Aspect Oriented Programming (AOP) via source code

// ##aspect=AutoComment

using AOP.Common;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace Aspectimum.Demo.Lib
{

    [AopTemplate("ClassLevelTemplateForMethods", NameFilter = "First")]
    [AopTemplate("StaticAnalyzer", Action = AopTemplateAction.Classes)]
    [AopTemplate("DependencyInjection", AdvicePriority = 500, Action = AopTemplateAction.PostProcessingClasses)]
    [AopTemplate("ResourceReplacer", AdvicePriority = 1000, ExtraTag = "ResourceFile=Demo.resx,ResourceClass=Demo", Action = AopTemplateAction.PostProcessingClasses)]
    public class ConsoleDemo
    {
        public virtual Person FirstDemo(string firstName, string lastName, int age)
        {
            Console.Out.WriteLine("FirstDemo: 1");

            // ##aspect="FirstDemoComment" extra data here

            return new Person()
            {
                FirstName = firstName,
                LastName = lastName,
                Age = age,
            };
        }

        private static IConfigurationRoot _configuration = inject;
        private IDataService _service { get; } = inject;
        private Person _somePerson = inject;

        [AopTemplate("LogExceptionMethod")]
        [AopTemplate("StopWatchMethod")]
        [AopTemplate("MethodFinallyDemo", AdvicePriority = 100)]
        public Customer[] SecondDemo(Person[] people)
        {
            IEnumerable<Customer> Customers;

            Console.Out.WriteLine("SecondDemo: 1");

            Console.Out.WriteLine(i18("SecondDemo: i18"));

            int configDelayMS = inject;
            string configServerName = inject;

            using (new AopTemplate("SecondDemoUsing", extraTag: "test extra"))
            {

                Customers = people.Select(s => new Customer()
                {
                    FirstName = s.FirstName,
                    LastName = s.LastName,
                    Age = s.Age,
                    Id = s.Id
                });

                _service.Init(Customers);

                foreach (var customer in Customers)
                {
                    Console.Out.WriteLine(i18($"First Name {customer.FirstName} Last Name {customer.LastName}"));
                    Console.Out.WriteLine("SecondDemo: 2 " + i18("First Name ") + customer.FirstName + i18(" Last Name   ") + customer.LastName);
                }
            }

            Console.Out.WriteLine(i18(String.Format("SecondDemo: {0}", "3")));
            Console.Out.WriteLine($"Server {configServerName} default delay {configDelayMS}");
            Console.Out.WriteLine($"Customer for ID=5 is {_service.GetCustomerName(5)}");

            return Customers.ToArray();
        }

        protected static string i18(string s) => s;
        protected static dynamic inject;

        [AopTemplate("NotifyPropertyChangedClass", Action = AopTemplateAction.Classes)]
        [AopTemplate("NotifyPropertyChanged", Action = AopTemplateAction.Properties)]
        public class Person
        {
            [AopTemplate("CacheProperty", extraTag: "{ \"CacheKey\": \"name_of_cache_key\", \"ExpiresInMinutes\": 10 }")]
            public string FullName
            {
                get
                {
                    // ##aspect="FullNameComment" extra data here
                    return $"{FirstName} {LastName}";
                }
            }

            public int Id { get; set; }
            public string FirstName { get; set; }
            public string LastName { get; set; }
            public int Age { get; set; }
        }

        [AopTemplate("NotifyPropertyChanged", Action = AopTemplateAction.Properties)]
        public class Customer : Person
        {
            public double CreditScore { get; set; }
        }

        public interface IDataService
        {
            void Init(IEnumerable<Customer> customers);
            string GetCustomerName(int customerId);
        }

        public class DataService: IDataService
        {
            private IEnumerable<Customer> _customers;
            public void Init(IEnumerable<Customer> customers)
            {
                _customers = customers;
            }

            public string GetCustomerName(int customerId)
            {
                return _customers.FirstOrDefault(w => w.Id == customerId)?.FullName;
            }
        }

        public class MockDataService : IDataService
        {
            private IEnumerable<Customer> _customers;
            public void Init(IEnumerable<Customer> customers)
            {
                if(customers == null)
                    throw (new Exception("IDataService.Init(customers == null)"));
            }

            public string GetCustomerName(int customerId)
            {
                if (customerId < 0)
                    throw (new Exception("IDataService.GetCustomerName: customerId cannot be negative"));

                if (customerId == 0)
                    throw (new Exception("IDataService.GetCustomerName: customerId cannot be zero"));

                return $"FirstName{customerId} LastName{customerId}";
            }
        }
    }
}

