SPMS_API/SPMS.Infrastructure/Persistence/Repositories/Repository.cs

using System.Linq.Expressions;
using Microsoft.EntityFrameworkCore;
using SPMS.Domain.Entities;
using SPMS.Domain.Interfaces;

namespace SPMS.Infrastructure.Persistence.Repositories;

public class Repository<T> : IRepository<T> where T : BaseEntity
{
    protected readonly AppDbContext _context;
    protected readonly DbSet<T> _dbSet;

    public Repository(AppDbContext context)
    {
        _context = context;
        _dbSet = context.Set<T>();
    }

    public async Task<T?> GetByIdAsync(long id)
        => await _dbSet.FindAsync(id);

    public async Task<IReadOnlyList<T>> GetAllAsync()
        => await _dbSet.ToListAsync();

    public async Task<IReadOnlyList<T>> FindAsync(Expression<Func<T, bool>> predicate)
        => await _dbSet.Where(predicate).ToListAsync();

    public async Task<(IReadOnlyList<T> Items, int TotalCount)> GetPagedAsync(
        int page, int size,
        Expression<Func<T, bool>>? predicate = null,
        Expression<Func<T, object>>? orderBy = null,
        bool descending = true)
    {
        IQueryable<T> query = _dbSet;

        if (predicate is not null)
            query = query.Where(predicate);

        var totalCount = await query.CountAsync();

        if (orderBy is not null)
            query = descending ? query.OrderByDescending(orderBy) : query.OrderBy(orderBy);
        else
            query = query.OrderByDescending(e => e.Id);

        var items = await query
            .Skip((page - 1) * size)
            .Take(size)
            .ToListAsync();

        return (items, totalCount);
    }

    public async Task<int> CountAsync(Expression<Func<T, bool>>? predicate = null)
        => predicate is null
            ? await _dbSet.CountAsync()
            : await _dbSet.CountAsync(predicate);

    public async Task<bool> ExistsAsync(Expression<Func<T, bool>> predicate)
        => await _dbSet.AnyAsync(predicate);

    public async Task AddAsync(T entity)
        => await _dbSet.AddAsync(entity);

    public void Update(T entity)
        => _dbSet.Update(entity);

    public void Delete(T entity)
        => _dbSet.Remove(entity);
}