-    public required ProviderSettings Settings { get; set; }
+    public required EmailChannelSettings Settings { get; set; }
     public int? DailyLimit { get; set; }
     public int? MonthlyLimit { get; set; }
     public int WarnThresholdPercent { get; set; } = 90;
     public bool IsActive { get; set; } = true;
-}
+}

HrynCo.NotificationService.DAL.Abstract/Providers/EmailChannelSettings.cs

@@ -1,13 +1,13 @@
 namespace HrynCo.NotificationService.DAL.Abstract.Providers;
 
-public abstract class ProviderSettings
+public abstract class EmailChannelSettings
 {
-    public abstract ProviderType ProviderType { get; }
+    public abstract EmailChannelType EmailChannelType { get; }
 }
 
-public class SmtpProviderSettings : ProviderSettings
+public class SmtpChannelSettings : EmailChannelSettings
 {
-    public override ProviderType ProviderType => ProviderType.Smtp;
+    public override EmailChannelType EmailChannelType => EmailChannelType.Smtp;
 
     public required string Host { get; set; }
     public int Port { get; set; } = 587;

HrynCo.NotificationService.DAL.Abstract/Providers/EmailChannelType.cs

@@ -1,6 +1,7 @@
 namespace HrynCo.NotificationService.DAL.Abstract.Providers;
 
-public enum ProviderType
+public enum EmailChannelType
 {
+    Undefined = 0,
     Smtp = 1
 }

HrynCo.NotificationService.DAL.Abstract/Providers/EmailChannelUsage.cs

@@ -3,10 +3,10 @@ using HrynCo.NotificationService.DAL.Abstract.Entities;
 namespace HrynCo.NotificationService.DAL.Abstract.Providers;
 
 /// <summary>
-/// Tracks email send counts per provider per calendar day.
+/// Tracks email send counts per EmailChannel per calendar day.
 /// Monthly counts are derived by summing daily records within a month.
 /// </summary>
-public class ProviderUsage : Entity
+public class EmailChannelUsage : Entity
 {
     public Guid ProviderId { get; set; }
     public DateOnly Date { get; set; }

HrynCo.NotificationService.DAL.Abstract/Repositories/IEmailChannelRepository.cs

@@ -0,0 +1,12 @@
+using HrynCo.NotificationService.DAL.Abstract.Providers;
+
+namespace HrynCo.NotificationService.DAL.Abstract.Repositories;
+
+public interface IEmailChannelRepository
+{
+    Task<IReadOnlyList<EmailChannel>> GetByServiceAsync(string serviceName, CancellationToken ct = default);
+    Task<EmailChannel?> GetByIdAsync(Guid id, CancellationToken ct = default);
+    Task AddAsync(EmailChannel channel, CancellationToken ct = default);
+    Task UpdateAsync(EmailChannel channel, CancellationToken ct = default);
+    Task DeleteAsync(EmailChannel channel, CancellationToken ct = default);
+}

HrynCo.NotificationService.DAL.Abstract/Repositories/IEmailChannelUsageRepository.cs

@@ -2,9 +2,9 @@ using HrynCo.NotificationService.DAL.Abstract.Providers;
 
 namespace HrynCo.NotificationService.DAL.Abstract.Repositories;
 
-public interface IProviderUsageRepository
+public interface IEmailChannelUsageRepository
 {
     Task<int> GetDailyCountAsync(Guid providerId, DateOnly date, CancellationToken ct = default);
     Task<int> GetMonthlyCountAsync(Guid providerId, int year, int month, CancellationToken ct = default);
-    Task IncrementAsync(Guid providerId, DateOnly date, CancellationToken ct = default);
+    Task IncrementUsageAsync(Guid providerId, DateOnly date, CancellationToken ct = default);
 }

HrynCo.NotificationService.DAL.Abstract/Repositories/IEmailTemplateRepository.cs

@@ -0,0 +1,12 @@
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+
+namespace HrynCo.NotificationService.DAL.Abstract.Repositories;
+
+public interface IEmailEmailTemplateRepository
+{
+    Task<IReadOnlyList<EmailTemplate>> GetByServiceAsync(string serviceName, CancellationToken ct = default);
+    Task<EmailTemplate?> GetAsync(string serviceName, string key, string languageCode, CancellationToken ct = default);
+    Task AddAsync(EmailTemplate EmailTemplate, CancellationToken ct = default);
+    Task UpdateAsync(EmailTemplate EmailTemplate, CancellationToken ct = default);
+    Task DeleteAsync(EmailTemplate EmailTemplate, CancellationToken ct = default);
+}

