using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Net;
using System.Reflection;
using System.Text;
using Newtonsoft.Json.Linq;

namespace McMan
{
    internal class Program
    {
        public static void Main(string[] args)
        {
            if (args.Length == 0)
            {
                args = new string[1];
                Console.WriteLine("Username");
                Console.Write("> ");
                args[0] = Console.ReadLine();
            }
            if (args.Length == 1)
            {
                args = new [] {args[0], "choose"};
            }
            if (args.Length == 2)
            {
                Console.WriteLine("Max memory (empty for 2G)");
                Console.Write("> ");
                args = new [] {args[0], args[1], Console.ReadLine()};
            }
            if (Directory.Exists("assets"))
                Directory.Delete("assets", true);
            if (Directory.Exists("Game"))
                Directory.Delete("Game", true);
            Directory.CreateDirectory("Game");
            using WebClient client = new WebClient();
            string maxMem = args[2];
            maxMem = string.IsNullOrWhiteSpace(maxMem) ? "2G" : maxMem;
            Environment.CurrentDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
            JObject gameJson = GetMinecraftJson(client, args[1], out string ver);
            DownloadClient(client, gameJson["downloads"]["client"]);
            DownloadAssets(client, gameJson["assetIndex"], ver);
            string classpath = DownloadLibs(client, (JArray) gameJson["libraries"]);
            Console.WriteLine("Creating launch script");
            classpath += "client.jar";
            const string mainClass = "net.minecraft.client.main.Main";
            const string java = "javaw";
            const string lowMem = "768M";
            string javaOptions =
                $"-server -splash:splash.png -d64 -da -dsa -Xrs -Xms{lowMem} -Xmx{maxMem} -XX:NewSize={lowMem} -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -XX:+DisableExplicitGC -Djava.library.path=libraries -cp {classpath}  {mainClass}";
            string jvmBat =
                $"start /D %cd% /I /HIGH {java} {javaOptions} --username {args[0]} --version {ver} --gameDir %cd% --assetsDir assets --assetIndex {gameJson.Value<string>("assets")} --uuid 2536abce90e8476a871679918164abc5 --accessToken 99abe417230342cb8e9e2168ab46297a --userType legacy --versionType release --nativeLauncherVersion 307";
            File.WriteAllText(Path.Combine("Game", "start.bat"), jvmBat);
            Console.WriteLine("Done!");
        }

        //Downloads a JRE, doesn't start
        /*private static void GetJRE(WebClient client, bool x64)
        {
            Console.WriteLine("Fetching JRE Versions...");
            IEnumerable<JToken> json = JArray.Parse(client.DownloadString("https://api.adoptopenjdk.net/v2/info/releases/openjdk11"))
                .SelectMany(s => (JArray)s["binaries"]);
            Console.WriteLine("Selecting version...");
            string download = json.Last(s =>
                    s.Value<string>("os") == "windows" && s.Value<string>("architecture") == (x64 ? "x64" : "x32") &&
                    s.Value<string>("binary_type") == "jre" && s.Value<string>("heap_size") == "normal")
                .Value<string>("binary_link");
            Console.WriteLine($"Downloading from {download}...");
            if (Directory.Exists("jdk"))
                Directory.Delete("jdk", true);
            Directory.CreateDirectory("jdk");
            using MemoryStream ms = new MemoryStream(client.DownloadData(download));
            Console.WriteLine("Extracting...");
            using ZipArchive archive = new ZipArchive(ms);
            archive.ExtractToDirectory("jdk");
            Microsoft.VisualBasic.FileIO.FileSystem.CopyDirectory(Directory.GetDirectories("jdk")[0], "Game");
            Directory.Delete("jdk", true);
        }*/

        private static string DownloadLibs(WebClient client, JArray libraries)
        {
            string output = "";
            string libdir = Path.Combine("Game", "libraries");
            Console.WriteLine("Downloading libs...");
            Directory.CreateDirectory(libdir);
            Console.CursorTop++;
            JToken[] tmp = libraries.ToArray();
            for (int i = 0; i < tmp.Length; i++)
            {
                JToken lib = tmp[i];
                if (lib["downloads"].Any(s => ((JProperty) s).Name == "classifiers"))
                    output = lib["downloads"]["classifiers"].Where(lib2 => ((JProperty) lib2).Name == "natives-windows")
                        .Aggregate(
                            output,
                            (current, lib2) => current + DownloadLib(client, lib2.First.Value<string>("sha1"),
                                lib2.First.Value<string>("url"), lib2.First.Value<string>("path"),
                                libdir));
                Console.CursorLeft = 0;
                Console.CursorTop--;
                Console.WriteLine($"[{i + 1}/{tmp.Length}] Getting {lib["downloads"]["artifact"].Value<string>("path")}{new string(' ', 10)}");
                output += DownloadLib(client,
                    lib["downloads"]["artifact"].Value<string>("sha1"),
                    lib["downloads"]["artifact"].Value<string>("url"),
                    lib["downloads"]["artifact"].Value<string>("path"),
                    libdir);
            }
            return output;
        }

