import * as io from "socket.io";
import { Server } from "http";
import { DatabaseManager } from "./database/database";
import Logging from "@hibas123/logging";
import Query from "./database/query";
import Session from "./database/session";
import shortid = require("shortid");

type QueryTypes = "get" | "set" | "push" | "subscribe" | "unsubscribe";

export class ConnectionManager {
   static server: io.Server;

   static bind(server: Server) {
      this.server = io(server);
      this.server.on("connection", this.onConnection.bind(this));
   }

   private static onConnection(socket: io.Socket) {
      Logging.debug("New Connection:", socket.id);
      const reqMap = new Map<string, [number, number]>();
      const stored = new Map<string, Query>();
      const session = new Session();

      const answer = (id: string, data: any, err: boolean = false) => {
         let time = process.hrtime(reqMap.get(id));
         reqMap.delete(id);
         // Logging.debug(`Sending answer for ${id} with data`, data, err ? "as error" : "", "Took", time[1] / 1000, "us");
         socket.emit("message", id, err, data);
      }

      socket.on("login", (id: string) => {
         //TODO: implement
      })

      socket.on("query", async (id: string, type: QueryTypes, database: string, path: string[], data: any) => {
         Logging.debug(`Request with id '${id}' from type '${type}' for database '${database}' and path '${path}' with data`, data)
         reqMap.set(id, process.hrtime());
         try {
            const db = DatabaseManager.getDatabase(database);
            const perms = db.rules.hasPermission(path, session);
            const noperm = new Error("No permisison!");
            if (!db)
               answer(id, "Database not found!", true);
            else {
               const query = stored.get(id) || db.getQuery(path);

               switch (type) {
                  case "get":
                     if (!perms.read)
                        throw noperm;
                     answer(id, await query.get());
                     return;
                  case "set":
                     if (!perms.write)
                        throw noperm;
                     answer(id, await query.set(data));
                     return;
                  case "push":
                     if (!perms.write)
                        throw noperm;
                     answer(id, await query.push(data));
                     return;
                  case "subscribe":
                     if (!perms.read)
                        throw noperm;

                     let subscriptionID = shortid.generate();

                     query.subscribe(data, (data) => {
                        socket.emit("event", subscriptionID, data);
                     });
                     stored.set(id, query);
                     answer(id, subscriptionID);
                     return;
                  case "unsubscribe":
                     query.unsubscribe();
                     stored.delete(id);
                     answer(id, true);
                     return;
               }

               answer(id, "Invalid request!", true);
            }
         } catch (err) {
            Logging.error(err);
            answer(id, err.message, true);
         }

      })

      socket.on("disconnect", () => {
         reqMap.clear();
         stored.clear();
         socket.removeAllListeners();
      })
   }
}