ADVANCED RELATIONS

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Attributes/InjectAttribute.cs

@@ -0,0 +1,8 @@
+namespace P01_BillsPaymentSystem.Core.Attributes
+{
+    using System;
+
+    public class InjectAttribute : Attribute
+    {
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/CommandInterpreter.cs

@@ -0,0 +1,51 @@
+namespace P01_BillsPaymentSystem.Core
+{
+    using P01_BillsPaymentSystem.Core.Attributes;
+    using P01_BillsPaymentSystem.Core.Commands.Contracts;
+    using P01_BillsPaymentSystem.Core.Contracts;
+
+    using System;
+    using System.Linq;
+    using System.Reflection;
+
+    public class CommandInterpreter : ICommandInterpreter
+    {
+        private const string suffix = "Command";
+
+        private readonly IServiceProvider serviceProvider; 
+
+        public CommandInterpreter(IServiceProvider serviceProvider)
+        {
+            this.serviceProvider = serviceProvider;
+        }
+
+        public IExecutable InterpretCommand(string[] data)
+        {
+            var commandType = data[0] + suffix;
+            data = data.Skip(1).ToArray();
+
+            Assembly assembly = Assembly.GetCallingAssembly();
+            var model = assembly.GetTypes().FirstOrDefault(x => x.Name == commandType);
+
+            if (model == null)
+            {
+                throw new ArgumentException("Invalid type!");
+            }
+
+            PropertyInfo[] propertiesToInject = model
+                .GetProperties(BindingFlags.Instance | BindingFlags.Public)
+                .Where(p => p.GetCustomAttributes<InjectAttribute>().Any())
+                .ToArray();
+
+            var injectProps = propertiesToInject
+                .Select(p => this.serviceProvider.GetService(p.PropertyType))
+                .ToArray();
+
+            var joinedParams = new object[] { data }.Concat(injectProps).ToArray();
+
+            IExecutable command = (IExecutable)Activator.CreateInstance(model, joinedParams);
+
+            return command; 
+        }
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Commands/Command.cs

@@ -0,0 +1,16 @@
+namespace P01_BillsPaymentSystem.Core.Commands
+{
+    using P01_BillsPaymentSystem.Core.Commands.Contracts;
+
+    public abstract class Command : IExecutable
+    {
+        public Command(string[] data)
+        {
+            this.Data = data;
+        }
+
+        public string[] Data { get; protected set; }
+
+        public abstract void Execute();
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Commands/Contracts/IExecutable.cs

@@ -0,0 +1,7 @@
+namespace P01_BillsPaymentSystem.Core.Commands.Contracts
+{
+    public interface IExecutable
+    {
+        void Execute();
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Commands/PayBillsCommand.cs

@@ -0,0 +1,38 @@
+namespace P01_BillsPaymentSystem.Core.Commands
+{
+    using Attributes;
+    using IO.Contracts;
+    using P01_BillsPaymentSystem.Data;
+
+    public class PayBillsCommand : Command
+    {
+        public PayBillsCommand(string[] data, IUnitOfWork unitOfWork, IReader reader, IWriter writer)
+           : base(data)
+        {
+            this.UnitOfWork = unitOfWork;
+            this.Reader = reader;
+            this.Writer = writer;
+        }
+
+        [Inject]
+        public IUnitOfWork UnitOfWork { get; set; }
+
+        [Inject]
+        public IReader Reader { get; set; }
+
+        [Inject]
+        public IWriter Writer { get; set; }
+
+        public override void Execute()
+        {
+            var id = int.Parse(this.Data[0]);
+            var amount = decimal.Parse(this.Data[1]); 
+
+            this.Writer.WriteLine(OutputMessages.Loading);
+            var reuslt = this.UnitOfWork.Users.PayBills(id, amount);
+            this.Writer.WriteLine(reuslt);
+
+            this.UnitOfWork.Complete(); 
+        }
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Commands/UserInfoCommand.cs

@@ -0,0 +1,35 @@
+namespace P01_BillsPaymentSystem.Core.Commands
+{
+    using Attributes;
+    using IO.Contracts;
+    using P01_BillsPaymentSystem.Data;
+
+    public class UserInfoCommand : Command
+    {
+        public UserInfoCommand(string[] data, IUnitOfWork unitOfWork, IReader reader, IWriter writer)
+            : base(data)
+        {
+            this.UnitOfWork = unitOfWork;
+            this.Reader = reader;
+            this.Writer = writer;
+        }
+
+        [Inject]
+        public IUnitOfWork UnitOfWork { get; set; }
+
+        [Inject]
+        public IReader Reader { get; set; }
+
+        [Inject]
+        public IWriter Writer { get; set; }
+
+        public override void Execute()
+        {
+            var id = int.Parse(this.Data[0]);
+
+            this.Writer.WriteLine(OutputMessages.Loading);
+            var reuslt = this.UnitOfWork.Users.GetUserAndAllPayments(id);
+            this.Writer.WriteLine(reuslt);
+        }
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Contracts/ICommandInterpreter.cs

