/**
 * 消息模型。
 */
"use strict";

let MessageRepo = require('../../repository/mysql/message.repo');
let RedisModel = require('./../redis.model.js');
let SessionRepo = require('../../repository/mysql/session.repo');
let RedisClient = require('../../repository/redis/redis.client.js');
let ModelUtil = require('../../util/model.util');
var ObjectUtil = require("../../util/object.util.js");

let redis = RedisClient.redisClient().connection;
let log = require('../../util/log.js');
let configFile = require('../../include/commons').CONFIG_FILE;
let config = require('../../resources/config/' + configFile);
let logger = require('../../util/log');

const REDIS_KEYS = require('../../include/commons').REDIS_KEYS;

class Messages extends RedisModel {
    constructor() {
        super();
    }

    /**
     * 根据topicId获取对应的议题的信息列表
     * @param topicId
     */
    getMessagesByTopicId(topicId) {
    }

    /**
     * 分页
     * 根据topicId获取对应的议题的成员信息
     * @param topicId
     * @param page
     * @param pagesize
     */
    getMessagesByTopicIdForPage(topicId, page, pagesize) {
    }

    /**
     * 获取消息MySQL
     * @param sessionId
     * @param page
     * @param pagesize
     * @param handler
     */
    getMessageFromMySQL(sessionId, page, pagesize, messageType, handler) {
        MessageRepo.findBySessionId(sessionId, page, pagesize, messageType, handler);
    }

    /**
     * 获取消息MySQL
     * @param sessionId
     * @param page
     * @param pagesize
     * @param handler
     */
    getMessageByType(sessionId, page, pagesize, messageType) {
        let self = this;
        page = parseInt(page);
        pagesize = parseInt(pagesize);
        MessageRepo.findBySessionId(sessionId, page, pagesize, messageType, function (err, res) {
            if (err) {
                ModelUtil.emitError(self.eventEmitter, {message: "Error get message by session and type : " + err});
            } else {
                ModelUtil.emitOK(self.eventEmitter, {data: res});
            }
        });
    }

    /**
     * 获取单条消息
     *
     * @param messageId
     */
    getMessageById(messageId) {
    }

    /**
     * 将消息保存至REDIS，并更新会话的最后状态，清理会话的过期消息。
     *
     * PS：更新此处的消息缓存代码，记得更新Users.login()
     *
     * @param messageId
     * @param sessionId
     * @param sessionType
     * @param message
     */
    saveMessageToRedis(sessionId, sessionType, messageId, message) {
        let sessionKey = RedisModel.makeRedisKey(REDIS_KEYS.Session, sessionId);
        let messageKey = RedisModel.makeRedisKey(REDIS_KEYS.Messages, sessionId);
        let messageTimestampKey = RedisModel.makeRedisKey(REDIS_KEYS.MessagesByTimestamp, sessionId);

        let msgJson = {
            id: message.id,
            sender_id: message.sender_id,
            sender_name: message.sender_name,
            timestamp: message.timestamp.getTime(),
            content_type: message.content_type,
            content: message.content
        };

        redis.multi()
            .hset(messageKey, messageId, JSON.stringify(msgJson))               // 保存消息
            .zadd(messageTimestampKey, message.timestamp.getTime(), messageId)  // 保存消息时间
            .execAsync()
            .then(function (res) {
                Messages.updateLastContent(sessionKey, sessionType, null, message);
                Messages.cleanOutRangeMessage(sessionId); // clean out range messages
            });
    }

    /**
     * 保存Message 到mysql
     * @param message 消息对象
     * @param sessionType
     * @param messageId
     * @param sessionId
     * @param handler
     * @type type 会话类型，1表示MUC会话，2表示P2P，3表示群会话，4表示临时讨论组
     */
    saveMessageToMysql(sessionId, sessionType, messageId, message, handler) {
        MessageRepo.save(message, sessionType, messageId, sessionId, handler);
    }

    /**
     * 更新会话最后一条消息
     *
     * @param sessionKey rediskey
     * @param sessionType
     * @param name 议题名称
     * @param message
     * @param businessType
     * @returns {*}
     */
    static updateLastContent(sessionKey, sessionType, name, message, businessType) {
        redis.hmsetAsync(sessionKey,
            "create_date", message.timestamp.getTime(),
            "last_content", message.content,
            "last_content_type", message.content_type,
            "sender_id", message.sender_id,
            "sender_name", message.sender_name
        );

        let sessionid = sessionKey.replace("sessions:", "");
        SessionRepo.updateSessionLastStatus(message.sender_id,
            message.sender_name,
            message.timestamp,
            message.content,
            message.content_type,
            sessionid, function (err, res) {
                if (err) logger.error("Update session last status failed: ", err);
            });

        if (name != null) redis.hsetAsync(sessionKey, "name", name);
        if (sessionType != null) redis.hsetAsync(sessionKey, "type", sessionType);
        if (businessType != null) redis.hsetAsync(sessionKey, "business_type", businessType);
    }

    /**
     * 清理会话中超出范围的消息。
     *
     * 目前只实现超出1000条数据清理的逻辑，7天前的消息清除逻辑暂不实现。
     *
     * @param sessionId
     */
    static cleanOutRangeMessage(sessionId) {
        let maxMessageCacheCount = config.sessionConfig.maxMessageCount;
        let messageById = this.makeRedisKey(REDIS_KEYS.Messages, sessionId);
        let messagesByTimestampKey = this.makeRedisKey(REDIS_KEYS.MessagesByTimestamp, sessionId);
        redis.zcardAsync(messagesByTimestampKey).then(function (count) {
            if (count > maxMessageCacheCount) {
                redis.zrevrangeAsync(messagesByTimestampKey, 0, count - maxMessageCacheCount).then(function (idList) {
                    redis.zremAsync(messagesByTimestampKey, idList).then(function (res) {
                        redis.hdel(messageById, idList);
                    })
                });
            }
        });
    }
}

// Expose class
module.exports = Messages;