//------------------------------------------------------------------------------
// <auto-generated> 
//     This code was generated from a template.
// 
//     Manual changes to this file may cause unexpected behavior in your application.
//     Manual changes to this file will be overwritten if the code is regenerated.
//
//  Generated base on file: ConsoleDemo.cs
//  ##sha256: ekmmxFSeH5ev8Epvl7QvDL+D77DHwq1gHDnCxzeBWcw
//  Created By: JohnSmith
//  Created Machine: 127.0.0.1
//  Created At: 2020-09-19T23:18:07.2061273-04:00
//
// </auto-generated>
//------------------------------------------------------------------------------
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Linq;

namespace Aspectimum.Demo.Lib
{
    public class ConsoleDemo
    {
        public virtual Person FirstDemo(string firstName, string lastName, int age)
        {
            Console.Out.WriteLine("FirstDemo: 1");
            // FirstDemoComment replacement extra data here
            return new Person()
            {FirstName = firstName, LastName = lastName, Age = age, };
        }

        private static IConfigurationRoot _configuration = new ConfigurationBuilder()
            .SetBasePath(System.IO.Path.Combine(AppContext.BaseDirectory))
            .AddJsonFile("appsettings.json", optional: true)
            .Build();
        
        private IDataService _service { get; } = new DataService();

#error Cannot find injection rule for Person _somePerson
        private Person _somePerson = inject;

        public Customer[] SecondDemo(Person[] people)
        {
            try
            {
#error variable "Customers" doesn't match code standard rules
                IEnumerable<Customer> Customers;
                
                Console.Out.WriteLine("SecondDemo: 1");

#error Cannot find resource for a string "SecondDemo: i18", please add it to resources
                Console.Out.WriteLine(i18("SecondDemo: i18"));

                int configDelayMS = Int32.Parse(_configuration["delay_ms"]);
                string configServerName = _configuration["server_name"];
                {
                    // second demo test extra
                    {
                        Customers = people.Select(s => new Customer()
                        {FirstName = s.FirstName, LastName = s.LastName, Age = s.Age, Id = s.Id});
                        _service.Init(Customers);
                        foreach (var customer in Customers)
                        {
                            Console.Out.WriteLine(String.Format(Demo.First_Last_Names_Formatted, customer.FirstName, customer.LastName));
                            Console.Out.WriteLine("SecondDemo: 2 " + (Demo.First_Name + " ") + customer.FirstName + (" " + Demo.Last_Name + "   ") + customer.LastName);
                        }
                    }
                }

#error Argument for i18 method must be either string literal or interpolated string, but instead got Microsoft.CodeAnalysis.CSharp.Syntax.InvocationExpressionSyntax
#warning Please replace String.Format with string interpolation format.
                Console.Out.WriteLine(i18(String.Format("SecondDemo: {0}", "3")));
                Console.Out.WriteLine($"Server {configServerName} default delay {configDelayMS}");
                Console.Out.WriteLine($"Customer for ID=5 is {_service.GetCustomerName(5)}");

                return Customers.ToArray();
            }
            catch (Exception logExpn)
            {
                Console.Error.WriteLine($"Exception in SecondDemo\r\n{logExpn.Message}\r\n{logExpn.StackTrace}");
                throw;
            }
        }

        protected static string i18(string s) => s;
        protected static dynamic inject;
        public class Person : System.ComponentModel.INotifyPropertyChanged
        {
            public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged;
            protected void NotifyPropertyChanged([System.Runtime.CompilerServices.CallerMemberName] string propertyName = "")
            {
                PropertyChanged?.Invoke(this, new System.ComponentModel.PropertyChangedEventArgs(propertyName));
            }

            public string FullName
            {
                get
                {
                    System.Runtime.Caching.ObjectCache cache = System.Runtime.Caching.MemoryCache.Default;
                    string cachedData = cache["name_of_cache_key"] as string;
                    if (cachedData == null)
                    {
                        cachedData = GetPropertyData();
                        if (cachedData != null)
                        {
                            cache.Set("name_of_cache_key", cachedData, System.DateTimeOffset.Now.AddMinutes(10));
                        }
                    }

                    return cachedData;
                    string GetPropertyData()
                    {
                        // FullNameComment FullName
                        return $"{FirstName} {LastName}";
                    }
                }
            }

            private int _id;
            public int Id
            {
                get
                {
                    return _id;
                }

                set
                {
                    if (_id != value)
                    {
                        _id = value;
                        NotifyPropertyChanged();
                    }
                }
            }

