<?php
    /**
    * o------------------------------------------------------------------------------o
    * | This package is dual licensed as GPL and a commercial license.               |
    * | If you use the code commercially (or if you don't want to be restricted by   |
    * | the GPL license), you will need the commercial license. It's only £49 (GBP - |
    * | roughly $98 depending on the exchange rate) and helps me out a lot. Thanks.  |
    * o------------------------------------------------------------------------------o
    *
    * © Copyright Richard Heyes
    */
    
    /**
    * Common functionality for console scripts
    */

    class Console
    {
        /**
        * Stdin file pointer
        */
        public static $stdin;


        /**
        * Returns stdin file pointer
        *
        * @return resource STDIN file pointer
        */
        private static function GetStdin()
        {
            if (!self::$stdin) {
                self::$stdin = fopen('php://stdin', 'r');
            }
            
            return self::$stdin;
        }


        /**
        * Pauses execution until enter is pressed
        */
        public static function Pause()
        {
            
            fgets(self::GetStdin(), 8192);
        }
        
        
        /**
        * Asks a boolean style yes/no question. Valid input is:
        *
        *  o Yes: 1/y/yes/true
        *  o No:  0/n/no/false
        *
        * @param string $question The string to print. Should be a yes/no
        *                         question the user can answer. The following
        *                         will be appended to the question:
        *                         "[Yes]/No"
        * @param bool   $default  The default answer if only enter is pressed.
        */
        public static function BooleanQuestion($question, $default = null)
        {
            if (!is_null($default)) {
                $defaultStr = $default ? '[Yes]/No' : 'Yes/[No]';
            } else {
                $defaultStr = 'Yes/No';
            }
            
            $fp = self::GetStdin();
            
            while (true) {
                echo $question, " ", $defaultStr, ": ";
                $response = trim(fgets($fp, 8192));
                
                if (!is_null($default) AND $response == '') {
                    return $default;
                }
    
                switch (strtolower($response)) {
                    case 'y':
                    case '1':
                    case 'yes':
                    case 'true':
                        return true;
                    
                    case 'n':
                    case '0':
                    case 'no':
                    case 'false':
                        return false;
                    
                    default:
                        continue;
                }
            }
        }
    

        /**
        * Clears the screen. Specific to Linux (and possibly bash too)
        */
        public static function ClearScreen()
        {
            echo chr(033), "cm";
        }
        
        
        /**
        * Returns a line of input from the screen with the corresponding
        * LF character appended (if appropriate).
        *
        * @param int $buffer Line buffer. Defaults to 8192
        */
        public static function GetLine($buffer = 8192)
        {
            return fgets(self::GetStdin(), $buffer);
        }


        /**
        * Shows a console menu
        *
        * @param array $items The menu items. Should be a two dimensional array. 2nd
        *                     dimensional should be associative containing the following
        *                     keys:
        *                      o identifier - The key/combo the user should enter to activate
        *                                     this menu. Usually a single character or number.
        *                                     This is lower cased when used for comparison, so
        *                                     mixing upper/lower case identifiers will not work.
        *                      o text       - The description associated with this menu item.
        *                      o callback   - Optional. If specified this callback is called
        *                                     using call_user_func(). If not specified then the
        *                                     identifier is returned instead, (after the callback
        *                                     has run the identifier is returned also). The callback
        *                                     is given one argument, which is the identifier of the
        *                                     menu item.
        * @param bool  $clear Whether to clear the screen before printing the menu.
        *                     Defaults to false.
        */
        public static function ShowMenu($items, $clear = false)
        {
            // Find the longest identifier
            $max_length = 0;
            foreach ($items as $k => $v) {
                $identifiers[strtolower($v['identifier'])] = $k;
                $max_length  = max(strlen($v['identifier']), $max_length);
            }
            
            while (true) {
                if ($clear) {
                    self::ClearScreen();
                }
                
                echo "Please select one of the following options:\n\n";
                
                // Print the menu
                foreach ($items as $k => $v) {
                    echo str_pad($v['identifier'], $max_length, ' ', STR_PAD_LEFT), ") ", $v['text'], "\n";
                }
                
                echo "\nSelect: ";
                $input = trim(strtolower(self::GetLine()));

                // Invalid menu item chosen
                if (!isset($identifiers[$input])) {
                    echo "Invalid menu item chosen...\n";
                    sleep(1);
                    continue;
                
                // Valid menu item chosen
                } else {
                    $item = $items[$identifiers[$input]];
                    if (!empty($item['callback']) AND is_callable($item['callback'])) {
                        call_user_func($item['callback'], $input);
                    }
                    
                    return $input;
                }
            }
        }
    }
?>