Allow to add and remove processors from machine details in admin view.

Marechai/Services/ProcessorsByMachineService.cs

@@ -0,0 +1,49 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Marechai.Database.Models;
+using Marechai.ViewModels;
+using Microsoft.EntityFrameworkCore;
+
+namespace Marechai.Services
+{
+    public class ProcessorsByMachineService
+    {
+        readonly MarechaiContext _context;
+
+        public ProcessorsByMachineService(MarechaiContext context) => _context = context;
+
+        public async Task<List<ProcessorByMachineViewModel>> GetByMachine(int machineId) =>
+            await _context.ProcessorsByMachine.Where(p => p.MachineId == machineId).
+                           Select(p => new ProcessorByMachineViewModel
+                           {
+                               Id          = p.Id, Name = p.Processor.Name, CompanyName = p.Processor.Company.Name,
+                               ProcessorId = p.ProcessorId, MachineId = p.MachineId, Speed = p.Speed
+                           }).OrderBy(p => p.CompanyName).ThenBy(p => p.Name).ToListAsync();
+
+        public async Task DeleteAsync(long id)
+        {
+            ProcessorsByMachine item = await _context.ProcessorsByMachine.FindAsync(id);
+
+            if(item is null)
+                return;
+
+            _context.ProcessorsByMachine.Remove(item);
+
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task<long> CreateAsync(int processorId, int machineId, float? speed)
+        {
+            var item = new ProcessorsByMachine
+            {
+                ProcessorId = processorId, MachineId = machineId, Speed = speed
+            };
+
+            await _context.ProcessorsByMachine.AddAsync(item);
+            await _context.SaveChangesAsync();
+
+            return item.Id;
+        }
+    }
+}