<?php

namespace NoccyLabs\GdLabel;

class FontRegistry
{

    private $fonts = [];

    private static $instance = null;

    public static function getInstance()
    {
        if (!self::$instance) {
            self::$instance = new FontRegistry();
            self::$instance->load();
        }
        return self::$instance;
    }

    public function load(string $lang='en')
    {
        exec("fc-list -v", $out, $ret);
        $meta = []; $curr = [];
        foreach ($out as $line) {
            if (trim($line)) {
                $curr[] = $line;
            } else {
                $meta[] = $curr;
                $curr = [];
            }
        }

        foreach ($meta as $font) {
            $this->parseMeta($font, $lang);
        }
    }

    private function parseMeta(array $meta, string $lang)
    {
        $coll = [];
        foreach ($meta as $line) {
            if (9 != ord($line[0]) or strpos($line,": ") === false or ctype_digit($line[1])) {
                continue;
            }
            list ($key, $values) = explode(": ", substr($line, 1), 2);
            if (preg_match('/.+lang$/', $key)) {
                $base = substr($key, 0, -4);
                $baseMeta = $coll[$base];
                $vals = str_getcsv($baseMeta, ' ', '"');
                $langs = str_getcsv($values, ' ', '"');
                $keep = [];
                while (count($langs)>0) {
                    $l = $this->parseValue(array_shift($langs));
                    $v = $this->parseValue(array_shift($vals));
                    if ($l == $lang) {
                        $keep[] = $v;
                    }
                }
                $coll[$base] = $keep;
            } else {
                $coll[$key] = $values;
            }
        }
        foreach ($coll as $key=>$values) {
            if (is_array($values)) {
                continue;
            }
            $coll[$key] = $this->parseValue($values);
        }
        $langs = explode("|", $coll['lang']);
        if (!in_array($lang, $langs)) {
            return;
        }
        $this->fonts[] = (object)$coll;
    }

    private function parseValue($value)
    {
        if (substr($value, -3, 3) == "(s)") {
            $value = substr($value, 0, -3);
            if ($value && $value[0] == '"') {
                $value = substr($value, 1, strpos($value, '"', 2)-1);
            }
        } 
        if (substr($value, -3, 3) == "(i)") {
            $value = intval($value);
        } 
        return $value;
    }

    public function findFont($family, $styles='regular')
    {
        $styles = explode(" ",$styles);
        foreach ($this->fonts as $font) {
            $families = array_map("strtolower", (array)$font->family);
            if (!in_array(strtolower($family), $families)) {
                continue;
            }
            $fontStyles = array_map("strtolower", $font->style);
            foreach ($styles as $style) {
                if (!in_array($style, $fontStyles)) {
                    continue(2);
                }
            }
            if (count(array_diff($fontStyles, $styles))>0) {
                continue;
            }
            return $font->file;
        }
    }

}