using System;

using System.Collections.Generic;

using System.Linq;

using Microsoft.Data.SqlClient;

​

​

namespace MyNamespace

{

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Hello World");

​

            DoStuff();  

            Hawk myHawk = new Hawk();

            Rabbit myRabbit = new Rabbit();

            Fish myFish = new Fish();           

            myHawk.Hunt();  

            myRabbit.Flee();

            myFish.Hunt();

            myFish.Flee();

​

        }

        //This method connects to a SQL Server database

        //It takes NO arguments and returns a SQLConnection object

        //

        public static SqlConnection ConnectToDatabase()

        {

            string ConnectionString = "Server=SQLEXPRESS;Catalog=CompanyDatabase;User Id=sa;Password=2BeChanged!;";

            SqlConnection conn = new SqlConnection(ConnectionString);

            try

            {

                conn.Open();

            }

            catch (SqlException ex) when (ex.Number == 1)           

            {

                //Handle this error

                Console.WriteLine($"We hit the SqlException catch block #1 - message = {ex.Message}");

            }

            catch (SqlException ex) when (ex.Number == 2)

            {

                //Handle this error

                Console.WriteLine($"We hit the SqlException catch block #2 - message = {ex.Message}");

            }

            finally

            {

                Console.WriteLine("We hit the finally code block. This block always executes.");

            }           

            return conn;

        }   

        //This method returns a SqlDataReader object

        //It requires both a SqlConnection object (conn) and a query as a string (queryString)

        //It executes the query and returns the dataset as a SqlDataReader object

        //

        public static SqlDataReader QueryDatabaseReturnReader(SqlConnection conn, string queryString)

        {

            SqlDataReader reader = null;

            try

            {

                SqlCommand Cmd = new SqlCommand(queryString,conn);

                reader = Cmd.ExecuteReader();

            }

            catch (SqlException ex) when (ex.Number == 1)

            {

                Console.WriteLine("We hit the 1st catch block with error message = {ex.Message}");

            }

            catch (SqlException ex) when (ex.Number == 2)

            {

                //Handle this error

                Console.WriteLine($"We hit the SqlException catch block #2 - message = {ex.Message}");

            }

            finally

            {

                Console.WriteLine("We hit the finally block. This block always executes.");

            }

            return reader;

        }

​

        // This is a method that has a log of classes, method calls and other things to demonstrate server/data access, 

        // List of strings and List of integers, arrays, StringBuilder class, IEnumeragle, LINQ as well as OOP C# concepts like

        // Abstract Classes, Virtual Methods, Inheritence, Interfaces, Polymorphysim, Abstraction, Overiding and Overloading.

        //

        public static void DoStuff()

        {

            int counter = 0;

            string queryString = "SELECT FirstName FROM Customer;";

            if (queryString == "")

            {

                Console.WriteLine("The query string is empty");

            }

            //SqlConnection conn = new SqlConnection();

            //conn = ConnectToDatabase();

            //SqlDataReader reader = QueryDatabaseReturnReader(conn,queryString);

            //while (reader.Read())

            //{

            //  Console.WriteLine(String.Format("{0}",reader["FirstName"]));

            //} 

            do {

                Console.WriteLine($"The value of counter in the do/while loop is: {counter}");

                counter++;

            } while (counter < 5);

​

            while (counter < 10)

            {

                Console.WriteLine($"The value of counter in the While loop is: {counter}");

                counter++;                      

            }

​

            var planoNames= new List<string> {"Roger","Tracy","Brandon"};  //This is list of string

            planoNames.Add("Esther");

            planoNames.Add("Cinco");

            planoNames.Add("Gizzy");

            planoNames.Add("Rascal");

​

            List<string> missouriNames = new List<string>();  //This is list of string

            missouriNames.Add("Bryson");

            missouriNames.Add("Kristen");

            missouriNames.Add("Finn");

            missouriNames.Add("Obi");

            missouriNames.Add("Penny");

            missouriNames.Add("Bella");

            missouriNames.Add("Milo");

            missouriNames.Add("Rue");

​

            List<int> numbers = new List<int>();  //This is list of string

            numbers.Add(1);

            numbers.Add(2);

            numbers.Add(3);

            numbers.Add(4);

            numbers.Add(5); 

​

            var names = new string[] {"Scott", "Ana", "Felipe" }; //This is an array, which is fixed in length

            names = [..names,"Roger"]; // This is how you can add to an array.

​

            //Lets create a list of integers

            var moreNumbers = new List<int> {8,5,3,4,2,6,7,1,9};

​

            foreach (string name in planoNames)

            {

                Console.WriteLine($"The value of name is: {name.ToUpper()}");

            }

​

            foreach (string name in missouriNames)

            {

                Console.WriteLine($"The value of name is: {name.ToUpper()}");

            }

​

            foreach (int number in numbers)

            {

                Console.WriteLine($"The value of number is: {number}");

            }

​

            Console.WriteLine($"The element in the 2nd element in planoNames collection is: {planoNames[1]}");  //The second element is 1 because the collection index starts at zero --  We are expecting "Tracy" here.

