<?php
/**
 * The attribute parser parses a simple attribute selector.
 *
 * @license http://www.opensource.org/licenses/mit-license.php The MIT License
 * @copyright Copyright 2010-2014 PhpCss Team
 */

namespace PhpCss\Parser {

  use PhpCss;
  use PhpCss\Ast;
  use PhpCss\Scanner;

  /**
   * The attribute parser parses a simple attribute selector.
   *
   * The attribute value can be an string if a string start is found it delegates to a string
   * parser.
   */
  class Attribute extends PhpCss\Parser {

    private $_operators = [
      '^=' => Ast\Selector\Simple\Attribute::MATCH_PREFIX,
      '$=' => Ast\Selector\Simple\Attribute::MATCH_SUFFIX,
      '*=' => Ast\Selector\Simple\Attribute::MATCH_SUBSTRING,
      '=' => Ast\Selector\Simple\Attribute::MATCH_EQUALS,
      '~=' => Ast\Selector\Simple\Attribute::MATCH_INCLUDES,
      '|=' => Ast\Selector\Simple\Attribute::MATCH_DASHMATCH,
    ];

    /**
     * @return Ast\Node
     * @throws PhpCss\Exception\ParserException
     */
    public function parse(): Ast\Node {
      $token = $this->read(Scanner\Token::IDENTIFIER);
      $attribute = new Ast\Selector\Simple\Attribute($token->content);
      $token = $this->read(
        [
          Scanner\Token::ATTRIBUTE_OPERATOR,
          Scanner\Token::ATTRIBUTE_SELECTOR_END,
        ]
      );
      if ($token->type === Scanner\Token::ATTRIBUTE_OPERATOR) {
        $attribute->match = $this->_operators[$token->content];
        $token = $this->read(
          [
            Scanner\Token::NUMBER,
            Scanner\Token::IDENTIFIER,
            Scanner\Token::SINGLEQUOTE_STRING_START,
            Scanner\Token::DOUBLEQUOTE_STRING_START,
          ]
        );
        switch ($token->type) {
        case Scanner\Token::NUMBER :
        case Scanner\Token::IDENTIFIER :
          $attribute->literal = new Ast\Value\Literal($token->content);
          break;
        case Scanner\Token::SINGLEQUOTE_STRING_START :
        case Scanner\Token::DOUBLEQUOTE_STRING_START :
          $attribute->literal = $this->delegate(Text::CLASS);
          break;
        }
        $this->read(Scanner\Token::ATTRIBUTE_SELECTOR_END);
      }
      return $attribute;
    }
  }
}