community-repo/community-contributions/report-generator/src/block-interval.ts

// import {ApiPromise, WsProvider} from "@polkadot/api";
// import {Hash, Header} from "@polkadot/types/interfaces/runtime";
// import { types } from '@joystream/types'
//
// async function main() {
//     let startDate = new Date(2020, 4, 20, 13, 0);
//     console.log(startDate);
//     let endDate = new Date(2020, 4, 29, 23, 59);
//
//     // Initialise the provider to connect to the local node
//     const provider = new WsProvider('wss://rome-rpc-endpoint.joystream.org:9944');
//
//     // Create the API and wait until ready
//     const api = await ApiPromise.create({provider, types});
//
//     let blockInterval = await getBlockInterval(api, startDate.getTime(), endDate.getTime());
//     console.log(blockInterval);
// }
//
// async function getBlockInterval(api: ApiPromise, startTimestamp: number, endTimestamp: number) {
//
//     let approximateStartBlockHash = await getApproximatedBlockHash(api, startTimestamp);
//     let startBlock = await adjustApproximatedBlockHash(api, startTimestamp, approximateStartBlockHash);
//
//     let approximateEndBlockHash = await getApproximatedBlockHash(api, endTimestamp);
//     let endBlock = await adjustApproximatedBlockHash(api, endTimestamp, approximateEndBlockHash);
//
//     let startBlockHeader = await api.rpc.chain.getHeader(startBlock) as Header;
//     let endBlockHeader = await api.rpc.chain.getHeader(endBlock) as Header;
//
//     return {
//         'startBlock':
//             startBlockHeader.number.unwrap().toNumber(),
//         'endBlock':
//             endBlockHeader.number.unwrap().toNumber()
//     };
// }
//
// async function getApproximatedBlockHash(api: ApiPromise, timestampToFound: number): Promise<Hash> {
//     let lastHeader = await api.rpc.chain.getHeader();
//     let lastHash = lastHeader.hash.toString();
//     let lastTimestamp = parseInt((await api.query.timestamp.now.at(lastHash)).toString());
//
//     let prevousBlockHash = lastHeader.parentHash;
//     let previousBlockTimestamp = parseInt((await api.query.timestamp.now.at(prevousBlockHash)).toString());
//
//     let secondsPerBlock = lastTimestamp - previousBlockTimestamp;
//
//     let blocksDiff = Math.floor((lastTimestamp - timestampToFound) / secondsPerBlock);
//     let lastBlockNumber = lastHeader.number.unwrap();
//     let approximatedBlockNr = lastBlockNumber.toNumber() - blocksDiff;
//     return await api.rpc.chain.getBlockHash(approximatedBlockNr);
// }
//
// async function adjustApproximatedBlockHash(api: ApiPromise, timestamp: number, hash: Hash) {
//     let approximatedBlockTimestamp = parseInt((await api.query.timestamp.now.at(hash)).toString());
//
//     if (timestamp == approximatedBlockTimestamp) {
//         return hash;
//     }
//
//     let step = 1;
//     if (timestamp < approximatedBlockTimestamp) {
//         step = -1;
//     }
//
//     let approximatedBlockHeader = await api.rpc.chain.getHeader(hash);
//     let blockNumber = approximatedBlockHeader.number.unwrap().toNumber();
//     let lastHashFound = hash;
//     do {
//         blockNumber += step;
//         let nextBlockHash = await api.rpc.chain.getBlockHash(blockNumber);
//         let nextBlockTimeStamp = parseInt((await api.query.timestamp.now.at(nextBlockHash)).toString());
//
//         if (Math.abs(approximatedBlockTimestamp - timestamp) < Math.abs(nextBlockTimeStamp - timestamp)) {
//             return lastHashFound;
//         }
//
//         approximatedBlockTimestamp = nextBlockTimeStamp;
//         lastHashFound = nextBlockHash;
//
//     } while (true);
// }
//
// main();