<?php
/**
 * PHP Command Line Tools
 *
 * This source file is subject to the MIT license that is bundled
 * with this package in the file LICENSE.
 *
 * @author    James Logsdon <[email protected]>
 * @copyright 2010 James Logsdom (http://girsbrain.org)
 * @license   http://www.opensource.org/licenses/mit-license.php The MIT License
 */

namespace cli;

/**
 * The `Shell` class is a utility class for shell related tasks such as
 * information on width.
 */
class Shell {

    /**
     * Returns the number of columns the current shell has for display.
     *
     * @return int  The number of columns.
     * @todo Test on more systems.
     */
    static public function columns() {
        static $columns;

        if ( getenv( 'PHP_CLI_TOOLS_TEST_SHELL_COLUMNS_RESET' ) ) {
            $columns = null;
        }
        if ( null === $columns ) {
            if ( function_exists( 'exec' ) ) {
                if ( self::is_windows() ) {
                    // Cater for shells such as Cygwin and Git bash where `mode CON` returns an incorrect value for columns.
                    if ( ( $shell = getenv( 'SHELL' ) ) && preg_match( '/(?:bash|zsh)(?:\.exe)?$/', $shell ) && getenv( 'TERM' ) ) {
                        $columns = (int) exec( 'tput cols' );
                    }
                    if ( ! $columns ) {
                        $return_var = -1;
                        $output = array();
                        exec( 'mode CON', $output, $return_var );
                        if ( 0 === $return_var && $output ) {
                            // Look for second line ending in ": <number>" (searching for "Columns:" will fail on non-English locales).
                            if ( preg_match( '/:\s*[0-9]+\n[^:]+:\s*([0-9]+)\n/', implode( "\n", $output ), $matches ) ) {
                                $columns = (int) $matches[1];
                            }
                        }
                    }
                } else {
                    if ( ! ( $columns = (int) getenv( 'COLUMNS' ) ) ) {
                        $size = exec( '/usr/bin/env stty size 2>/dev/null' );
                        if ( '' !== $size && preg_match( '/[0-9]+ ([0-9]+)/', $size, $matches ) ) {
                            $columns = (int) $matches[1];
                        }
                        if ( ! $columns ) {
                            if ( getenv( 'TERM' ) ) {
                                $columns = (int) exec( '/usr/bin/env tput cols 2>/dev/null' );
                            }
                        }
                    }
                }
            }

            if ( ! $columns ) {
                $columns = 80; // default width of cmd window on Windows OS
            }
        }

        return $columns;
    }

    /**
     * Checks whether the output of the current script is a TTY or a pipe / redirect
     *
     * Returns true if STDOUT output is being redirected to a pipe or a file; false is
     * output is being sent directly to the terminal.
     *
     * If an env variable SHELL_PIPE exists, returned result depends it's
     * value. Strings like 1, 0, yes, no, that validate to booleans are accepted.
     *
     * To enable ASCII formatting even when shell is piped, use the
     * ENV variable SHELL_PIPE=0
     *
     * @return bool
     */
    static public function isPiped() {
        $shellPipe = getenv('SHELL_PIPE');

        if ($shellPipe !== false) {
            return filter_var($shellPipe, FILTER_VALIDATE_BOOLEAN);
        } else {
            if ( function_exists('stream_isatty') ) {
                return !stream_isatty(STDOUT);
            } else {
                return (function_exists('posix_isatty') && !posix_isatty(STDOUT));
            }
        }
    }

    /**
     * Uses `stty` to hide input/output completely.
     * @param boolean $hidden Will hide/show the next data. Defaults to true.
     */
    static public function hide($hidden = true) {
        system( 'stty ' . ( $hidden? '-echo' : 'echo' ) );
    }

    /**
     * Is this shell in Windows?
     *
     * @return bool
     */
    static private function is_windows() {
        return strtoupper(substr(PHP_OS, 0, 3)) === 'WIN';
    }

}

?>