<?php
declare(strict_types=1);

/**
 * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 * @link          https://cakephp.org CakePHP(tm) Project
 * @since         3.0.0
 * @license       https://opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Database\Driver;

use Cake\Database\Driver;
use Cake\Database\DriverFeatureEnum;
use Cake\Database\Expression\FunctionExpression;
use Cake\Database\Expression\TupleComparison;
use Cake\Database\Schema\SchemaDialect;
use Cake\Database\Schema\SqliteSchemaDialect;
use Cake\Database\Statement\SqliteStatement;
use InvalidArgumentException;
use PDO;

/**
 * Class Sqlite
 */
class Sqlite extends Driver
{
    use TupleComparisonTranslatorTrait;

    /**
     * @inheritDoc
     */
    protected const STATEMENT_CLASS = SqliteStatement::class;

    /**
     * Base configuration settings for Sqlite driver
     *
     * - `mask` The mask used for created database
     *
     * @var array<string, mixed>
     */
    protected array $_baseConfig = [
        'persistent' => false,
        'username' => null,
        'password' => null,
        'database' => ':memory:',
        'encoding' => 'utf8',
        'mask' => 0644,
        'cache' => null,
        'mode' => null,
        'flags' => [],
        'init' => [],
    ];

    /**
     * Whether the connected server supports window functions.
     *
     * @var bool|null
     */
    protected ?bool $_supportsWindowFunctions = null;

    /**
     * String used to start a database identifier quoting to make it safe
     *
     * @var string
     */
    protected string $_startQuote = '"';

    /**
     * String used to end a database identifier quoting to make it safe
     *
     * @var string
     */
    protected string $_endQuote = '"';

    /**
     * Mapping of date parts.
     *
     * @var array<string, string>
     */
    protected array $_dateParts = [
        'day' => 'd',
        'hour' => 'H',
        'month' => 'm',
        'minute' => 'M',
        'second' => 'S',
        'week' => 'W',
        'year' => 'Y',
    ];

    /**
     * Mapping of feature to db server version for feature availability checks.
     *
     * @var array<string, string>
     */
    protected array $featureVersions = [
        'cte' => '3.8.3',
        'window' => '3.28.0',
    ];

    /**
     * @inheritDoc
     */
    public function connect(): void
    {
        if ($this->pdo !== null) {
            return;
        }
        $config = $this->_config;
        $config['flags'] += [
            PDO::ATTR_PERSISTENT => $config['persistent'],
            PDO::ATTR_EMULATE_PREPARES => false,
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
        ];
        if (!is_string($config['database']) || $config['database'] === '') {
            $name = $config['name'] ?? 'unknown';
            throw new InvalidArgumentException(
                "The `database` key for the `{$name}` SQLite connection needs to be a non-empty string.",
            );
        }

        $chmodFile = false;
        if ($config['database'] !== ':memory:' && $config['mode'] !== 'memory') {
            $chmodFile = !file_exists($config['database']);
        }

        $params = [];
        if ($config['cache']) {
            $params[] = 'cache=' . $config['cache'];
        }
        if ($config['mode']) {
            $params[] = 'mode=' . $config['mode'];
        }

        if ($params) {
            $dsn = 'sqlite:file:' . $config['database'] . '?' . implode('&', $params);
        } else {
            $dsn = 'sqlite:' . $config['database'];
        }

        $this->pdo = $this->createPdo($dsn, $config);
        if ($chmodFile) {
            // phpcs:disable
            @chmod($config['database'], $config['mask']);
            // phpcs:enable
        }

        if (!empty($config['init'])) {
            foreach ((array)$config['init'] as $command) {
                $this->pdo->exec($command);
            }
        }
    }

    /**
     * Returns whether php is able to use this driver for connecting to database
     *
     * @return bool true if it is valid to use this driver
     */
    public function enabled(): bool
    {
        return in_array('sqlite', PDO::getAvailableDrivers(), true);
    }

    /**
     * Get the SQL for disabling foreign keys.
     *
     * @return string
     */
    public function disableForeignKeySQL(): string
    {
        return 'PRAGMA foreign_keys = OFF';
    }

