using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Json;
using System.Text;
using System.Text.Json;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using static MinecraftClient.Settings;

namespace MinecraftClient.Protocol.Message
{
    /// <summary>
    /// This class parses JSON chat data from MC 1.6+ and returns the appropriate string to be printed.
    /// </summary>
    static class ChatParser
    {
        public enum MessageType
        {
            CHAT,
            SAY_COMMAND,
            MSG_COMMAND_INCOMING,
            MSG_COMMAND_OUTGOING,
            TEAM_MSG_COMMAND_INCOMING,
            TEAM_MSG_COMMAND_OUTGOING,
            EMOTE_COMMAND,
            RAW_MSG
        };

        public static Dictionary<int, MessageType>? ChatId2Type;

        // Used to store Chat Types in 1.20.6+
        public static void ReadChatType(Dictionary<int, string> data)
        {
            var chatTypeDictionary = ChatId2Type ?? new Dictionary<int, MessageType>();

            foreach (var (chatId, chatName) in data)
            {
                chatTypeDictionary[chatId] = chatName switch
                {
                    "minecraft:chat" => MessageType.CHAT,
                    "minecraft:emote_command" => MessageType.EMOTE_COMMAND,
                    "minecraft:msg_command_incoming" => MessageType.MSG_COMMAND_INCOMING,
                    "minecraft:msg_command_outgoing" => MessageType.MSG_COMMAND_OUTGOING,
                    "minecraft:say_command" => MessageType.SAY_COMMAND,
                    "minecraft:team_msg_command_incoming" => MessageType.TEAM_MSG_COMMAND_INCOMING,
                    "minecraft:team_msg_command_outgoing" => MessageType.TEAM_MSG_COMMAND_OUTGOING,
                    _ => MessageType.CHAT,
                };
            }

            ChatId2Type = chatTypeDictionary;
        }

        public static void ReadChatType(Dictionary<string, object> registryCodec)
        {
            Dictionary<int, MessageType> chatTypeDictionary = ChatId2Type ?? new();
            
            // Check if the chat type registry is in the correct format
            if (!registryCodec.ContainsKey("minecraft:chat_type")) {
                
                // If not, then we force the registry to be in the correct format
                if (registryCodec.ContainsKey("chat_type")) {
                    
                    foreach (var key in registryCodec.Keys.ToArray()) {
                        // Skip entries with a namespace already
                        if (key.Contains(':', StringComparison.OrdinalIgnoreCase)) continue;

                        // Assume all other entries are in the minecraft namespace
                        registryCodec["minecraft:" + key] = registryCodec[key];
                        registryCodec.Remove(key);
                    }
                }
            }
            
            var chatTypeListNbt = (object[])(((Dictionary<string, object>)registryCodec["minecraft:chat_type"])["value"]);
            foreach (var (chatName, chatId) in from Dictionary<string, object> chatTypeNbt in chatTypeListNbt
                     let chatName = (string)chatTypeNbt["name"]
                     let chatId = (int)chatTypeNbt["id"]
                     select (chatName, chatId))
            {
                chatTypeDictionary[chatId] = chatName switch
                {
                    "minecraft:chat" => MessageType.CHAT,
                    "minecraft:emote_command" => MessageType.EMOTE_COMMAND,
                    "minecraft:msg_command_incoming" => MessageType.MSG_COMMAND_INCOMING,
                    "minecraft:msg_command_outgoing" => MessageType.MSG_COMMAND_OUTGOING,
                    "minecraft:say_command" => MessageType.SAY_COMMAND,
                    "minecraft:team_msg_command_incoming" => MessageType.TEAM_MSG_COMMAND_INCOMING,
                    "minecraft:team_msg_command_outgoing" => MessageType.TEAM_MSG_COMMAND_OUTGOING,
                    _ => MessageType.CHAT,
                };
            }

            ChatId2Type = chatTypeDictionary;
        }

        /// <summary>
        /// The main function to convert text from MC 1.6+ JSON to MC 1.5.2 formatted text
        /// </summary>
        /// <param name="json">JSON serialized text</param>
        /// <param name="links">Optional container for links from JSON serialized text</param>
        /// <returns>Returns the translated text</returns>
        public static string ParseText(string json, List<string>? links = null)
        {
            return JSONData2String(Json.ParseJson(json), "", links);
        }

        public static string ParseText(Dictionary<string, object> nbt)
        {
            return NbtToString(nbt);
        }

