using CommandLine;
using AoC.API;
using System.IO;
using System.Reflection;

const string levelFilePathTemplate = "{0}/inputs/{1}/{2}/input.txt";

// find git repo base path
DirectoryInfo? gitParentDirectory = new FileInfo(
    Path.GetDirectoryName(Assembly.GetAssembly(typeof(Options)).Location)).Directory;

while(gitParentDirectory != null && !gitParentDirectory.ToString().EndsWith("LevelInputProvider"))
{
    gitParentDirectory = gitParentDirectory?.Parent;
}

string gitBasePath = gitParentDirectory?.ToString() + Path.DirectorySeparatorChar + "LevelInputProvider";

Parser.Default.ParseArguments<Options>(args)
    .WithParsed<Options>(o =>
    {
        if (string.IsNullOrEmpty(o.Cookie))
        {
            var env_cookie = System.Environment.GetEnvironmentVariable("SESSION_COOKIE");
            if(string.IsNullOrEmpty(env_cookie))
            {
                throw new Exception("A session cookie must be provided!");
            }
            o.Cookie = env_cookie;
        }

        EntryPoint(o);
    });

bool InputAlreadyExists(int year, int day)
{
    return File.Exists(string.Format(levelFilePathTemplate, gitBasePath, year, day));
}

void EnsureDirectoryExists(string filePath) 
{ 
    FileInfo fi = new FileInfo(filePath);
    if (!fi.Directory.Exists) 
    { 
        System.IO.Directory.CreateDirectory(fi.DirectoryName); 
    } 
}

void EntryPoint(Options o)
{
    var currentYear = DateTime.Now.Year;
    var currentMonth = DateTime.Now.Month;
    var currentDay = DateTime.Now.Day;

    if(currentMonth != 12)
    {
        throw new Exception("Tsk Tsk, it isn't even December yet!");
    }

    for(int i = 1; i <= currentDay; i++)
    {
        Console.WriteLine("Attempt to get input " + i + " for year " + currentYear + "");
        if(InputAlreadyExists(currentYear, i))
        {
            Console.WriteLine("Input " + i + " already exists!");
            continue;
        }

        var client = new Session(o.Cookie, currentYear, i);
        var inputTextTask = client.GetInputTextAsync();
        string inputText = inputTextTask.Result;
        var fileName = string.Format(levelFilePathTemplate, gitBasePath, currentYear, i);
        EnsureDirectoryExists(fileName);
        using(var sw = new StreamWriter(fileName))
        {
            sw.Write(inputText);
        }
    }

    Console.WriteLine("Finished input fetching!");
}

public class Options
{
    [Option('c', "cookie", Required = false, HelpText = "The AoC session cookie to use.")]
    public string Cookie { get; set; } = "";
}