import { api, id, log, chatRoom, redis, Initializer } from "../index";
import { Connection } from "../classes/connection";
import * as ChatModule from "./../modules/chatRoom";

export interface ChatRoomApi {
  middleware: {
    [key: string]: ChatModule.chatRoom.ChatMiddleware;
  };
  globalMiddleware: Array<string>;
  keys: { [keys: string]: string };
  messageChannel: string;
  broadcast?: Function;
  generateMessagePayload?: Function;
  runMiddleware?: Function;
  incomingMessagePerConnection?: Function;
  incomingMessage?: Function;
}

/**
 * Chat & Realtime Communication Methods
 */
export class ChatRoom extends Initializer {
  constructor() {
    super();
    this.name = "chatRoom";
    this.loadPriority = 520;
    this.startPriority = 200;
  }

  async initialize(config) {
    api.chatRoom = {
      middleware: {},
      globalMiddleware: [],
      messageChannel: "/actionhero/chat/chat",
      keys: {
        rooms: "actionhero:chatRoom:rooms",
        members: "actionhero:chatRoom:members:",
      },
    };

    /**
     * Send a message to all members of a chat room.  This is used by the server.
     */
    api.chatRoom.broadcast = async (
      connection: Connection,
      room: string,
      message: object | Array<any> | string
    ) => {
      if (!room || !message) {
        throw new Error(config.errors.connectionRoomAndMessage(connection));
      } else if (
        connection.rooms === undefined ||
        connection.rooms.indexOf(room) > -1
      ) {
        const payload: ChatModule.chatRoom.ChatPubSubMessage = {
          messageType: "chat",
          serverToken: config.general.serverToken,
          serverId: id,
          message: message,
          sentAt: new Date().getTime(),
          connection: {
            id: connection.id || "0",
            room: room,
          },
        };

        const messagePayload = api.chatRoom.generateMessagePayload(payload);
        const newPayload = await api.chatRoom.runMiddleware(
          connection,
          messagePayload.room,
          "onSayReceive",
          messagePayload
        );
        const payloadToSend: ChatModule.chatRoom.ChatPubSubMessage = {
          messageType: "chat",
          serverToken: config.general.serverToken,
          serverId: id,
          message: newPayload.message,
          sentAt: newPayload.sentAt,
          connection: {
            id: newPayload.from,
            room: newPayload.room,
          },
        };

        await redis.publish(payloadToSend);
      } else {
        throw new Error(config.errors.connectionNotInRoom(connection, room));
      }
    };

    api.chatRoom.generateMessagePayload = (message) => {
      return {
        message: message.message,
        room: message.connection.room,
        from: message.connection.id,
        context: "user",
        sentAt: message.sentAt,
      };
    };

    api.chatRoom.incomingMessage = (message) => {
      const messagePayload = api.chatRoom.generateMessagePayload(message);
      Object.keys(api.connections.connections).forEach((connectionId) => {
        const connection = api.connections.connections[connectionId];
        // we can parallelize this, no need to await
        api.chatRoom.incomingMessagePerConnection(connection, messagePayload);
      });
    };

    api.chatRoom.incomingMessagePerConnection = async (
      connection: Connection,
      messagePayload: ChatModule.chatRoom.ChatPubSubMessage
    ) => {
      if (
        connection.canChat === true &&
        connection.rooms.indexOf(messagePayload.room) > -1
      ) {
        try {
          const newMessagePayload = await api.chatRoom.runMiddleware(
            connection,
            messagePayload.room,
            "say",
            messagePayload
          );
          connection.sendMessage(newMessagePayload, "say");
        } catch (error) {
          log(error, "warning", { messagePayload, connection });
        }
      }
    };

    api.chatRoom.runMiddleware = async (
      connection: Connection,
      room: string,
      direction: string,
      messagePayload: ChatModule.chatRoom.ChatPubSubMessage
    ) => {
      let newMessagePayload: ChatModule.chatRoom.ChatPubSubMessage;
      if (messagePayload) {
        newMessagePayload = Object.assign({}, messagePayload);
      }

      for (const name of api.chatRoom.globalMiddleware) {
        const m = api.chatRoom.middleware[name];
        if (typeof m[direction] === "function") {
          if (messagePayload) {
            const data = await m[direction](
              connection,
              room,
              newMessagePayload
            );
            if (data) {
              newMessagePayload = data;
            }
          } else {
            await m[direction](connection, room);
          }
        }
      }
      return newMessagePayload;
    };
  }

  async start(config) {
    api.redis.subscriptionHandlers.chat = (message) => {
      if (api.chatRoom) {
        api.chatRoom.incomingMessage(message);
      }
    };

    if (config.general.startingChatRooms) {
      const rooms = Object.keys(config.general.startingChatRooms);
      for (const room of rooms) {
        log(`ensuring the existence of the chatRoom: ${room}`);
        try {
          await chatRoom.add(room);
        } catch (error) {
          if (
            !error
              .toString()
              .match(await config.errors.connectionRoomExists(room))
          ) {
            throw error;
          }
        }
      }
    }
  }
}