        /// <summary>
        /// The main function to convert text from MC 1.9+ JSON to MC 1.5.2 formatted text
        /// </summary>
        /// <param name="message">Message received</param>
        /// <param name="links">Optional container for links from JSON serialized text</param>
        /// <returns>Returns the translated text</returns>
        public static string ParseSignedChat(ChatMessage message, List<string>? links = null)
        {
            string sender = message.isSenderJson ? ParseText(message.displayName!) : message.displayName!;
            string content;
            if (Config.Signature.ShowModifiedChat && message.unsignedContent is not null)
            {
                content = ParseText(message.unsignedContent!);
                if (string.IsNullOrEmpty(content))
                    content = message.unsignedContent!;
            }
            else
            {
                content = message.isJson ? ParseText(message.content) : message.content;
                if (string.IsNullOrEmpty(content))
                    content = message.content!;
            }

            string text;
            List<string> usingData = new();

            MessageType chatType;
            if (message.chatTypeId == -1)
                chatType = MessageType.RAW_MSG;
            else if (!ChatId2Type!.TryGetValue(message.chatTypeId, out chatType))
                chatType = MessageType.CHAT;
            switch (chatType)
            {
                case MessageType.CHAT:
                    usingData.Add(sender);
                    usingData.Add(content);
                    text = TranslateString("chat.type.text", usingData);
                    break;
                case MessageType.SAY_COMMAND:
                    usingData.Add(sender);
                    usingData.Add(content);
                    text = TranslateString("chat.type.announcement", usingData);
                    break;
                case MessageType.MSG_COMMAND_INCOMING:
                    usingData.Add(sender);
                    usingData.Add(content);
                    text = TranslateString("commands.message.display.incoming", usingData);
                    break;
                case MessageType.MSG_COMMAND_OUTGOING:
                    usingData.Add(sender);
                    usingData.Add(content);
                    text = TranslateString("commands.message.display.outgoing", usingData);
                    break;
                case MessageType.TEAM_MSG_COMMAND_INCOMING:
                    usingData.Add(message.teamName!);
                    usingData.Add(sender);
                    usingData.Add(content);
                    text = TranslateString("chat.type.team.text", usingData);
                    break;
                case MessageType.TEAM_MSG_COMMAND_OUTGOING:
                    usingData.Add(message.teamName!);
                    usingData.Add(sender);
                    usingData.Add(content);
                    text = TranslateString("chat.type.team.sent", usingData);
                    break;
                case MessageType.EMOTE_COMMAND:
                    usingData.Add(sender);
                    usingData.Add(content);
                    text = TranslateString("chat.type.emote", usingData);
                    break;
                case MessageType.RAW_MSG:
                    text = content;
                    break;
                default:
                    goto case MessageType.CHAT;
            }

            return text;
        }

        /// <summary>
        /// Get the classic color tag corresponding to a color name
        /// </summary>
        /// <param name="colorname">Color Name</param>
        /// <returns>Color code</returns>
        private static string Color2tag(string colorname)
        {
            return colorname.ToLower() switch
            {
#pragma warning disable format // @formatter:off

           /*   MC 1.7+ Name   ||   MC 1.6 Name   ||   Classic tag   */
                "black"                           =>      "§0",
                "dark_blue"                       =>      "§1",
                "dark_green"                      =>      "§2",
                "dark_aqua"    or  "dark_cyan"    =>      "§3",
                "dark_red"                        =>      "§4",
                "dark_purple"  or  "dark_magenta" =>      "§5",
                "gold"         or  "dark_yellow"  =>      "§6",
                "gray"                            =>      "§7",
                "dark_gray"                       =>      "§8",
                "blue"                            =>      "§9",
                "green"                           =>      "§a",
                "aqua"         or  "cyan"         =>      "§b",
                "red"                             =>      "§c",
                "light_purple" or  "magenta"      =>      "§d",
                "yellow"                          =>      "§e",
                "white"                           =>      "§f",
                _                                 =>       "" ,

#pragma warning restore format // @formatter:on
            };
        }

        /// <summary>
        /// Specify whether translation rules have been loaded
        /// </summary>
        private static bool RulesInitialized = false;
        private static readonly Lock RulesInitializationLock = new();
        private static Task? RulesRefreshTask = null;

        /// <summary>
        /// Set of translation rules for formatting text
        /// </summary>
        private static Dictionary<string, string> TranslationRules = new();

        /// <summary>
        /// Initialize translation rules.
        /// Necessary for properly printing some chat messages.
        /// </summary>
        public static void InitTranslations()
        {
            lock (RulesInitializationLock)
            {
                if (RulesInitialized)
                    return;

