<?php

class Item implements JsonSerializable
{

    // TODO: create a persist() method that updates the line if the offset where
    //       it originally existed in is given by 'ftell'. If it doesn't have an
    //       ID, then try to find it in the file and if it doesn't exist, append
    //
    // TODO: Maybe implement tags as an associative array or somethign?
    //
    // TODO: Change to id here in all occurrences
    //

    private string $hash;
    private string $extension;
    private array $tags = [];

    public static function load(MediaDB $db, string $id): ?Item
    {
        $ret = null;

        $db->map(function ($line) use (&$ret, $id) {
            if ($line[0] == $id) {
                $ret = Item::fromLine($line);
                return true;
            }

            return false;
        });

        return $ret;
    }

    public static function fromLine(array $line): Item
    {
        $ret = new Item();

        $ret->hash = array_shift($line);
        $ret->tags = $line;
        $ret->extensionFromTags();

        return $ret;
    }

    // ::upload() requires the PHP file upload ARRAY from $_FILES
    public static function upload(array $php_file): Item
    {
        $from_path = $php_file['tmp_name'] ?? null;

        // --- CHECKS ---
        if (!is_string($from_path))
            Json::error('Passed invalid upload structure')->die();
        if (!is_uploaded_file($from_path))
            Json::error('Trying to upload illegal or non-existent file')->die();

        // --- INITIALIZE ---
        $item = new Item();
        $item->hash = hash_file('sha256', $from_path);
        $item->extensionFromUpload($php_file);

        // --- ACTUALLY GRAB FILE ---
        $new_path = $item->getPath();
        if (file_exists($new_path))
            Json::error('File already exists')->die();
        if (!move_uploaded_file($from_path, $new_path))
            Json::error('Failed to move uploaded file')->die();

        MediaDB::add($item);

        return $item;
    }

    private function extensionFromTags()
    {
        foreach ($this->tags as $i_tag) {
            $parts = explode(':', $i_tag);
            if ($parts[0] == 'format') {
                $this->extension = $parts[1];
                return;
            }
        }

        Json::error('Detected file without file format tag')->die();
    }

    // Assumes is_uploaded_file has been done
    private function extensionFromUpload(array $php_file)
    {
        $path = $php_file['tmp_name'] ?? false;
        $name = $php_file['name'] ?? null;

        // Try to get extension from mimetype
        $ext = (new finfo(FILEINFO_EXTENSION))->file($path);

        // REVIEW: Maybe change it so it doesn't have to be separated like this but
        //         do somethign like ['mime/type', null] be equivalent to this?
        if (array_search($ext, ['webp', 'png', 'jpeg']) !== false) {
            goto success;
        }

        // If it doesn't work, try to figure it out from the original extension
        if ($ext == '???') {
            // We mustn't accept everything straight away, so we're only accepting
            // mime-type and original extension combinations that make sense
            $whitelist = [
                ['application/zip', 'kra'],
                ['application/zip', 'krz'],
            ];

            // NOTE: The original extension has to be grabbed from the original name
            $mime = mime_content_type($path);
            $ext  = pathinfo($name, PATHINFO_EXTENSION);

            if (array_search([$mime, $ext], $whitelist) !== false) {
                goto success;
            }
        }

        Json::error('File mime-type and or extension not allowed.')->die();

        success:
        $this->extension = $ext;
        $this->tags[] = 'format:' . $ext;

        return;
    }

    public function getHash(): string
    {
        return $this->hash;
    }

    public function getExtension(): string
    {
        return $this->extension;
    }

    public function getTags(): array
    {
        return $this->tags;
    }

    public function getPath(bool $absolute = false): string
    {
        return sprintf(
            '%s/%s.%s',
            $GLOBALS[$absolute ? 'path_media' : 'path_media'],
            $this->hash,
            $this->extension
        );
    }
    public function getUri(): string
    {
        // TODO: Implement relative
        return sprintf(
            '%s/%s/%s.%s',
            $GLOBALS['base_root'],
            $GLOBALS['base_media'],
            $this->hash,
            $this->extension,
        );
    }

    public function jsonSerialize(): array
    {
        return [
            'id'   => $this->hash,
            'link' => $this->getUri(),
            'tags' => $this->tags,
        ];
    }

    public function getJson(): Json
    {
        return Json::new($this);
    }
}