<?php
// Hoplite
// Copyright (c) 2016 Blue Static
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program.  If not, see <http://www.gnu.org/licenses/>.

namespace hoplite\http2;

require_once HOPLITE_ROOT . '/http2/middleware.php';
require_once HOPLITE_ROOT . '/http2/request.php';
require_once HOPLITE_ROOT . '/http2/response.php';

class Pipeline {
  private $middleware = [];

  public function add($middleware) {
    array_push($this->middleware, $middleware);
    return $this;
  }

  public function build() {
    return $this->_build(new Sentinel(new NotFoundResponse()));
  }

  public function buildWithTail($tail) {
    $chain = new Sentinel(new NotFoundResponse());
    $chain = $this->buildMiddleware($tail, $chain);
    return $this->_build($chain);
  }

  public function buildMiddleware($args, $next) {
    if ($args instanceof \Closure) {
      return new ClosureMiddleware($this, $next, $args);
    } else if ($args instanceof Pipeline) {
      return $args->_build($next);
    } else if (is_array($args)) {
      $class = array_shift($args);
      array_unshift($args, $this, $next);
      return new $class(...$args);
    } else {
      return new $args($this, $next);
    }
  }

  private function _build($chain) {
    for ($i = count($this->middleware) - 1; $i >= 0; --$i) {
      $chain = $this->buildMiddleware($this->middleware[$i], $chain);
    }
    return $chain;
  }

  public function run(Middleware $chain) {
    $response = $chain->execute(new Request());
    $response->generate();
  }

  public function buildAndRun() {
    $this->run($this->build());
  }
}