<?php
/**
 * Generate .mo files from .po files.
 * Run: php generate-mo.php
 * Or use Poedit / WP-CLI: wp i18n make-mo .
 */

if (php_sapi_name() !== 'cli') {
    die('CLI only');
}

$dir = __DIR__;
$po_files = glob($dir . '/*.po');

foreach ($po_files as $po_file) {
    $mo_file = preg_replace('/\.po$/', '.mo', $po_file);
    echo "Converting: " . basename($po_file) . " -> " . basename($mo_file) . "\n";

    $entries = parse_po($po_file);
    write_mo($mo_file, $entries);
    echo "Done. " . count($entries) . " entries.\n";
}

function parse_po($file) {
    $content = file_get_contents($file);
    $entries = array();
    $current_msgid = null;
    $current_msgstr = array();
    $current_msgid_plural = null;
    $state = '';

    $lines = explode("\n", $content);
    foreach ($lines as $line) {
        $line = trim($line);

        // Skip comments
        if (empty($line) || $line[0] === '#') {
            if ($current_msgid !== null && $state !== '') {
                save_entry($entries, $current_msgid, $current_msgid_plural, $current_msgstr);
                $current_msgid = null;
                $current_msgid_plural = null;
                $current_msgstr = array();
                $state = '';
            }
            continue;
        }

        if (preg_match('/^msgid\s+"(.*)"$/', $line, $m)) {
            if ($current_msgid !== null) {
                save_entry($entries, $current_msgid, $current_msgid_plural, $current_msgstr);
            }
            $current_msgid = stripcslashes($m[1]);
            $current_msgid_plural = null;
            $current_msgstr = array();
            $state = 'msgid';
        } elseif (preg_match('/^msgid_plural\s+"(.*)"$/', $line, $m)) {
            $current_msgid_plural = stripcslashes($m[1]);
            $state = 'msgid_plural';
        } elseif (preg_match('/^msgstr\s+"(.*)"$/', $line, $m)) {
            $current_msgstr[0] = stripcslashes($m[1]);
            $state = 'msgstr';
        } elseif (preg_match('/^msgstr\[(\d+)\]\s+"(.*)"$/', $line, $m)) {
            $current_msgstr[(int)$m[1]] = stripcslashes($m[2]);
            $state = 'msgstr[' . $m[1] . ']';
        } elseif (preg_match('/^"(.*)"$/', $line, $m)) {
            $val = stripcslashes($m[1]);
            if ($state === 'msgid') {
                $current_msgid .= $val;
            } elseif ($state === 'msgid_plural') {
                $current_msgid_plural .= $val;
            } elseif (preg_match('/^msgstr/', $state)) {
                $idx = 0;
                if (preg_match('/\[(\d+)\]/', $state, $im)) {
                    $idx = (int)$im[1];
                }
                $current_msgstr[$idx] = ($current_msgstr[$idx] ?? '') . $val;
            }
        }
    }

    if ($current_msgid !== null) {
        save_entry($entries, $current_msgid, $current_msgid_plural, $current_msgstr);
    }

    return $entries;
}

function save_entry(&$entries, $msgid, $msgid_plural, $msgstr) {
    if ($msgid === null) return;

    if ($msgid_plural !== null) {
        $key = $msgid . "\x00" . $msgid_plural;
        ksort($msgstr);
        $val = implode("\x00", $msgstr);
    } else {
        $key = $msgid;
        $val = $msgstr[0] ?? '';
    }

    $entries[$key] = $val;
}

function write_mo($file, $entries) {
    ksort($entries);
    $offsets = array();
    $ids = '';
    $strs = '';

    foreach ($entries as $id => $str) {
        $offsets[] = array(strlen($id), strlen($ids), strlen($str), strlen($strs));
        $ids .= $id . "\x00";
        $strs .= $str . "\x00";
    }

    $count = count($offsets);
    $header_size = 28;
    $key_offset_start = $header_size;
    $val_offset_start = $key_offset_start + $count * 8;
    $keys_start = $val_offset_start + $count * 8;
    $vals_start = $keys_start + strlen($ids);

    $output = pack('V', 0x950412de);  // magic
    $output .= pack('V', 0);          // revision
    $output .= pack('V', $count);     // number of strings
    $output .= pack('V', $key_offset_start);  // offset of original strings table
    $output .= pack('V', $val_offset_start);  // offset of translated strings table
    $output .= pack('V', 0);          // hash table size
    $output .= pack('V', 0);          // hash table offset

    // Original strings offsets
    foreach ($offsets as $o) {
        $output .= pack('V', $o[0]);                // length
        $output .= pack('V', $keys_start + $o[1]);  // offset
    }

    // Translated strings offsets
    foreach ($offsets as $o) {
        $output .= pack('V', $o[2]);                // length
        $output .= pack('V', $vals_start + $o[3]);  // offset
    }

    $output .= $ids;
    $output .= $strs;

    file_put_contents($file, $output);
}