                RulesInitialized = true;
                RulesRefreshTask = InitRulesAsync();
                _ = ObserveInitRulesAsync(RulesRefreshTask);
            }
        }

        /// <summary>
        /// Internal rule initialization method. Looks for local rule file and refreshes it from Mojang asset servers if needed.
        /// </summary>
        private static async Task InitRulesAsync()
        {
            if (Config.Main.Advanced.Language == "en_us")
            {
                TranslationRules = LoadEmbeddedTranslationRules();
                return;
            }

            //Language file in a subfolder, depending on the language setting
            if (!Directory.Exists("lang"))
                Directory.CreateDirectory("lang");

            string languageFilePath = "lang" + Path.DirectorySeparatorChar + Config.Main.Advanced.Language + ".json";

            if (TryLoadTranslationRulesFromFile(languageFilePath, out Dictionary<string, string>? translationRules))
                TranslationRules = translationRules;
            else TranslationRules = LoadEmbeddedTranslationRules();

            if (TranslationRules.TryGetValue("Version", out string? version) &&
                version == Settings.TranslationsFile_Version)
            {
                if (Config.Logging.DebugMessages)
                    ConsoleIO.WriteLineFormatted(Translations.chat_loaded, acceptnewlines: true);
                return;
            }

            // Try downloading language file from Mojang's servers?
            ConsoleIO.WriteLineFormatted(
                "§8" + string.Format(Translations.chat_download, Config.Main.Advanced.Language));
            using HttpClient httpClient = new();
            try
            {
                string fetchIndex = await httpClient.GetStringAsync(TranslationsFile_Website_Index);
                Match match = Regex.Match(fetchIndex,
                    $"minecraft/lang/{Config.Main.Advanced.Language}.json" + @""":\s\{""hash"":\s""([\d\w]{40})""");
                if (match.Success && match.Groups.Count == 2)
                {
                    string hash = match.Groups[1].Value;
                    string translation_file_location = TranslationsFile_Website_Download + '/' + hash[..2] + '/' + hash;
                    if (Config.Logging.DebugMessages)
                        ConsoleIO.WriteLineFormatted(
                            string.Format(Translations.chat_request, translation_file_location));

                    Dictionary<string, string>? fetchedFile =
                        await httpClient.GetFromJsonAsync<Dictionary<string, string>>(translation_file_location);
                    if (fetchedFile is not null && fetchedFile.Count > 0)
                    {
                        TranslationRules = fetchedFile;
                        TranslationRules["Version"] = TranslationsFile_Version;
                        await File.WriteAllTextAsync(languageFilePath,
                            JsonSerializer.Serialize(TranslationRules, typeof(Dictionary<string, string>)),
                            Encoding.UTF8);

                        ConsoleIO.WriteLineFormatted("§8" + string.Format(Translations.chat_done, languageFilePath));
                        return;
                    }
                }
                else
                {
                    ConsoleIO.WriteLineFormatted("§8" + Translations.chat_fail, acceptnewlines: true);
                }
            }
            catch (HttpRequestException)
            {
                ConsoleIO.WriteLineFormatted("§8" + Translations.chat_fail, acceptnewlines: true);
            }
            catch (IOException)
            {
                ConsoleIO.WriteLineFormatted("§8" + string.Format(Translations.chat_save_fail, languageFilePath),
                    acceptnewlines: true);
            }
            catch (Exception e)
            {
                ConsoleIO.WriteLineFormatted("§8" + Translations.chat_fail, acceptnewlines: true);
                ConsoleIO.WriteLine(e.Message);
                if (Config.Logging.DebugMessages && !string.IsNullOrEmpty(e.StackTrace))
                    ConsoleIO.WriteLine(e.StackTrace);
            }
            TranslationRules = LoadEmbeddedTranslationRules();
            ConsoleIO.WriteLine(Translations.chat_use_default);
        }

        private static async Task ObserveInitRulesAsync(Task initRulesTask)
        {
            try
            {
                await initRulesTask;
            }
            catch (Exception e)
            {
                TranslationRules = LoadEmbeddedTranslationRules();
                if (Config.Logging.DebugMessages)
                    ConsoleIO.WriteLine(e.ToString());
            }
        }

        private static Dictionary<string, string> LoadEmbeddedTranslationRules()
        {
            return JsonSerializer.Deserialize<Dictionary<string, string>>(
                (byte[])MinecraftAssets.ResourceManager.GetObject("en_us.json")!)!;
        }

