/*

Project name: PatternMatcher

Project Type : Console App.

Nugget dependencies : Nunit

                      CommandLineParser

PatternMatcher output all pattern in a string input that occur more than once; using a specific pattern length to 

decide allowed pattern.

​

Project component : Unit Test for various scenarios (including edge cases)

                    Light exception handling.

Assumptions: Matching is not case sensitive.

For production-ready system; the following improvement can be made: 

-  Use of dependecy injection : 

-  Proper seperation of concerns

-  Better Error Handling 

-  CommandLine App implementation using (CommandLineParser / Microsoft.Extensions.CommandLineUtils)

- */

​

​

using System;

using System.Text;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        WriteApplicationDescription();

        PromptUserForInput();

    }

​

    /// <summary>

    /// Collects and process user input 

    /// </summary>

    private static List<string> PromptUserForInput()

    {

        bool invalidInput = false;

        do

        {

            Console.WriteLine("Please enter an operation type: r to run unit test. m to start patter matching operation");

            var operation = Console.ReadLine();

            if (operation != OperationTypes.RunTest || operation != OperationTypes.MatchPattern)

            {

                Console.WriteLine($"Invalid operation: {operation}");

            }

        } while(invalidInput);

        return null;

    }

    /// <summary>

    /// Writes general information for the Application .

    /// </summary>  

    private static void WriteApplicationDescription()

    {

        var appDesciptionBuilder = new StringBuilder();

        appDesciptionBuilder.AppendLine("PatternMatcher 1.0.0");

        appDesciptionBuilder.AppendLine("Copyright (c) 2020 Taiwo Afolabi");

        appDesciptionBuilder.AppendLine("");

        appDesciptionBuilder.AppendLine("operations:");

        appDesciptionBuilder.AppendLine("       --r : execute unit test");

        appDesciptionBuilder.AppendLine("       --m : initiate pattern matching operation");

        Console.WriteLine(appDesciptionBuilder.ToString());

    }

    ///<summary>

    /// Tupes of operations allowed

    ///<summary>

    private static class OperationTypes

    {

      public const string RunTest = "r";

      public const string MatchPattern = "m";

    }

​

}