import http from 'http'
import { URL } from 'url'

// taken from isobject npm library
function isObject(val) {
  return val != null && typeof val === 'object' && Array.isArray(val) === false
}

function defaults(options, def) {
  let out = { }

  if (options) {
    Object.keys(options || {}).forEach(key => {
      out[key] = options[key]

      if (Array.isArray(out[key])) {
        out[key] = out[key].map(item => {
          if (isObject(item)) return defaults(item)
          return item
        })
      } else if (out[key] && typeof out[key] === 'object') {
        out[key] = defaults(options[key], def && def[key])
      }
    })
  }

  if (def) {
    Object.keys(def).forEach(function(key) {
      if (typeof out[key] === 'undefined') {
        out[key] = def[key]
      }
    })
  }

  return out
}

export default function Client(port, opts) {
  this.options = defaults(opts, {})
  this.prefix = `http://localhost:${port}`
}

Client.prototype.customRequest = function(method = 'GET', path, body, options) {
  if (path.slice(0, 4) !== 'http') {
    path = this.prefix + path
  }
  let urlObj = new URL(path)

  return new Promise((resolve, reject) => {
    const opts = defaults(defaults(options, {
      method: method,
      timeout: 500,
      protocol: urlObj.protocol,
      username: urlObj.username,
      password: urlObj.password,
      host: urlObj.hostname,
      port: Number(urlObj.port),
      path: urlObj.pathname + urlObj.search,
    }))

    const req = http.request(opts)
    if (body) {
      req.write(body)
    }

    req.on('error', reject)
    req.on('timeout', function() { reject(new Error(`Request ${method} ${path} timed out`)) })
    req.on('response', res => {
      res.setEncoding('utf8')
      let output = ''

      res.on('data', function (chunk) {
        output += chunk.toString()
      })

      res.on('end', function () {
        try {
          output = JSON.parse(output)
        } catch (e) {
          return reject(new Error(`${e.message} while decoding: ${output}`))
        }
        if (output.status) {
          let err = new Error(`Request failed [${output.status}]: ${output.message}`)
          err.body = output
          return reject(err)
        }
        resolve(output)
      })
    })
    req.end()
  })
}

Client.prototype.get = function(path = '/') {
  return this.customRequest('GET', path, null)
}