import * as util from "util";
import * as fs from "fs";
import { EventEmitter } from "events";
import * as path from "path";

const Reset = "\x1b[0m"
const Bright = "\x1b[1m"
const Dim = "\x1b[2m"
const Underscore = "\x1b[4m"
const Blink = "\x1b[5m"
const Reverse = "\x1b[7m"
const Hidden = "\x1b[8m"

const FgBlack = "\x1b[30m"
const FgRed = "\x1b[31m"
const FgGreen = "\x1b[32m"
const FgYellow = "\x1b[33m"
const FgBlue = "\x1b[34m"
const FgMagenta = "\x1b[35m"
const FgCyan = "\x1b[36m"
const FgWhite = "\x1b[37m"

const BgBlack = "\x1b[40m"
const BgRed = "\x1b[41m"
const BgGreen = "\x1b[42m"
const BgYellow = "\x1b[43m"
const BgBlue = "\x1b[44m"
const BgMagenta = "\x1b[45m"
const BgCyan = "\x1b[46m"
const BgWhite = "\x1b[47m"

export class Logging {
   private static logFileLocation: string = "./logs/";
   private static stdout: boolean = true;

   private static fileStream: fs.WriteStream;
   private static errorStream: fs.WriteStream;

   private static writing = false;
   private static queue = new Array<{ message: string, error: boolean }>();

   static events: EventEmitter = new EventEmitter();

   static config(logfolder: string, stdout: boolean) {
      this.logFileLocation = logfolder;
      this.stdout = stdout;
   }

   static debug(...message: any[]) {
      Logging.message(LoggingTypes.Debug, message);
   }

   static log(...message: any[]) {
      Logging.message(LoggingTypes.Log, message);
   }

   static warning(...message: any[]) {
      Logging.message(LoggingTypes.Log, message);
   }

   static logWithCustomColors(type: LoggingTypes, colors: string, ...message: any[]) {
      Logging.message(type, message, colors);
   }

   static error(error: Error | string) {
      if (typeof error === "string") {
         Logging.errorMessage(error);
         return;
      }
      let m = "";
      (<any>error.stack).forEach(e => {
         m += e.toString() + "\n";
      })
      var message = error.name + " " + error.message + "\n" + m;
      Logging.message(LoggingTypes.Error, [message]);
   }

   static errorMessage(...message: string[]) {
      Logging.message(LoggingTypes.Error, message);
   }

   private static async message(type: LoggingTypes, message: any[] | string, customColors?: string) {
      var consoleLogFormat = Reset;
      if (!customColors) {
         switch (type) {
            case LoggingTypes.Log:
               //m += FgWhite + BgBlack;
               break;
            case LoggingTypes.Error:
               consoleLogFormat += FgRed;//FgWhite + BgRed + FgWhite;
               break;
            case LoggingTypes.Debug:
               consoleLogFormat += FgCyan;
               break;
            case LoggingTypes.Warning:
               consoleLogFormat += FgYellow;
               break;
         }
      } else {
         consoleLogFormat += customColors;
      }
      var mb = "";
      if (typeof message === "string") {
         mb = message;
      } else {
         message.forEach(e => {
            if (typeof e !== "string") e = util.inspect(e, false, null);
            if (e.endsWith("\n")) {
               mb += e;
            } else {
               mb += e + " ";
            }
         });
      }

      var m = "[" + LoggingTypes[type] + "][" + _getCallerFile() + "][" + new Date().toISOString().replace(/T/, ' ').replace(/\..+/, '') + "]: " + mb;
      if (this.logFileLocation) {
         if (!this.fileStream || !this.errorStream) {
            await Logging.initializeFile();
         }
         Logging.writeMessageToFile(m, type === LoggingTypes.Error);
      }
      Logging.events.emit("message", { type: type, message: mb });
      if (this.stdout) console.log(consoleLogFormat + m + Reset);
   }

   private static writeMessageToFile(message: string, error?: boolean) {
      Logging.queue.push({ message: message.replace("\n", " "), error: error });
      Logging.checkQueue();
   }

   private static checkQueue() {
      if (Logging.writing) return;
      if (Logging.queue.length <= 0) return;
      Logging.writing = true;
      var message = Logging.queue[0];
      Logging.fileStream.write(message.message + "\n", () => {
         if (message.error) {
            Logging.errorStream.write(message.message + "\n", () => {
               Logging.queue.splice(Logging.queue.indexOf(message), 1);
               Logging.writing = false;
               Logging.checkQueue();
            });
         } else {
            Logging.queue.splice(Logging.queue.indexOf(message), 1);
            Logging.writing = false;
            Logging.checkQueue();
         }
      });
   }

   private static async initializeFile() {
      if (this.fileStream && this.errorStream) return;
      if (!this.logFileLocation) return;
      try {
         var exists = util.promisify(fs.exists);
         await new Promise((resolve, reject) => {
            fs.exists(this.logFileLocation, (exists) => {
               if (!exists) {
                  fs.mkdir(this.logFileLocation, (err) => {
                     if (err) {
                        reject(err);
                     } else {
                        resolve();
                     }
                  });
               } else resolve();
            });
         });

         Logging.fileStream = fs.createWriteStream(this.logFileLocation + "all.log", { flags: "a" });
         Logging.fileStream.write("\n");
         Logging.errorStream = fs.createWriteStream(this.logFileLocation + "error.log", { flags: "a" });
         Logging.errorStream.write("\n");
      } catch (e) {
         console.log(e);
      }
   }
}

function _getCallerFile() {
   try {
      var err = new Error();
      var caller_file: string;
      var current_file: string;

      (<any>Error).prepareStackTrace = function (err, stack) { return stack; };

      current_file = (<any>err.stack).shift().getFileName();

      while (err.stack.length) {
         caller_file = (<any>err.stack).shift().getFileName();
         if (current_file !== caller_file) return path.basename(caller_file);
      }
   } catch (err) { }
   return undefined;
}

export enum LoggingTypes {
   Log,
   Warning,
   Error,
   Debug
}