HrynCo.NotificationService.DAL.Abstract/Repositories/IProviderRepository.cs

@@ -1,12 +0,0 @@
-using HrynCo.NotificationService.DAL.Abstract.Providers;
-
-namespace HrynCo.NotificationService.DAL.Abstract.Repositories;
-
-public interface IProviderRepository
-{
-    Task<IReadOnlyList<Provider>> GetByServiceAsync(string serviceName, CancellationToken ct = default);
-    Task<Provider?> GetByIdAsync(Guid id, CancellationToken ct = default);
-    Task AddAsync(Provider provider, CancellationToken ct = default);
-    Task UpdateAsync(Provider provider, CancellationToken ct = default);
-    Task DeleteAsync(Provider provider, CancellationToken ct = default);
-}

HrynCo.NotificationService.DAL.Abstract/Repositories/ITemplateRepository.cs

@@ -1,12 +0,0 @@
-using HrynCo.NotificationService.DAL.Abstract.Templates;
-
-namespace HrynCo.NotificationService.DAL.Abstract.Repositories;
-
-public interface ITemplateRepository
-{
-    Task<IReadOnlyList<Template>> GetByServiceAsync(string serviceName, CancellationToken ct = default);
-    Task<Template?> GetAsync(string serviceName, string key, string languageCode, CancellationToken ct = default);
-    Task AddAsync(Template template, CancellationToken ct = default);
-    Task UpdateAsync(Template template, CancellationToken ct = default);
-    Task DeleteAsync(Template template, CancellationToken ct = default);
-}

HrynCo.NotificationService.DAL.Abstract/Templates/EmailTemplate.cs

@@ -2,7 +2,7 @@ using HrynCo.NotificationService.DAL.Abstract.Entities;
 
 namespace HrynCo.NotificationService.DAL.Abstract.Templates;
 
-public class Template : Entity
+public class EmailTemplate : Entity
 {
     public required string ServiceName { get; set; }
     public required string Key { get; set; }
@@ -10,5 +10,5 @@ public class Template : Entity
     public required string Subject { get; set; }
     public required string HtmlBody { get; set; }
     public required string TextBody { get; set; }
-    public IReadOnlyList<TemplateVariable> Variables { get; set; } = [];
+    public IReadOnlyList<EmailTemplateVariable> Variables { get; set; } = [];
 }

HrynCo.NotificationService.DAL.Abstract/Templates/TemplateVariable.cs

@@ -1,6 +1,6 @@
 namespace HrynCo.NotificationService.DAL.Abstract.Templates;
 
-public record TemplateVariable
+public record EmailTemplateVariable
 {
     public required string Name { get; init; }
     public bool Required { get; init; }

HrynCo.NotificationService.DAL.EF/Configurations/EmailChannelEntityConfiguration.cs

@@ -4,9 +4,9 @@ using Microsoft.EntityFrameworkCore.Metadata.Builders;
 
 namespace HrynCo.NotificationService.DAL.EF.Configurations;
 
-internal class ProviderEntityConfiguration : IEntityTypeConfiguration<ProviderEntity>
+internal class EmailChannelEntityConfiguration : IEntityTypeConfiguration<EmailChannelEntity>
 {
-    public void Configure(EntityTypeBuilder<ProviderEntity> builder)
+    public void Configure(EntityTypeBuilder<EmailChannelEntity> builder)
     {
         builder.ToTable("providers");
 
@@ -22,7 +22,7 @@ internal class ProviderEntityConfiguration : IEntityTypeConfiguration<ProviderEn
 
         builder.Property(x => x.Priority).HasColumnName("priority");
 
-        builder.Property(x => x.ProviderType).HasColumnName("provider_type");
+        builder.Property(x => x.EmailChannelType).HasColumnName("provider_type");
 
         builder.Property(x => x.SettingsJson)
             .HasColumnName("settings")