            private string _firstName;
            public string FirstName
            {
                get
                {
                    return _firstName;
                }

                set
                {
                    if (_firstName != value)
                    {
                        _firstName = value;
                        NotifyPropertyChanged();
                    }
                }
            }

            private string _lastName;
            public string LastName
            {
                get
                {
                    return _lastName;
                }

                set
                {
                    if (_lastName != value)
                    {
                        _lastName = value;
                        NotifyPropertyChanged();
                    }
                }
            }

            private int _age;
            public int Age
            {
                get
                {
                    return _age;
                }

                set
                {
                    if (_age != value)
                    {
                        _age = value;
                        NotifyPropertyChanged();
                    }
                }
            }
        }

        public class Customer : Person
        {
            private double _creditScore;
            public double CreditScore
            {
                get
                {
                    return _creditScore;
                }

                set
                {
                    if (_creditScore != value)
                    {
                        _creditScore = value;
                        NotifyPropertyChanged();
                    }
                }
            }
        }

        public interface IDataService
        {
            void Init(IEnumerable<Customer> customers);
            string GetCustomerName(int customerId);
        }

        public class DataService : IDataService
        {
            private IEnumerable<Customer> _customers;
            public void Init(IEnumerable<Customer> customers)
            {
                _customers = customers;
            }

            public string GetCustomerName(int customerId)
            {
                return _customers.FirstOrDefault(w => w.Id == customerId)?.FullName;
            }
        }

        public class MockDataService : IDataService
        {
            private IEnumerable<Customer> _customers;
            public void Init(IEnumerable<Customer> customers)
            {
                if (customers == null)
                    throw (new Exception("IDataService.Init(customers == null)"));
            }

            public string GetCustomerName(int customerId)
            {
                if (customerId < 0)
                    throw (new Exception("IDataService.GetCustomerName: customerId cannot be negative"));
                if (customerId == 0)
                    throw (new Exception("IDataService.GetCustomerName: customerId cannot be zero"));
                return $"FirstName{customerId} LastName{customerId}";
            }
        }
    }
}

// ##template=AutoComment sha256=Qz6vshTZl2/u+NgtcV4u5W5RZMb9JPkJ2Zj0yvQBH9w
// ##template=AopCsharp.ttinclude sha256=2QR7LE4yvfWYNl+JVKQzvEBwcWvReeupVpslWTSWQ0c
// ##template=FirstDemoComment sha256=eIleHCim5r9F/33Mv9B7pcNQ/dlfEhDVXJVhA7+3OgY
// ##template=FullNameComment sha256=2/Ipn8fk2y+o/FVQHAWnrOlhqS5ka204YctZkwl/CUs
// ##template=NotifyPropertyChangedClass sha256=sxRrSjUSrynQSPjo85tmQywQ7K4fXFR7nN2mX87fCnk
// ##template=StaticAnalyzer sha256=zmJsj/FWmjqDDnpZXhoAxQB61nYujd41ILaQ4whcHyY
// ##template=LogExceptionMethod sha256=+zTre3r3LR9dm+bLPEEXg6u2OtjFg+/V6aCnJKijfcg
// ##template=NotifyPropertyChanged sha256=PMgorLSwEChpIPnEWXfEuUzUm4GO/6pMmoJdF7qcgn8
// ##template=CacheProperty sha256=oktDGTfC2hHoqpbKkeNABQaPdq6SrVLRFEQdNMoY4zE
// ##template=DependencyInjection sha256=nPq/ZxVBpgrDzyH+uLtJvD1aKbajKinX/DUBQ4BGG9g
// ##template=ResourceReplacer sha256=ZyUljjKKj0jLlM2nUIr1oJc1L7otYUI8WqWN7um6NxI

<#@ include file="AopCsharp.ttinclude" #>
<#
	// the class already implements INotifyPropertyChanged, nothing to do here
	if(ImplementsBaseType(ClassNode, "INotifyPropertyChanged", "System.ComponentModel.INotifyPropertyChanged"))
		return null;

	var classNode = AddBaseTypes<ClassDeclarationSyntax>(ClassNode, "System.ComponentModel.INotifyPropertyChanged"); 
#>

<#= ClassStart(classNode) #>
            public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged;

            protected void NotifyPropertyChanged([System.Runtime.CompilerServices.CallerMemberName] string propertyName = "")
            {
                PropertyChanged?.Invoke(this, new System.ComponentModel.PropertyChangedEventArgs(propertyName));
            }

