Program.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace VehicleInventory
{
	class Program
	{
		static void Main(string[] args)
		{
            // filepath will be unique to your computer. You must tell the program where the
            // VehicleInventory.csv file can be found on your hard disk.
			string filepath = @"/Volumes/krb11010/3220/CarInventory-Complete/VehicleInventory.csv";

            // Use our static FileHelper class defined in the FileHelper file to load our inventory
			List<Car> cars = FileHelper.GetCars(filepath);

            // This is a neat trick to make a command line application never complete. We use a
            // while loop with a condition that always evaluates to true (or in this case, is the
            // keyword true. This way, or program operates inside an infinite loop, and only closes
            // if we meet a condition that tells it to explicitly. 
			while (true)
			{
                // Clear the window
				Console.Clear();

                // Provide instructions how to use the program
				Console.WriteLine("Input the number for what you're trying to search by:");
				Console.WriteLine("1 - Search by manufacturer");
				Console.WriteLine("2 - Search by year");
				Console.WriteLine("3 - Search by mileage range");
				Console.WriteLine("4 - Search by price range");
				Console.WriteLine("10 - Exit");

                // Get a response from the person for what they wish to do
				string action = Console.ReadLine();

                // SCOPE! We want to access our search results later, so we declare an empty list for them
                // now, use our switch statement to fill them in, and process them after the switch is complete
				List<Car> searchResult = new List<Car>();

                // Based on the value of our action variable (user's response), do one of the following:
				switch (action)
				{
					case "1": // Search by manufacturer

                        // Ask for which manufacturer they're looking for?
						Console.WriteLine("What vehicle manufacturer is the customer interested in?");
						string make = Console.ReadLine();

                        // Use Linq to parse through the cars list, and retrieve only those entries where
                        // the Make property equals the value we have stored in the make variable.
                        // Linq uses a lambda expression to determine which entries should be taken. It is
                        // essentially passing a short function that is evaluated for each item in the cars
                        // list. "w" can be anything you want, it simply refers to the item in the list that
                        // is currently being evaluated. 
						searchResult = cars.Where(w => w.Make == make).ToList();
						break;
					case "2": // Search by year
                        // Same process as condition 1
						Console.WriteLine("What year vehicle is the customer interested in?");
						double year = Convert.ToDouble(Console.ReadLine());

						searchResult = cars.Where(w => w.Year == year).ToList();
						break;
					case "3": // Search by mileage range
						Console.WriteLine("What is the minimum number of acceptable miles?");
						double mileMinimum = Convert.ToDouble(Console.ReadLine());

						Console.WriteLine("What is the maximum number of acceptable miles?");
						double mileMaximum = Convert.ToDouble(Console.ReadLine());

                        // Essentially the same as the first case, but this time we have to verify that the
                        // results are greater than the minimum AND (&&) below the maximum.
						searchResult = cars.Where(w => w.Mileage >= mileMinimum && w.Mileage <= mileMaximum).ToList();
						break;
					case "4": // Search by price range
						Console.WriteLine("What is the minimum price the customer wants to pay?");
						decimal priceMinimum = Convert.ToDecimal(Console.ReadLine());

						Console.WriteLine("What is the maximum price the customer wants to pay?");
						decimal priceMaximum = Convert.ToDecimal(Console.ReadLine());

                        // Same idea as case 3
						searchResult = cars.Where(w => w.Price >= priceMinimum && w.Price <= priceMaximum).ToList();
						break;
					case "10": // The person wants to exit the program
                        // Environment is a static class that represents the current computing "environment" and
                        // contains a method that lets you exit the program. When your program exits, it should
                        // specify an exit code, and 0 means "Program exited intentionally"
						Environment.Exit(0);
						break;
					default:
                        // This code runs if none of the above cases are met. We can pretty safely assume
                        // our user input a bad value.
						Console.WriteLine("Please input a valid response. Hit return to try again...");
						Console.ReadLine();

						// Start the loop over because we have no results to display and we need to ask what to do again
						continue; 
				}

				// Did we find results?
				if (searchResult.Count > 0)
				{
					// We did, lets show them
					Console.Clear();
					Console.WriteLine("Search Results");
					Console.WriteLine();

					// Loop through the results, using the GetDetails method on the Car class to print out details
					foreach (Car car in searchResult)
					{
						Console.WriteLine(car.GetDetails());
					}

					Console.WriteLine();
					Console.WriteLine("Press return to search again");
					Console.ReadLine();
				}
				else
				{
					// No results were found, let the user know and allow them to try again.
					Console.WriteLine("No results were found, sorry!");
					Console.WriteLine("Press return to search again");
					Console.ReadLine();
				}
			}
		}
	}
}