HrynCo.NotificationService.DAL.EF/Configurations/EmailChannelUsageEntityConfiguration.cs

@@ -4,9 +4,9 @@ using Microsoft.EntityFrameworkCore.Metadata.Builders;
 
 namespace HrynCo.NotificationService.DAL.EF.Configurations;
 
-internal class ProviderUsageEntityConfiguration : IEntityTypeConfiguration<ProviderUsageEntity>
+internal class EmailChannelUsageEntityConfiguration : IEntityTypeConfiguration<EmailChannelUsageEntity>
 {
-    public void Configure(EntityTypeBuilder<ProviderUsageEntity> builder)
+    public void Configure(EntityTypeBuilder<EmailChannelUsageEntity> builder)
     {
         builder.ToTable("provider_usage");
 

HrynCo.NotificationService.DAL.EF/Configurations/EmailTemplateEntityConfiguration.cs

@@ -4,9 +4,9 @@ using Microsoft.EntityFrameworkCore.Metadata.Builders;
 
 namespace HrynCo.NotificationService.DAL.EF.Configurations;
 
-internal class TemplateEntityConfiguration : IEntityTypeConfiguration<TemplateEntity>
+internal class EmailEmailTemplateEntityConfiguration : IEntityTypeConfiguration<EmailTemplateEntity>
 {
-    public void Configure(EntityTypeBuilder<TemplateEntity> builder)
+    public void Configure(EntityTypeBuilder<EmailTemplateEntity> builder)
     {
         builder.ToTable("templates");
 

HrynCo.NotificationService.DAL.EF/Core/EfRepository.cs

@@ -18,40 +18,28 @@ internal abstract class EfRepository<TEntity>
     protected async Task AddAsync(TEntity entity, CancellationToken ct = default)
     {
         await DbSet.AddAsync(entity, ct);
-        await DbContext.SaveChangesAsync(ct);
     }
 
     protected async Task AddRangeAsync(IEnumerable<TEntity> entities, CancellationToken ct = default)
     {
         await DbSet.AddRangeAsync(entities, ct);
-        await DbContext.SaveChangesAsync(ct);
     }
 
-    protected async Task UpdateAsync(TEntity entity, CancellationToken ct = default)
+    protected void Update(TEntity entity)
     {
         DbSet.Update(entity);
-        await DbContext.SaveChangesAsync(ct);
     }
 
-    protected async Task DeleteAsync(TEntity entity, CancellationToken ct = default)
+    protected void Delete(TEntity entity)
     {
         DbSet.Remove(entity);
-        await DbContext.SaveChangesAsync(ct);
     }
 
-    protected async Task DeleteRangeAsync(IEnumerable<TEntity> entities, CancellationToken ct = default)
+    protected void DeleteRange(IEnumerable<TEntity> entities)
     {
         DbSet.RemoveRange(entities);
-        await DbContext.SaveChangesAsync(ct);
     }
 
-    protected Task<bool> ExistsAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken ct = default)
+    protected Task<bool> ExistsAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken ct = default) =>
-    {
+        DbSet.AnyAsync(predicate, ct);
-        return DbSet.AnyAsync(predicate, ct);
-    }
-
-    protected Task SaveAsync(CancellationToken ct = default)
-    {
-        return DbContext.SaveChangesAsync(ct);
-    }
 }

HrynCo.NotificationService.DAL.EF/Core/EfUnitOfWork.cs

@@ -15,6 +15,11 @@ internal abstract class EfUnitOfWork<TDbContext> : IUnitOfWork
         _context = context;
     }
 
+    public Task SaveChangesAsync(CancellationToken cancellationToken = default)
+    {
+        return _context.SaveChangesAsync(cancellationToken);
+    }
+
     public async Task<ITransaction> BeginTransactionAsync(CancellationToken cancellationToken = default)
     {
         if (_currentTransaction != null)

HrynCo.NotificationService.DAL.EF/Entities/EmailChannelEntity.cs

@@ -3,15 +3,15 @@ using HrynCo.NotificationService.DAL.Abstract.Providers;
 
 namespace HrynCo.NotificationService.DAL.EF.Entities;
 
