Creates the rarity similar to Opensea

rarityScore.js

/*

- yarn init -y

- update package.json :)
        {
        "name": "rarity",
        "version": "1.0.0",
        "main": "index.js",
        "license": "MIT",
        "type": "module",
        "dependencies": {
            "node-fetch": "^3.3.0"
        }
    }

- node app.js    
*/

import fetch from "node-fetch";
import fs from "fs";

const randomNumber = () => {
  const min = 1;
  const max = 10;
  const diff = max - min; // return 5
  const randomNumber = Math.random(); // function returns integers between from 0 -> 1 [ex: 0.001,0.2]
  const randomNumnerInRange = Math.floor(randomNumber * diff + min);

  return randomNumnerInRange;
};

const fetchMetaData = async (i) => {
  let obj = {};

  const baseUrls = [
    "https://cloudflare-ipfs.com/ipfs/Qmdu6QgAMJqiwRcGGMadPMkkdSCDv6NoQG2neTN8fYirN9/",
    "https://gateway.pinata.cloud/ipfs/Qmdu6QgAMJqiwRcGGMadPMkkdSCDv6NoQG2neTN8fYirN9/",
    "https://ipfs.fleek.co/ipfs/Qmdu6QgAMJqiwRcGGMadPMkkdSCDv6NoQG2neTN8fYirN9/",
    "https://gateway.ipfs.io/ipfs/Qmdu6QgAMJqiwRcGGMadPMkkdSCDv6NoQG2neTN8fYirN9/",
    "https://via0.com/ipfs/Qmdu6QgAMJqiwRcGGMadPMkkdSCDv6NoQG2neTN8fYirN9/",
    "https://ipfs.smartholdem.io/ipfs/Qmdu6QgAMJqiwRcGGMadPMkkdSCDv6NoQG2neTN8fYirN9/",
    "https://bafybeihhf3zmdzulp5jhsc5pj463dbfuippnprdy4irjz3rijiqlf76uay.ipfs.cf-ipfs.com/",
    "https://bafybeihhf3zmdzulp5jhsc5pj463dbfuippnprdy4irjz3rijiqlf76uay.ipfs.nftstorage.link/",
    "https://bafybeihhf3zmdzulp5jhsc5pj463dbfuippnprdy4irjz3rijiqlf76uay.ipfs.storry.tv/",
    "https://crustwebsites.net/ipfs/Qmdu6QgAMJqiwRcGGMadPMkkdSCDv6NoQG2neTN8fYirN9/",
  ];

  let baseUrl = baseUrls[i % 10] + i;

  try {
    const response = await fetch(baseUrl, {
      method: "GET",
      headers: {
        "Content-Type": "application/json",
        Accept: "application/json",
      },
    });
    const data = await response.json();
    obj = {
      name: data.name ? data.name : "No Name",
      description: data.description ? data.description : "No Description",
      attributes: data.attributes ? data.attributes : "No Attributes",
    };
  } catch (error) {
    obj = {
      name: "No Name",
      description: "No Description",
      attributes: "No Attributes",
    };
    console.log("ERROR In Fetching.......", error);
  }
  return obj;
};

// Use to fetch the metadata of NFTs
const main = async () => {
  console.time("codezup");

  let metadataList = [];

  // Range of tokeIds
  for (let i = 2; i <= 5; i++) {
    let obj = await fetchMetaData(i);
    console.log("OBJ -: ", i, obj);
    metadataList.push(obj);
  }

  // save to file
  fs.writeFileSync("metadata10.json", JSON.stringify(metadataList));
  console.timeEnd("codezup");
};

const findRarity = async () => {
  // Read json file
  let json = fs.readFileSync("metadata10.json");
  let metadataList = JSON.parse(json);

  const allUniqueTraits = {};

  for (let i = 0; i < metadataList.length; i++) {
    for (let j = 0; j < metadataList[i].attributes.length; j++) {
      if (!allUniqueTraits[metadataList[i].attributes[j].value]) {
        allUniqueTraits[metadataList[i].attributes[j].value] = 1;
      } else {
        allUniqueTraits[metadataList[i].attributes[j].value] += 1;
      }
    }
  }

  let totalNFTs = metadataList.length;
  let keys = Object.keys(allUniqueTraits);

  for (let i = 0; i < keys.length; i++) {
    let key = keys[i];
    let value = allUniqueTraits[key];
    let percentage = (value / totalNFTs) * 100;
    allUniqueTraits[key] = percentage;
  }

  console.log(keys.length);

  const NFTs = [];

  for (let i = 0; i < metadataList.length; i++) {
    const obj = {};
    obj.name = metadataList[i].name;
    obj.traits = [];

    for (let j = 0; j < metadataList[i].attributes.length; j++) {
      obj.traits.push(allUniqueTraits[metadataList[i].attributes[j].value]);
    }

    NFTs.push(obj);
  }

  const finalNFTs = [];

  for (let i = 0; i < NFTs.length; i++) {
    let sum = 0;
    let final = 0;
    const obj = {};

    for (let j = 0; j < NFTs[i].traits.length; j++) {
      sum = sum + NFTs[i].traits[j];
      final = sum / NFTs[i].traits.length;
    }

    obj.name = NFTs[i].name;
    obj.traits = final;

    finalNFTs.push(obj);
  }

  finalNFTs.sort((a, b) => {
    return a.traits - b.traits;
  });

  console.log(finalNFTs.slice(0, 20));
};

async function master() {
  await main();
  await findRarity();
}

master();