Merge pull request #4 from yazilimacademy/Application

[Feature]: Category/GetAll and Create operations completed.

Author: altudev

src/YazilimAcademy.Application/Common/Interfaces/IApplicationDbContext.cs

@@ -1,6 +1,17 @@
+using Microsoft.EntityFrameworkCore;
+using YazilimAcademy.Domain.Entities;
+
 namespace YazilimAcademy.Application.Common.Interfaces;
 
 public interface IApplicationDbContext
 {
+    DbSet<Category> Categories { get; }
+    DbSet<Course> Courses { get; }
+    DbSet<CourseCategory> CourseCategories { get; }
+    DbSet<CourseSection> CourseSections { get; }
+    DbSet<CourseLecture> CourseLectures { get; }
+    DbSet<CourseLectureResource> CourseLectureResources { get; }
 
+    Task<int> SaveChangesAsync(CancellationToken cancellationToken);
+    int SaveChanges();
 }

src/YazilimAcademy.Application/Common/Interfaces/ISqlConnectionFactory.cs

@@ -0,0 +1,8 @@
+using System.Data;
+
+namespace YazilimAcademy.Application.Common.Interfaces;
+
+public interface ISqlConnectionFactory
+{
+    IDbConnection CreateConnection();
+}

src/YazilimAcademy.Application/Common/Models/Errors/ValidationError.cs

@@ -0,0 +1,18 @@
+namespace YazilimAcademy.Application.Common.Models.Errors;
+
+public sealed record ValidationError
+{
+    public string PropertyName { get; init; }
+    public IEnumerable<string> ErrorMessages { get; init; }
+
+    public ValidationError(string propertyName, IEnumerable<string> errorMessages)
+    {
+        PropertyName = propertyName;
+        ErrorMessages = errorMessages;
+    }
+
+    public ValidationError(string propertyName, string errorMessage)
+        : this(propertyName, new List<string> { errorMessage })
+    {
+    }
+}

src/YazilimAcademy.Application/Common/Models/Pagination/PaginatedList.cs

@@ -0,0 +1,66 @@
+using System.Text.Json.Serialization;
+using Microsoft.EntityFrameworkCore;
+
+namespace YazilimAcademy.Application.Common.Models.Pagination;
+
+public sealed record PaginatedList<T>
+{
+    public IReadOnlyCollection<T> Items { get; }
+    public int PageNumber { get; }
+    public int TotalPages { get; }
+    public int TotalCount { get; }
+    public int PageSize { get; set; }
+
+    public PaginatedList(IEnumerable<T> items, int totalCount, int pageNumber, int pageSize)
+    {
+        Items = items.ToList().AsReadOnly();
+
+        TotalCount = totalCount;
+
+        PageNumber = pageNumber;
+
+        PageSize = pageSize;
+
+        TotalPages = (int)Math.Ceiling(totalCount / (double)pageSize);
+    }
+
+    [JsonConstructor]
+    public PaginatedList(IReadOnlyCollection<T> items, int totalCount, int pageNumber, int pageSize)
+    {
+        PageNumber = pageNumber;
+        TotalPages = (int)Math.Ceiling(totalCount / (double)pageSize);
+        TotalCount = totalCount;
+        Items = items;
+        PageSize = pageSize;
+    }
+
+    public bool HasPreviousPage => PageNumber > 1;
+
+    public bool HasNextPage => PageNumber < TotalPages;
+
+    public static async Task<PaginatedList<T>> CreateAsync(IQueryable<T> source, int pageNumber, int pageSize)
+    {
+        var count = await source.CountAsync();
+
+        var items = await source
+        .Skip((pageNumber - 1) * pageSize)
+        .Take(pageSize)
+        .ToListAsync();
+
+        return new PaginatedList<T>(items, count, pageNumber, pageSize);
+    }
+
+    public static PaginatedList<T> Create(IEnumerable<T> source, int pageNumber, int pageSize)
+    {
+        var count = source.Count();
+
+        var items = source.Skip((pageNumber - 1) * pageSize).Take(pageSize).ToList();
+
+        return new PaginatedList<T>(items, count, pageNumber, pageSize);
+    }
+
+    public static PaginatedList<T> Create(List<T> source, int totalCount, int pageNumber, int pageSize)
+    {
+        return new PaginatedList<T>(source, totalCount, pageNumber, pageSize);
+    }
+}

src/YazilimAcademy.Application/Common/Models/Responses/ResponseDto.cs

@@ -0,0 +1,32 @@
+using YazilimAcademy.Application.Common.Models.Errors;
+
+namespace YazilimAcademy.Application.Common.Models.Responses;
+
+public sealed record ResponseDto<T>
+{
+    public T? Data { get; init; }
+    public string? Message { get; init; }
+    public bool IsSuccess { get; init; }
+    public IReadOnlyList<ValidationError> ValidationErrors { get; init; }
+
+    public ResponseDto(T? data, string? message, bool isSuccess, IReadOnlyList<ValidationError>? validationErrors = null)
+    {
+        Data = data;
+        Message = message;
+        IsSuccess = isSuccess;
+        ValidationErrors = validationErrors ?? Array.Empty<ValidationError>();
+    }
+
+    public static ResponseDto<T> Success(T data, string message)
+        => new(data, message, true);
+
+    public static ResponseDto<T?> Success(string message)
+        => new(default, message, true);
+
+    public static ResponseDto<T> Error(string message, List<ValidationError>? validationErrors = null)
+        => new(default, message, false, validationErrors);
+
+    public static ResponseDto<T> Error(string message, ValidationError validationError)
+        => new(default, message, false, new[] { validationError });
+}
+