-internal class ProviderEntity : Entity
+internal class EmailChannelEntity : Entity
 {
     public required string ServiceName { get; set; }
     public int Priority { get; set; }
-    public ProviderType ProviderType { get; set; }
+    public EmailChannelType EmailChannelType { get; set; }
 
     /// <summary>
-    /// Provider-specific credentials and settings stored as JSONB.
+    /// EmailChannel-specific credentials and settings stored as JSONB.
-    /// Deserialized based on <see cref="ProviderType"/> in the repository.
+    /// Deserialized based on <see cref="EmailChannelType"/> in the repository.
     /// </summary>
     public required string SettingsJson { get; set; }
 

HrynCo.NotificationService.DAL.EF/Entities/EmailChannelUsageEntity.cs

@@ -2,7 +2,7 @@ using HrynCo.NotificationService.DAL.Abstract.Entities;
 
 namespace HrynCo.NotificationService.DAL.EF.Entities;
 
-internal class ProviderUsageEntity : Entity
+internal class EmailChannelUsageEntity : Entity
 {
     public Guid ProviderId { get; set; }
     public DateOnly Date { get; set; }

HrynCo.NotificationService.DAL.EF/Entities/EmailTemplateEntity.cs

@@ -2,7 +2,7 @@ using HrynCo.NotificationService.DAL.Abstract.Entities;
 
 namespace HrynCo.NotificationService.DAL.EF.Entities;
 
-internal class TemplateEntity : Entity
+internal class EmailTemplateEntity : Entity
 {
     public required string ServiceName { get; set; }
     public required string Key { get; set; }
@@ -10,10 +10,10 @@ internal class TemplateEntity : Entity
     public required string Subject { get; set; }
     public required string HtmlBody { get; set; }
     public required string TextBody { get; set; }
-    public List<TemplateVariableData> Variables { get; set; } = [];
+    public List<EmailTemplateVariableData> Variables { get; set; } = [];
 }
 
-internal class TemplateVariableData
+internal class EmailTemplateVariableData
 {
     public required string Name { get; set; }
     public bool Required { get; set; }

HrynCo.NotificationService.DAL.EF/NotificationDbContext.cs

@@ -10,9 +10,9 @@ public class NotificationDbContext : DbContext
     {
     }
 
-    internal DbSet<TemplateEntity> Templates => Set<TemplateEntity>();
+    internal DbSet<EmailTemplateEntity> Templates => Set<EmailTemplateEntity>();
-    internal DbSet<ProviderEntity> Providers => Set<ProviderEntity>();
+    internal DbSet<EmailChannelEntity> Providers => Set<EmailChannelEntity>();
-    internal DbSet<ProviderUsageEntity> ProviderUsage => Set<ProviderUsageEntity>();
+    internal DbSet<EmailChannelUsageEntity> EmailChannelUsage => Set<EmailChannelUsageEntity>();
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {

