#!/usr/bin/env node

var fs = require('fs')

var browserslist = require('./') var pkg = require('./package.json') var args = process.argv.slice(2)

var USAGE = 'Usage:n' +

'  ' + pkg.name + '\n' +
'  ' + pkg.name + ' "QUERIES"\n' +
'  ' + pkg.name + ' --json "QUERIES"\n' +
'  ' + pkg.name + ' --config="path/to/browserlist/file"\n' +
'  ' + pkg.name + ' --coverage "QUERIES"\n' +
'  ' + pkg.name + ' --coverage=US "QUERIES"\n' +
'  ' + pkg.name + ' --coverage=US,RU,global "QUERIES"\n' +
'  ' + pkg.name + ' --env="environment name defined in config"\n' +
'  ' + pkg.name + ' --stats="path/to/browserlist/stats/file"'

function isArg (arg) {

return args.some(function (str) {
  return str === arg || str.indexOf(arg + '=') === 0
})

}

function error (msg) {

process.stderr.write(pkg.name + ': ' + msg + '\n')
process.exit(1)

}

if (isArg('–help') || isArg('-h')) {

process.stdout.write(pkg.description + '.\n\n' + USAGE + '\n')

} else if (isArg('–version') || isArg('-v')) {

process.stdout.write(pkg.name + ' ' + pkg.version + '\n')

} else {

var mode = 'browsers'
var opts = { }
var queries
var areas

for (var i = 0; i < args.length; i++) {
  if (args[i][0] !== '-') {
    queries = args[i].replace(/^["']|["']$/g, '')
    continue
  }

  var arg = args[i].split('=')
  var name = arg[0]
  var value = arg[1]

  if (value) value = value.replace(/^["']|["']$/g, '')

  if (name === '--config' || name === '-b') {
    opts.config = value
  } else if (name === '--env' || name === '-e') {
    opts.env = value
  } else if (name === '--stats' || name === '-s') {
    opts.stats = value
  } else if (name === '--coverage' || name === '-c') {
    if (mode !== 'json') mode = 'coverage'
    if (value) {
      areas = value.split(',')
    } else {
      areas = ['global']
    }
  } else if (name === '--json') {
    mode = 'json'
  } else {
    error('Unknown arguments ' + args[i] + '.\n\n' + USAGE)
  }
}

var browsers
try {
  browsers = browserslist(queries, opts)
} catch (e) {
  if (e.name === 'BrowserslistError') {
    error(e.message)
  } else {
    throw e
  }
}

var coverage
if (mode === 'browsers') {
  browsers.forEach(function (browser) {
    process.stdout.write(browser + '\n')
  })
} else if (areas) {
  coverage = areas.map(function (area) {
    var stats
    if (area !== 'global') {
      stats = area
    } else if (opts.stats) {
      stats = JSON.parse(fs.readFileSync(opts.stats))
    }
    var result = browserslist.coverage(browsers, stats)
    var round = Math.round(result * 100) / 100.0

    return [area, round]
  })

  if (mode === 'coverage') {
    var prefix = 'These browsers account for '
    process.stdout.write(prefix)
    coverage.forEach(function (data, index) {
      var area = data[0]
      var round = data[1]
      var end = 'globally'
      if (area && area !== 'global') {
        end = 'in the ' + area.toUpperCase()
      } else if (opts.stats) {
        end = 'in custom statistics'
      }

      if (index !== 0) {
        process.stdout.write(prefix.replace(/./g, ' '))
      }

      process.stdout.write(round + '% of all users ' + end + '\n')
    })
  }
}

if (mode === 'json') {
  var data = { browsers: browsers }
  if (coverage) {
    data.coverage = coverage.reduce(function (object, j) {
      object[j[0]] = j[1]
      return object
    }, { })
  }
  process.stdout.write(JSON.stringify(data, null, '  ') + '\n')
}

}