backend/fastify/get-post/server.js

// Optimized postHotness function
function postHotness(upvotes, created) {
  let s = 0;
  for (let i = 1; i <= upvotes; i++) {
    if (i <= 3) {
      s += 1;
    } else if (i <= 6) {
      s += 3;
    } else if (i <= 10) {
      s += 3;
    } else if (i <= 20) {
      s += 4;
    } else if (i <= 40) {
      s += 5;
    } else {
      s += 6;
    }
  }

  const order = Math.log10(Math.max(Math.abs(s), 1));
  let sign = 0;
  if (s > 0) {
    sign = 1;
  } else if (s < 0) {
    sign = -1;
  }

  const interval = 45000; // or 69000
  const createdDate = new Date(created);
  const seconds = createdDate.getTime() / 1000;
  const hotness = order + (sign * seconds) / interval;
  return Math.round(hotness * 10000000);
}

module.exports = function (fastify, opts, done) {
  const pb = opts.pb;

  fastify.post("/get-post", async (request, reply) => {
    const data = request.body;

    let filter;
    const sort = data?.sortingPosts === "hot" ? "-upvote" : "-created";
    let pinnedPost;
    let posts;

    try {
      if (data?.seenPostId.length !== 0) {
        filter = data?.seenPostId?.map((id) => `id!="${id}"`).join("&&");

        //applies only for profile and user directory
        if (data?.userId) {
          filter += `&& user="${data?.userId}" && pinned=false`;
        }

        if (data?.filterTicker) {
          filter += `&& tagline="${data?.filterTicker}" && pinned=false`;
        }

        if (data?.sortingPosts === "hot") {
          //community page code space
          // In case of sort === 'hot' show the most recent post up to 7 week by ranking them with the function postHotness

          let endDate = new Date();
          // Get the date one week earlier
          let startDate = new Date();
          startDate.setDate(endDate.getDate() - 180);
          endDate.setDate(endDate.getDate() + 1);

          // Format the dates as needed (e.g., "YYYY-MM-DD")
          let endDateStr = endDate.toISOString().split("T")[0];
          let startDateStr = startDate.toISOString().split("T")[0];

          filter += `&& created >= "${startDateStr}" && created <= "${endDateStr}" && pinned = false`;
        }

        posts = (
          await pb.collection("posts").getList(data?.startPage, 10, {
            sort: "-created",
            filter: filter,
            expand: "user,comments(post),alreadyVoted(post)",
            fields:
              "*,expand.user,expand.comments(post), expand.alreadyVoted(post).user,expand.alreadyVoted(post).type",
          })
        )?.items;

        if (data?.sortingPosts === "hot") {
          // Add hotness property to each post
          posts?.forEach((post) => {
            post.hotness = postHotness(post?.upvote, post?.created);
          });
          posts?.sort((a, b) => b?.hotness - a?.hotness);
        }
      } else {
        if (data?.userId) {
          posts = (
            await pb.collection("posts").getList(data?.startPage, 10, {
              sort: sort,
              filter: `user="${data?.userId}" && pinned=false`,
              expand: `user,comments(post),alreadyVoted(post)`,
              fields:
                "*,expand.user,expand.comments(post), expand.alreadyVoted(post).user,expand.alreadyVoted(post).type",
            })
          )?.items;
        } else if (data?.filterTicker) {
          posts = await pb.collection("posts").getList(data?.startPage, 10, {
            sort: sort,
            filter: `tagline="${data?.filterTicker}" && pinned=false`,
            expand: `user,comments(post),alreadyVoted(post)`,
            fields:
              "*,expand.user,expand.comments(post), expand.alreadyVoted(post).user,expand.alreadyVoted(post).type",
          });
        } else {
          //community page code space
          // In case of sort === 'hot' show the most recent post up to 7 week by ranking them with the function postHotness

          if (data?.sortingPosts === "hot") {
            let endDate = new Date();
            // Get the date one week earlier
            let startDate = new Date();
            startDate.setDate(endDate.getDate() - 30);
            endDate.setDate(endDate.getDate() + 1);

            // Format the dates as needed (e.g., "YYYY-MM-DD")
            let endDateStr = endDate.toISOString().split("T")[0];
            let startDateStr = startDate.toISOString().split("T")[0];

            filter = `created >= "${startDateStr}" && created <= "${endDateStr}" && pinned = false`;
          } else {
            filter = `pinned=false`;
          }
          posts = await pb.collection("posts").getList(1, 10, {
            sort: "-created",
            filter: filter,
            expand: "user, comments(post), alreadyVoted(post)",
            fields:
              "*,expand.user,expand.comments(post), expand.alreadyVoted(post).user,expand.alreadyVoted(post).type",
          });

          posts = posts.items;
          // Add hotness property to each post
          if (data?.sortingPosts === "hot") {
            posts?.forEach((post) => {
              post.hotness = postHotness(post?.upvote, post?.created);
            });

            posts?.sort((a, b) => b?.hotness - a?.hotness);
          }

          pinnedPost = await pb.collection("posts").getFullList({
            filter: `pinned=true`,
            sort: "-created",
            expand: `user,comments(post),alreadyVoted(post)`,
            fields:
              "*,expand.user,expand.comments(post), expand.alreadyVoted(post).user,expand.alreadyVoted(post).type",
          });

          for (let i = pinnedPost?.length - 1; i >= 0; i--) {
            posts?.unshift(pinnedPost[i]);
          }
        }
      }
    } catch (e) {
      //console.log(e)
      posts = [];
    }

    reply.send({ items: posts });
  });

  done();
};