    /**
     * @inheritDoc
     */
    public function enableForeignKeySQL(): string
    {
        return 'PRAGMA foreign_keys = ON';
    }

    /**
     * @inheritDoc
     */
    public function supports(DriverFeatureEnum $feature): bool
    {
        return match ($feature) {
            DriverFeatureEnum::DISABLE_CONSTRAINT_WITHOUT_TRANSACTION,
            DriverFeatureEnum::SAVEPOINT,
            DriverFeatureEnum::TRUNCATE_WITH_CONSTRAINTS => true,

            DriverFeatureEnum::JSON => false,

            DriverFeatureEnum::CTE,
            DriverFeatureEnum::WINDOW => version_compare(
                $this->version(),
                $this->featureVersions[$feature->value],
                '>=',
            ),
            DriverFeatureEnum::INTERSECT => true,
            DriverFeatureEnum::INTERSECT_ALL => false,
            DriverFeatureEnum::SET_OPERATIONS_ORDER_BY => false,
            DriverFeatureEnum::OPTIMIZER_HINT_COMMENT => false,
            DriverFeatureEnum::CHECK_CONSTRAINTS => true,
        };
    }

    /**
     * @inheritDoc
     */
    public function schemaDialect(): SchemaDialect
    {
        return $this->_schemaDialect ?? ($this->_schemaDialect = new SqliteSchemaDialect($this));
    }

    /**
     * @inheritDoc
     */
    protected function _expressionTranslators(): array
    {
        return [
            FunctionExpression::class => '_transformFunctionExpression',
            TupleComparison::class => '_transformTupleComparison',
        ];
    }

    /**
     * Receives a FunctionExpression and changes it so that it conforms to this
     * SQL dialect.
     *
     * @param \Cake\Database\Expression\FunctionExpression $expression The function expression to convert to TSQL.
     * @return void
     */
    protected function _transformFunctionExpression(FunctionExpression $expression): void
    {
        switch ($expression->getName()) {
            case 'CONCAT':
                // CONCAT function is expressed as exp1 || exp2
                $expression->setName('')->setConjunction(' ||');
                break;
            case 'DATEDIFF':
                $expression
                    ->setName('ROUND')
                    ->setConjunction('-')
                    ->iterateParts(function ($p) {
                        return new FunctionExpression('JULIANDAY', [$p['value']], [$p['type']]);
                    });
                break;
            case 'NOW':
                $expression->setName('DATETIME')->add(["'now'" => 'literal']);
                break;
            case 'RAND':
                $expression
                    ->setName('ABS')
                    ->add(['RANDOM() % 1' => 'literal'], [], true);
                break;
            case 'CURRENT_DATE':
                $expression->setName('DATE')->add(["'now'" => 'literal']);
                break;
            case 'CURRENT_TIME':
                $expression->setName('TIME')->add(["'now'" => 'literal']);
                break;
            case 'EXTRACT':
                $expression
                    ->setName('STRFTIME')
                    ->setConjunction(' ,')
                    ->iterateParts(function ($p, $key) {
                        if ($key === 0) {
                            $value = rtrim(strtolower($p), 's');
                            if (isset($this->_dateParts[$value])) {
                                $p = ['value' => '%' . $this->_dateParts[$value], 'type' => null];
                            }
                        }

                        return $p;
                    });
                break;
            case 'DATE_ADD':
                $expression
                    ->setName('DATE')
                    ->setConjunction(',')
                    ->iterateParts(function ($p, $key) {
                        if ($key === 1) {
                            return ['value' => $p, 'type' => null];
                        }

                        return $p;
                    });
                break;
            case 'DAYOFWEEK':
                $expression
                    ->setName('STRFTIME')
                    ->setConjunction(' ')
                    ->add(["'%w', " => 'literal'], [], true)
                    ->add([') + (1' => 'literal']); // Sqlite starts on index 0 but Sunday should be 1
                break;
            case 'JSON_VALUE':
                $expression->setName('JSON_EXTRACT');
                break;
        }
    }
}