load

#! /usr/bin/env node

const Promise = require('bluebird')
const Client = require('pg').Client
const fs = require('fs')
const program = require('commander')
const readline = require('readline')

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
})

program
  .usage('[options] <file ...>')
  .option('-s, --schema <schema>', 'schema name to store the data under (default \'ds\')')
  .parse(process.argv)

const schema = program.schema || 'ds'

if (program.args.length === 0) {
  console.error('no files provided!')
  program.help()
}

const client = new Client()

const filenames = program.args
const useJsonb = true
const co = Promise.coroutine
const readFile = Promise.promisify(fs.readFile)

const load = co(function* (filename) {
  let data = yield readFile(filename, 'utf8')
  try {
    data = JSON.parse(data)
  } catch (err) {
    console.error(err)
  }

  try {
    yield client.query(`CREATE SCHEMA "${schema}";`)
    console.log('created schema', schema)
  } catch (err) {
    // schema already exists
  }

  for (const tableName in data) {
    try {
      yield client.query(`
CREATE TABLE "${schema}"."${tableName}" (
  id text NOT NULL,
  val ${useJsonb ? 'jsonb' : 'text'} NOT NULL,
  PRIMARY KEY (id)
);`
      )
      console.log('created table', tableName)
    } catch (err) {
      // table already exists
      console.log(`WARNING: the table ${tableName}, already exists`)
    }
    const tableData = data[tableName]

    let recordCount = 0
    for (const recordName in tableData) {
      yield client.query(`
INSERT INTO "${schema}"."${tableName}" (id, val) VALUES
($1, $2)
ON CONFLICT (id)
DO UPDATE SET val = EXCLUDED.val;`,
        [recordName, { _d: tableData[recordName], _v: 1 }]
      )
      recordCount++
    }
    console.log('inserted', recordCount, 'records into table', tableName)
  }
})

const loadAll = co(function* () {
  for (const filename of filenames) {
    yield load(filename)
  }
})

client.connect()
  .then(loadAll)
  .then(client.end)
  .catch(console.error.bind(null, 'an error occurred:'))