#!/usr/bin/env node

'use strict'

const path = require('path')
const mygreat = require('../index')
const program = require('commander')
const ConflictError = require('../errors/conflict')
const environment = process.env.NODE_ENV || 'development'
const fallback = (value, defaultValue) => value || defaultValue

const configFactory = (dir) => {
  return Object.assign(
    { shutdown: () => { } },
    require(path.resolve(process.cwd(), dir))(environment)
  )
}

const errorHandler = (err) => {
  console.log('│')
  console.log('│')

  if (err instanceof ConflictError) {
    console.error('│  ┌')
    console.error('│  │ [ error: conflict ]')
    console.error('│  │ unable to proceed due possible integrity break')
    console.error('│  │')
    console.error('│  │ any of the following scenarios could couse this error:')
    console.error('│  │  - a synced migration file has been renamed;')
    console.error('│  │  - a new migration has been named wrongly - all new')
    console.error('├──┤    migrations should be placed as last, considering')
    console.error('│  │    an ascending order;')
    console.error('│  │  - a synced migration file has been deleted before')
    console.error('│  │    been migrated-down;')
    console.error('│  │  - migrating down should alway revert the most recent')
    console.error('│  │    migration execution registry, otherwise the next')
    console.error('│  │    execution could trigger this error;')
    console.error('│  └')
  } else {
    console.error('│  ┌')
    console.error(`├──┤ [ error: ${err.name} ]`)
    console.error('│  │', err.message)
    console.error('│  └')
  }

  console.log('│')
  console.log('└─ [ » exit 1 ]')
  process.exit(1)
}

const action = async (file, direction) => {
  console.log(['  ╔═════════', (direction === 'up') ? '═══╗' : '═════╗'].join(''))
  console.log(['┌─║ migrate ', (direction === 'up') ? 'up ║' : 'down ║'].join(''))
  console.log(['│ ╚═════════', (direction === 'up') ? '═══╝' : '═════╝'].join(''))
  console.log('│')
  console.log('├─ setting up...')
  const config = configFactory(file)
  const migrate = mygreat.from(config.local, config.remote)
  const setup = await config.setup()
  const fn = migrate[direction]
  console.log('├─ migrating...')
  const result = await fn(setup)

  if (!result || result.content.length === 0) {
    console.log('│ └─ nothing to migrate')
    console.log('│')
    console.log('└─ [ » exit 0 ]')
    config.shutdown()
    return
  }
  console.log('│ └─ migrated')
  console.log('│')
  console.log('│')
  console.log('│ ╔══════════════════════════════════════════════════════════════╗')
  console.log(`└─║ migration execution id #${result.name} ║─┐`)
  console.log('  ╚══════════════════════════════════════════════════════════════╝ │')
  console.log('        ┌──────────────────────────────────────────────────┐       │')
  console.log('┌───────┤ the following migration files have been executed │───────┘')
  console.log('│       └──────────────────────────────────────────────────┘')
  console.log('│')
  result.content.forEach(file => { console.log(`├─ file "${file}" / method "${direction}"`) })
  console.log('│')
  console.log('└─ [ » exit 0 ]')

  return config.shutdown()
}

;(async () => {
  program
    .version(process.env.npm_package_version)
    .option('-f, --file <dir>', 'path to mygreat configuration file', fallback, './.mygreat.js')

  program
    .command('up')
    .action(options => action(options.parent.file, 'up').catch(errorHandler))

  program
    .command('down')
    .action(options => action(options.parent.file, 'down').catch(errorHandler))

  program.parse(process.argv)
})()