feat: add API controllers for template and channel management

- ApiResponse<T>, ApiError in Api/Infrastructure
- ApiControllerBase with IMediator, FromServiceResult, MapServiceError
- EmailTemplatesController: GET list, GET one, POST, PUT, DELETE
- EmailChannelsController: GET list, GET one, POST, PUT, DELETE

Ref: IT-628

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

HrynCo.NotificationService.Api/Controllers/ApiControllerBase.cs

@@ -0,0 +1,38 @@
+using HrynCo.NotificationService.Api.Infrastructure;
+using HrynCo.NotificationService.Services.Core;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace HrynCo.NotificationService.Api.Controllers;
+
+[Route("api/v1/[controller]")]
+[ApiController]
+public abstract class ApiControllerBase : ControllerBase
+{
+    protected ApiControllerBase(IMediator mediator)
+    {
+        Mediator = mediator;
+    }
+
+    protected IMediator Mediator { get; }
+
+    protected IActionResult FromServiceResult<T>(ServiceResult<T> result) =>
+        result.IsSuccess ? Ok(result.Result) : MapServiceError(result.Error!);
+
+    protected IActionResult MapServiceError(ServiceError error)
+    {
+        string code = error.Code?.ToString() ?? "Unknown";
+
+        return error.Code switch
+        {
+            ServiceErrorCode.NotFound => NotFound(ErrorResponse(code, error.Message)),
+            ServiceErrorCode.Conflict => Conflict(ErrorResponse(code, error.Message)),
+            ServiceErrorCode.InvalidRequest => BadRequest(ErrorResponse(code, error.Message)),
+            null => throw new InvalidOperationException("Error code was null for failed result."),
+            _ => throw new ArgumentOutOfRangeException(nameof(error), error, "Unexpected error code.")
+        };
+    }
+
+    private static ApiResponse<object> ErrorResponse(string code, string message) =>
+        new() { Success = false, Error = new ApiError { Code = code, Message = message } };
+}

HrynCo.NotificationService.Api/Controllers/EmailChannels/CreateEmailChannelRequest.cs

@@ -0,0 +1,14 @@
+using HrynCo.NotificationService.DAL.Abstract.Providers;
+
+namespace HrynCo.NotificationService.Api.Controllers.EmailChannels;
+
+public sealed record CreateEmailChannelRequest(
+    string ServiceName,
+    int Priority,
+    EmailChannelType ChannelType,
+    EmailChannelSettings Settings,
+    int? DailyLimit,
+    int? MonthlyLimit,
+    int WarnThresholdPercent,
+    bool IsActive
+);

HrynCo.NotificationService.Api/Controllers/EmailChannels/EmailChannelsController.cs

@@ -0,0 +1,75 @@
+using HrynCo.NotificationService.Services.EmailChannels.Create;
+using HrynCo.NotificationService.Services.EmailChannels.Delete;
+using HrynCo.NotificationService.Services.EmailChannels.Get;
+using HrynCo.NotificationService.Services.EmailChannels.GetByService;
+using HrynCo.NotificationService.Services.EmailChannels.Update;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace HrynCo.NotificationService.Api.Controllers.EmailChannels;
+
+[Route("api/v1/email-channels")]
+public sealed class EmailChannelsController : ApiControllerBase
+{
+    public EmailChannelsController(IMediator mediator) : base(mediator) { }
+
+    [HttpGet]
+    public async Task<IActionResult> GetAll([FromQuery] string serviceName, CancellationToken cancellationToken)
+    {
+        var result = await Mediator.Send(new GetEmailChannelsQuery(serviceName), cancellationToken);
+        return FromServiceResult(result);
+    }
+
+    [HttpGet("{id:guid}")]
+    public async Task<IActionResult> Get(Guid id, CancellationToken cancellationToken)
+    {
+        var result = await Mediator.Send(new GetEmailChannelQuery(id), cancellationToken);
+        return FromServiceResult(result);
+    }
+
+    [HttpPost]
+    public async Task<IActionResult> Create([FromBody] CreateEmailChannelRequest request, CancellationToken cancellationToken)
+    {
+        var command = new CreateEmailChannelCommand(
+            request.ServiceName,
+            request.Priority,
+            request.ChannelType,
+            request.Settings,
+            request.DailyLimit,
+            request.MonthlyLimit,
+            request.WarnThresholdPercent,
+            request.IsActive
+        );
+
+        var result = await Mediator.Send(command, cancellationToken);
+
+        if (!result.IsSuccess)
+            return MapServiceError(result.Error!);
+
+        return CreatedAtAction(nameof(Get), new { id = result.Result }, result.Result);
+    }
+
+    [HttpPut("{id:guid}")]
+    public async Task<IActionResult> Update(Guid id, [FromBody] UpdateEmailChannelRequest request, CancellationToken cancellationToken)
+    {
+        var command = new UpdateEmailChannelCommand(
+            id,
+            request.Priority,
+            request.Settings,
+            request.DailyLimit,
+            request.MonthlyLimit,
+            request.WarnThresholdPercent,
+            request.IsActive
+        );
+
+        var result = await Mediator.Send(command, cancellationToken);
+        return FromServiceResult(result);
+    }
+
+    [HttpDelete("{id:guid}")]
+    public async Task<IActionResult> Delete(Guid id, CancellationToken cancellationToken)
+    {
+        var result = await Mediator.Send(new DeleteEmailChannelCommand(id), cancellationToken);
+        return FromServiceResult(result);
+    }
+}