<#= ClassBody(classNode) #>
<#= ClassEnd(classNode) #>

using Mono.Cecil;
using Mono.Cecil.Cil;
using Mono.Cecil.Rocks;

public partial class ModuleWeaver
{
    public void InjectINotifyPropertyChangedInterface(TypeDefinition targetType)
    {
        targetType.Interfaces.Add(new InterfaceImplementation(PropChangedInterfaceReference));
        WeaveEvent(targetType);
    }

    void WeaveEvent(TypeDefinition type)
    {
        var propertyChangedFieldDef = new FieldDefinition("PropertyChanged", FieldAttributes.Private | FieldAttributes.NotSerialized, PropChangedHandlerReference);
        type.Fields.Add(propertyChangedFieldDef);
        var propertyChangedField = propertyChangedFieldDef.GetGeneric();

        var eventDefinition = new EventDefinition("PropertyChanged", EventAttributes.None, PropChangedHandlerReference)
            {
                AddMethod = CreateEventMethod("add_PropertyChanged", DelegateCombineMethodRef, propertyChangedField),
                RemoveMethod = CreateEventMethod("remove_PropertyChanged", DelegateRemoveMethodRef, propertyChangedField)
            };

        type.Methods.Add(eventDefinition.AddMethod);
        type.Methods.Add(eventDefinition.RemoveMethod);
        type.Events.Add(eventDefinition);
    }

    MethodDefinition CreateEventMethod(string methodName, MethodReference delegateMethodReference, FieldReference propertyChangedField)
    {
        const MethodAttributes Attributes = MethodAttributes.Public |
                                            MethodAttributes.HideBySig |
                                            MethodAttributes.Final |
                                            MethodAttributes.SpecialName |
                                            MethodAttributes.NewSlot |
                                            MethodAttributes.Virtual;

        var method = new MethodDefinition(methodName, Attributes, TypeSystem.VoidReference);

        method.Parameters.Add(new ParameterDefinition("value", ParameterAttributes.None, PropChangedHandlerReference));
        var handlerVariable0 = new VariableDefinition(PropChangedHandlerReference);
        method.Body.Variables.Add(handlerVariable0);
        var handlerVariable1 = new VariableDefinition(PropChangedHandlerReference);
        method.Body.Variables.Add(handlerVariable1);
        var handlerVariable2 = new VariableDefinition(PropChangedHandlerReference);
        method.Body.Variables.Add(handlerVariable2);

        var loopBegin = Instruction.Create(OpCodes.Ldloc, handlerVariable0);
        method.Body.Instructions.Append(
            Instruction.Create(OpCodes.Ldarg_0),
            Instruction.Create(OpCodes.Ldfld, propertyChangedField),
            Instruction.Create(OpCodes.Stloc, handlerVariable0),
            loopBegin,
            Instruction.Create(OpCodes.Stloc, handlerVariable1),
            Instruction.Create(OpCodes.Ldloc, handlerVariable1),
            Instruction.Create(OpCodes.Ldarg_1),
            Instruction.Create(OpCodes.Call, delegateMethodReference),
            Instruction.Create(OpCodes.Castclass, PropChangedHandlerReference),
            Instruction.Create(OpCodes.Stloc, handlerVariable2),
            Instruction.Create(OpCodes.Ldarg_0),
            Instruction.Create(OpCodes.Ldflda, propertyChangedField),
            Instruction.Create(OpCodes.Ldloc, handlerVariable2),
            Instruction.Create(OpCodes.Ldloc, handlerVariable1),
            Instruction.Create(OpCodes.Call, InterlockedCompareExchangeForPropChangedHandler),
            Instruction.Create(OpCodes.Stloc, handlerVariable0),
            Instruction.Create(OpCodes.Ldloc, handlerVariable0),
            Instruction.Create(OpCodes.Ldloc, handlerVariable1),
            Instruction.Create(OpCodes.Bne_Un_S, loopBegin), // go to begin of loop
            Instruction.Create(OpCodes.Ret));
        method.Body.InitLocals = true;
        method.Body.OptimizeMacros();

        return method;
    }
}

<#@ include file="AopCsharp.ttinclude" #>
<#
 	if(!(PropertyHasEmptyGetBlock() && PropertyHasEmptySetBlock()))
		return null;

	string privateUnqiueName = GetUniquePrivatePropertyName(ClassNode, PropertyNode.Identifier.ToString());
#>

	private <#= PropertyNode.Type.ToFullString() #> <#= privateUnqiueName #><#= PropertyNode.Initializer != null ? " = " + PropertyNode.Initializer.ToFullString() : "" #>;

