using System;
using System.Collections.Generic;
using System.Text;

namespace SelectionExamples
{
    /******************************************
     * This program provides examples of selection 
     * structures including several versions of the 
     * if and if else statements and the switch structure
     * which it uses to create a menu. It also introduces a 
     * while loop which belongs to the next chapter.
     * Steve Conger 10/22/2008
     * *****************************************/
    class Program
    {
        static void Main(string[] args)
        {
            //call the menu
            Menu();
            
        }

        static void Menu()
        {
            int choice = 0;

            //the while loop belongs to the next chapter. It makes it so we
            //don't have to stop each time, but don't worry about it yet
            while (choice != 6)
            {
                //clear the console each time, then write
                //the menu
                Console.Clear();
                Console.WriteLine("*****************************");

                Console.WriteLine("* 1. Simple if");
                Console.WriteLine("* 2. Simple if else ");
                Console.WriteLine("* 3 And Or examples");
                Console.WriteLine("* 4 If Else If Examples");
                Console.WriteLine("* 5 Nested Example");
                Console.WriteLine("* 6 Exit");
                Console.WriteLine("*****************************");
                Console.WriteLine();
                Console.WriteLine("Enter the number for your choice");
                choice = int.Parse(Console.ReadLine());

                //this is an example of a switch structure
                //it calls the method you choose
                switch (choice)
                {
                    case 1:
                        SimpleIf();
                        break;
                    case 2:
                        SimpleIfElse();
                        break;
                    case 3:
                        AndORExamples();
                        break;
                    case 4:
                        IfElseIfExample();
                        break;
                    case 5:
                        NestedifExample();
                        break;
                    case 6:
                        Console.WriteLine("Press any key to exit");
                        break;
                    default:
                        Console.WriteLine("Not a valid choice");
                        break;
                }
                Console.ReadKey();
            }
        }

        static void SimpleIf()
        {
            //this method uses simple if statements to say whether
            //a value is greater than, less than or equal to
            //50
            Console.WriteLine("Enter an integer between 1 and 100");
            int number = int.Parse(Console.ReadLine());

            if (number < 50)
                Console.WriteLine("The number is less than 50");

            if (number > 50)
                Console.WriteLine("The number is greater than 50");

            if (number == 50)
                Console.WriteLine("The number equals 50");

        }

        static void SimpleIfElse()
        {
            //this method uses a simple if else structure
            //to determine if a give number is even
            //or odd. Note that equality uses == rather
            // than just =
            Console.WriteLine("Enter any integer");
            int number = int.Parse(Console.ReadLine());

            if (number % 2 == 0)
            {
                Console.WriteLine("The number is even");
            }
            else
            {
                Console.WriteLine("The number is odd");
            }
        }

        static void AndORExamples()
        {
            //this method uses one or and several
            //ands to look at a range of ages and 
            //return a comment
            Console.WriteLine("Enter your age");
            int age = int.Parse(Console.ReadLine());

            if (age < 3 || age > 120)
            {
                Console.WriteLine("I don't think you are telling the truth");
            }

            if (age > 2 && age < 13)
            {
                Console.WriteLine("A mere child");
            }

            if (age > 12 && age < 20)
            {
                Console.WriteLine("A teenager");
            }

            if (age > 20 && age < 60)
            {
                Console.WriteLine("prime of life");
            }

            if (age > 59)
            {
                Console.WriteLine("Starting to get a touch of gray");
            }
        }
       
        static void IfElseIfExample()
        {
            //this method uses an if else if block to 
            //evaluate a temperature
            //Note that technically a temperature of say
            //79 is greater than not only 60, but also greater
            //that 45 or 30, but when you use a block
            //like this the program stops with the first
            //true statement. It is important that you
            //arrange them in the right order
            Console.WriteLine("Enter the day's Temperature");
            int temperature = int.Parse(Console.ReadLine());

            if (temperature > 100)
            {
                Console.WriteLine("Way too hot");
            }
            else if (temperature > 80)
            {
                Console.WriteLine("Hot day");
            }
            else if (temperature > 60)
            {
                Console.WriteLine("Just right");
            }
            else if (temperature > 45)
            {
                Console.WriteLine("A touch of Autumn");
            }
            else if (temperature > 30)
            {
                Console.WriteLine("Cold day");
            }
            else
            {
                Console.WriteLine("Just plain cold");
            }

        }

        static void NestedifExample()
        {
            //this method uses a nested if
            //the outer if makes sure the value is valid
            //if it is, it passes it to the inner if else if
            //structure that evaluates it, if not
            //it passes it to the outer else clause
            // that lets you know it is an invalid average

            Console.WriteLine("Enter your GradePoint average");
            double gpa = double.Parse(Console.ReadLine());
            char grade;

            //outer if
            if (gpa >= 0 && gpa <= 4)
            {
                //inner if else block
                if (gpa > 3.5)
                {
                    grade = 'A';
                }
                else if (gpa > 3)
                {
                    grade = 'B';
                }
                else if (gpa > 2)
                {
                    grade = 'C';
                }

                else if (gpa > 1)
                {
                    grade = 'D';
                }
                else //inner else
                {
                    grade = 'F';
                }
            }
            else  //outer else
            {
                Console.WriteLine("Invalid Grade");
                return; //the return keeps it from executing 
                //the last line
            }

            Console.WriteLine("Your grade is {0}", grade);
        }


    }
}