resolve_conflicts.js

/**
 * ### Модуль разрешения конфликтов в пользу последнего
 *
 * @module  resolve_conflicts
 *
 * Created 18.06.2019
 */

/**
 * ### Переменные окружения
 * DEBUG "wb:*,-not_this"
 * ZONE 21
 * DBUSER admin
 * DBPWD admin
 * COUCHPATH http://cou221:5984/wb_
 */

'use strict';

const debug = require('debug')('wb:resolve_conflicts');
const PouchDB = require('./pouchdb')
  .plugin(require('pouchdb-find'));
const fs = require('fs');

debug('required');

const yargs = require('yargs')
  .usage('Usage: $0 [options] <command>')
  .demand(1)
  .strict()
  .alias('d', 'database').nargs('d', 1).describe('d', 'Database name')
  .version('v', 'Show version', '0.0.1').alias('v', 'version')
  .help('h').alias('h', 'help')
  .example('node resolve_conflicts id cat.characteristics|00000000-0000-0000-0000-000000000000', 'Resolve conflicts in id `cat.characteristics|00000000-0000-0000-0000-000000000000`, database by default wb_21_doc')
  .example('node resolve_conflicts json_file file.json', 'Resolve conflicts from JSON file `file.json` in database wb_21_doc')
  .command(
    'id [name]',
    'Resolve conflicts in id `name`',
    yargs => yargs.positional('name', {type: 'string', describe: 'Empty document id'}),
    args => {
      const { d, name } = args;
      if (name) {

        // инициализируем параметры сеанса и метаданные
        const {ZONE, DBUSER, DBPWD, COUCHPATH} = process.env;
        const prefix = 'wb_';

        const path = d ? `${COUCHPATH.replace(prefix, '')}${d}` : `${COUCHPATH}${ZONE}_doc`;

        const db = new PouchDB(path, {
          auth: {
            username: DBUSER,
            password: DBPWD
          },
          skip_setup: true,
          ajax: {timeout: 100000}
        });

        db.info()
          .then(info => {
            console.log(`connected to ${info.host}, doc count: ${info.doc_count}`);
          })
          .then(() => resolve_conflicts(db, name))
          .then(() => {
            console.log('all done');
          })
          .catch(err => {
            console.log(`error find ${name}: ${err && err.message}`);
          });
      }
      else {
        yargs.showHelp();
        process.exit(1);
      }
    }
  )
  .command(
    'json_file [name]',
    'Resolve conflicts from JSON file `name`',
    yargs => yargs.positional('name', {type: 'string', describe: 'Empty JSON file name'}),
    args => {
      const { d, name } = args;
      if (name) {

        // инициализируем параметры сеанса и метаданные
        const {ZONE, DBUSER, DBPWD, COUCHPATH} = process.env;
        const prefix = 'wb_';

        const path = d ? `${COUCHPATH.replace(prefix, '')}${d}` : `${COUCHPATH}${ZONE}_doc`;

        const db = new PouchDB(path, {
          auth: {
            username: DBUSER,
            password: DBPWD
          },
          skip_setup: true,
          ajax: {timeout: 100000}
        });

        db.info()
          .then(info => {
            console.log(`connected to ${info.host}, doc count: ${info.doc_count}`);
          })
          .then(() => {
            return new Promise((resolve, reject) => {
              fs.readFile(name, {encoding: 'utf-8'}, (err, data) => {
                if (err) {
                  reject(err);
                } else {
                  resolve(data);
                }
              });
            })
              .then(data => {
                const json = JSON.parse(data);
                if (!json) {
                  throw new Error({
                    error: true,
                    message: 'bad JSON format'
                  });
                }

                return resolve_from_json(db, json);
              });
          })
          .then(() => {
            console.log('all done');
          })
          .catch(err => {
            console.log(`error update from ${name}: ${err && err.message}`);
          });
      }
      else {
        yargs.showHelp();
        process.exit(1);
      }
    }
  )
  .epilog('\nMore information about the library: https://github.com/oknosoft/windowbuilder');

const {argv} = yargs;
if (!argv._.length) {
  yargs.showHelp();
  process.exit(1);
}

async function resolve_from_json(db, json) {
  if (json.items && typeof json.items === 'object') {
    for (const field in json.items) {
      if (json.items[field] instanceof Array) {
        for (const item of json.items[field]) {
          if (typeof item === 'object' && item.ref) {
            await resolve_conflicts(db, `${field}|${item.ref}`);
          }
        }
      }
    }
  }
}

function resolve_conflicts(db, id) {
  console.log(`processing ${id} started`);

  // запрашиваем документ
  return db.get(id, {conflicts: true})
    .then(res => {
      console.log(`${res._id} loaded successful`);

      // удаляем конфликтные ревизии документа
      if (res._conflicts) {
        return res._conflicts.reduce((prev, rev) => {
          return prev.then(() => {
            return db.remove(res._id, rev)
              .catch(err => {
                console.log(`revision ${rev} cannot be remove: ${err && err.message}`);
              });
          });
        }, Promise.resolve())
        .then(() => {
          console.log(`conflicts in ${res._id} resolved successful`);
        });
      }
    })
    .catch(err => {
      console.log(`error get ${id}: ${err && err.message}`);
    });
}