<#= PropertyNode.AttributeLists.ToFullString() + PropertyNode.Modifiers.ToFullString() + PropertyNode.Type.ToFullString() + PropertyNode.Identifier.ToFullString() #>
	{
		get { return <#= privateUnqiueName #>; }
		set 
		{
			if(<#= privateUnqiueName #> != value)
			{
				<#= privateUnqiueName #> = value;
				NotifyPropertyChanged();
			}
		}
	}

<#@ include file="AopCsharp.ttinclude" #>
<#
	// The template accepts a configuration value from extraTag in two ways
	// 1. as a number of minutes to use for expiration (example: 8)
	// 2. as a string in JSON in format { CacheKey: "name_of_cache_key", CacheKeyVariable: "name_of_variable", ExpiresInMinutes: 10, ExpiresVariable: "name_of_variable" }
	//
	//    CacheKey (optional) name of the cache key, the name will be used as a literal string (example: my_key)
	//    CacheKeyVariable (optional) name of variable that holds the cache key (example: GlobalConsts.MyKeyName)
	//
	//    ExpiresInMinutes (optional) number minutes that the cache value will expires (example: 12)
	//    ExpiresVariable (optional) name of a variable that the expiration value will be get from (example: AppConfig.EXPIRE_CACHE)
	//
	// if any of expiration values are not specified, 5 minutes default expiration will be used

	if(!PropertyHasAnyGetBlock())
		return null;

	const int DEFAULT_EXPIRES_IN_MINUTES = 5;

	string propertyName = PropertyNode.Identifier.ToFullString().Trim();
	string propertyType = PropertyNode.Type.ToFullString().Trim();
	string expiresInMinutes = DEFAULT_EXPIRES_IN_MINUTES.ToString();
	string cacheKey = "\"" + ClassNode.Identifier.ToFullString() + ":" + propertyName + "\"";

	if(!String.IsNullOrEmpty(ExtraTag))
	{
		if(Int32.TryParse(ExtraTag, out int exp))
		{
			expiresInMinutes = exp.ToString();
		}
		else
		{
			JsonDocument json = ExtraTagAsJson();
			if(json != null && json.RootElement.ValueKind  == JsonValueKind.Object)
			{
				if(json.RootElement.TryGetProperty("CacheKey", out JsonElement cacheKeyElement))
				{
					string s = cacheKeyElement.GetString();
					if(!String.IsNullOrEmpty(s))
						cacheKey = "\"" + s + "\"";
				}
				else if(json.RootElement.TryGetProperty("CacheKeyVariable", out JsonElement cacheVariableElement))
				{
					string s = cacheVariableElement.GetString();
					if(!String.IsNullOrEmpty(s))
						cacheKey = s;
				}

				if(json.RootElement.TryGetProperty("ExpiresInMinutes", out JsonElement expiresInMinutesElement))
				{
					if(expiresInMinutesElement.TryGetInt32(out int v) && v > 0)
						expiresInMinutes = "" + v;
				} 
				else if(json.RootElement.TryGetProperty("ExpiresVariable", out JsonElement expiresVariableElement))
				{				
					string s = expiresVariableElement.GetString();
					if(!String.IsNullOrEmpty(s))
						expiresInMinutes = s;
				}
			}
		}
	}

#>


<#= PropertyDefinition() #>
	{
		get 
		{ 
			System.Runtime.Caching.ObjectCache cache = System.Runtime.Caching.MemoryCache.Default;			

			<#= propertyType #> cachedData = cache[<#= cacheKey #>] as <#= propertyType #>;
			if(cachedData == null)
			{
				cachedData = GetPropertyData();
				if(cachedData != null)
				{					
					cache.Set(<#= cacheKey #>, cachedData, System.DateTimeOffset.Now.AddMinutes(<#= expiresInMinutes #>)); 
				}
			}

			return cachedData;

			<#= propertyType #> GetPropertyData()
			{
				<# if(PropertyNode.ExpressionBody != null ) { #>
				return (<#= PropertyNode.ExpressionBody.Expression.ToFullString() #>);
				<# } else if(PropertyNode?.AccessorList?.Accessors.FirstOrDefault(w => w.ExpressionBody != null && w.Keyword.ToString() == "get") != null) { #>
				return (<#= PropertyNode?.AccessorList?.Accessors.FirstOrDefault(w => w.ExpressionBody != null && w.Keyword.ToString() == "get").ExpressionBody.Expression.ToFullString() #>);
				<# } else { #>
				<#= PropertyGetBlock() #>
				<# } #>
			}
       }

