const DBName = "EMI_SOCIAL";

let userProfileCache = {};

userDB = (DB) => {
    DB.profileCols = DB.db.db(DBName).collection("profiles");

    DB.newProfile = (profileObj) => {
        return DB.profileCols.insertOne(profileObj.toObj()).catch((err) => {
            console.log(err);
            return false;
        });
    }

    DB.removeProfile = (profileid) => {
        const _id = DB.ObjectID(profileid);
        if (userProfileCache[profileid]) delete userProfileCache[profileid];
        return DB.profileCols.deleteOne({_id}).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.updateProfile = async (profileid, profileObj) => {
        let tempProfile = profileObj.toObj();
        const query = {_id: profileid};
        const update = {
            $set: {
                profile: tempProfile.profile,
                data: tempProfile.data
            }
        };
        let r = await DB.profileCols.updateOne(query, update).catch((err) => {
            console.log(err);
            return false;
        });
        return r;
    }

    DB.getProfile = async (profileId) => {
        //if (userProfileCache[profileId] && !userProfileCache[profileId].isGroup) return userProfileCache[profileId];
        if(!profileId) return false;
        try{
            const _id = DB.ObjectID(profileId);
            let r = await DB.profileCols.findOne({ _id }).catch((err) => {
                console.log(err);
                return false;
            });
            if (r) userProfileCache[profileId] = r;
            return r;
        }catch(_){
            return {};
        }
    }

    DB.getPopularProfiles = async (limit = 10) => {
        return DB.profileCols.aggregate([
            {
                $match: {isGroup: {$ne: true}}
            },
            {
                $addFields: { subscribed_count: {$size: { "$ifNull": [ "$following", [] ] } } }
            },
            {   
                $sort: {"subscribed_count":-1} 
            },
            {
                $project: {_id: 1, "subscribed_count": 1}
            }
        ]).limit(limit).toArray().catch((err) => {
            console.log(err);
            return [];
        });
    }

    DB.getPopularGroups = async (limit = 10) => {
        return DB.profileCols.aggregate([
            {
                $match: {isGroup: true, isPrivate: {$ne: true}, isCourse: {$ne: true}}
            },
            {
                $addFields: { subscribed_count: {$size: { "$ifNull": [ {"$objectToArray" : "$subscribed"}, [] ] } } }
            },
            {   
                $sort: {"subscribed_count":-1} 
            },
            {
                $project: {_id: 1, "subscribed_count": 1}
            }
        ]).limit(limit).toArray().catch((err) => {
            console.log(err);
            return [];
        });
    }

    DB.getFriendsFriends = async (profileId, limit = 10) => {
        const profile = await DB.getProfile(profileId);
        if(!profile) return [];
        let ids = profile.following.map((id)=>DB.ObjectID(id));
        let alreadyFollowingMap = {};
        alreadyFollowingMap[profileId] = 1; //skip that profile
        profile.following.forEach(id => {
            if(!alreadyFollowingMap[id]) alreadyFollowingMap[id] = 1;
        })
        return DB.profileCols.find({_id:{$in: ids}}).project({following: 1}).limit(limit).toArray().then(profiles => {
            let friendsOfFriendsMap = {};
            profiles.forEach(p => {
                p.following.forEach(followingId => {
                    if(alreadyFollowingMap[followingId]) return 0;
                    if(!friendsOfFriendsMap[followingId]) friendsOfFriendsMap[followingId] = 0;
                    friendsOfFriendsMap[followingId] = friendsOfFriendsMap[followingId] + 1;
                });
            });
            // sort by most related?
            return Object.keys(friendsOfFriendsMap);
        }).catch((err) => {
            console.log(err);
            return [];
        });
    }

    DB.getProfileCache = async (profileId) => {
        if (userProfileCache[profileId] && !userProfileCache[profileId].isGroup) return userProfileCache[profileId];
        return DB.getProfile(profileId);
    }