        private static bool TryLoadTranslationRulesFromFile(string languageFilePath, out Dictionary<string, string>? translationRules)
        {
            translationRules = null;
            if (!File.Exists(languageFilePath))
                return false;

            try
            {
                translationRules =
                    JsonSerializer.Deserialize<Dictionary<string, string>>(File.OpenRead(languageFilePath))!;
                return translationRules is not null;
            }
            catch (IOException)
            {
                return false;
            }
            catch (JsonException)
            {
                return false;
            }
        }

        public static string? TranslateString(string rulename)
        {
            if (TranslationRules.TryGetValue(rulename, out string? result))
                return result;
            else
                return null;
        }

        /// <summary>
        /// Format text using a specific formatting rule.
        /// Example : * %s %s + ["ORelio", "is doing something"] = * ORelio is doing something
        /// </summary>
        /// <param name="rulename">Name of the rule, chosen by the server</param>
        /// <param name="using_data">Data to be used in the rule</param>
        /// <returns>Returns the formatted text according to the given data</returns>
        private static string TranslateString(string rulename, List<string> using_data)
        {
            if (!RulesInitialized)
                InitTranslations();

            if (TranslationRules.ContainsKey(rulename))
            {
                int using_idx = 0;
                string rule = TranslationRules[rulename];
                StringBuilder result = new();
                for (int i = 0; i < rule.Length; i++)
                {
                    if (rule[i] == '%' && i + 1 < rule.Length)
                    {
                        //Using string or int with %s or %d
                        if (rule[i + 1] == 's' || rule[i + 1] == 'd')
                        {
                            if (using_data.Count > using_idx)
                            {
                                result.Append(using_data[using_idx]);
                                using_idx++;
                                i += 1;
                                continue;
                            }
                        }

                        //Using specified string or int with %1$s, %2$s...
                        else if (char.IsDigit(rule[i + 1])
                                 && i + 3 < rule.Length && rule[i + 2] == '$'
                                 && (rule[i + 3] == 's' || rule[i + 3] == 'd'))
                        {
                            int specified_idx = rule[i + 1] - '1';
                            if (using_data.Count > specified_idx)
                            {
                                result.Append(using_data[specified_idx]);
                                using_idx++;
                                i += 3;
                                continue;
                            }
                        }
                    }

                    result.Append(rule[i]);
                }

                return result.ToString();
            }
            else return "[" + rulename + "] " + string.Join(" ", using_data);
        }

        /// <summary>
        /// Mapping from JSON/NBT property names to Minecraft formatting codes (without §).
        /// Both "underlined" (canonical Minecraft name) and "underline" (alias) are supported.
        /// </summary>
        private static readonly Dictionary<string, string> FormattingCodes = new()
        {
            { "obfuscated",    "k" },
            { "bold",          "l" },
            { "strikethrough", "m" },
            { "underlined",    "n" },
            { "underline",     "n" },
            { "italic",        "o" },
        };

        /// <summary>Matches a single color code (§0–§9, §a–§f). Used to strip color when replacing.</summary>
        private static readonly Regex ColorCodeRegex = new(@"§[0-9a-f]", RegexOptions.Compiled);

        /// <summary>
        /// Use a JSON Object to build the corresponding string
        /// </summary>
        /// <param name="data">JSON object to convert</param>
        /// <param name="formatting">Inherited formatting codes from parent elements (set to "" for function init)</param>
        /// <param name="links">Container for links from JSON serialized text</param>
        /// <returns>returns the Minecraft-formatted string</returns>
        private static string JSONData2String(System.Text.Json.Nodes.JsonNode? data, string formatting, List<string>? links)
        {
            string extra_result = "";
            switch (data)
            {
                case System.Text.Json.Nodes.JsonObject obj:
                    if (obj.ContainsKey("color"))
                    {
                        formatting = ColorCodeRegex.Replace(formatting, "");
                        formatting += Color2tag(JSONData2String(obj["color"], "", links));
                    }

                    foreach (var (key, code) in FormattingCodes)
                    {
                        if (obj.ContainsKey(key))
                        {
                            string val = obj[key]!.GetStringValue();
                            if (val == "true")
                                formatting += "§" + code;
                            else if (val == "false")
                                formatting = formatting.Replace("§" + code, "");
                        }
                    }

                    if (obj.ContainsKey("clickEvent") && links is not null)
                    {
                        var clickEvent = obj["clickEvent"]!.AsObject();
                        if (clickEvent.ContainsKey("action")
                            && clickEvent.ContainsKey("value")
                            && clickEvent["action"]!.GetStringValue() == "open_url"
                            && !string.IsNullOrEmpty(clickEvent["value"]!.GetStringValue()))
                        {
                            links.Add(clickEvent["value"]!.GetStringValue());
                        }
                    }

                    if (obj.ContainsKey("extra"))
                    {
                        foreach (var item in obj["extra"]!.AsArray())
                            extra_result += JSONData2String(item, "§r" + formatting, links);
                    }