		<#
		
		if(PropertyHasAnySetBlock()) { #>
		set 
		{
			System.Runtime.Caching.ObjectCache cache = System.Runtime.Caching.MemoryCache.Default;  

			cache.Remove(<#= cacheKey #>); // invalidate cache for the property		
			
			<#= PropertySetBlock() #>			
		}
		<# } #>

	}

<#@ include file="AopCsharp.ttinclude" #>
<#
	var syntaxNode = FieldsInjection(SyntaxNode);
	syntaxNode = VariablesInjection(syntaxNode);
	syntaxNode = PropertiesInjection(syntaxNode);	

	if(syntaxNode == SyntaxNode)
		return null;
#>

<#= syntaxNode.ToFullString() #>

<#+
	private SyntaxNode VariablesInjection(SyntaxNode syntaxNode)
	{
		return RewriteNodes<LocalDeclarationStatementSyntax >(syntaxNode, OnLocalVariablesInjection);	
	
		SyntaxNode OnLocalVariablesInjection(LocalDeclarationStatementSyntax node)
		{
			var errorMsgs = new System.Text.StringBuilder();

			SyntaxNode syntaxNode = RewriteNodes<VariableDeclaratorSyntax>(node, (n) => OnVariableDeclaratorVisit(n, node.Declaration.Type, errorMsgs));

			if(errorMsgs.Length > 0)
				return AddErrorMessageTrivia(syntaxNode, errorMsgs.ToString());

			return syntaxNode;
		}
	}

	private SyntaxNode PropertiesInjection(SyntaxNode syntaxNode)
	{
		return RewriteNodes<PropertyDeclarationSyntax>(syntaxNode, OnPropertyInjection);	
	
		SyntaxNode OnPropertyInjection(PropertyDeclarationSyntax node)
		{
			if(node.Initializer?.Value?.ToString() != "inject")
				return node;

			var errorMsgs = new System.Text.StringBuilder();

			SyntaxNode syntaxNode = DoInjection(node, node.Identifier.ToString().Trim(), node.Initializer.Value, node.Type, errorMsgs);

			if(errorMsgs.Length > 0)
				return AddErrorMessageTrivia(syntaxNode, errorMsgs.ToString());

			return syntaxNode;
		}
	}

	private SyntaxNode FieldsInjection(SyntaxNode syntaxNode)
	{
		return RewriteNodes<BaseFieldDeclarationSyntax>(syntaxNode, OnFieldsInjection);	
	
		SyntaxNode OnFieldsInjection(BaseFieldDeclarationSyntax node)
		{
			var errorMsgs = new System.Text.StringBuilder();

			SyntaxNode syntaxNode = RewriteNodes<VariableDeclaratorSyntax>(node, (n) => OnVariableDeclaratorVisit(n, node.Declaration.Type, errorMsgs));

			if(errorMsgs.Length > 0)
				return AddErrorMessageTrivia(syntaxNode, errorMsgs.ToString());

			return syntaxNode;
		}
	}

	private SyntaxNode OnVariableDeclaratorVisit(VariableDeclaratorSyntax node, TypeSyntax typeSyntax, System.Text.StringBuilder errorMsgs)
	{
		if(node.Initializer?.Value?.ToString() != "inject")
			return node;

		return DoInjection(node, node.Identifier.ToString().Trim(), node.Initializer.Value, typeSyntax, errorMsgs);
	}

	private SyntaxNode DoInjection(SyntaxNode node, string varName, ExpressionSyntax initializerNode, TypeSyntax typeSyntax, System.Text.StringBuilder errorMsgs)
	{		
		string varType = typeSyntax.ToString().Trim();

		Log($"{varName} {varType} {initializerNode.ToString()}");

		if(varName.StartsWith("config"))
		{
			string configName = Regex.Replace(Regex.Replace(varName, "^config", ""), "([a-z])([A-Z])", (m) => m.Groups[1].Value + "_" + m.Groups[2].Value).ToLower();
			ExpressionSyntax configNode = CreateElementAccess("_configuration", CreateStringLiteral(configName));

			if(varType == "int")
			{
				configNode = CreateMemberAccessInvocation("Int32", "Parse", configNode);
			}

			return node.ReplaceNode(initializerNode, configNode);
		}

		switch(varType)
		{
			case "Microsoft.Extensions.Configuration.IConfigurationRoot":
			case "IConfigurationRoot":
				EnsureUsing("Microsoft.Extensions.Configuration");

				ExpressionSyntax pathCombineArg = CreateMemberAccessInvocation("System.IO.Path", "Combine", CreateMemberAccess("AppContext", "BaseDirectory"));

