import { createLogger, format, Logger, transports } from "winston";
import { SPLITCHAR } from "../helpers/objectMethods";

/**
 * Contains the Valid Types of the Loger.
 */
export type LoggerLevel = 'error' | 'warn' | 'info' | 'http' | 'verbose' | 'debug' | 'silly';

const order: {[K in LoggerLevel]: number} = { 
  error: 0, 
  warn: 1, 
  info: 2, 
  http: 3,
  verbose: 4, 
  debug: 5, 
  silly: 6 
}

const reverseOrder: {[index:number]: LoggerLevel} = {};
Object.getOwnPropertyNames(order).map((key: LoggerLevel) => reverseOrder[order[key]] = key);

function _selectLevel(master: LoggerLevel, slave: LoggerLevel){
  const masterLevel = order[master];
  const slaveLevel = order[slave];

  return reverseOrder[Math.min(masterLevel,slaveLevel)];
}

/**
 * Helper Function to generate default Logger Options.
 * This results in creating a Logger with a specific label,
 * and rendering format.
 *
 * @export
 * @param {LoggerLevel} level The Level, which should be rendered
 * @param {string} [label=''] An Lable for the Logger. Every Message beginns with that lable.
 * @return {*} The Loger-Options as Object
 */
function _generateLoggerOptions(level: LoggerLevel, label: string = '') {
  let readableFormat: any;

  if (label) {
    readableFormat = format.printf(({ level, message, timestamp, label }) => {
      return `[${timestamp} ${level}] - ${label}: ${message}`;
    });
  } else {
    readableFormat = format.printf(({ level, message, timestamp }) => {
      return `[${timestamp} ${level}]: ${message}`;
    });
  }

  return {
    level,
    format: label ? format.combine(
      format.timestamp({
        format: 'YYYY-MM-DD HH:mm:ss:ms'
      }),
      format.label({ label }),
      format.errors({ stack: true }),
      readableFormat
    ) : format.combine(
      format.timestamp({
        format: 'YYYY-MM-DD HH:mm:ss:ms'
      }),
      format.errors({ stack: true }),
      readableFormat
    ),
    exitOnError: false,
    transports: [
      new (transports.Console)({
        format: format.combine(
          format.colorize(),
          readableFormat
        )
      }),
    ]
  }
}

/**
 * Helper Function, to create a Logger.
 * Therefore it uses a specific Level and a Lable of the 
 * Logger
 *
 * @export
 * @param {LoggerLevel} level The Level, which should be rendered
 * @param {string} [label=''] An Lable for the Logger. Every Message beginns with that lable.
 * @return {*} Returns a Logger.
 */
function _getLogger(level: LoggerLevel, label: string = '') {
  return createLogger(_generateLoggerOptions(level, label));
}

export class NopeLogger {

    protected _logger: Logger;
    protected _loggers: Map<string, Logger>;

    set level(value: LoggerLevel) {
        if (!this.isLocked) {
            this._level = value;
            this.setLoglevel('core' + SPLITCHAR, value);
        }
    }

    get level() {
        return this._level;
    }

    public _level: LoggerLevel = 'debug';

    /**
     * Create or returns the provided Logger
     * @param name 
     * @param level 
     */
    getLogger(name: string = '', level: LoggerLevel = this.level) {
        if (!this._loggers.has(name)) {
            this._loggers.set(
                name,
                _getLogger(_selectLevel(this.level, level), name)
            );
        }
        return this._loggers.get(name) as Logger;
    }

    /**
     * Function to a Stream to the Logger
     * @param stream 
     */
    addStream(stream) {
        // Store the Stream for new Streams
        this._logger.add(stream)
    }


    /**
     * Function to determine the Logger Level
     * @param loggerGroup The specified group, which should be addressed
     * @param level The Level to Set
     */
    setLoglevel(loggerGroup: string, level: LoggerLevel) {
        if (!loggerGroup.startsWith('core' + SPLITCHAR)) {
            loggerGroup = 'core' + SPLITCHAR + loggerGroup;
        }

        if (!loggerGroup.endsWith(SPLITCHAR)) {
            loggerGroup += SPLITCHAR;
        }

        /** Iterate over all Loggers and close the unused Loggers */
        for (let [name, logger] of this._loggers.entries()) {

            if (!name.startsWith('core' + SPLITCHAR)) {
                name = 'core' + SPLITCHAR + name;
            }

            if (!name.endsWith(SPLITCHAR)) {
                name += SPLITCHAR;
            }

            if (name == loggerGroup || name.startsWith(loggerGroup)) {
                /** Update the Level */
                logger.level = level;
            }
        }
    }

    /**
     * Function, to check, whether a specific logger is logging or not
     * @param loggerName Name of the Logger
     * @param level The Log-Level to Test
     */
    isLogging(loggerName: string, level: LoggerLevel) {
      return order[this.getLogger(loggerName).level] >= order[level];
    }



    /**
     * Creates A Logger-Manager
     */
    constructor() {
        this._loggers = new Map<string, Logger>();

        this._logger = _getLogger('debug', 'root');
        this._loggers.set('', this._logger);
    }

    protected _pw: string = '';

    /**
     * Lock the Logger Level with a password
     *
     * @param {string} pw The Password to Lock the Logger
     * @memberof NopeLogger
     */
    lock(pw: string) {
        if (this._pw !== '') {
            this._loggers.get('').error('Please unlock before');
        } else {
            this._pw = pw;
        }
    }

    /**
     * Unlock the Logger, therefore the password used for locking is
     * required. After unlocking, the log-level can be adapted.
     *
     * @param {string} pw
     * @memberof NopeLogger
     */
    unlock(pw: string) {
        if (this._pw === pw) {
            this._pw = '';
        } else {
          this._loggers.get('').error('Unlocking wasnt successfull');
        }
    }

    /**
     * Flag indicating, whether the logger is locked or not.
     *
     * @readonly
     * @memberof NopeLogger
     */
    public get isLocked() {
        return this._pw !== '';
    }
}