HrynCo.NotificationService.DAL.EF/Repositories/EmailChannelRepository.cs

@@ -0,0 +1,100 @@
+using System.Text.Json;
+using HrynCo.NotificationService.DAL.Abstract.Providers;
+using HrynCo.NotificationService.DAL.Abstract.Repositories;
+using HrynCo.NotificationService.DAL.EF.Core;
+using HrynCo.NotificationService.DAL.EF.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace HrynCo.NotificationService.DAL.EF.Repositories;
+
+internal sealed class EmailChannelRepository : EfRepository<EmailChannelEntity>, IEmailChannelRepository
+{
+    public EmailChannelRepository(NotificationDbContext dbContext) : base(dbContext)
+    {
+    }
+
+    public async Task<IReadOnlyList<EmailChannel>> GetByServiceAsync(string serviceName, CancellationToken ct = default)
+    {
+        var entities = await DbSet
+            .Where(x => x.ServiceName == serviceName)
+            .OrderBy(x => x.Priority)
+            .ToListAsync(ct);
+
+        return entities.Select(MapToDomain).ToList();
+    }
+
+    public async Task<EmailChannel?> GetByIdAsync(Guid id, CancellationToken ct = default)
+    {
+        EmailChannelEntity? entity = await DbSet.FindAsync([id], ct);
+        return entity is null ? null : MapToDomain(entity);
+    }
+
+    public Task AddAsync(EmailChannel channel, CancellationToken ct = default)
+    {
+        return base.AddAsync(MapToEntity(channel), ct);
+    }
+
+    public Task UpdateAsync(EmailChannel channel, CancellationToken ct = default)
+    {
+        EmailChannelEntity entity = MapToEntity(channel);
+        entity.Updated = DateTimeOffset.UtcNow;
+        Update(entity);
+        return Task.CompletedTask;
+    }
+
+    public async Task DeleteAsync(EmailChannel channel, CancellationToken ct = default)
+    {
+        EmailChannelEntity? entity = await DbSet.FindAsync([channel.Id], ct);
+        if (entity is not null)
+        {
+            Delete(entity);
+        }
+    }
+
+    private static EmailChannel MapToDomain(EmailChannelEntity e)
+    {
+        return new EmailChannel
+        {
+            Id = e.Id,
+            ServiceName = e.ServiceName,
+            Priority = e.Priority,
+            EmailChannelType = e.EmailChannelType,
+            Settings = DeserializeSettings(e.EmailChannelType, e.SettingsJson),
+            DailyLimit = e.DailyLimit,
+            MonthlyLimit = e.MonthlyLimit,
+            WarnThresholdPercent = e.WarnThresholdPercent,
+            IsActive = e.IsActive,
+            Created = e.Created,
+            Updated = e.Updated
+        };
+    }
+
+    private static EmailChannelEntity MapToEntity(EmailChannel p)
+    {
+        return new EmailChannelEntity
+        {
+            Id = p.Id,
+            ServiceName = p.ServiceName,
+            Priority = p.Priority,
+            EmailChannelType = p.EmailChannelType,
+            SettingsJson = JsonSerializer.Serialize(p.Settings),
+            DailyLimit = p.DailyLimit,
+            MonthlyLimit = p.MonthlyLimit,
+            WarnThresholdPercent = p.WarnThresholdPercent,
+            IsActive = p.IsActive,
+            Created = p.Created,
+            Updated = p.Updated
+        };
+    }
+
+    private static EmailChannelSettings DeserializeSettings(EmailChannelType type, string json)
+    {
+        return type switch
+        {
+            EmailChannelType.Smtp => JsonSerializer.Deserialize<SmtpChannelSettings>(json)
+                                 ?? throw new InvalidOperationException(
+                                     "Failed to deserialize SMTP EmailChannel settings."),
+            _ => throw new InvalidOperationException($"Unknown or undefined email channel type: {type}")
+        };
+    }
+}

HrynCo.NotificationService.DAL.EF/Repositories/EmailChannelUsageRepository.cs

@@ -5,15 +5,15 @@ using Microsoft.EntityFrameworkCore;
 
 namespace HrynCo.NotificationService.DAL.EF.Repositories;
 
-internal sealed class ProviderUsageRepository : EfRepository<ProviderUsageEntity>, IProviderUsageRepository
+internal sealed class EmailChannelUsageRepository : EfRepository<EmailChannelUsageEntity>, IEmailChannelUsageRepository
 {
-    public ProviderUsageRepository(NotificationDbContext dbContext) : base(dbContext)
+    public EmailChannelUsageRepository(NotificationDbContext dbContext) : base(dbContext)
     {
     }
 
     public async Task<int> GetDailyCountAsync(Guid providerId, DateOnly date, CancellationToken ct = default)
     {
-        ProviderUsageEntity? entity = await DbSet
+        EmailChannelUsageEntity? entity = await DbSet
             .FirstOrDefaultAsync(x => x.ProviderId == providerId && x.Date == date, ct);
 
         return entity?.SentCount ?? 0;
@@ -28,18 +28,17 @@ internal sealed class ProviderUsageRepository : EfRepository<ProviderUsageEntity
             .SumAsync(x => x.SentCount, ct);
     }
 
-    public async Task IncrementAsync(Guid providerId, DateOnly date, CancellationToken ct = default)
+    public async Task IncrementUsageAsync(Guid providerId, DateOnly date, CancellationToken ct = default)
     {
-        DateTimeOffset now = DateTimeOffset.UtcNow;
+        EmailChannelUsageEntity? entity = await DbSet
+            .FirstOrDefaultAsync(x => x.ProviderId == providerId && x.Date == date, ct);
 
