<?php

declare(strict_types=1);

class Media extends DB\SQL\Mapper
{
    public function __construct(DB\SQL $db)
    {
        parent::__construct($db, 'media');
    }

    public static function bootstrap(DB\SQL $db): void
    {
        $db->exec('CREATE TABLE IF NOT EXISTS media (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            file_name TEXT NOT NULL UNIQUE,
            alt TEXT NOT NULL DEFAULT \'\',
            width INTEGER NOT NULL,
            height INTEGER NOT NULL,
            created_at TEXT NOT NULL
        )');
        $db->exec('CREATE INDEX IF NOT EXISTS idx_media_created_at ON media(created_at DESC)');
    }

    public function all(): array
    {
        return array_map(
            fn (self $m): array => $this->decorate($m->cast()),
            $this->find(null, ['order' => 'created_at DESC, id DESC']) ?: []
        );
    }

    public function findById(int $id): ?array
    {
        if ($id <= 0) {
            return null;
        }

        $this->load(['id = ?', $id]);
        return $this->dry() ? null : $this->decorate($this->cast());
    }

    public function findByFileName(string $fileName): ?array
    {
        $this->load(['file_name = ?', $fileName]);
        return $this->dry() ? null : $this->decorate($this->cast());
    }

    // Reçoit le chemin absolu déposé par Web::receive() et le nom d'origine
    // pour dériver un texte alternatif lisible.
    public function upload(string $srcPath, string $originalName = ''): int
    {
        // Image::dump() gère le chargement et la compression.
        // Attention : en JPEG, la transparence n'est pas conservée.
        try {
            $img = new Image($srcPath, false, '');
        } catch (Throwable) {
            throw new RuntimeException('Fichier image invalide ou format source non supporté.');
        }

        $data = $img->dump('jpeg', 85);

        $fileName = bin2hex(random_bytes(16)) . '.jpg';
        $target   = app_public_media_dir() . '/' . $fileName;

        if (!Base::instance()->write($target, $data)) {
            throw new RuntimeException('Impossible d\'enregistrer cette image.');
        }

        @unlink($srcPath);

        $this->reset();
        $this->file_name  = $fileName;
        $this->alt        = $originalName !== '' ? self::altFromFilename($originalName) : '';
        $this->width      = $img->width();
        $this->height     = $img->height();
        $this->created_at = app_now();
        $this->save();

        return (int) $this->get('id');
    }

    public function updateAlt(int $id, string $alt): void
    {
        $this->load(['id = ?', $id]);
        if ($this->dry()) {
            throw new RuntimeException('Image introuvable.');
        }

        $this->alt = trim($alt);
        $this->save();
    }

    public function delete(int $id): void
    {
        $item = $this->findById($id);
        if ($item === null) {
            throw new RuntimeException('Image introuvable.');
        }

        if ($this->isUsed($item)) {
            throw new RuntimeException('Cette image est encore utilisée par un article.');
        }

        $path = app_public_media_dir() . '/' . $item['file_name'];

        $this->db->begin();
        try {
            $this->erase();
            if (is_file($path) && !unlink($path)) {
                throw new RuntimeException('Impossible de supprimer le fichier image.');
            }
            $this->db->commit();
        } catch (Throwable $e) {
            $this->db->rollback();
            throw $e instanceof RuntimeException ? $e : new RuntimeException('Suppression impossible.');
        }
    }

    // Dérive un texte alternatif lisible depuis le nom de fichier d'origine.
    private static function altFromFilename(string $filename): string
    {
        $name = pathinfo($filename, PATHINFO_FILENAME);
        $name = trim((string) preg_replace('/[-_]+/', ' ', $name));
        // mb_ucfirst() n'existe qu'en PHP 8.4 — on l'émule.
        return mb_strtoupper(mb_substr($name, 0, 1)) . mb_strtolower(mb_substr($name, 1));
    }

    // Une seule requête SQL pour les deux cas d'utilisation (couverture et body).
    private function isUsed(array $item): bool
    {
        return $this->db->exec(
            'SELECT 1 FROM posts WHERE cover_media_id = ? OR body_markdown LIKE ? LIMIT 1',
            [$item['id'], '%media:' . $item['file_name'] . '%']
        ) !== [];
    }

    private function decorate(array $row): array
    {
        $alt = (string) $row['alt'];

        return [
            'id'               => (int) $row['id'],
            'file_name'        => (string) $row['file_name'],
            'alt'              => $alt,
            'width'            => (int) $row['width'],
            'height'           => (int) $row['height'],
            'created_at'       => (string) $row['created_at'],
            'created_at_label' => app_format_datetime_fr((string) $row['created_at']),
            'url'              => app_media_url((string) $row['file_name']),
            'markdown'         => '![' . $alt . '](media:' . $row['file_name'] . ')',
        ];
    }
}