const db = require('./surreal');

async function SetTrending(){
    try{
        const posts = await db.query(`SELECT * FROM posts`);
        const trending = [];
        for(let i = 0; i < posts.length; i++){
            trending.push(posts[i]);
        }
        trending.sort((a, b) => {
            return b.viewcount - a.viewcount;
        });
        const trendingPosts = trending.slice(0, 20);
        const trendingPostsDB = await db.query(`UPDATE homepage SET trending = "${trendingPosts}"`);

        if(trendingPostsDB) {
            console.log("Trending posts updated");
            return true;
        }
        else {
            console.log("Trending posts not updated");
            return false;
        }
    }
    catch(err){
        console.log(err);
    }
}

async function UpdatePostRanking(){
    try{
        const posts = await db.query(`SELECT * FROM posts`);
        //find posts with most likes
        const mostLiked = [];
        for(let i = 0; i < posts.length; i++){
            mostLiked.push(posts[i]);
        }
        mostLiked.sort((a, b) => {
            return b.likes.length - a.likes.length;
        });
        const mostLikedPosts = mostLiked.slice(0, 50);
        const mostLikedPostsDB = await db.query(`UPDATE homepage SET mostLiked = "${mostLikedPosts}"`);

        //find posts with most comments
        const mostCommented = [];
        for(let i = 0; i < posts.length; i++){
            mostCommented.push(posts[i]);
        }
        mostCommented.sort((a, b) => {
            return b.comments.length - a.comments.length;
        });
        const mostCommentedPosts = mostCommented.slice(0, 50);
        const mostCommentedPostsDB = await db.query(`UPDATE homepage SET mostCommented = "${mostCommentedPosts}"`);

        //find posts with most saves
        const mostSaved = [];
        for(let i = 0; i < posts.length; i++){
            mostSaved.push(posts[i]);
        }
        mostSaved.sort((a, b) => {
            return b.saves.length - a.saves.length;
        });
        const mostSavedPosts = mostSaved.slice(0, 50);
        const mostSavedPostsDB = await db.query(`UPDATE homepage SET mostSaved = "${mostSavedPosts}"`);

        if(mostLikedPostsDB && mostCommentedPostsDB && mostSavedPostsDB) {
            console.log("Post rankings updated");
            return true;
        }
        else {
            console.log("Post rankings not updated");
            return false;
        }
    }
    catch(err){
        console.log(err);
    }
}

async function UpdateUserRanking(){
    try{
        const users = await db.query(`SELECT activity FROM users`);

        //calculate user activity points do this by looking at activity array and looking at the date of each activity than use formula to calculate points
        //then sort users by activity points
        //then update homepage with top 20 users

        const MostPopularUsers = [];

        for(i = 0; i < users.length; i++){
            //calculate activity points
            let tempPoints = 0;
            for(j = 0; j < users[i].activity.length; j++){
                //calculate points
                const actionDate = new Date(users[i].activity[j].date);

                const currentDate = new Date();

                const timeDifference = currentDate - actionDate;

                const timeDifferenceInDays = timeDifference / (1000 * 3600 * 24);

                const points = Math.max(0, 100 - daysAgo);

                tempPoints += points;
            }
            //update activity points
            const user = await db.query(`UPDATE users SET activityPoints = "${tempPoints}" WHERE username = "${users[i].username}"`);
            //check if user is has more points than the last user in the array
            if(MostPopularUsers.length == 0){
                MostPopularUsers.push(users[i]);
            }
            else if(MostPopularUsers[MostPopularUsers.length - 1].activityPoints < tempPoints){
                MostPopularUsers.push(users[i]);
            }

            //sort array
            MostPopularUsers.sort((a, b) => {
                return b.activityPoints - a.activityPoints;
            });

            //remove last user in array if array is longer than 100
            if(MostPopularUsers.length > 100){
                MostPopularUsers.pop();
            }
        }


    }
    catch(err){
        console.log(err);
    }
}

async function UpdateAll(){
    const trending = await SetTrending();
    const postRanking = await UpdatePostRanking();
    const userRanking = await UpdateUserRanking();

    if(trending && postRanking && userRanking){
        console.log("All rankings updated");
        return true;
    }
    else{
        console.log("All rankings not updated");
        return false;
    }
}

module.exports = {SetTrending, UpdatePostRanking, UpdateUserRanking, UpdateAll};