    DB.searchProfile = async (queryStr) => {
        let regEx = new RegExp(queryStr, 'i');
        let query = {
            isGroup: false,
            isChat: {$ne: true},
            $or: [
                {"profile.firstName": {
                    $regex: regEx
                }},
                {"profile.lastName": {
                    $regex: regEx
                }},
                {"profile.description": {
                    $regex: regEx
                }},
            ]
        };
        let r = await DB.profileCols.find(queryStr ? query : {isGroup: false, isChat: {$ne: true}})
                .sort({ lastUpdate: -1 }).limit(20)
                .toArray().catch((err) => {
            console.log(err);
            return false;
        });
        return r;
    }

    DB.getUserProfiles = async (userId) => {
        const userid = DB.ObjectID(userId);
        return await DB.profileCols.find({ userid }).toArray().catch((err) => {
            console.log(err);
            return false;
        });
    }

    DB.latestProfile = async (userId) => {
        const userid = DB.ObjectID(userId);
        let r = await DB.profileCols.find({ userid })
                .sort({ lastUpdate: -1 })
                .toArray().catch((err) => {
            console.log(err);
            return false;
        });
        let index = 0;
        while(r[index].isGroup || r[index].isChat) index += 1;
        if (r[index]) userProfileCache[r[index]._id] = r[index];
        return r[index];
    }

    DB.followProfile = async (profileId, followProfileId)=>{
        const _id = DB.ObjectID(profileId);
        let update = {
            $addToSet:{
                following: followProfileId + '' //converts to str
            }            
        }
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.unfollowProfile = async (profileId, followProfileId)=>{
        const _id = DB.ObjectID(profileId);
        let update = {
            $pull:{
                following: followProfileId + '' //converts to str
            }            
        }
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.getFollowingTheProfile = async (profileId) => {
        //const profile_id = DB.ObjectID(profileId);
        let r = await DB.profileCols.find({ following: (profileId+'') })
            .toArray().catch((err) => {
                console.log(err);
                return [];
            });
        return r;
    }

    DB.getData = async (profileid, key) => {
        let profile = await DB.getProfile(profileid);
        return profile.data[key];
    }

    DB.setData = async (profileid, key, value) => {
        const _id = DB.ObjectID(profileid);
        let update = {
            $set:{
                ["data." + key]: value
            }            
        }
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.setProfileToken = (profileid, token)=>{
        if(!token) return false;
        const _id = DB.ObjectID(profileid);
        let update = {
            $addToSet:{
                token
            }            
        }
        if (userProfileCache[profileid]) delete userProfileCache[profileid];
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.setWebSubscription = (profileid, webSubscription)=>{
        const _id = DB.ObjectID(profileid);
        let update = {
            $set:{
                webSubscription
            }            
        }
        if (userProfileCache[profileid]) delete userProfileCache[profileid];
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.addNotification = async (profileid, message, postid, commentIndx, actorid) => {
        const _id = DB.ObjectID(profileid);
        let update = {
            $push:{
                notifications: {
                    ts: new Date(),
                    body: message,
                    postid,
                    commentIndx,
                    actorid,
                }
            }            
        }
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.isSubscriptor = async (profileid) => {
        const profile = DB.getProfileCache(profileid);
        return profile && profile.subscription && profile.subscription > (new Date() - 0);
    }

    //Groups
    DB.getGroups = async (excludePrivate = false) => {
        let query = {
            isGroup: true, 
            isCourse: {$ne: true},
            isChat: {$ne: true},
        };
        if(excludePrivate) query.isPrivate = false;
        let r = await DB.profileCols.find(query).sort({ lastUpdate: -1 }).limit(10)
            .toArray().catch((err) => {
                console.log(err);
                return false;
        });
        return r;
    }

    DB.getFollowingGroups = async (profileid) => {
        const profile = await DB.getProfile(profileid);
        let ids = [];
        for(id in profile.following){
            try{
                let oId = DB.ObjectID(profile.following[id]);
                let checkProfile = await DB.getProfileCache(oId)
                if(checkProfile && checkProfile.isGroup && !checkProfile.isChat){
                    ids.push(oId)
                }
            }catch{