-        // Atomic upsert: insert with count=1 or increment existing count.
+        if (entity is null)
-        await DbContext.Database.ExecuteSqlAsync(
+            await AddAsync(new EmailChannelUsageEntity { ProviderId = providerId, Date = date, SentCount = 1 }, ct);
-            $"""
+        else
-             INSERT INTO provider_usage (id, provider_id, date, sent_count, created)
+        {
-             VALUES ({Guid.NewGuid()}, {providerId}, {date}, 1, {now})
+            entity.SentCount++;
-             ON CONFLICT (provider_id, date) DO UPDATE SET
+            Update(entity);
-                 sent_count = provider_usage.sent_count + 1,
+        }
-                 updated    = {now}
-             """, ct);
     }
-}
+}

HrynCo.NotificationService.DAL.EF/Repositories/EmailTemplateRepository.cs

@@ -0,0 +1,77 @@
+using HrynCo.NotificationService.DAL.Abstract.Repositories;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+using HrynCo.NotificationService.DAL.EF.Core;
+using HrynCo.NotificationService.DAL.EF.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace HrynCo.NotificationService.DAL.EF.Repositories;
+
+internal sealed class EmailTemplateRepository : EfRepository<EmailTemplateEntity>, IEmailEmailTemplateRepository
+{
+    public EmailTemplateRepository(NotificationDbContext dbContext) : base(dbContext)
+    {
+    }
+
+    public async Task<IReadOnlyList<EmailTemplate>> GetByServiceAsync(string serviceName, CancellationToken ct = default)
+    {
+        List<EmailTemplateEntity> entities = await DbSet
+            .Where(x => x.ServiceName == serviceName)
+            .ToListAsync(ct);
+
+        return entities.Select(MapToDomain).ToList();
+    }
+
+    public async Task<EmailTemplate?> GetAsync(string serviceName, string key, string languageCode, CancellationToken ct = default)
+    {
+        EmailTemplateEntity? entity = await DbSet.FirstOrDefaultAsync(
+            x => x.ServiceName == serviceName && x.Key == key && x.LanguageCode == languageCode, ct);
+
+        return entity is null ? null : MapToDomain(entity);
+    }
+
+    public Task AddAsync(EmailTemplate EmailTemplate, CancellationToken ct = default) =>
+        base.AddAsync(MapToEntity(EmailTemplate), ct);
+
+    public Task UpdateAsync(EmailTemplate EmailTemplate, CancellationToken ct = default)
+    {
+        EmailTemplateEntity entity = MapToEntity(EmailTemplate);
+        entity.Updated = DateTimeOffset.UtcNow;
+        Update(entity);
+        return Task.CompletedTask;
+    }
+
+    public async Task DeleteAsync(EmailTemplate EmailTemplate, CancellationToken ct = default)
+    {
+        EmailTemplateEntity? entity = await DbSet.FindAsync([EmailTemplate.Id], ct);
+        if (entity is not null)
+            Delete(entity);
+    }
+
+    private static EmailTemplate MapToDomain(EmailTemplateEntity e) => new()
+    {
+        Id = e.Id,
+        ServiceName = e.ServiceName,
+        Key = e.Key,
+        LanguageCode = e.LanguageCode,
+        Subject = e.Subject,
+        HtmlBody = e.HtmlBody,
+        TextBody = e.TextBody,
+        Variables = e.Variables.Select(v => new EmailTemplateVariable { Name = v.Name, Required = v.Required }).ToList(),
+        Created = e.Created,
+        Updated = e.Updated
+    };
+
+    private static EmailTemplateEntity MapToEntity(EmailTemplate t) => new()
+    {
+        Id = t.Id,
+        ServiceName = t.ServiceName,
+        Key = t.Key,
+        LanguageCode = t.LanguageCode,
+        Subject = t.Subject,
+        HtmlBody = t.HtmlBody,
+        TextBody = t.TextBody,
+        Variables = t.Variables.Select(v => new EmailTemplateVariableData { Name = v.Name, Required = v.Required }).ToList(),
+        Created = t.Created,
+        Updated = t.Updated
+    };
+}

