import OrderedList from "misago/utils/ordered-list"

export class Misago {
  constructor() {
    this._initializers = []
    this._context = {}
  }

  addInitializer(initializer) {
    this._initializers.push({
      key: initializer.name,

      item: initializer.initializer,

      after: initializer.after,
      before: initializer.before
    })
  }

  init(context) {
    this._context = context

    var initOrder = new OrderedList(this._initializers).orderedValues()
    initOrder.forEach(initializer => {
      initializer(this)
    })
  }

  // context accessors
  has(key) {
    return !!this._context[key]
  }

  get(key, fallback) {
    if (this.has(key)) {
      return this._context[key]
    } else {
      return fallback || undefined
    }
  }

  pop(key) {
    if (this.has(key)) {
      let value = this._context[key]
      this._context[key] = null
      return value
    } else {
      return undefined
    }
  }
}

// create  singleton
var misago = new Misago()

// expose it globally
global.misago = misago

// and export it for tests and stuff
export default misago