Adopt OOP design

[neocotic]

Currently, the API is a bit confusing with the whole connect/disconnect aspect that means you can only use it for one endpoint at a time. I think it's time to adopt an object-orientated programming (OOP) design that would make the API more open, configurable/extensible, easier to maintain/understand, and support the ability to connect to multiple YOURLS endpoints at any given time.

[neocotic]

Since OOP will also make unit testing much easier, I've moved #5 to v3 as well.

[neocotic]

Here's a proposal of what the new API could look like:

var yourls = new YOURLS('https://example.com/yourls-api.php')
// OR:
var yourls = new YOURLS({
  url: 'https://example.com/yourls-api.php',
  format: 'json',
  method: 'post',
  credentials: {
    username: 'admin',
    password: 'qwerty'
  }
})

yourls.shorten('https://github.com/neocotic/yourls-api', function(result, response) {
  console.log(result.shorturl)
  //=> "https://example.com/abc123"
  console.log(result.title)
  //=> "https://github.com/neocotic/yourls-api"
  console.log(result.url.keyword)
  //=> "abc123"
})
// OR:
yourls.shorten({
  url: 'https://github.com/neocotic/yourls-api',
  keyword: 'yourls',
  title: 'YOURLS API'
}, function(result, response) {
  console.log(result.shorturl)
  //=> "https://example.com/yourls"
  console.log(result.title)
  //=> "YOURLS API"
  console.log(result.url.keyword)
  //=> "yourls"
})

yourls.stats(function(result, response) {
  console.log(result.stats.total_clicks)
  //=> "98765"
  console.log(result.stats.total_links)
  //=> "123"
})
// OR:
yourls.stats({
  filter: 'last',
  limit: 5,
  start: 5
}, function(result, response) {
  console.log(result.links.length)
  //=> 5
  console.log(result.links[0].shorturl)
  //=> "https://example.com/abc123"
  console.log(result.stats.total_links)
  //=> "123"
})

yourls.db.stats(function(result, response) {
  console.log(result.total_clicks)
  //=> "98765"
  console.log(result.total_links)
  //=> "123"
})

yourls.version(function(result, response) {
  console.log(result.version)
  //=> "1.7"
})
// OR:
yourls.version({
  db: true
}, function(result, response) {
  console.log(result.version)
  //=> "1.7"
  console.log(result.db_version)
  //=> "482"
})

var myUrl = yourls.url('yourls')
// myUrl instanceof YOURLS.URL

myUrl.expand(function(result, response) {
  console.log(result.keyword)
  //=> "yourls"
  console.log(result.longurl)
  //=> "https://github.com/neocotic/yourls-api"
  console.log(result.shorturl)
  //=> "https://example.com/yourls"
})

myUrl.stats(function(result, response) {
  console.log(result.clicks)
  //=> "123"
  console.log(result.title)
  //=> "neocotic/yourls-api: JavaScript bindings for the YOURLS API"
  console.log(result.url)
  //=> "https://github.com/neocotic/yourls-api"
})

console.log(YOURLS.VERSION)
//=> "3.0.0"

This is just a draft, but you get the idea.