src/YazilimAcademy.Application/Features/Categories/Commands/Create/CreateCategoryCommand.cs

@@ -0,0 +1,5 @@
+using MediatR;
+
+namespace YazilimAcademy.Application.Features.Categories.Commands.Create;
+
+public sealed record CreateCategoryCommand(string Name, string Description) : IRequest<Guid>;

src/YazilimAcademy.Application/Features/Categories/Commands/Create/CreateCategoryCommandHandler.cs

@@ -0,0 +1,27 @@
+using System;
+using MediatR;
+using YazilimAcademy.Application.Common.Interfaces;
+using YazilimAcademy.Domain.Entities;
+
+namespace YazilimAcademy.Application.Features.Categories.Commands.Create;
+
+public sealed class CreateCategoryCommandHandler : IRequestHandler<CreateCategoryCommand, Guid>
+{
+    private readonly IApplicationDbContext _dbContext;
+
+    public CreateCategoryCommandHandler(IApplicationDbContext dbContext)
+    {
+        _dbContext = dbContext;
+    }
+
+    public async Task<Guid> Handle(CreateCategoryCommand request, CancellationToken cancellationToken)
+    {
+        var category = Category.Create(request.Name, request.Description);
+
+        _dbContext.Categories.Add(category);
+
+        await _dbContext.SaveChangesAsync(cancellationToken);
+
+        return category.Id;
+    }
+}

src/YazilimAcademy.Application/Features/Categories/Commands/Create/CreateCategoryCommandValidator.cs

@@ -0,0 +1,43 @@
+using System;
+using FluentValidation;
+using Microsoft.EntityFrameworkCore;
+using YazilimAcademy.Application.Common.Interfaces;
+namespace YazilimAcademy.Application.Features.Categories.Commands.Create;
+
+public sealed class CreateCategoryCommandValidator : AbstractValidator<CreateCategoryCommand>
+{
+    private readonly IApplicationDbContext _dbContext;
+
+    public CreateCategoryCommandValidator(IApplicationDbContext dbContext)
+    {
+        _dbContext = dbContext;
+
+        RuleFor(c => c.Name)
+        .NotEmpty()
+        .WithMessage("Kategori adı boş olamaz.")
+        .MaximumLength(100)
+        .WithMessage("Kategori adı en fazla 100 karakter olmalıdır.")
+        .MinimumLength(3)
+        .WithMessage("Kategori adı en az 3 karakter olmalıdır.");
+
+        RuleFor(c => c.Description)
+        .NotEmpty()
+        .When(c => !string.IsNullOrWhiteSpace(c.Description))
+        .WithMessage("Kategori açıklaması boş olamaz.")
+        .MaximumLength(1000)
+        .WithMessage("Kategori açıklaması en fazla 1000 karakter olmalıdır.")
+        .MinimumLength(10)
+        .WithMessage("Kategori açıklaması en az 10 karakter olmalıdır.");
+
+        RuleFor(c => c.Name)
+        .MustAsync(IsCategoryNameUniqueAsync)
+        .WithMessage("Bu kategori adı zaten mevcuttur.");
+    }
+
+    private async Task<bool> IsCategoryNameUniqueAsync(string name, CancellationToken cancellationToken)
+    {
+        return !await _dbContext
+        .Categories
+        .AnyAsync(c => c.Name.ToLower() == name.ToLower(), cancellationToken);
+    }
+}

src/YazilimAcademy.Application/Features/Categories/Queries/GetAll/GetAllCategoriesDto.cs

@@ -0,0 +1,13 @@
+namespace YazilimAcademy.Application.Features.Categories.Queries.GetAll;
+
+public sealed record GetAllCategoriesDto
+{
+    public Guid Id { get; set; }
+    public string Name { get; set; }
+
+    public GetAllCategoriesDto(Guid id, string name)
+    {
+        Id = id;
+        Name = name;
+    }
+}

src/YazilimAcademy.Application/Features/Categories/Queries/GetAll/GetAllCategoriesQuery.cs

@@ -0,0 +1,6 @@
+using MediatR;
+using YazilimAcademy.Application.Common.Models.Pagination;
+
+namespace YazilimAcademy.Application.Features.Categories.Queries.GetAll;
+
+public sealed record GetAllCategoriesQuery(int PageNumber, int PageSize) : IRequest<PaginatedList<GetAllCategoriesDto>>;