HrynCo.NotificationService.DAL.EF/Repositories/ProviderRepository.cs

@@ -1,85 +0,0 @@
-using System.Text.Json;
-using HrynCo.NotificationService.DAL.Abstract.Providers;
-using HrynCo.NotificationService.DAL.Abstract.Repositories;
-using HrynCo.NotificationService.DAL.EF.Core;
-using HrynCo.NotificationService.DAL.EF.Entities;
-using Microsoft.EntityFrameworkCore;
-
-namespace HrynCo.NotificationService.DAL.EF.Repositories;
-
-internal sealed class ProviderRepository : EfRepository<ProviderEntity>, IProviderRepository
-{
-    public ProviderRepository(NotificationDbContext dbContext) : base(dbContext)
-    {
-    }
-
-    public async Task<IReadOnlyList<Provider>> GetByServiceAsync(string serviceName, CancellationToken ct = default)
-    {
-        List<ProviderEntity> entities = await DbSet
-            .Where(x => x.ServiceName == serviceName)
-            .OrderBy(x => x.Priority)
-            .ToListAsync(ct);
-
-        return entities.Select(MapToDomain).ToList();
-    }
-
-    public async Task<Provider?> GetByIdAsync(Guid id, CancellationToken ct = default)
-    {
-        ProviderEntity? entity = await DbSet.FindAsync([id], ct);
-        return entity is null ? null : MapToDomain(entity);
-    }
-
-    public Task AddAsync(Provider provider, CancellationToken ct = default) =>
-        base.AddAsync(MapToEntity(provider), ct);
-
-    public Task UpdateAsync(Provider provider, CancellationToken ct = default)
-    {
-        ProviderEntity entity = MapToEntity(provider);
-        entity.Updated = DateTimeOffset.UtcNow;
-        return base.UpdateAsync(entity, ct);
-    }
-
-    public async Task DeleteAsync(Provider provider, CancellationToken ct = default)
-    {
-        ProviderEntity? entity = await DbSet.FindAsync([provider.Id], ct);
-        if (entity is not null)
-            await base.DeleteAsync(entity, ct);
-    }
-
-    private static Provider MapToDomain(ProviderEntity e) => new()
-    {
-        Id = e.Id,
-        ServiceName = e.ServiceName,
-        Priority = e.Priority,
-        ProviderType = e.ProviderType,
-        Settings = DeserializeSettings(e.ProviderType, e.SettingsJson),
-        DailyLimit = e.DailyLimit,
-        MonthlyLimit = e.MonthlyLimit,
-        WarnThresholdPercent = e.WarnThresholdPercent,
-        IsActive = e.IsActive,
-        Created = e.Created,
-        Updated = e.Updated
-    };
-
-    private static ProviderEntity MapToEntity(Provider p) => new()
-    {
-        Id = p.Id,
-        ServiceName = p.ServiceName,
-        Priority = p.Priority,
-        ProviderType = p.ProviderType,
-        SettingsJson = JsonSerializer.Serialize(p.Settings),
-        DailyLimit = p.DailyLimit,
-        MonthlyLimit = p.MonthlyLimit,
-        WarnThresholdPercent = p.WarnThresholdPercent,
-        IsActive = p.IsActive,
-        Created = p.Created,
-        Updated = p.Updated
-    };
-
-    private static ProviderSettings DeserializeSettings(ProviderType type, string json) => type switch
-    {
-        ProviderType.Smtp => JsonSerializer.Deserialize<SmtpProviderSettings>(json)
-            ?? throw new InvalidOperationException("Failed to deserialize SMTP provider settings."),
-        _ => throw new InvalidOperationException($"Unknown provider type: {type}")
-    };
-}

