import { batchEthBlocks } from "chain/chain.api";
import logger from "logger/logger";
import { RedisClient } from "redis/RedisClient";

const MAX_BATCH_AMOUNT = 500
const REQUEST_INTERVAL = 0.5 * 1000

export async function divQueryPassBlocks({chainId, rpc, fromBlock, amount}
  : {chainId: number, rpc: string, fromBlock: number, amount: number}) {
  const middleBlock = fromBlock + Math.floor(amount / 2)
  const firstBlocks = await getPastBlocks({chainId, rpc, fromBlock, amount: middleBlock - fromBlock})
  const secondBlocks = await getPastBlocks({chainId, rpc, fromBlock: middleBlock, amount: amount - (middleBlock - fromBlock)})
  return [...firstBlocks, ...secondBlocks]
}

export async function getPastBlocks({chainId, rpc, fromBlock, amount}
  : {chainId: number, rpc: string, fromBlock: number, amount: number}) {
  let blocks = []
  logger.log(`getPastBlocks: ${chainId} from: ${fromBlock} amount: ${amount}`)
  let blockNumber = fromBlock
  const redisKey = `blocknum_${chainId}`
  try {
    let res = await batchEthBlocks(rpc, blockNumber, amount)
    if (res.error) {
      throw new Error(res.error.message)
    }
    for (let i = 0; i < res.length; i++) {
      const block = res[i].result;
      if (block) {
        blocks.push(block)
      }
    }
    await new RedisClient().set(redisKey, blockNumber + amount + '')
    await new Promise(resolve => setTimeout(resolve, REQUEST_INTERVAL))
  } catch (e) {
    logger.log(e.message || e)
    if (e.message && /Too Many Requests/.test(e.message) && amount > 1) {
      blocks = await divQueryPassBlocks({chainId, rpc, fromBlock, amount})
    } else if (e.message && /Public RPC Rate Limit Hit, limit will reset in \d+ seconds/.test(e.message)) {
      const match = e.message.match(/Public RPC Rate Limit Hit, limit will reset in (\d+) seconds/)
      const seconds = parseInt(match[1])
      await new Promise(resolve => setTimeout(resolve, seconds * 1000))
      blocks = await getPastBlocks({chainId, rpc, fromBlock, amount})
    }else {
      throw e
    }
  }
  return blocks
}

export function* getPastBlocksIter({chainId, rpc, fromBlock, amount}
  : {chainId: number, rpc: string, fromBlock: number, amount: number}) {
  logger.debug(`*getPastBlocksIter: ${chainId} from: ${fromBlock} amount: ${amount}`)
  let remain = amount
  while (remain > 0) {
    yield getPastBlocks({chainId, rpc, fromBlock, amount: Math.min(MAX_BATCH_AMOUNT, remain)})
    fromBlock += MAX_BATCH_AMOUNT
    remain -= MAX_BATCH_AMOUNT
  }
}