<?php

namespace SilverStripe\Dev;

/**
 * Class to facilitate command-line output.
 * Support less-trivial output stuff such as colours (on xterm-color)
 */
class CLI
{
    /**
     * Returns true if the current STDOUT supports the use of colour control codes.
     */
    public static function supports_colour()
    {
        // Special case for buildbot
        if (isset($_ENV['_']) && strpos($_ENV['_'] ?? '', 'buildbot') !== false) {
            return false;
        }

        if (!defined('STDOUT')) {
            define('STDOUT', fopen("php://stdout", "w"));
        }
        return function_exists('posix_isatty') ? @posix_isatty(STDOUT) : false;
    }

    /**
     * Return text encoded for CLI output, optionally coloured
     *
     * @param string $text
     * @param string $fgColour The foreground colour - black, red, green, yellow, blue, magenta, cyan, white.
     *                         Null is default.
     * @param string $bgColour The foreground colour - black, red, green, yellow, blue, magenta, cyan, white.
     *                         Null is default.
     * @param bool $bold A boolean variable - bold or not.
     * @return string
     */
    public static function text($text, $fgColour = null, $bgColour = null, $bold = false)
    {
        if (!self::supports_colour()) {
            return $text;
        }

        if ($fgColour || $bgColour || $bold) {
            $prefix = self::start_colour($fgColour, $bgColour, $bold);
            $suffix = self::end_colour();
        } else {
            $prefix = $suffix = "";
        }

        return $prefix . $text . $suffix;
    }

    /**
     * Send control codes for changing text to the given colour
     * @param string $fgColour The foreground colour - black, red, green, yellow, blue, magenta, cyan, white.
     *                         Null is default.
     * @param string $bgColour The foreground colour - black, red, green, yellow, blue, magenta, cyan, white.
     *                         Null is default.
     * @param bool $bold A boolean variable - bold or not.
     * @return string
     */
    public static function start_colour($fgColour = null, $bgColour = null, $bold = false)
    {
        if (!self::supports_colour()) {
            return "";
        }
        $colours = [
            'black' => 0,
            'red' => 1,
            'green' => 2,
            'yellow' => 3,
            'blue' => 4,
            'magenta' => 5,
            'cyan' => 6,
            'white' => 7,
        ];

        $prefix = "";

        if ($fgColour || $bold) {
            if (!$fgColour) {
                $fgColour = "white";
            }
            $prefix .= "\033[" . ($bold ? "1;" :"") . "3" . $colours[$fgColour] . "m";
        }


        if ($bgColour) {
            $prefix .= "\033[4" . $colours[$bgColour] . "m";
        }

        return $prefix;
    }

    /**
     * Send control codes for returning to normal colour
     */
    public static function end_colour()
    {
        return self::supports_colour() ? "\033[0m" : "";
    }
}