'use strict'

var fs = require('fs')

/*
 * Parses a string or buffer into an object
 * @param {String|Buffer} src - source to be parsed
 * @returns {Object}
*/
function parse (src) {
  var obj = {}

  // convert Buffers before splitting into lines and processing
  src.toString().split('\n').forEach(function (line) {
    // matching "KEY' and 'VAL' in 'KEY=VAL'
    var keyValueArr = line.match(/^\s*([\w\.\-]+)\s*=\s*(.*)?\s*$/)
    // matched?
    if (keyValueArr != null) {
      var key = keyValueArr[1]

      // default undefined or missing values to empty string
      var value = keyValueArr[2] ? keyValueArr[2] : ''

      // expand newlines in quoted values
      var len = value ? value.length : 0
      if (len > 0 && value.charAt(0) === '"' && value.charAt(len - 1) === '"') {
        value = value.replace(/\\n/gm, '\n')
      }

      // remove any surrounding quotes and extra spaces
      value = value.replace(/(^['"]|['"]$)/g, '').trim()

      obj[key] = value
    }
  })

  return obj
}

/*
 * Main entry point into dotenv. Allows configuration before loading .env
 * @param {Object} options - valid options: path ('.env'), encoding ('utf8')
 * @returns {Boolean}
*/
function config (options) {
  var path = '.env'
  var encoding = 'utf8'

  if (options) {
    if (options.path) {
      path = options.path
    }
    if (options.encoding) {
      encoding = options.encoding
    }
  }

  try {
    // specifying an encoding returns a string instead of a buffer
    var parsedObj = parse(fs.readFileSync(path, { encoding: encoding }))

    Object.keys(parsedObj).forEach(function (key) {
      process.env[key] = process.env[key] || parsedObj[key]
    })

    return { parsed: parsedObj }
  } catch (e) {
    return { error: e }
  }
}

module.exports.config = config
module.exports.load = config
module.exports.parse = parse