/**
 * 用户集合。管理Redis中的用户列表。
 *
 * author: Sand
 * since: 12/13/2016
 */
"use strict";

let RedisModel = require('../redis.model');
let Doctor = require('./doctor');
let Patient = require('./patient');

let ImDb = require('../../repository/mysql/db/im.db');
let ParticipantRepo = require('../../repository/mysql/participant.repo');
let DoctorRepo = require('../../repository/mysql/doctor.repo');
let PatientRepo = require('../../repository/mysql/patient.repo');
let AppStatusRepo = require('../../repository/mysql/app.status.repo');
let SessionRepo = require('../../repository/mysql/session.repo');
let TopicRepo = require('../../repository/mysql/topic.repo');
let MessageRepo = require('../../repository/mysql/message.repo');
let ModelUtil = require('../../util/model.util');
let RedisClient = require('../../repository/redis/redis.client');

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

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

class Users extends RedisModel {
    constructor() {
        super();

        this._key = REDIS_KEYS.Users;
    }

    /**
     * 获取用户，直接从MYSQL获取，缓存是否有在不能确定。
     *
     * @param userId
     * @param outCallback
     */
    getUser(userId, outCallback) {
        let self = this;
        async.waterfall([
            // determine user type
            function (callback) {
                self.isPatientId(userId, function (err, isPatient) {
                    callback(null, isPatient);
                });
            },
            // get from mysql
            function (isPatientId) {
                let repoProto = isPatientId ? PatientRepo : DoctorRepo;
                repoProto.findOne(userId, function (err, res) {
                    let user = isPatientId ? new Doctor() : new Patient();
                    if (res.length > 0) {
                        user.name = res[0].name;
                        user.sex = res[0].sex;
                        user.birthdate = res[0].birthdate;
                        user.avatar = res[0].avatar;
                    }

                    outCallback(null, user);
                });
            }
        ]);
    }

    /**
     * 取得用户微信端状态。
     *
     * @param userId
     * @param outCallback
     */
    getWechatStatus(userId) {
        let self = this;
        redisConn.hgetallAsync(self.makeRedisKey(REDIS_KEYS.UserWechatStatus, userId))
            .then(function (res) {
                if (res) {
                    ModelUtil.emitData(self, res);
                } else {
                    ModelUtil.emitDataNotFound(self, {"message": "User is offline, unable to get wechat status."});
                }
            });
    }

    /**
     * 获取客户端App状态。
     *
     * @param userId
     * @param outCallback
     */
    getAppStatus(userId, outCallback) {
        let self = this;
        async.waterfall([
            // get from redis
            function (callback) {
                let userStatusKey = self.makeRedisKey(REDIS_KEYS.UserStatus, userId);
                redisConn.hgetallAsync(userStatusKey).then(function (res) {
                    if (res === null) {
                        callback(null);  // get from mysql
                    } else {
                        outCallback(null, res);
                    }
                });
            },
            // get from MySQL
            function () {
                AppStatusRepo.findOne(userId, function (err, res) {
                    let userStatus = null;
                    if (res.length > 0) {
                        userStatus = {};
                        userStatus.platform = res[0].platform;
                        userStatus.token = res[0].token;
                        userStatus.client_id = res[0].client_id;
                        userStatus.app_in_bg = res[0].app_in_bg;
                        userStatus.last_login_time = res[0].last_login_time;
                    }

                    outCallback(null, userStatus);
                });
            }
        ]);
    }

    /**
     * 更新客户端App状态。
     *
     * @param userId
     * @param appInBg
     */
    updateAppStatus(userId, appInBg) {
        let self = this;
        redisConn.hsetAsync(self.makeRedisKey(REDIS_KEYS.UserAppStatus, userId), 'app_in_bg', appInBg)
            .then(function (res) {
                if (res) {
                    ModelUtil.emitData(self.eventEmitter, {});
                } else {
                    ModelUtil.emitDataNotFound(self.eventEmitter, {"message": "User is offline, unable to update app status."});
                }
            });
    }

    /**
     * 用户登录。
     *
     * 用户登录时会加载与之相关的会话列表，会话消息，用户自身信息：App状态与微信状态。
     *
     * @param userId
     * @param platform
     * @param token
     * @param clientId
     *
     * @return 用户token
     */
    login(userId, platform, token, clientId) {
        let self = this;
        let loginFromApp = platform !== PLATFORMS.Wechat;

        let usersKey = REDIS_KEYS.Users;
        let userKey = self.makeRedisKey(REDIS_KEYS.User, userId);
        let userStatusKey = self.makeRedisKey(loginFromApp ? REDIS_KEYS.UserAppStatus : REDIS_KEYS.UserWechatStatus, userId);
        let lastLoginTime = new Date();

        async.waterfall([
            // get user info from mysql
            function (callback) {
                self.getUser(userId, function (err, userInfo) {
                    if (userInfo === null) {
                        ModelUtil.emitDataNotFound(self, 'User not exists.');
                        return;
                    }

                    callback(null, userInfo);
                })
            },
            // cache user info and app/wechat status
            function (userInfo, callback) {
                let multi = redisConn.multi()
                    .zadd(usersKey, lastLoginTime.getMilliseconds(), userId)
                    .hmset(userKey, 'avatar', userInfo.avatar ? userInfo.avatar : '', 'birthdate', userInfo.birthdate? userInfo.birthdate : '',
                        'name', userInfo.name, 'role', loginFromApp ? 'doctor' : 'patient');

                if (loginFromApp) {
                    // cache app status
                    multi = multi.hmset(userStatusKey, 'platform', platform, 'app_in_bg', false, 'client_id', clientId,
                        'token', token, 'last_login_time', lastLoginTime);
                } else {
                    // cache wechat status
                    multi = multi.hmset(userKey, 'open_id', userInfo.open_id);
                }

                multi.execAsync().then(function (res) {
                    callback(null);
                });
            },
            // cache sessions, participants, topics, messages
            function (callback) {
                SessionRepo.findAll(userId, function (err, sessions) {
                    for (let session in sessions) {
                        let sessionId = session.id;
                        let name = session.name;
                        let type = session.type;
                        let createDate = session.create_date;