            }
        }
        let query = {
            isGroup: true, 
            isCourse: {$ne: true},
            isChat: {$ne: true},
            _id: {
                $in: ids
            }
        };
        let r = await DB.profileCols.find(query).sort({ lastUpdate: -1 })
            .toArray().catch((err) => {
                console.log(err);
                return false;
        });
        return r;
    }

    DB.searchGroups = async (queryStr, coursesB = false) => {
        let regEx = new RegExp(queryStr, 'i');
        let query = queryStr ? {
            isGroup: true,
            isChat: {$ne: true},
            isCourse: coursesB,
            $or: [
                {"profile.firstName": {
                    $regex: regEx
                }},
                {"profile.lastName": {
                    $regex: regEx
                }},
                {"profile.description": {
                    $regex: regEx
                }},
                {"data.author": {
                    $regex: regEx
                }}
            ]
        } : {isGroup: true, isChat: {$ne: true}, isCourse: coursesB};
        let r = await DB.profileCols.find(query)
                .sort({ lastUpdate: -1 }).limit(20)
                .toArray().catch((err) => {
            console.log(err);
            return false;
        });
        return r;
    }

    let privateGroupsCache = {};
    DB.isGroupPrivate = async (groupid) => {
        if(userProfileCache[groupid]) return userProfileCache[groupid].isPrivate;
        let g = await DB.getGroup(groupid);
        return g ? g.isPrivate : false;
    }

    DB.isGroupNewsOnly = async (groupid) => {
        if(userProfileCache[groupid]) return userProfileCache[groupid].newsOnly;
        let g = await DB.getGroup(groupid);
        return g ? g.newsOnly : false;
    }

    DB.isOwnerOfGroup = async (profileid, groupid) => {
        let profile = await DB.getProfileCache(profileid);
        let group = userProfileCache[groupid] ? userProfileCache[groupid] : await DB.getGroup(groupid);
        return profile.userid == group.userid;
    }

    DB.getGroup = async (groupid) => {
        const _id = DB.ObjectID(groupid);
        //if(userProfileCache[groupid]) return userProfileCache[groupid];
        let r = await DB.profileCols.findOne({_id, isGroup: true, isChat: {$ne: true},}).catch((err) => {
            console.log(err);
            return false;
        });
        if (r) userProfileCache[r.id] = r;
        return r;
    }

    DB.subscribeToGroup = async (profileid, groupid, reqSubscription = false) => {
        const _id = DB.ObjectID(groupid);
        const subOrRequest = reqSubscription ? "pending." : "subscribed.";
        let update = {
            $set:{
                [subOrRequest + profileid]: new Date()
            }            
        }
        if(!reqSubscription) DB.followProfile(profileid, groupid);
        delete userProfileCache[groupid];
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.acceptGroupJoinReq = async (profileid, groupid) => {
        const _id = DB.ObjectID(groupid);
        let update = {
            $set:{
                ["subscribed." + profileid]: new Date()
            },
            $unset:{
                ["pending." + profileid]: ""
            }
        }
        DB.followProfile(profileid, groupid);
        delete userProfileCache[groupid];
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.rejectGroupJoinReq = async (profileid, groupid) => {
        const _id = DB.ObjectID(groupid);
        let update = {
            $unset:{
                ["pending." + profileid]: ""
            }
        }
        delete userProfileCache[groupid];
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    DB.unsubscribeToGroup = async (profileid, groupid) => {
        const _id = DB.ObjectID(groupid);
        let update = {
            $unset:{
                ["subscribed." + profileid]: "",
            }            
        }
        DB.unfollowProfile(profileid, groupid)
        return DB.profileCols.updateOne({_id}, update).catch((err)=>{
            console.log(err);
            return false;
        });
    }

    //Courses
    DB.getCourses = async () => {
        let r = await DB.profileCols.find({isGroup: true, isCourse: true, isChat: {$ne: true}})
                .sort({ lastUpdate: -1 }).limit(20)
                .toArray().catch((err) => {
            console.log(err);
            return false;
        });
        return r;
    }

}

module.exports = userDB;