				ExpressionSyntax builderNode = CreateNewType("ConfigurationBuilder").WithTrailingTrivia(SyntaxFactory.EndOfLine("\r\n"));
				builderNode  = CreateMemberAccessInvocation(builderNode, "SetBasePath", pathCombineArg).WithTrailingTrivia(SyntaxFactory.EndOfLine("\r\n"));

				ExpressionSyntax addJsonFileArg = CreateMemberAccessInvocation("System.IO.Path", "Combine", CreateMemberAccess("AppContext", "BaseDirectory"));

				builderNode  = CreateMemberAccessInvocationNamedArgs(builderNode, "AddJsonFile", 
																		(null, CreateStringLiteral("appsettings.json")), 
																		("optional",  SyntaxFactory.LiteralExpression(SyntaxKind.TrueLiteralExpression))).WithTrailingTrivia(SyntaxFactory.EndOfLine("\r\n"));

				if(GetGlobalSetting("env")?.ToLower() == "test")
				{
					builderNode  = CreateMemberAccessInvocationNamedArgs(builderNode, "AddJsonFile", 
																			(null, CreateStringLiteral("appsettings.test.json")), 
																			("optional",  SyntaxFactory.LiteralExpression(SyntaxKind.FalseLiteralExpression)));
				}

				builderNode  = CreateMemberAccessInvocation(builderNode, "Build");

				return node.ReplaceNode(initializerNode, builderNode);
				
			case "IDataService":
			{
				string className = (GetGlobalSetting("env")?.ToLower() == "test" ? "MockDataService" : "DataService");

				return node.ReplaceNode(initializerNode, CreateNewType(className));
			}
		}

		errorMsgs.AppendLine($"Cannot find injection rule for {varType} {varName}");

		return node;
	}

#>

<#@ include file="AopCsharp.ttinclude" #>
<#
	var syntaxNode = AnalyzeLocalVariables(SyntaxNode);
	syntaxNode = AnalyzeStringFormat(syntaxNode);	

	if(syntaxNode == SyntaxNode)
		return null;
#>

<#= syntaxNode.ToFullString() #>

<#+

	private SyntaxNode AnalyzeLocalVariables(SyntaxNode syntaxNode)
	{
		return RewriteNodes<LocalDeclarationStatementSyntax>(syntaxNode, OnAnalyzeLocalVariablesNodeVisit);	
	
		SyntaxNode OnAnalyzeLocalVariablesNodeVisit(LocalDeclarationStatementSyntax node)
		{
			var errorMsgs = new System.Text.StringBuilder();
			
			string d = "";
			foreach(VariableDeclaratorSyntax variableNode in node.DescendantNodes().OfType<VariableDeclaratorSyntax>().Where(w => Regex.IsMatch(w.Identifier.ToString(), "^[A-Z]")))
			{
				LogDebug($"variable: {variableNode.Identifier.ToString()}");

				errorMsgs.Append(d + $"variable \"{variableNode.Identifier.ToString()}\" doesn't match code standard rules");
				d = ", ";
			}

			if(errorMsgs.Length > 0)
				return AddErrorMessageTrivia(node, errorMsgs.ToString());

			return node;
		}
	}


	private SyntaxNode AnalyzeStringFormat(SyntaxNode syntaxNode)
	{
		return RewriteLeafStatementNodes(syntaxNode, OnAnalyzeStringFormat);	
	
		SyntaxNode OnAnalyzeStringFormat(StatementSyntax node)
		{
			bool hasStringFormat = false;

			foreach(MemberAccessExpressionSyntax memberAccessNode in node.DescendantNodes().OfType<MemberAccessExpressionSyntax>())
			{
				if(memberAccessNode.Name.ToString().Trim() != "Format")
					continue;

				string expr = memberAccessNode.Expression.ToString().Trim().ToLower();
				if(expr != "string" && expr != "system.string")
					continue;

				hasStringFormat = true;
				break;
			}

			if(hasStringFormat)
				return AddWarningMessageTrivia(node, "Please replace String.Format with string interpolation format.");

			return node;
		}
	}
#>

<#@ include file="AopCsharp.ttinclude" #>
<#

	Dictionary<string, string> options = ExtraTagAsDictionary();
	_resources = LoadResources(options["ResourceFile"]);
	_resourceClass = options["ResourceClass"];

	var syntaxNode = RewriteLeafStatementNodes(SyntaxNode, OnStatementNodeVisit);	
#>