HrynCo.NotificationService.Api/Controllers/EmailChannels/UpdateEmailChannelRequest.cs

@@ -0,0 +1,12 @@
+using HrynCo.NotificationService.DAL.Abstract.Providers;
+
+namespace HrynCo.NotificationService.Api.Controllers.EmailChannels;
+
+public sealed record UpdateEmailChannelRequest(
+    int Priority,
+    EmailChannelSettings Settings,
+    int? DailyLimit,
+    int? MonthlyLimit,
+    int WarnThresholdPercent,
+    bool IsActive
+);

HrynCo.NotificationService.Api/Controllers/EmailTemplates/CreateEmailTemplateRequest.cs

@@ -0,0 +1,13 @@
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+
+namespace HrynCo.NotificationService.Api.Controllers.EmailTemplates;
+
+public sealed record CreateEmailTemplateRequest(
+    string ServiceName,
+    string Key,
+    string LanguageCode,
+    string Subject,
+    string HtmlBody,
+    string TextBody,
+    IReadOnlyList<EmailTemplateVariable> Variables
+);

HrynCo.NotificationService.Api/Controllers/EmailTemplates/EmailTemplatesController.cs

@@ -0,0 +1,83 @@
+using HrynCo.NotificationService.Services.EmailTemplates.Create;
+using HrynCo.NotificationService.Services.EmailTemplates.Delete;
+using HrynCo.NotificationService.Services.EmailTemplates.Get;
+using HrynCo.NotificationService.Services.EmailTemplates.GetByService;
+using HrynCo.NotificationService.Services.EmailTemplates.Update;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace HrynCo.NotificationService.Api.Controllers.EmailTemplates;
+
+[Route("api/v1/email-templates")]
+public sealed class EmailTemplatesController : ApiControllerBase
+{
+    public EmailTemplatesController(IMediator mediator) : base(mediator) { }
+
+    [HttpGet]
+    public async Task<IActionResult> GetAll([FromQuery] string serviceName, CancellationToken cancellationToken)
+    {
+        var result = await Mediator.Send(new GetEmailTemplatesQuery(serviceName), cancellationToken);
+        return FromServiceResult(result);
+    }
+
+    [HttpGet("{serviceName}/{key}/{languageCode}")]
+    public async Task<IActionResult> Get(string serviceName, string key, string languageCode, CancellationToken cancellationToken)
+    {
+        var result = await Mediator.Send(new GetEmailTemplateQuery(serviceName, key, languageCode), cancellationToken);
+        return FromServiceResult(result);
+    }
+
+    [HttpPost]
+    public async Task<IActionResult> Create([FromBody] CreateEmailTemplateRequest request, CancellationToken cancellationToken)
+    {
+        var command = new CreateEmailTemplateCommand(
+            request.ServiceName,
+            request.Key,
+            request.LanguageCode,
+            request.Subject,
+            request.HtmlBody,
+            request.TextBody,
+            request.Variables
+        );
+
+        var result = await Mediator.Send(command, cancellationToken);
+
+        if (!result.IsSuccess)
+            return MapServiceError(result.Error!);
+
+        return CreatedAtAction(
+            nameof(Get),
+            new { serviceName = request.ServiceName, key = request.Key, languageCode = request.LanguageCode },
+            result.Result
+        );
+    }
+
+    [HttpPut("{serviceName}/{key}/{languageCode}")]
+    public async Task<IActionResult> Update(
+        string serviceName,
+        string key,
+        string languageCode,
+        [FromBody] UpdateEmailTemplateRequest request,
+        CancellationToken cancellationToken)
+    {
+        var command = new UpdateEmailTemplateCommand(
+            serviceName,
+            key,
+            languageCode,
+            request.Subject,
+            request.HtmlBody,
+            request.TextBody,
+            request.Variables
+        );
+
+        var result = await Mediator.Send(command, cancellationToken);
+        return FromServiceResult(result);
+    }
+
+    [HttpDelete("{serviceName}/{key}/{languageCode}")]
+    public async Task<IActionResult> Delete(string serviceName, string key, string languageCode, CancellationToken cancellationToken)
+    {
+        var result = await Mediator.Send(new DeleteEmailTemplateCommand(serviceName, key, languageCode), cancellationToken);
+        return FromServiceResult(result);
+    }
+}

HrynCo.NotificationService.Api/Controllers/EmailTemplates/UpdateEmailTemplateRequest.cs

@@ -0,0 +1,10 @@
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+
+namespace HrynCo.NotificationService.Api.Controllers.EmailTemplates;
+
+public sealed record UpdateEmailTemplateRequest(
+    string Subject,
+    string HtmlBody,
+    string TextBody,
+    IReadOnlyList<EmailTemplateVariable> Variables
+);

HrynCo.NotificationService.Api/Infrastructure/ApiResponse.cs

@@ -0,0 +1,14 @@
+namespace HrynCo.NotificationService.Api.Infrastructure;
+
+public sealed class ApiResponse<T>
+{
+    public T? Data { get; init; } = default;
+    public ApiError? Error { get; init; }
+    public bool Success { get; init; }
+}
+
+public sealed class ApiError
+{
+    public required string Code { get; init; }
+    public required string Message { get; init; }
+}