<?php

namespace Doctrine\Common\Cache;

use SQLite3;
use SQLite3Result;
use const SQLITE3_ASSOC;
use const SQLITE3_BLOB;
use const SQLITE3_TEXT;
use function array_search;
use function implode;
use function serialize;
use function sprintf;
use function time;
use function unserialize;
/**
 * SQLite3 cache provider.
 */
class SQLite3Cache extends \Doctrine\Common\Cache\CacheProvider
{
    /**
     * The ID field will store the cache key.
     */
    public const ID_FIELD = 'k';
    /**
     * The data field will store the serialized PHP value.
     */
    public const DATA_FIELD = 'd';
    /**
     * The expiration field will store a date value indicating when the
     * cache entry should expire.
     */
    public const EXPIRATION_FIELD = 'e';
    /** @var SQLite3 */
    private $sqlite;
    /** @var string */
    private $table;
    /**
     * Calling the constructor will ensure that the database file and table
     * exist and will create both if they don't.
     *
     * @param string $table
     */
    public function __construct(SQLite3 $sqlite, $table)
    {
        $this->sqlite = $sqlite;
        $this->table = (string) $table;
        $this->ensureTableExists();
    }
    private function ensureTableExists() : void
    {
        $this->sqlite->exec(sprintf('CREATE TABLE IF NOT EXISTS %s(%s TEXT PRIMARY KEY NOT NULL, %s BLOB, %s INTEGER)', $this->table, static::ID_FIELD, static::DATA_FIELD, static::EXPIRATION_FIELD));
    }
    /**
     * {@inheritdoc}
     */
    protected function doFetch($id)
    {
        $item = $this->findById($id);
        if (!$item) {
            return \false;
        }
        return unserialize($item[self::DATA_FIELD]);
    }
    /**
     * {@inheritdoc}
     */
    protected function doContains($id)
    {
        return $this->findById($id, \false) !== null;
    }
    /**
     * {@inheritdoc}
     */
    protected function doSave($id, $data, $lifeTime = 0)
    {
        $statement = $this->sqlite->prepare(sprintf('INSERT OR REPLACE INTO %s (%s) VALUES (:id, :data, :expire)', $this->table, implode(',', $this->getFields())));
        $statement->bindValue(':id', $id);
        $statement->bindValue(':data', serialize($data), SQLITE3_BLOB);
        $statement->bindValue(':expire', $lifeTime > 0 ? time() + $lifeTime : null);
        return $statement->execute() instanceof SQLite3Result;
    }
    /**
     * {@inheritdoc}
     */
    protected function doDelete($id)
    {
        [$idField] = $this->getFields();
        $statement = $this->sqlite->prepare(sprintf('DELETE FROM %s WHERE %s = :id', $this->table, $idField));
        $statement->bindValue(':id', $id);
        return $statement->execute() instanceof SQLite3Result;
    }
    /**
     * {@inheritdoc}
     */
    protected function doFlush()
    {
        return $this->sqlite->exec(sprintf('DELETE FROM %s', $this->table));
    }
    /**
     * {@inheritdoc}
     */
    protected function doGetStats()
    {
        // no-op.
    }
    /**
     * Find a single row by ID.
     *
     * @param mixed $id
     *
     * @return array|null
     */
    private function findById($id, bool $includeData = \true) : ?array
    {
        [$idField] = $fields = $this->getFields();
        if (!$includeData) {
            $key = array_search(static::DATA_FIELD, $fields);
            unset($fields[$key]);
        }
        $statement = $this->sqlite->prepare(sprintf('SELECT %s FROM %s WHERE %s = :id LIMIT 1', implode(',', $fields), $this->table, $idField));
        $statement->bindValue(':id', $id, SQLITE3_TEXT);
        $item = $statement->execute()->fetchArray(SQLITE3_ASSOC);
        if ($item === \false) {
            return null;
        }
        if ($this->isExpired($item)) {
            $this->doDelete($id);
            return null;
        }
        return $item;
    }
    /**
     * Gets an array of the fields in our table.
     *
     * @return array
     */
    private function getFields() : array
    {
        return [static::ID_FIELD, static::DATA_FIELD, static::EXPIRATION_FIELD];
    }
    /**
     * Check if the item is expired.
     *
     * @param array $item
     */
    private function isExpired(array $item) : bool
    {
        return isset($item[static::EXPIRATION_FIELD]) && $item[self::EXPIRATION_FIELD] !== null && $item[self::EXPIRATION_FIELD] < time();
    }
}