        private static string DownloadLib(WebClient client, string hash, string url, string path, string libdir)
        {
            string tmp = path.Split('/').Aggregate(libdir, Path.Combine);
            byte[] libB = client.DownloadData(url);
            if (Tools.Hash(libB) != hash)
            {
                Console.WriteLine("ERROR: HASH MISMATCH IN LIBRARY");
                throw new Exception();
            }
            Directory.CreateDirectory(Path.GetDirectoryName(tmp));
            File.WriteAllBytes(tmp, libB);
            return $"{path.Split('/').Aggregate("libraries", Path.Combine)};";
        }

        private static void DownloadAssets(WebClient client, JToken assetIndex, string version)
        {
            bool success = false;
            byte[] indexB = new byte[0];
            while (!success)
            {
                Console.WriteLine("Downloading asset index...");
                indexB = client.DownloadData(assetIndex.Value<string>("url"));
                success = Tools.Hash(indexB) == assetIndex.Value<string>("sha1");
            }
            JObject index = JObject.Parse(Encoding.Default.GetString(indexB));
            string assetPath = Path.Combine("Game", "assets");
            Directory.CreateDirectory(Path.Combine(assetPath, "indexes"));
            File.WriteAllBytes(Path.Combine(assetPath, "indexes", Path.GetFileName(assetIndex.Value<string>("url"))), indexB);
            Console.WriteLine("Processing...");
            Console.CursorTop++;
            JToken[] tmp = Enumerable.ToArray(index["objects"]);
            for (int i = 0; i < tmp.Length; i++)
            {
                JProperty asset = (JProperty)tmp[i];
                string name = asset.Name;
                Console.CursorLeft = 0;
                Console.CursorTop--;
                Console.WriteLine($"[{i + 1}/{tmp.Length}] Getting {name}{new string(' ', 10)}");
                string hash = asset.First.Value<string>("hash");
                string url = $"http://resources.download.minecraft.net/{string.Join("", hash.Substring(0, 2))}/{hash}";
                byte[] file = client.DownloadData(url);
                if (Tools.Hash(file) != hash)
                {
                    Console.WriteLine("ERROR: HASH MISMATCH IN ASSET");
                    throw new Exception();
                }
                string path = Path.Combine(assetPath, "objects", hash.Substring(0, 2));
                if (!Directory.Exists(path))
                    Directory.CreateDirectory(path);
                File.WriteAllBytes(Path.Combine(path, hash), file);
            }
        }

        private static void DownloadClient(WebClient client, JToken clientJson)
        {
            bool success = false;
            byte[] mcClient = new byte[0];
            while (!success)
            {
                Console.WriteLine("Downloading client...");
                mcClient = client.DownloadData(clientJson.Value<string>("url"));
                success = Tools.Hash(mcClient) == clientJson.Value<string>("sha1");
            }
            File.WriteAllBytes(Path.Combine("Game", "client.jar"), mcClient);
        }

        private static JObject GetMinecraftJson(WebClient client, string verdat, out string version)
        {
            Tuple<string, string> tmp;
            Tuple<string, string>[] versions = GetVersions(client);
            if (verdat == "choose")
            {
                Console.WriteLine("Select a Version (empty for latest)");
                for (int i = 0; i < versions.Length; i++) Console.WriteLine($"{i + 1}\t- {versions[i].Item1}");
                Console.Write("> ");
                string inp = Console.ReadLine();
                tmp = string.IsNullOrWhiteSpace(inp) ? versions.Last() : versions[int.Parse(inp) - 1];
            }
            else
                tmp = versions.First(s => s.Item1.ToLower().Equals(verdat.ToLower(), StringComparison.InvariantCultureIgnoreCase));
            version = tmp.Item1;
            Console.WriteLine($"Using minecraft {version}");
            return JObject.Parse(client.DownloadString(tmp.Item2));
        }

        private static Tuple<string, string>[] GetVersions(WebClient client)
        {
            JObject tmp =
                JObject.Parse(client.DownloadString("https://launchermeta.mojang.com/mc/game/version_manifest.json"));
            return tmp["versions"].Where(token => token.Value<string>("type") == "release").Select(token => new Tuple<string, string>(token.Value<string>("id"), token.Value<string>("url"))).OrderBy(s => Version.Parse(s.Item1)).ToArray();
        }
    }
}