<#= syntaxNode.ToFullString() #>

<#+ 
	private SyntaxNode OnStatementNodeVisit(StatementSyntax node)
	{
		if(!node.DescendantNodes().OfType<InvocationExpressionSyntax>().Any(w => (w.Expression is IdentifierNameSyntax) && ((IdentifierNameSyntax)w.Expression).Identifier.ToString() == "i18"  ))
			return node;

		var errorMsgs = new System.Text.StringBuilder();

		SyntaxNode syntaxNode = RewriteNodes<InvocationExpressionSyntax>(node, (n) => OnInvocationExpressionVisit(n, errorMsgs));

		if(errorMsgs.Length > 0)
			return AddErrorMessageTrivia(syntaxNode, errorMsgs.ToString());

		return syntaxNode;
	}

    private SyntaxNode OnInvocationExpressionVisit(InvocationExpressionSyntax node, System.Text.StringBuilder errorMsgs)
	{
		if(!(node.Expression is IdentifierNameSyntax && ((IdentifierNameSyntax)node.Expression).Identifier.ToString() == "i18"  ))
			return node;

		ArgumentSyntax arg = node.ArgumentList.Arguments.Single(); // We know that i18 method accepts only one argument. Keep in mind that it is just a demo and in real life you could be more inventive
		
		var expr = arg.Expression;
		if(!(expr is LiteralExpressionSyntax || expr is InterpolatedStringExpressionSyntax))
		{
			errorMsgs.AppendLine($"Argument for i18 method must be either string literal or interpolated string, but instead got {arg.Expression.GetType().ToString()}");

			return node;
		}
		
		string s = expr.ToString();
		if(s.StartsWith("$"))
		{
			(string format, List<ExpressionSyntax> expressions) = ConvertInterpolatedStringToFormat((InterpolatedStringExpressionSyntax)expr);

			ExpressionSyntax stringNode = ReplaceStringWithResource("\"" + format + "\"", errorMsgs);
			if(stringNode != null)
			{
				var memberAccess = CreateMemberAccess("String", "Format");
			
				var arguments = new List<ArgumentSyntax>();
	
				arguments.Add(SyntaxFactory.Argument(stringNode));
				expressions.ForEach(item => arguments.Add(SyntaxFactory.Argument(item)));

				var argumentList = SyntaxFactory.SeparatedList(arguments);

				return SyntaxFactory.InvocationExpression(memberAccess, SyntaxFactory.ArgumentList(argumentList));
			}
		}
		else
		{
			SyntaxNode stringNode = ReplaceStringWithResource(s, errorMsgs);
			if(stringNode != null)
				return stringNode;
		}

		return node;
	}

	private ExpressionSyntax ReplaceStringWithResource(string s, System.Text.StringBuilder errorMsgs)
	{
		Match m = System.Text.RegularExpressions.Regex.Match(s, "^\"(\\s*)(.*?)(\\s*)\"$");
		if(!m.Success)
		{
			errorMsgs.AppendLine($"String doesn't match search criteria");

			return null;
		}

		if(!_resources.TryGetValue(m.Groups[2].Value, out string resourceName))
		{

			errorMsgs.AppendLine($"Cannot find resource for a string {s}, please add it to resources");
			return null;
		}

		string csharpName = Regex.Replace(resourceName, "[^A-Za-z0-9]", "_");

		ExpressionSyntax stringNode = CreateMemberAccess(_resourceClass, csharpName);

		if(!String.IsNullOrEmpty(m.Groups[1].Value) || !String.IsNullOrEmpty(m.Groups[3].Value))
		{
			if(!String.IsNullOrEmpty(m.Groups[1].Value))
			{
				stringNode = SyntaxFactory.BinaryExpression(SyntaxKind.AddExpression, 
																CreateStringLiteral(m.Groups[1].Value), 
																stringNode);
			}

			if(!String.IsNullOrEmpty(m.Groups[3].Value))
			{
				stringNode = SyntaxFactory.BinaryExpression(SyntaxKind.AddExpression, 
															stringNode, 
															CreateStringLiteral(m.Groups[3].Value));
			}

			stringNode = SyntaxFactory.ParenthesizedExpression(stringNode);
		}

		return stringNode;
	}	

	private string _resourceClass;
	private Dictionary<string,string> _resources;
#>

public class Demo 
{
// ...

    public static string First_Last_Names_Formatted
    {
        get
        {
            return ResourceManager.GetString("First Last Names Formatted", resourceCulture);
        }
    }

    public static string First_Name
    {
        get
        {
            return ResourceManager.GetString("First Name", resourceCulture);
        }
    }

    public static string Last_Name
    {
        get
        {
            return ResourceManager.GetString("Last Name", resourceCulture);
        }
    }
}