<?php
// MariaDBStatement.php
// Created: 2021-05-02
// Updated: 2023-01-01

namespace Index\Data\MariaDB;

use mysqli_stmt;
use InvalidArgumentException;
use RuntimeException;
use Index\Data\DbType;
use Index\Data\QueryExecuteException;
use Index\Data\IDbStatement;
use Index\IO\Stream;

/**
 * Represents a MariaDB/MySQL prepared statement.
 */
class MariaDBStatement implements IDbStatement {
    private mysqli_stmt $statement;
    private array $params = [];

    /**
     * Creates a MariaDBStatement.
     *
     * @param mysqli_stmt $statement Underlying statement object.
     * @return MariaDBStatement A new statement instance.
     */
    public function __construct(mysqli_stmt $statement) {
        $this->statement = $statement;
    }

    private static bool $constructed = false;
    private static string $resultImplementation;

    /**
     * Determines which MariaDBResult implementation should be used.
     *
     * @internal
     */
    public static function construct(): void {
        if(self::$constructed !== false)
            throw new RuntimeException('Static constructor was already called.');
        self::$constructed = true;
        self::$resultImplementation = function_exists('mysqli_stmt_get_result')
            ? MariaDBResultNative::class
            : MariaDBResultLib::class;
    }

    public function getParameterCount(): int {
        return $this->statement->param_count;
    }

    public function addParameter(int $ordinal, mixed $value, int $type = DbType::AUTO): void {
        if($ordinal < 1 || $ordinal > $this->getParameterCount())
            throw new InvalidArgumentException('$ordinal is not a valid parameter number.');
        $this->params[$ordinal - 1] = new MariaDBParameter($ordinal, $type, $value);
    }

    /**
     * Gets the last error code.
     *
     * @return int Last error code.
     */
    public function getLastErrorCode(): int {
        return $this->statement->errno;
    }

    /**
     * Gets the last error string.
     *
     * @return string Last error string.
     */
    public function getLastErrorString(): string {
        return $this->statement->error;
    }

    /**
     * Gets the current SQL State of this statement.
     *
     * @return string Current SQL State.
     */
    public function getSQLState(): string {
        return $this->statement->sqlstate;
    }

    /**
     * Gets a list of errors from the last command.
     *
     * @return array List of last errors.
     */
    public function getLastErrors(): array {
        return MariaDBWarning::fromLastErrors($this->statement->error_list);
    }

    /**
     * Gets list of warnings.
     *
     * The result of SHOW WARNINGS;
     *
     * @return array List of warnings.
     */
    public function getWarnings(): array {
        return MariaDBWarning::fromGetWarnings($this->statement->get_warnings());
    }

    public function getResult(): MariaDBResult {
        return new self::$resultImplementation($this->statement);
    }

    public function getLastInsertId(): int|string {
        return $this->statement->insert_id;
    }

    public function execute(): void {
        $args = [''];

        foreach($this->params as $key => $param) {
            $args[0] .= $param->getBindType();
            $type = $param->getDbType();
            $value = $param->getValue();

            if($type === DbType::NULL)
                $value = null;
            elseif($type === DbType::BLOB) {
                if($value instanceof Stream) {
                    while(($data = $value->read(8192)) !== null)
                        $this->statement->send_long_data($key, $data);
                } elseif(is_resource($value)) {
                    while($data = fread($value, 8192))
                        $this->statement->send_long_data($key, $data);
                } else
                    $this->statement->send_long_data($key, (string)$value);

                $value = null;
            }


            ${"value{$key}"} = $value;
            $args[] = &${"value{$key}"};
        }

        if(!empty($args[0]))
            call_user_func_array([$this->statement, 'bind_param'], $args);

        if(!$this->statement->execute())
            throw new QueryExecuteException($this->getLastErrorString(), $this->getLastErrorCode());
    }

    public function reset(): void {
        $this->params = [];
        if(!$this->statement->reset())
            throw new QueryExecuteException($this->getLastErrorString(), $this->getLastErrorCode());
    }

    public function close(): void {
        $this->statement->close();
    }

    public function __destruct() {
        $this->close();
    }
}

MariaDBStatement::construct();