/*
In jurisdictions that recognize copyright waivers, I've waived all copyright
and related or neighboring rights for to this project. In areas where these
waivers are not recognized, BSD-3-Clause is enforced.
See the (UN)LICENSE file in the project root for more information.
*/
namespace Tomas.Kernel;

public class Kernel : Os.Kernel
{
    // This method is called before the Run method
    protected override void BeforeRun()
    {
        // Initialize the file system
        SysFS.Initialize();

        // If the file system is not enabled, print an error message indicating that the system booted with errors
        if (!SysMeta.IsFSEnabled)
            Console.WriteLine($"{SysMeta.NAME} booted with errors.");
        // If the file system is enabled, print a message indicating that the system booted successfully
        else
            Console.WriteLine($"{SysMeta.NAME} booted successfully.");
    }

    protected override void Run()
    {
        // Run the loop indefinitely
        while (true)
        {
            // Create a new instance of the Shell class
            var shell = new Shell();

            // Read a line of input from the user
            var command = shell.ReadLine;

            // Split the command into words
            var words = command.Split(' ');

            // If there are no words, skip this iteration
            if (words.Length == 0)
                continue;

            // Get the program name
            var programName = words[0];

            // Get the dictionary of programs from the shell
            var programs = shell.Programs;

            // If the program doesn't exist, display an error message
            if (!programs.TryGetValue(programName, out var program))
            {
                Console.WriteLine($"{programName}: command not found");
                continue;
            }

            // Get the arguments
            var arguments = words.Skip(1).ToArray();

            // Parse and validate the arguments
            var parsedArguments = shell.ParseArguments(program, arguments);
            if (parsedArguments == null)
            {
                // If the arguments are invalid, display an error message
                Console.WriteLine($"{programName}: invalid arguments");
                continue;
            }

            // Try to run the program and handle any exceptions that may be thrown
            try
            {
                // Run the program and store the returned value in the 'result' variable
                var result = program.Entry(shell, parsedArguments);

                switch (result)
                {
                    case true:
                        continue;
                    case false:
                        Console.WriteLine("Program closed unexpectedly.");
                        continue;
                }

            }
            catch (Exception err)
            {
                // If an exception is caught, print the error message and continue to the next iteration of the loop
                Console.WriteLine(err.Message);
            }
        }
    }
}