BaseController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using AutoMapper;
using AutoMapper.QueryableExtensions;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using MyProject.Api.ExceptionHandling.CustomExceptions;
using MyProject.Api.SearchModels;
using MyProject.Dal.Core;

namespace MyProject.Api.Core
{
    [Route("api/[controller]")]
    public abstract class BaseController : Controller
    {
        protected readonly string AuditUser;
        protected readonly DbContext Context;

        protected BaseController(DbContext context, IHttpContextAccessor accessor)
        {
            this.Context = context;
            this.AuditUser = accessor.HttpContext.User.Identity.Name;
        }
    }

    // Without Search
    [Route("api/[controller]")]
    public abstract class BaseController<TEntity, TModel> : Controller
        where TEntity : BaseEntity
        where TModel : BaseModel
    {
        protected readonly string AuditUser;
        protected readonly DbContext Context;

        protected BaseController(DbContext context, IHttpContextAccessor accessor)
        {
            this.Context = context;
            this.AuditUser = accessor.HttpContext.User.Identity.Name;
        }

        [Route("get")]
        [HttpGet]
        public virtual async Task<TModel> Get(int id)
        {
            var result = await this.Context.Set<TEntity>().FindAsync(id);
            return Mapper.Map<TModel>(result);
        }

        [Route("list")]
        [HttpGet]
        public virtual async Task<IEnumerable<TModel>> List()
        {
            return await this.Context.Set<TEntity>().ProjectTo<TModel>().ToListAsync();
        }

        [Route("search")]
        [HttpPost]
        public virtual async Task<IEnumerable<TModel>> Search([FromBody] object model)
        {
            throw new NotImplementedException();
        }
        
        [Route("createupdate")]
        [HttpPost]
        public virtual async Task<int> CreateUpdate([FromBody] TModel model)
        {
            // ToDo: Handle duplicate checks. Potentially solved by creating composite key definitions.
            //  Ex: Local.HasKey(e => new { e.LocalCode, e.ActiveFlag };
            if (!this.ModelState.IsValid)
            {
                throw new FilteredException($"Unable to save {typeof(TEntity).Name}. Please make sure all required fields are filled in.");
            }

            model.AuditUser = this.AuditUser;
            TEntity entity;
            if (model.IsNewRecord)
            {
                entity = Activator.CreateInstance<TEntity>();
                Mapper.Map(model, entity);
                this.Context.Set<TEntity>().Add(entity);
            }
            else
            {
                entity = await this.Context.Set<TEntity>().FindAsync(model.GetId());
                Mapper.Map(model, entity);
                this.Context.Set<TEntity>().Update(entity);
            }

            await this.Context.SaveChangesAsync();

            return entity.GetIdValue();
        }

        [Route("delete")]
        [HttpDelete]
        public virtual async Task Delete(int id)
        {
            var entity = await this.Context.Set<TEntity>().FindAsync(id);
            this.Context.Set<TEntity>().Remove(entity);
            await this.Context.SaveChangesAsync();
        }

    }

    // With Search
    [Route("api/[controller]")]
    public abstract class BaseController<TEntity, TModel, TSearchModel> : Controller
        where TEntity : BaseEntity
        where TModel : BaseModel
        where TSearchModel : IPredicateBuilder<TEntity>
    {
        protected readonly string AuditUser;
        protected readonly DbContext Context;

        protected BaseController(DbContext context, IHttpContextAccessor accessor)
        {
            this.Context = context;
            this.AuditUser = accessor.HttpContext.User.Identity.Name;
        }

        [Route("get")]
        [HttpGet]
        public virtual async Task<TModel> Get(int id)
        {
            var result = await this.Context.Set<TEntity>().FindAsync(id);
            return Mapper.Map<TModel>(result);
        }

        [Route("list")]
        [HttpGet]
        public virtual async Task<IEnumerable<TModel>> List()
        {
            return await this.Context.Set<TEntity>().ProjectTo<TModel>().ToListAsync();
        }

        [Route("search")]
        [HttpPost]
        public virtual async Task<IEnumerable<TModel>> Search([FromBody] TSearchModel model)
        {
            List<TModel> results = await this.Context.Set<TEntity>()
                .Where(model.BuildPredicate())
                .Take(1000)
                .ProjectTo<TModel>()
                .ToListAsync();

            return results;
        }

        [Route("createupdate")]
        [HttpPost]
        public virtual async Task<int> CreateUpdate([FromBody] TModel model)
        {
            // ToDo: Handle duplicate checks. Potentially solved by creating composite key definitions.
            //  Ex: Local.HasKey(e => new { e.FirstKey, e.SecondKey };
            if (!this.ModelState.IsValid)
            {
                throw new FilteredException($"Unable to save {typeof(TEntity).Name}. Please make sure all required fields are filled in.");
            }

            model.AuditUser = this.AuditUser;
            TEntity entity;
            if (model.IsNewRecord)
            {
                entity = Activator.CreateInstance<TEntity>();
                Mapper.Map(model, entity);
                this.Context.Set<TEntity>().Add(entity);
            }
            else
            {
                entity = await this.Context.Set<TEntity>().FindAsync(model.GetId());
                Mapper.Map(model, entity);
                this.Context.Set<TEntity>().Update(entity);
            }

            await this.Context.SaveChangesAsync();

            return entity.GetIdValue();
        }

        [Route("delete")]
        [HttpDelete]
        public virtual async Task Delete(int id)
        {
            var entity = await this.Context.Set<TEntity>().FindAsync(id);
            this.Context.Set<TEntity>().Remove(entity);
            await this.Context.SaveChangesAsync();
        }

    }
}