​

            //Now, let's get the next to last element in the planoNames collection -- We are expecting "Gizzy" here

            Console.WriteLine($"The next to last element in the planoNames collection is: {planoNames[^2]}");  //The ^ character designates to start at the end and move the index back by the number of elements specified

​

            //Now, let's get the 3rd, 4th and 5th elements in the planoNames collection -- We are expecting "Brandon", "Esther" and "Cinco"

            foreach (var name in planoNames[2..5])

            {

                Console.WriteLine($"Hello {name.ToUpper()}");

            }   

​

            //Lets try to sort one of the list of strings

            planoNames.Sort();

​

            foreach (var name in planoNames)

            {

                Console.WriteLine($"Sorted! {name.ToUpper()}");

            }   

​

            foreach (var number in moreNumbers)

            {

                Console.WriteLine($"{number}");

            }       

​

            //Now, lets find the value of 2 at it's index

            Console.WriteLine($"I found 7 at index {moreNumbers.IndexOf(7)}");

​

​

            //Finally, we will sort the contents of the moreNumbers list of integers and see the result in the output.

            moreNumbers.Sort();

            foreach (var number in moreNumbers)

            {

                Console.WriteLine($"{number}");

            }       

​

            //LINQ example

​

            //Define the data to query first

            List<int> scores = [97, 98, 81, 60, 50];

​

            Console.WriteLine("LINQ query output");

            //Define the query expression next - Essentially we're populating the scoreQuery object

            IEnumerable<int> scoreQuery = 

                from score in scores

                where score > 50

                select score;

            //Execute the query now

            foreach (int i in scoreQuery)  //Finally, we are iterating through the query result.

            {

                Console.WriteLine(i + " ");

            }

​

            //Lets do another LINQ query

​

            //Define the data to query first

            List<int> scores2 = [3,45,82,97,92,100,81,60,50,40];

​

            Console.WriteLine("LINQ query output for scores2 list");

            //Define the query expression next

            IEnumerable<int> scoreQuery2 =        // query variable (required)

                from score in scores2             // (required)

                where score > 60                  // optional

                orderby score descending          // optional

                select score;                     // must end with select or group

​

            //Finally, we will iterate through the results.

            foreach (int i in scoreQuery2)

            {

                Console.WriteLine(i + " ");

            }

​

            //This is an example of using the ternary operator

            string GetWeatherDisplay(double tempInCelsius) => tempInCelsius < 20.0 ? "Cold." : "Perfect!";

            Console.WriteLine(GetWeatherDisplay(15));  // output: Cold.

            Console.WriteLine(GetWeatherDisplay(34));  // output: Perfect!

​

            //Now, let's revisit the LINQ query above, and do a variant on it to make the iteration through the results easier.

            IEnumerable<string> scoreQuery3 = 

                from score in scores2

                where score < 80

                orderby score descending

                select $"The score is {score}";  //This is called "string interpolation"

​

            foreach (string i in scoreQuery3)

            {

                Console.WriteLine(i);

            }

            Console.WriteLine("Hello OOP!");

            var p1 = new Person("Roger", "Barnes", new DateOnly(1964,6,25));

            var p2 = new Person("Tracy", "Barnes", new DateOnly(1965,8,30));

            var p3 = new Person("Brandon", "Barnes", new DateOnly(1996,2,16));

            List<Person> people = [p1,p2,p3];

            Console.WriteLine(people.Count);

            //Pets

            Pet myPet = new Pet();

            myPet.FindAnimal();

            Console.WriteLine("Is my pet living? " + myPet.IsLiving.ToString());

            myPet.GoForAWalk();         

            //Trucks inherited from Vehicle

            Truck myTruck = new Truck();

            myTruck.HasEightFootBed = true;

            myTruck.HasReceiverHitch = true;

            myTruck.Honk();

            myTruck.Tow();

            //Creatures (cats and dogs)

            //First, attempt to instantiate a new class from the abstract class "creature" -- it won't allow us to do this because it is abstract.

            //Creature myCreature = new Creature(); <-  This line fails to compile.

            //Now, since we created both the Cat and Dog classes to inherit from the Abstract class "Creature", let's instantiate classes of those

            Dog myDog = new Dog();

            Cat myCat = new Cat();

            //These work just fine since they inherit from the "Creatures" abstract class. 

            //This is a polymorphic relationship because a cat and dog are both creatures but they do make different sounds.

