import { PoolInfo, PoolStats } from '../mempool.interfaces';
import BlocksRepository, { EmptyBlocks } from '../repositories/BlocksRepository';
import PoolsRepository from '../repositories/PoolsRepository';
import HashratesRepository from '../repositories/HashratesRepository';
import bitcoinClient from './bitcoin/bitcoin-client';
import logger from '../logger';

class Mining {
  hashrateIndexingStarted = false;

  constructor() {
  }

  /**
   * Generate high level overview of the pool ranks and general stats
   */
  public async $getPoolsStats(interval: string | null): Promise<object> {
    const poolsStatistics = {};

    const poolsInfo: PoolInfo[] = await PoolsRepository.$getPoolsInfo(interval);
    const emptyBlocks: EmptyBlocks[] = await BlocksRepository.$getEmptyBlocks(null, interval);

    const poolsStats: PoolStats[] = [];
    let rank = 1;

    poolsInfo.forEach((poolInfo: PoolInfo) => {
      const poolStat: PoolStats = {
        poolId: poolInfo.poolId, // mysql row id
        name: poolInfo.name,
        link: poolInfo.link,
        blockCount: poolInfo.blockCount,
        rank: rank++,
        emptyBlocks: 0
      };
      for (let i = 0; i < emptyBlocks.length; ++i) {
        if (emptyBlocks[i].poolId === poolInfo.poolId) {
          poolStat.emptyBlocks++;
        }
      }
      poolsStats.push(poolStat);
    });

    poolsStatistics['pools'] = poolsStats;

    const oldestBlock = new Date(await BlocksRepository.$oldestBlockTimestamp());
    poolsStatistics['oldestIndexedBlockTimestamp'] = oldestBlock.getTime();

    const blockCount: number = await BlocksRepository.$blockCount(null, interval);
    poolsStatistics['blockCount'] = blockCount;

    const blockHeightTip = await bitcoinClient.getBlockCount();
    const lastBlockHashrate = await bitcoinClient.getNetworkHashPs(144, blockHeightTip);
    poolsStatistics['lastEstimatedHashrate'] = lastBlockHashrate;

    return poolsStatistics;
  }

  /**
   * Get all mining pool stats for a pool
   */
  public async $getPoolStat(interval: string | null, poolId: number): Promise<object> {
    const pool = await PoolsRepository.$getPool(poolId);
    if (!pool) {
      throw new Error(`This mining pool does not exist`);
    }

    const blockCount: number = await BlocksRepository.$blockCount(poolId, interval);
    const emptyBlocks: EmptyBlocks[] = await BlocksRepository.$getEmptyBlocks(poolId, interval);

    return {
      pool: pool,
      blockCount: blockCount,
      emptyBlocks: emptyBlocks,
    };
  }

  /**
   * Return the historical difficulty adjustments and oldest indexed block timestamp
   */
  public async $getHistoricalDifficulty(interval: string | null): Promise<object> {
    const difficultyAdjustments = await BlocksRepository.$getBlocksDifficulty(interval);
    const oldestBlock = new Date(await BlocksRepository.$oldestBlockTimestamp());

    return {
      adjustments: difficultyAdjustments,
      oldestIndexedBlockTimestamp: oldestBlock.getTime(),
    };
  }

  /**
   * Return the historical hashrates and oldest indexed block timestamp
   */
  public async $getHistoricalHashrates(interval: string | null): Promise<object> {
    const hashrates = await HashratesRepository.$get(interval);
    const oldestBlock = new Date(await BlocksRepository.$oldestBlockTimestamp());

    return {
      hashrates: hashrates,
      oldestIndexedBlockTimestamp: oldestBlock.getTime(),
    };
  }

  /**
   * Generate daily hashrate data
   */
  public async $generateNetworkHashrateHistory(): Promise<void> {
    // We only run this once a day
    const latestTimestamp = await HashratesRepository.$getLatestRunTimestamp();
    const now = new Date().getTime() / 1000;
    if (now - latestTimestamp < 86400) {
      return;
    }

    if (this.hashrateIndexingStarted) {
      return;
    }
    this.hashrateIndexingStarted = true;

    logger.info(`Indexing hashrates`);

    const totalDayIndexed = (await BlocksRepository.$blockCount(null, null)) / 144;
    const indexedTimestamp = (await HashratesRepository.$get(null)).map(hashrate => hashrate.timestamp);
    let startedAt = new Date().getTime() / 1000;
    const genesisTimestamp = 1231006505; // bitcoin-cli getblock 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
    const lastMidnight = new Date();
    lastMidnight.setUTCHours(0); lastMidnight.setUTCMinutes(0); lastMidnight.setUTCSeconds(0); lastMidnight.setUTCMilliseconds(0);
    let toTimestamp = Math.round(lastMidnight.getTime() / 1000);
    let indexedThisRun = 0;
    let totalIndexed = 0;

    while (toTimestamp > genesisTimestamp) {
      const fromTimestamp = toTimestamp - 86400;
      if (indexedTimestamp.includes(fromTimestamp)) {
        toTimestamp -= 86400;
        ++totalIndexed;
        continue;
      }

      const blockStats: any = await BlocksRepository.$blockCountBetweenTimestamp(
        null, fromTimestamp, toTimestamp
      );

      if (blockStats.blockCount === 0) { // We are done indexing, no blocks left
        break;
      }

      let lastBlockHashrate = 0;
      lastBlockHashrate = await bitcoinClient.getNetworkHashPs(blockStats.blockCount,
        blockStats.lastBlockHeight);

      const elapsedSeconds = Math.max(1, Math.round((new Date().getTime() / 1000) - startedAt));
      if (elapsedSeconds > 10) {
        const daysPerSeconds = Math.max(1, Math.round(indexedThisRun / elapsedSeconds));
        const formattedDate = new Date(fromTimestamp * 1000).toUTCString();
        const daysLeft = Math.round(totalDayIndexed - totalIndexed);
        logger.debug(`Getting hashrate for ${formattedDate} | ~${daysPerSeconds} days/sec | ~${daysLeft} days left to index`);
        startedAt = new Date().getTime() / 1000;
        indexedThisRun = 0;
      }

      await HashratesRepository.$saveDailyStat({
        hashrateTimestamp: fromTimestamp,
        avgHashrate: lastBlockHashrate,
        poolId: null,
      });

      toTimestamp -= 86400;
      ++indexedThisRun;
      ++totalIndexed;
    }

    await HashratesRepository.$setLatestRunTimestamp();
    this.hashrateIndexingStarted = false;

    logger.info(`Hashrates indexing completed`);
  }

}

export default new Mining();