HrynCo.NotificationService.DAL.EF/Repositories/TemplateRepository.cs

@@ -1,76 +0,0 @@
-using HrynCo.NotificationService.DAL.Abstract.Repositories;
-using HrynCo.NotificationService.DAL.Abstract.Templates;
-using HrynCo.NotificationService.DAL.EF.Core;
-using HrynCo.NotificationService.DAL.EF.Entities;
-using Microsoft.EntityFrameworkCore;
-
-namespace HrynCo.NotificationService.DAL.EF.Repositories;
-
-internal sealed class TemplateRepository : EfRepository<TemplateEntity>, ITemplateRepository
-{
-    public TemplateRepository(NotificationDbContext dbContext) : base(dbContext)
-    {
-    }
-
-    public async Task<IReadOnlyList<Template>> GetByServiceAsync(string serviceName, CancellationToken ct = default)
-    {
-        List<TemplateEntity> entities = await DbSet
-            .Where(x => x.ServiceName == serviceName)
-            .ToListAsync(ct);
-
-        return entities.Select(MapToDomain).ToList();
-    }
-
-    public async Task<Template?> GetAsync(string serviceName, string key, string languageCode, CancellationToken ct = default)
-    {
-        TemplateEntity? entity = await DbSet.FirstOrDefaultAsync(
-            x => x.ServiceName == serviceName && x.Key == key && x.LanguageCode == languageCode, ct);
-
-        return entity is null ? null : MapToDomain(entity);
-    }
-
-    public Task AddAsync(Template template, CancellationToken ct = default) =>
-        base.AddAsync(MapToEntity(template), ct);
-
-    public Task UpdateAsync(Template template, CancellationToken ct = default)
-    {
-        TemplateEntity entity = MapToEntity(template);
-        entity.Updated = DateTimeOffset.UtcNow;
-        return base.UpdateAsync(entity, ct);
-    }
-
-    public async Task DeleteAsync(Template template, CancellationToken ct = default)
-    {
-        TemplateEntity? entity = await DbSet.FindAsync([template.Id], ct);
-        if (entity is not null)
-            await base.DeleteAsync(entity, ct);
-    }
-
-    private static Template MapToDomain(TemplateEntity e) => new()
-    {
-        Id = e.Id,
-        ServiceName = e.ServiceName,
-        Key = e.Key,
-        LanguageCode = e.LanguageCode,
-        Subject = e.Subject,
-        HtmlBody = e.HtmlBody,
-        TextBody = e.TextBody,
-        Variables = e.Variables.Select(v => new TemplateVariable { Name = v.Name, Required = v.Required }).ToList(),
-        Created = e.Created,
-        Updated = e.Updated
-    };
-
-    private static TemplateEntity MapToEntity(Template t) => new()
-    {
-        Id = t.Id,
-        ServiceName = t.ServiceName,
-        Key = t.Key,
-        LanguageCode = t.LanguageCode,
-        Subject = t.Subject,
-        HtmlBody = t.HtmlBody,
-        TextBody = t.TextBody,
-        Variables = t.Variables.Select(v => new TemplateVariableData { Name = v.Name, Required = v.Required }).ToList(),
-        Created = t.Created,
-        Updated = t.Updated
-    };
-}

HrynCo.NotificationService.Services/Behaviors/TransactionBehavior.cs

@@ -0,0 +1,25 @@
+using HrynCo.NotificationService.DAL.Abstract;
+using MediatR;
+
+namespace HrynCo.NotificationService.Services.Behaviors;
+
+public class TransactionBehavior<TRequest, TResponse> : IPipelineBehavior<TRequest, TResponse>
+    where TRequest : notnull
+{
+    private readonly IUnitOfWork _unitOfWork;
+
+    public TransactionBehavior(IUnitOfWork unitOfWork)
+    {
+        _unitOfWork = unitOfWork;
+    }
+
+    public Task<TResponse> Handle(TRequest request, RequestHandlerDelegate<TResponse> next, CancellationToken cancellationToken)
+    {
+        return _unitOfWork.ExecuteInTransactionAsync(async () =>
+        {
+            TResponse result = await next();
+            await _unitOfWork.SaveChangesAsync(cancellationToken);
+            return result;
+        });
+    }
+}

HrynCo.NotificationService.Services/HrynCo.NotificationService.Services.csproj

@@ -1,5 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
+  <ItemGroup>
+    <PackageReference Include="MediatR" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\HrynCo.NotificationService.DAL.Abstract\HrynCo.NotificationService.DAL.Abstract.csproj" />
   </ItemGroup>