                        (function (sessionId, userId) {
                            // cache sessions
                            redisConn.multi()
                                .zadd(self.makeRedisKey(REDIS_KEYS.Sessions), lastLoginTime)                // 会话的最后活动时间设置为此用户的登录时间
                                .zadd(self.makeRedisKey(REDIS_KEYS.UserSessions, userId), lastLoginTime)    // 会话的最后活动时间设置为此用户的登录时间
                                .hmset(self.makeRedisKey(REDIS_KEYS.Session, sessionId, 'name', name, 'type', type, 'create_date', createDate))
                                .execAsync().then(function (res) {

                                // cache participants
                                let sessionParticipantsKey = self.makeRedisKey(REDIS_KEYS.Participants, sessionId);
                                let sessionParticipantsRoleKey = self.makeRedisKey(REDIS_KEYS.ParticipantsRole, sessionId);
                                ParticipantRepo.findParticipants(sessionId, function (err, participants) {
                                    for (let participant in participants) {
                                        let participantId = participant.participant_id;
                                        let participantRole = participant.participant_role;
                                        let score = new Date().getMilliseconds();

                                        redisConn.multi()
                                            .zadd(sessionParticipantsKey, participantId, score)
                                            .hset(sessionParticipantsRoleKey, participantId, participantRole)
                                            .execAsync().then(function (res) {
                                        });
                                    }
                                });

                                // cache messages
                                let messagesKey = self.makeRedisKey(REDIS_KEYS.Messages, sessionId);
                                let messagesByTimestampKey = self.makeRedisKey(REDIS_KEYS.MessagesByTimestamp, sessionId);
                                MessageRepo.findBySessionId(sessionId, 0, config.sessionConfig.maxMessageCount, function (err, messages) {
                                    for (let message in messages) {
                                        let id = message.id;
                                        let msgJson = {
                                            sessionId: message.session_id,
                                            senderId: message.sender_id,
                                            senderName: message.sender_name,
                                            contentType: message.content_type,
                                            content: message.content,
                                            timestamp: message.timestamp
                                        };

                                        redisConn.multi()
                                            .hset(messagesKey, id, msgJson)
                                            .zadd(messagesByTimestampKey, id)
                                            .execAsync()
                                            .then(function (res) {
                                            });
                                    }
                                });

                                // cache topics for MUC
                                let topicsKey = self.makeRedisKey(REDIS_KEYS.Topics, sessionId);
                                TopicRepo.findAll(sessionId, function (err, topics) {
                                    for (let topic in topics) {
                                        let topicKey = self.makeRedisKey(REDIS_KEYS.Topic, topic.id);
                                        let topicId = topic.id;
                                        let name = topic.name;
                                        let createTime = topic.create_time;
                                        let endBy = topic.end_by;
                                        let endTime = topic.end_time;
                                        let startMessageId = topic.start_message_id;
                                        let endMessageId = topic.end_message_id;
                                        redisConn.multi()
                                            .zadd(topicsKey, topicId)
                                            .hmset(topicKey, 'name', name, 'session_id', sessionId, 'create_time',
                                                createTime, 'end_by', endBy, 'end_time', endTime, 'start_message_id',
                                                startMessageId, 'end_message_id', endMessageId)
                                            .execAsync().then(function (res) {
                                        });
                                    }
                                });
                            });
                        })(sessionId, userId);
                    }
                });

                ModelUtil.emitData(self.eventEmitter, {});
            }
        ]);
    }

    logout(userId) {
        let self = this;
        async.waterfall([
                function (callback) {
                    self.isPatientId(userId, function (err, isPatient) {
                        callback(null, isPatient)
                    });
                },
                function (callback, isPatient) {
                    let usersKey = REDIS_KEYS.Users;
                    let userKey = self.makeRedisKey(REDIS_KEYS.User, userId);
                    let userStatusKey = self.makeRedisKey(isPatient ? REDIS_KEYS.UserWechatStatus : REDIS_KEYS.UserAppStatus, userId);
                    redisConn.multiAsync()
                        .del(usersKey)
                        .del(userKey)
                        .del(userStatusKey)
                        .execAsync().then(function (res) {
                    })
                }],
            function (err, res) {
                ModelUtil.emitData(self.eventEmitter, {});
            }
        );
    }

    /**
     * 用户ID是否属于患者。
     *
     * @param userId
     * @param callback
     */
    isPatientId(userId, callback) {
        async.waterfall([
                function (callback) {
                    var sql = "select case when count(*) > 0 then true else false end 'is_patient' from patients where id = ?";

                    ImDb.execQuery({
                        "sql": sql,
                        "args": [userId],
                        "handler": function (err, res) {
                            if (err) callback(err, res);

                            callback(null, res);
                        }
                    });
                },
                function (res, callback) {
                    if (res.length === 0) return false;

                    callback(null, res[0].is_patient);
                }
            ],
            function (err, res) {
                if (err) {
                    log.error("User id check failed: ", err);
                    callback(null, false);
                    return;
                }

                callback(null, res !== 0);
            });
    }
}

let Promises = require('bluebird');
Promises.promisifyAll(Users.prototype);

module.exports = Users;