@@ -0,0 +1,9 @@
+namespace P01_BillsPaymentSystem.Core.Contracts
+{
+    using P01_BillsPaymentSystem.Core.Commands.Contracts;
+
+    public interface ICommandInterpreter
+    {
+        IExecutable InterpretCommand(string[] data); 
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Contracts/IEngine.cs

@@ -0,0 +1,7 @@
+namespace P01_BillsPaymentSystem.Core.Contracts
+{
+    public interface IEngine
+    {
+        void Run(); 
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/Engine.cs

@@ -0,0 +1,44 @@
+namespace P01_BillsPaymentSystem.Core
+{
+    using System;
+
+    using Contracts;
+    using P01_BillsPaymentSystem.Core.IO.Contracts;
+
+    public class Engine : IEngine
+    {
+        private readonly IReader reader;
+        private readonly IWriter writer;
+        private readonly ICommandInterpreter commandInterpreter;
+
+        public Engine(IReader reader, IWriter writer, ICommandInterpreter commandInterpreter)
+        {
+            this.reader = reader;
+            this.writer = writer;
+            this.commandInterpreter = commandInterpreter;
+        }
+
+        public void Run()
+        {
+            this.writer.WriteLine(OutputMessages.WelcomeString());
+
+            while (true)
+            {
+                try
+                {
+                    this.writer.WriteLine(OutputMessages.MenuOptions());
+
+                    var result = string.Empty;
+                    var input = this.reader.ReadLine().Split();
+
+                    var command = this.commandInterpreter.InterpretCommand(input);
+                    command.Execute(); 
+                }
+                catch (Exception)
+                {
+                    this.writer.WriteLine(OutputMessages.InvalidCommand); 
+                }
+            }
+        }
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/IO/ConsoleReader.cs

@@ -0,0 +1,14 @@
+namespace P01_BillsPaymentSystem.Core.IO
+{
+    using System;
+
+    using Contracts;
+
+    public class ConsoleReader : IReader
+    {
+        public string ReadLine()
+        {
+            return Console.ReadLine();
+        }
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/IO/ConsoleWriter.cs

@@ -0,0 +1,14 @@
+namespace P01_BillsPaymentSystem.Core.IO
+{
+    using System;
+
+    using Contracts;
+
+    public class ConsoleWriter : IWriter
+    {
+        public void WriteLine(string text)
+        {
+            Console.WriteLine(text);
+        }
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/IO/Contracts/IReader.cs

@@ -0,0 +1,7 @@
+namespace P01_BillsPaymentSystem.Core.IO.Contracts
+{
+    public interface IReader
+    {
+        string ReadLine(); 
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/IO/Contracts/IWriter.cs

@@ -0,0 +1,7 @@
+namespace P01_BillsPaymentSystem.Core.IO.Contracts
+{
+    public interface IWriter
+    {
+        void WriteLine(string text); 
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/OutputMessages.cs

@@ -0,0 +1,27 @@
+namespace P01_BillsPaymentSystem.Core
+{
+    using System.Text;
+
+    public static class OutputMessages
+    {
+        public static string EnterId => "Enter userId: ";
+
+        public static string Loading => "Loading...";
+
+        public static string InvalidCommand=> "Invalid Command! Try again";
+
+        public static string EnterIdAndAmount => "Enter userId and bills amount separated by white space: ";
+
+        public static string WelcomeString() => "Welcome to our BillPaymentSystem. Please choose one of the following options from the menu!";
+
+        public static string MenuOptions()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.AppendLine(); 
+            sb.AppendLine("Type 'UserInfo {id}' to see specific information about a user");
+            sb.AppendLine("Type 'PayBills {id} {billsAmount}' to try pay bills for a user");
+
+            return sb.ToString(); 
+        } 
+    }
+}

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Core/P01_BillsPaymentSystem.Core.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.2</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="2.2.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="2.2.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\P01_BillsPaymentSystem.Data\P01_BillsPaymentSystem.Data.csproj" />
+  </ItemGroup>
+
+</Project>

06.Advanced Relations/PaymentsSystem - with Patterns/P01_BillsPaymentSystem.Data.Models/Attributes/XorAttribute.cs

@@ -0,0 +1,30 @@
+namespace P01_BillsPaymentSystem.Data.Models.Attributes
+{
+    using System;
+    using System.ComponentModel.DataAnnotations;
+
+    [AttributeUsage(AttributeTargets.Property)]
+    public class XorAttribute : ValidationAttribute
+    {
+        private readonly string targetAttribute;
+
+        public XorAttribute(string targetAttribute)
+        {
+            this.targetAttribute = targetAttribute;
+        }
+
+        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+        {
+            var property = validationContext.ObjectType
+                                            .GetProperty(targetAttribute)
+                                            .GetValue(validationContext.ObjectInstance);
+
+            if ((property == null && value != null) || (property != null && value == null))
+            {
+                return ValidationResult.Success; 
+            }
+
+            return new ValidationResult("One of the props must be null!"); 
+        }
+    }
+}