import * as util from "util";
import * as fs from "fs";
import { EventEmitter } from "events";
import * as path from "path";
import { Lock, Observable } from "@hibas123/utils";
import { Adapter, LoggingTypes, Message } from "./types";
import { ConsoleWriter } from "./consolewriter";

const OriginalErrorStackFunction = (<any>Error.prototype).prepareStackTrace

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

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

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

export interface LoggingBaseOptions {
   /**
    * Name will be prefixed on Console output and added to logfiles, if not specified here
    */
   name: string,
   files: boolean | {
      /**
       * Filename/path of the logfile. Skip if generated with name
       */
      logfile: string;
      /**
       * Filename/path of the logfile. Skip if generated with name
       */
      errorfile: string;
   }
   /**
    * Prints output to console
    */
   console: boolean;
}


export class LoggingBase {
   private logFile: any;
   private errorFile: any;
   private adapter: Adapter[] = [];
   private adapter_init: Promise<void>[] = [];

   private messageObservable = new Observable<Message>();
   private name: string;

   constructor(options?: Partial<LoggingBaseOptions> | string) {
      let opt: Partial<LoggingBaseOptions>;
      if (!options) opt = {}
      else if (typeof options === "string") {
         opt = { name: options };
      } else {
         opt = options;
      }

      let config = {
         name: undefined,
         console: true,
         files: true,
         ...opt
      };

      if (typeof config.files === "boolean") {
         if (config.files === true) {
            let name = "";
            if (config.name)
               name = "." + config.name;
            config.files = {
               logfile: `./logs/all${name}.log`,
               errorfile: `./logs/error${name}.log`
            }
         } else {
            config.files = undefined;
         }
      }

      if (config.name)
         this.name = config.name;

      for (let key in this) {
         if (typeof this[key] === "function") this[key] = (<any>this[key]).bind(this);
      }

      if (typeof config.files !== "boolean" && config.files !== undefined && (config.files.logfile || config.files.errorfile)) {
         const { LoggingFiles } = require("./filewriter");
         if (config.files.logfile) {
            this.addAdapter(new LoggingFiles(config.files.logfile));
         }

         if (config.files.errorfile) {
            this.addAdapter(new LoggingFiles(config.files.errorfile, true));
         }
      }

      if (config.console) {
         this.addAdapter(new ConsoleWriter());
      }
   }

   addAdapter(adapter: Adapter) {
      this.adapter.push(adapter);
      let prms = Promise.resolve(adapter.init(this.messageObservable.getPublicApi(), this.name));
      this.adapter_init.push(prms);
   }

   flush(sync: true): void;
   flush(sync: false): Promise<void>;
   flush(sync: boolean): void | Promise<void> {
      if (sync) {
         this.adapter.forEach(elm => elm.flush(true));
      } else {
         return Promise.all(this.adapter.map(elm => elm.flush(false))).then(() => { });
      }
   }

   public waitForSetup() {
      return Promise.all(this.adapter_init);
   }

   public events: EventEmitter = new EventEmitter();

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

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

   warning(...message: any[]) {
      this.message(LoggingTypes.Warning, message);
   }

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

   error(error: Error | string) {
      if (!error) error = "Empty ERROR was passed, so no informations available";
      if (typeof error === "string") {
         let e = new Error()
         this.message(LoggingTypes.Error, [error, "\n", e.stack]);
      } else {
         this.message(LoggingTypes.Error, [error.message, "\n", error.stack], undefined, getCallerFromExisting(error));
      }
   }

   errorMessage(...message: any[]) {
      this.message(LoggingTypes.Error, message);
   }

   private message(type: LoggingTypes, message: any[] | string, customColors?: string, caller?: { file: string, line: number }) {
      let file_raw = caller || getCallerFile();
      let file = `${file_raw.file}:${String(file_raw.line).padEnd(3, " ")}`;

      let mb = "";
      if (typeof message === "string") {
         mb = message;
      } else {
         message.forEach((e, i) => {
            if (typeof e !== "string") e = util.inspect(e, false, null);
            if (e.endsWith("\n") || i === message.length - 1) {
               mb += e;
            } else {
               mb += e + " ";
            }
         });
      }

      let lines = mb.split("\n");

      let date = new Date().toISOString().replace(/T/, ' ').replace(/\..+/, '');
      let prefix = `[ ${date} ][${LoggingTypes[type].toUpperCase().padEnd(5, " ")}][${file}]: `;

      let formatted = lines.map(line => prefix + line);

      let msg: Message = {
         date: new Date(),
         file,
         name: this.name,
         text: {
            raw: lines,
            formatted
         },
         type,
         customColors
      }

      this.messageObservable.send(msg);
   }
}

export let Logging: LoggingBase = undefined;
if (process.env.LOGGING_NO_DEFAULT !== "true") {
   Logging = new LoggingBase();
}
export default Logging;



function getStack() {
   // Save original Error.prepareStackTrace
   let origPrepareStackTrace = (<any>Error).prepareStackTrace;

   // Override with function that just returns `stack`
   (<any>Error).prepareStackTrace = function (_, stack) {
      return stack
   }

   // Create a new `Error`, which automatically gets `stack`
   let err = new Error();

   // Evaluate `err.stack`, which calls our new `Error.prepareStackTrace`
   let stack: any[] = <any>err.stack;

   // Restore original `Error.prepareStackTrace`
   (<any>Error).prepareStackTrace = origPrepareStackTrace;

   // Remove superfluous function call on stack
   stack.shift(); // getStack --> Error

   return stack
}

function getCallerFile() {
   try {
      let stack = getStack()

      let current_file = stack.shift().getFileName();

      while (stack.length) {
         let caller_file = stack.shift();
         const util = require("util")
         if (current_file !== caller_file.getFileName())
            return {
               file: path.basename(caller_file.getFileName()),
               line: caller_file.getLineNumber()
            };
      }
   } catch (err) { }
   return { file: undefined, line: 0 };
}

function getCallerFromExisting(err: Error): { file: string, line: number } {
   if (!err || !err.stack) return { file: "NOFILE", line: 0 };
   let lines = err.stack.split("\n");
   let current = path.basename(__filename);
   lines.shift();// removing first line
   while (lines.length > 0) {
      let line = lines.shift();
      let matches = line.match(/[a-zA-Z_-]+[.][a-zA-Z_-]+[:][0-9]+/g)
      if (matches && matches.length > 0) {
         let [f, line] = matches[0].split(":")
         if (f != current) {
            return {
               file: f, line: Number(line)
            };
         }
      }
   }
}