                    // Strip any formatting codes that appear before the last §r, since §r resets all
                    // prior formatting. The greedy .* matches up to the last §r in the string.
                    formatting = Regex.Replace(formatting, ".*(§r.*)", "$1");

                    if (obj.ContainsKey("text"))
                    {
                        // Pass "" to the leaf text node: formatting is already prepended here,
                        // and the default: case would add it a second time if we passed formatting.
                        return formatting + JSONData2String(obj["text"], "", links) + extra_result;
                    }
                    else if (obj.ContainsKey("translate"))
                    {
                        List<string> using_data = new();
                        if (obj.ContainsKey("using") && !obj.ContainsKey("with"))
                            obj["with"] = obj["using"]!.DeepClone();
                        if (obj.ContainsKey("with"))
                        {
                            foreach (var item in obj["with"]!.AsArray())
                            {
                                using_data.Add(JSONData2String(item, formatting, links));
                            }
                        }

                        return formatting +
                               TranslateString(JSONData2String(obj["translate"], "", links), using_data) +
                               extra_result;
                    }
                    else return extra_result;

                case System.Text.Json.Nodes.JsonArray arr:
                    string result = "";
                    foreach (var item in arr)
                    {
                        result += JSONData2String(item, formatting, links);
                    }

                    return result;

                default:
                    return formatting + data.GetStringValue();
            }
        }

        private static string NbtToString(Dictionary<string, object> nbt, string formatting = "")
        {
            if (nbt.Count == 1 && nbt.TryGetValue("", out object? rootMessage))
            {
                return formatting + (rootMessage?.ToString() ?? string.Empty);
            }

            string message = string.Empty;
            StringBuilder extraBuilder = new();

            // Build formatting from color and formatting flags first
            if (nbt.TryGetValue("color", out object? color))
            {
                formatting = ColorCodeRegex.Replace(formatting, "");
                formatting += Color2tag((string)color);
            }

            foreach (var (key, code) in FormattingCodes)
            {
                if (nbt.TryGetValue(key, out object? flagValue))
                {
                    bool isActive = flagValue switch
                    {
                        byte b => b > 0,
                        bool b => b,
                        _ => flagValue?.ToString()?.ToLower() == "true"
                    };
                    if (isActive)
                        formatting += "§" + code;
                    else
                        formatting = formatting.Replace("§" + code, "");
                }
            }

            // Process text
            if (nbt.TryGetValue("text", out object? textValue))
                message = textValue?.ToString() ?? string.Empty;

            // Process translate
            if (nbt.TryGetValue("translate", out object? translate))
            {
                var translateKey = (string)translate;
                List<string> translateString = new();
                if (nbt.TryGetValue("with", out object? withComponent))
                {
                    var withs = (object[])withComponent;
                    for (var i = 0; i < withs.Length; i++)
                    {
                        var withDict = withs[i] switch
                        {
                            int => new Dictionary<string, object> { { "text", $"{withs[i]}" } },
                            string => new Dictionary<string, object> { { "text", (string)withs[i] } },
                            _ => (Dictionary<string, object>)withs[i]
                        };
                        translateString.Add(NbtToString(withDict, formatting));
                    }
                }
                message = TranslateString(translateKey, translateString);
            }

            // Process extras, each starting with a reset then inheriting the current formatting
            if (nbt.TryGetValue("extra", out object? extraValue))
            {
                object[] extras = (object[])extraValue;
                for (var i = 0; i < extras.Length; i++)
                {
                    var extraDict = extras[i] switch
                    {
                        int => new Dictionary<string, object> { { "text", $"{extras[i]}" } },
                        string => new Dictionary<string, object> { { "text", (string)extras[i] } },
                        _ => (Dictionary<string, object>)extras[i]
                    };
                    extraBuilder.Append(NbtToString(extraDict, "§r" + formatting));
                }
            }

            return formatting + message + extraBuilder.ToString();
        }
    }
}