<?php
/**
 * PHPCompatibility, an external standard for PHP_CodeSniffer.
 *
 * @package   PHPCompatibility
 * @copyright 2012-2019 PHPCompatibility Contributors
 * @license   https://opensource.org/licenses/LGPL-3.0 LGPL3
 * @link      https://github.com/PHPCompatibility/PHPCompatibility
 */

namespace PHPCompatibility;

use PHPCompatibility\Sniff;
use PHP_CodeSniffer_File as File;
use PHP_CodeSniffer_Tokens as Tokens;

/**
 * Abstract class to use as a base for examining the parameter values passed to function calls.
 *
 * @since 8.2.0
 */
abstract class AbstractFunctionCallParameterSniff extends Sniff {

	/**
	 * Is the sniff looking for a function call or a method call ?
	 *
	 * Note: the child class may need to do additional checks to make sure that
	 * the method called is of the right class/object.
	 * Checking that is outside of the scope of this abstract sniff.
	 *
	 * @since 8.2.0
	 *
	 * @var bool False (default) if the sniff is looking for function calls.
	 *           True if the sniff is looking for method calls.
	 */
	protected $isMethod = false;

	/**
	 * Functions the sniff is looking for. Should be defined in the child class.
	 *
	 * @since 8.2.0
	 *
	 * @var array The only requirement for this array is that the top level
	 *            array keys are the names of the functions you're looking for.
	 *            Other than that, the array can have arbitrary content
	 *            depending on your needs.
	 */
	protected $targetFunctions = array();

	/**
	 * List of tokens which when they preceed the $stackPtr indicate that this
	 * is not a function call.
	 *
	 * @since 8.2.0
	 *
	 * @var array
	 */
	private $ignoreTokens = array(
		\T_DOUBLE_COLON    => true,
		\T_OBJECT_OPERATOR => true,
		\T_FUNCTION        => true,
		\T_NEW             => true,
		\T_CONST           => true,
		\T_USE             => true,
	);


	/**
	 * Returns an array of tokens this test wants to listen for.
	 *
	 * @since 8.2.0
	 *
	 * @return array
	 */
	public function register() {
		// Handle case-insensitivity of function names.
		$this->targetFunctions = $this->arrayKeysToLowercase( $this->targetFunctions );

		return array( \T_STRING );
	}


	/**
	 * Processes this test, when one of its tokens is encountered.
	 *
	 * @since 8.2.0
	 *
	 * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned.
	 * @param int                   $stackPtr  The position of the current token in
	 *                                         the stack passed in $tokens.
	 *
	 * @return int|void Integer stack pointer to skip forward or void to continue
	 *                  normal file processing.
	 */
	public function process( File $phpcsFile, $stackPtr ) {
		if ( $this->bowOutEarly() === true ) {
			return;
		}

		$tokens     = $phpcsFile->getTokens();
		$function   = $tokens[ $stackPtr ]['content'];
		$functionLc = strtolower( $function );

		if ( isset( $this->targetFunctions[ $functionLc ] ) === false ) {
			return;
		}

		$prevNonEmpty = $phpcsFile->findPrevious( Tokens::$emptyTokens, ( $stackPtr - 1 ), null, true );

		if ( $this->isMethod === true ) {
			if ( $tokens[ $prevNonEmpty ]['code'] !== \T_DOUBLE_COLON
				&& $tokens[ $prevNonEmpty ]['code'] !== \T_OBJECT_OPERATOR
			) {
				// Not a call to a PHP method.
				return;
			}
		} else {
			if ( isset( $this->ignoreTokens[ $tokens[ $prevNonEmpty ]['code'] ] ) === true ) {
				// Not a call to a PHP function.
				return;
			}

			if ( $tokens[ $prevNonEmpty ]['code'] === \T_NS_SEPARATOR
				&& $tokens[ $prevNonEmpty - 1 ]['code'] === \T_STRING
			) {
				// Namespaced function.
				return;
			}
		}

		$parameters = $this->getFunctionCallParameters( $phpcsFile, $stackPtr );

		if ( empty( $parameters ) ) {
			return $this->processNoParameters( $phpcsFile, $stackPtr, $function );
		} else {
			return $this->processParameters( $phpcsFile, $stackPtr, $function, $parameters );
		}
	}


	/**
	 * Do a version check to determine if this sniff needs to run at all.
	 *
	 * @since 8.2.0
	 *
	 * If the check done in a child class is not specific to one PHP version,
	 * this function should return `false`.
	 *
	 * @return bool
	 */
	abstract protected function bowOutEarly();


	/**
	 * Process the parameters of a matched function.
	 *
	 * This method has to be made concrete in child classes.
	 *
	 * @since 8.2.0
	 *
	 * @param \PHP_CodeSniffer_File $phpcsFile    The file being scanned.
	 * @param int                   $stackPtr     The position of the current token in the stack.
	 * @param string                $functionName The token content (function name) which was matched.
	 * @param array                 $parameters   Array with information about the parameters.
	 *
	 * @return int|void Integer stack pointer to skip forward or void to continue
	 *                  normal file processing.
	 */
	abstract public function processParameters( File $phpcsFile, $stackPtr, $functionName, $parameters);


	/**
	 * Process the function if no parameters were found.
	 *
	 * Defaults to doing nothing. Can be overloaded in child classes to handle functions
	 * were parameters are expected, but none found.
	 *
	 * @since 8.2.0
	 *
	 * @param \PHP_CodeSniffer_File $phpcsFile    The file being scanned.
	 * @param int                   $stackPtr     The position of the current token in the stack.
	 * @param string                $functionName The token content (function name) which was matched.
	 *
	 * @return int|void Integer stack pointer to skip forward or void to continue
	 *                  normal file processing.
	 */
	public function processNoParameters( File $phpcsFile, $stackPtr, $functionName ) {
		return;
	}
}
