/*
 *  Importer code, handles all the syncing with chainquery into elasticsearch.
 */
import elasticsearch from 'elasticsearch';
import ElasticQueue from 'elastic-queue';
import winston from 'winston';
import winstonStream from 'winston-stream';
import jsonfile from 'jsonfile';
import path from 'path';
import rp from 'request-promise';
import appRoot from 'app-root-path';
import fs from 'fs';
import fileExists from 'file-exists';
import * as util from './util';
import {logErrorToSlack} from '../../index';
import mysql from 'mysql';

const elasticsearchloglevel = 'info';
const MaxClaimsToProcessPerIteration = 100000;
const BatchSize = 5000;
const loggerStream = winstonStream(winston, elasticsearchloglevel);
const eclient = new elasticsearch.Client({
  host: 'http://localhost:9200',

  log: {
    level : elasticsearchloglevel,
    type  : 'stream',
    stream: loggerStream,
  },
});
const queue = new ElasticQueue({elastic: eclient});

// Check that our syncState file exist.
fileExists(path.join(appRoot.path, 'syncState.json'), (err, exists) => {
  if (err) {
    throw err;
  }
  if (!exists) {
    fs.writeFileSync(path.join(appRoot.path, 'syncState.json'), '{}');
  }
});

let status = {info: 'startup successful'};

export async function claimSync () {
  try {
    let syncState = await getJSON(path.join(appRoot.path, 'syncState.json')); // get our persisted state
    if (!syncState.LastSyncTime) {
      syncState.LastSyncTime = '0001-01-01 00:00:00';
    }
    if (!syncState.LastID) {
      syncState.LastID = 0;
    }
    if (!syncState.StartSyncTime || syncState.LastID === 0) {
      syncState.StartSyncTime = new Date().toISOString().slice(0, 19).replace('T', ' ');
    }
    status.info = 'gettingClaimsToUpdate';
    let finished = false;
    let lastID = syncState.LastID;
    let iteration = 0;
    while (!finished) {
      let claimsResponse = await getClaimsSince(syncState.LastSyncTime, lastID, BatchSize);
      let claims = JSON.parse(claimsResponse).data;
      status.info = 'addingClaimsToElastic';
      for (let claim of claims) {
        if (claim.value === null) {
          console.log(claim);
          await logErrorToSlack('Failed to process claim ' + claim.claimId + ' due to missing value');
          continue;
        }
        claim.value = JSON.parse(claim.value).Claim;
        if (claim.name && claim.value) {
          claim.suggest_name = {
            input : '' + claim.name + '',
            weight: '30',
          };
        }
        if (claim.bid_state === 'Spent' || claim.bid_state === 'Expired') {
          deleteFromElastic(claim.claimId);
        } else {
          pushElastic(claim);
        }
        lastID = claim.id;
      }
      winston.log('info', '[Importer] Pushed ' + claims.length + ' claims to elastic search [LastID]' + lastID);
      finished = claims.length < BatchSize || (iteration * BatchSize + BatchSize >= MaxClaimsToProcessPerIteration);
      iteration++;
    }
    deleteBlockedClaims();
    // If not finished, store last id to run again later where we left off, otherwise update last sync time.
    if (iteration * BatchSize + BatchSize >= MaxClaimsToProcessPerIteration) {
      syncState.LastID = lastID;
    } else {
      syncState.LastID = 0;
      syncState.LastSyncTime = syncState.StartSyncTime;
    }
    await saveJSON(path.join(appRoot.path, 'syncState.json'), syncState);
    status.info = 'upToDate';
    status.syncState = syncState;
    await sleep(600000);
    claimSync();
  } catch (err) {
    await logErrorToSlack(err);
    status.err = err;
    await sleep(600000);
    claimSync();
  }
}

export function getStats () {
  return status;
}

async function deleteBlockedClaims () {
  winston.log('info', '[Importer] Removing blocked claims from search!');
  let blockedOutputsResponse = await getBlockedOutpoints();
  let outpointlist = JSON.parse(blockedOutputsResponse);
  for (let outpoint of outpointlist.data.outpoints) {
    let claimid = util.OutpointToClaimId(outpoint);
    deleteFromElastic(claimid);
  }
  winston.log('info', '[Importer] Done processing blocked claims!');
}

async function deleteFromElastic (claimid) {
  return new Promise(async (resolve, reject) => {
    queue.push({
      index: 'claims',
      type : 'claim',
      id   : claimid,
      body : {},
    });
  });
}

async function pushElastic (claim) {
  return new Promise(async (resolve, reject) => {
    queue.push({
      index: 'claims',
      type : 'claim',
      id   : claim.claimId,
      body : claim,
    });
  });
}

function getJSON (path) {
  return new Promise((resolve, reject) => {
    jsonfile.readFile(path, function (err, jsoncontent) {
      if (err) {
        logErrorToSlack(err);
        reject(err);
      } else {
        resolve(jsoncontent);
      }
    });
  });
}

function saveJSON (path, obj) {
  return new Promise((resolve, reject) => {
    jsonfile.writeFile(path, obj, function (err, jsoncontent) {
      if (err) {
        logErrorToSlack(err);
        reject(err);
      } else {
        resolve();
      }
    });
  });
}

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

function getBlockedOutpoints () {
  return new Promise((resolve, reject) => {
    rp(`https://api.lbry.com/file/list_blocked`)
      .then(function (htmlString) {
        resolve(htmlString);
      })
      .catch(function (err) {
        logErrorToSlack('[Importer] Error getting blocked outpoints. ' + err);
        reject(err);
      });
  });
}

let connection = null;
const chainqueryConfig = require('../../../chainquery-config.json');

function getClaimsSince (time, lastID, MaxClaimsInCall) {
  if (connection === null) {
    connection = mysql.createConnection({
      host    : chainqueryConfig.host,
      user    : chainqueryConfig.user,
      password: chainqueryConfig.password,
      database: chainqueryConfig.db,
    });
    connection.connect();
  }

  return new Promise((resolve, reject) => {
    let query = `SELECT c.id, c.name,p.name as channel, p.claim_id as channel_id, c.bid_state,c.effective_amount,COALESCE(p.effective_amount,1) as certificate_amount,c.claim_id as claimId,c.value_as_json as value FROM claim c LEFT JOIN claim p on p.claim_id = c.publisher_id WHERE c.id >${lastID} AND c.modified_at >='${time}' ORDER BY c.id LIMIT ${MaxClaimsInCall}`;
    // Outputs full query to console for copy/paste into chainquery (debugging)
    console.log(query);
    connection.query(query, function (err, results, fields) {
      if (err) {
        console.error(err);
        logErrorToSlack('[Importer] Error getting updated claims. ' + err);
        return reject(err);
      }
      resolve(JSON.parse(results));
    });
  });
}