<?php
require_once __DIR__ . "/db.php";

function e($str) {
    return htmlspecialchars((string)$str, ENT_QUOTES, "UTF-8");
}

function slugify($text) {
    $text = strtolower(trim($text));
    $text = preg_replace("/[^a-z0-9]+/", "-", $text);
    $text = trim($text, "-");
    return $text !== "" ? $text : "post-" . uniqid();
}

function get_categories() {
    return db()->query("SELECT * FROM categories ORDER BY id")->fetchAll();
}

function get_all_tags() {
    return db()->query("SELECT t.*, COUNT(at.article_id) cnt FROM tags t LEFT JOIN article_tags at ON t.id=at.tag_id GROUP BY t.id ORDER BY cnt DESC")->fetchAll();
}

function get_article_tags($articleId) {
    $st = db()->prepare("SELECT t.* FROM tags t JOIN article_tags at ON t.id=at.tag_id WHERE at.article_id=?");
    $st->execute([$articleId]);
    return $st->fetchAll();
}

function get_archives() {
    $sql = "SELECT DATE_FORMAT(created_at, ?) ym, COUNT(*) cnt FROM articles WHERE status=? GROUP BY ym ORDER BY ym DESC";
    $st = db()->prepare($sql);
    $st->execute(["%Y年%m月", "published"]);
    return $st->fetchAll();
}

function record_visit($page) {
    $ip = $_SERVER["REMOTE_ADDR"] ?? "";
    $ua = substr($_SERVER["HTTP_USER_AGENT"] ?? "", 0, 250);
    $st = db()->prepare("INSERT IGNORE INTO visitor_stats (visit_date, ip, page, ua) VALUES (CURDATE(), ?, ?, ?)");
    $st->execute([$ip, $page, $ua]);
}

function paginate($total, $page, $perPage) {
    $pages = max(1, (int)ceil($total / $perPage));
    $page = max(1, min($pages, (int)$page));
    return [
        "page" => $page,
        "pages" => $pages,
        "offset" => ($page - 1) * $perPage,
        "perPage" => $perPage,
    ];
}

function markdown($text) {
    static $parsedown = null;
    if ($parsedown === null) {
        require_once __DIR__ . "/Parsedown.php";
        $parsedown = new Parsedown();
        $parsedown->setBreaksEnabled(true);
    }
    return $parsedown->text((string)$text);
}