Average Stake Length (Weighted) and Current Stakers of HEX

averageHEXStakeLength.js

// https://codeakk.medium.com/hex-development-data-a1b1822446fa
// https://togosh.medium.com/hex-developer-guide-3b018a943a55
// https://en.wikipedia.org/wiki/Weighted_arithmetic_mean#Mathematical_definition

test();

async function test(){
  var { averageStakeLength, currentStakerCount } = await get_stakeStartData();
  console.log("Weighted Average Stake Length: " + averageStakeLength);
  console.log("Current Staker Count: " + currentStakerCount);
}

async function get_stakeStartData(){

  var $lastStakeId = 0;
  var stakedDaysSum = 0;
  var stakedCount = 0;
  var stakedHEXSum = 0;
  var weightedAverageSum = 0;
  var uniqueAddressList = [];
  var uniqueAddressCount = 0;

  while (true) {
    var data = await get_stakeStarts($lastStakeId);
    if (data.count <= 0) { break; }
    stakedCount += data.count;
    stakedDaysSum += data.stakedDaysSum;
    uniqueAddressList = uniqueAddressList.concat(data.uniqueAddresses);
    $lastStakeId = data.lastStakeId;
    stakedHEXSum += data.stakedHEX;
    weightedAverageSum += data.weightedAverageSum;

    console.log($lastStakeId);
    await sleep(100);
  }
  
  uniqueAddressCount = (new Set(uniqueAddressList)).size;

  var averageStakeLengthWeighted = 0.0;
  var averageStakeLengthWeightedYears = 0.0

  if (weightedAverageSum && stakedHEXSum) {
    averageStakeLengthWeighted = weightedAverageSum / stakedHEXSum;
    averageStakeLengthWeightedYears = averageStakeLengthWeighted / 365.0;
  }

  return {
    averageStakeLength: averageStakeLengthWeightedYears,
    currentStakerCount: uniqueAddressCount,
  }
}

async function get_stakeStarts($lastStakeId){
  return await fetch('https://api.thegraph.com/subgraphs/name/codeakk/hex', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ query: `
      query {
        stakeStarts(first: 1000, orderBy: stakeId, 
          where: { 
            stakeId_gt: "` + $lastStakeId + `",
            stakeEnd: null, 
            stakeGoodAccounting: null 
          }
        ) {
          stakeId
          stakedDays
          stakerAddr
          stakedHearts
        }
      }` 
    }),
  })
  .then(res => res.json())
  .then(res => {
    var stakeCount = Object.keys(res.data.stakeStarts).length;

    if (stakeCount <= 0) {
      return {  
        count: 0
      };
    } 
    else {
    var stakeStartsReduced = res.data.stakeStarts.reduce(function(previousValue, currentValue) {
      return {
        stakedDays: parseInt(previousValue.stakedDays, 10) + parseInt(currentValue.stakedDays, 10),
        stakedHearts: parseInt(previousValue.stakedHearts, 10) + parseInt(currentValue.stakedHearts, 10),
      }
    });
      
    var weightedAverageSum = 0.0;
    for (let i = 0; i < res.data.stakeStarts.length; i++) {
      weightedAverageSum += res.data.stakeStarts[i].stakedDays * (res.data.stakeStarts[i].stakedHearts / 100000000.0);
    }
      
    var uniqueAddresses = res.data.stakeStarts.map(a => a.stakerAddr).filter(onlyUnique);

    var lastStakeId = res.data.stakeStarts[(stakeCount - 1)].stakeId;

    var data = {  
      count: stakeCount, 
      stakedDaysSum: stakeStartsReduced.stakedDays,
      lastStakeId: lastStakeId,
      uniqueAddresses: uniqueAddresses,
      stakedHEX: stakeStartsReduced.stakedHearts / 100000000,
      weightedAverageSum: weightedAverageSum,
    };

    return data;
  }});
}

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

function onlyUnique(value, index, self) {
  return self.indexOf(value) === index;
}