	<?php

final class ConduitIterator implements Iterator {

  private $client;
  private $method;
  private $parameters;

  private $current;
  private $cursor;

  public function __construct(ConduitClient $client, string $method, array $parameters) {
    $this->client = $client;
    $this->method = $method;
    $this->parameters = $parameters;
  }

  private function execute(): void {
    $parameters = $this->parameters;

    if ($this->cursor !== null) {
      $parameters['after'] = $this->cursor['after'];
    }

    $response = $this->client->callMethodSynchronous($this->method, $parameters);

    $this->current = new ArrayIterator($response['data']);
    $this->cursor  = $response['cursor'];
  }

  private function getResults(): ArrayIterator {
    if ($this->current === null) {
      $this->execute();
    }

    return $this->current;
  }


/* -(  Iterator  )----------------------------------------------------------- */


  public function current() {
    return $this->getResults()->current();
  }

  public function key() {
    return $this->getResults()->key();
  }

  public function next(): void {
    $this->getResults()->next();
  }

  public function rewind(): void {
    $this->current = null;
    $this->cursor  = null;
  }

  public function valid(): bool {
    $valid = $this->getResults()->valid();

    if (!$valid) {
      if ($this->cursor['after'] === null) {
        return false;
      }

      $this->execute();
      return true;
    }

    return $valid;
  }

}