            Console.WriteLine($"My dog makes the sound: {myDog.Sound}");

            Console.WriteLine($"My cat makes the sound: {myCat.Sound}");

        }

        //Classes/Objects

        interface IPredator {

            void Hunt();

        }

        interface IPrey {

            void Flee();

        }           

        public class Person (string firstName, string lastName, DateOnly birthday)

        {   

            public string First {get; } = firstName;

            public string Last {get; } = lastName;

            public DateOnly Birthday {get; } = birthday;                    

        };  

        public class Animal

        {

            private bool _Exists = true;

            private bool _IsLiving = true;

            private bool _IsWarmBlooded = false;

            private bool _HasMammaryGlands = false;

            private bool _HasLungs = false;

            private bool _Has3BonesInMiddleEar = false;

            private bool _HasDiaphram = false;

            private bool _HasFourLegs = false;

            private bool _HasFourChamberedHeart = false;            

            public bool Exists

            {

                get {return _Exists;}

            }

            public bool IsLiving

            {

                get {return _IsLiving;}

            }

            public bool IsWarmBlooded

            {

                get {return _IsWarmBlooded; }

                set {_IsWarmBlooded = value;}

            }

            public bool HasMammaryGlands

            {

                get {return _HasMammaryGlands; }

                set {_HasMammaryGlands = value;}                

            }

            public bool HasLungs

            {

                get {return _HasLungs;}

                set {_HasLungs = value;}

            }

            public bool Has3BonesInMiddleEar

            {

                get {return Has3BonesInMiddleEar;}

                set {_Has3BonesInMiddleEar = value;}

            }

            public bool HasDiaphram

            {

                get {return _HasDiaphram;}

                set {HasDiaphram = value;}

            }

            public bool HasFourLegs

            {

                get {return _HasFourLegs;}

                set {_HasFourLegs = value;}

            }

            public bool HasFourChamberedHeart

            {

                get {return _HasFourChamberedHeart;}

                set {_HasFourChamberedHeart = value;}

            }

            public void FindAnimal()

            {               

                Console.WriteLine(GeoLocateAnimal() ? "Pet Was Found!" : "Pet Was Not Found");

            }

            private bool GeoLocateAnimal()

            {

                return true;

            }

        }

        public class Mammal : Animal

        {

            public bool HasHair {get; set;} = false;

            public bool Hasfur {get; set;} = false;         

        }

​

        public class Pet : Mammal

        {

            public void GoForAWalk()

            {

                Console.WriteLine("We went for a walk");

            }

        }       

        public class Vehicle

        {

            private string _VehicleMake = "Dodge";

            private bool _HasAnEngine = true;

            private bool _HasWheels = true;

            private bool _HasTires = true;

            private bool _HasFrontBumper = true;

            private bool _HasRearBumper = true;

            private bool _HasRadio = true;

            public string VehicleMake

            {

                get {return _VehicleMake; }

            }

            public bool HasAnEngine

            {

                get {return _HasAnEngine; }

            }

            public bool HasWheels

            {

                get {return _HasWheels; }                           

            }

            public bool HasTires

            {

                get {return _HasTires; }

            }

            public bool HasFrontBumper

            {

                get {return _HasFrontBumper; }

            }

            public bool HasRearBumper

            {

                get {return _HasRearBumper; }

            }

            public bool HasRadio

            {

                get {return _HasRadio; }

            }

            public virtual void Honk()  //We made this a virtual method so it can be overridden in inherited classes.

            {

                Console.WriteLine("Tooooooot!");

            }       

        }

        public class Truck : Vehicle

        {

            private bool _HasSixFootBed = false;

            private bool _HasEightFootBed = false;

            private bool _HasStepTailgate = false;

            private bool _HasReceiverHitch = false;

            private bool _HasSlidingGlassRearWindow = false;

​

            public bool HasSixFootBed

            {

                get{return _HasSixFootBed; }

                set{_HasSixFootBed = value; }                               

            }

            public bool HasEightFootBed

            {

                get{return _HasEightFootBed; }

                set{_HasEightFootBed = value; }

            }

            public bool HasStepTailgate

            {

                get{return _HasStepTailgate; }

                set{_HasStepTailgate = value; }

            }

            public bool HasReceiverHitch

            {

                get{return _HasReceiverHitch;}

                set{_HasReceiverHitch = value;}

            }

            public bool HasSlidingGlassRearWindow 

            {

                get{return _HasSlidingGlassRearWindow;}

                set{_HasSlidingGlassRearWindow = value;}

            }

            public void Tow()

            {

                Console.WriteLine("We are towing like Tow Mater!");

            }

            public override void Honk()

            {

                // In this a method override from the parent class, we will override the Honk() method to display "Beep Beep" instead of "Tooooooot"

                Console.WriteLine("Beep Beep!");

            }

        }

        public abstract class Creature

        {

            public abstract string Sound { get; }

​

            public virtual void Move()

            {

                Console.WriteLine("Moving...");

            }

        }

        public class Cat : Creature

        {

            public override string Sound => "Meow";

​

            public override void Move()

            {

                Console.WriteLine("Walking like a cat...");

            }

        }

​

        public class Dog : Creature

        {

            public override string Sound => "Woof";

​

            public override void Move()

            {

                Console.WriteLine("Running like a dog...");

            }

        }

        class Rabbit : IPrey

        {

            public void Flee()

            {

                Console.WriteLine("The rabbit runs away!");

            }

        }

        class Hawk : IPredator

        {

            public void Hunt(){

                Console.WriteLine("The hawk is searching for food!");

            }

        }

        class Fish : IPredator, IPrey

        {

            public void Hunt(){

                Console.WriteLine("The fish hunts for food");

            }

            public void Flee(){

                Console.WriteLine("The fish swims away");

            }

        }

    }

​

}