using System.Text.Json;
using System.Text.RegularExpressions;
using Microsoft.Extensions.Configuration;

namespace RandomWallpaper
{
    internal class Program
    {
        private static Queue<String> previouslyDisplayed;
        private static int maxDisplayQueueLength = 1000;

        const String queueFileName = ".queue";

        private static String[] targetDisplays = ["2"];
        static void Main(string[] args)
        {

            var configurationBuilder = new ConfigurationBuilder();

            configurationBuilder.SetBasePath(System.IO.Directory.GetCurrentDirectory());
            configurationBuilder.AddJsonFile(path: "appSettings.json", optional: false, reloadOnChange: true);

            var config = configurationBuilder.Build();
            
            if(File.Exists(queueFileName))
                previouslyDisplayed = JsonSerializer.Deserialize<Queue<String>>(File.ReadAllText(queueFileName));
            else
                previouslyDisplayed = new Queue<String>();

            String wallpaperFolder = config["WallpaperFolder"];
            
            foreach(String display in targetDisplays)
            {
                String id = "";
                String randomPaper;
                do
                {
                    randomPaper = GetRandomWallpaper(wallpaperFolder);
                    id = GetWallhavenID(randomPaper);                    
                }
                while(previouslyDisplayed.Contains(id));
                //set wallpaper
                String setWallpaperScript = KDEScripts.GetChangeWallpaperScript(display, randomPaper);
                KDEScripts.RunPlasmaScript(setWallpaperScript);
                AddToDisplayed(randomPaper);
            }

            File.WriteAllText(queueFileName, JsonSerializer.Serialize(previouslyDisplayed));
            Console.WriteLine("Changed");

        }

        static void AddToDisplayed(String fileName)
        {
            String pop;
            String wallhavenID = GetWallhavenID(fileName);
            if(previouslyDisplayed.Count >= maxDisplayQueueLength)
                previouslyDisplayed.TryDequeue(out pop);
            
            previouslyDisplayed.Enqueue(wallhavenID);
        }

        static String GetRandomWallpaper(String path)
        {
            String[] wallpaperFiles = Directory.GetFiles(path);
            int fileCount = wallpaperFiles.Length;
            Random rand = new ();
            int randomIndex = rand.Next(fileCount - 1);
            return wallpaperFiles[randomIndex];
        }

        static String GetWallhavenID(String fileName)
        {
            String id = Regex.Match(fileName, @"wallhaven-(?<id>[^\.]+)").Groups["id"].Value;
            return id;
        }

    }
}