Database.php

<?php

namespace FpDbTest;

use Exception;
use mysqli;

class Database implements DatabaseInterface
{
    private const string SKIP_VALUE = '__SKIP__';
    private mysqli $mysqli;

    public function __construct(mysqli $mysqli)
    {
        $this->mysqli = $mysqli;
    }
    public function buildQuery(string $query, array $args = []): string
    {
        $index = 0;
        $pattern = '/
                \{[^{}]*}   # Условные блоки: {*******}
                |           # ИЛИ
                \?          # Вопрос
                (?:         
                    \#      # Решетка
                    |       # ИЛИ
                    \w      # буква-цифра
                )?          
            /x';

        return preg_replace_callback($pattern, function (array $match) use (&$index, $args): string {
            if ($match[0][0] === '{') {
                return $this->processConditionalBlock(substr($match[0], 1, -1), $args, $index);
            }
            $value = $args[$index++];
            return $this->formatValue($value, $match[0]);
        }, $query);
    }

    public function skip(): string
    {
        return self::SKIP_VALUE;
    }

    private function processConditionalBlock(string $block, array $args, int &$index): string
    {
        $originalIndex = $index;
        $skipBlock = false;
        $pattern = '/
                \?          # Вопрос
                (?:         # 
                    \#      # Решетка 
                    |       # ИЛИ
                    \w      # буква-цифра
                )?
            /x';
        $processedBlock = preg_replace_callback($pattern, function (array $match) use (&$index, $args, &$skipBlock): string {
            $value = $args[$index++];
            if ($value === self::SKIP_VALUE) {
                $skipBlock = true;
                return '';
            }
            return $this->formatValue($value, $match[0]);
        }, $block);

        if ($skipBlock) {
            $index = $originalIndex;
            return '';
        }
        return $processedBlock;
    }

    private function formatValue(mixed $value, string $specifier): string
    {
        return match ($specifier) {
            '?' => $this->format($value),
            '?d' => $this->formatInteger($value),
            '?f' => $this->formatFloat($value),
            '?a' => $this->formatArray($value),
            '?#' => $this->formatIdentifier($value),
            default => throw new Exception("Unknown specifier: $specifier"),
        };
    }

    private function format(mixed $value): string
    {
        return match (true) {
            is_null($value) => 'NULL',
            is_bool($value) => $value ? '1' : '0',
            is_int($value) => (string)$value,
            is_float($value) => sprintf('%F', $value),
            is_string($value) => "'" . $this->escape($value) . "'",
            default => throw new Exception("Unsupported type"),
        };
    }

    private function formatInteger(mixed $value): string
    {
        if (is_null($value)) return 'NULL';
        if (is_bool($value)) return $value ? '1' : '0';
        return (string)intval($value);
    }

    private function formatFloat(mixed $value): string
    {
        if (is_null($value)) return 'NULL';
        return sprintf('%F', $value);
    }

    private function formatArray(mixed $value): string
    {
        if (empty($value)) return '';

        $formattedValues = [];
        if (array_is_list($value)) {
            foreach ($value as $v) {
                $formattedValues[] = is_int($v) ? (string)$v : $this->format($v);
            }
        } else {
            foreach ($value as $k => $v) {
                $formattedKey = $this->formatIdentifier($k);
                $formattedValue = $this->format($v);
                $formattedValues[] = "$formattedKey = $formattedValue";
            }
        }

        return implode(', ', $formattedValues);
    }

    private function formatIdentifier(mixed $value): string
    {
        if (is_array($value)) {
            $formattedValues = [];
            foreach ($value as $v) {
                $formattedValues[] = $this->formatIdentifier($v);
            }
            return implode(', ', $formattedValues);
        }
        return '`' . str_replace('`', '``', $value) . '`';
    }

    private function escape(string $value): string
    {
        return $this->mysqli->real_escape_string($value);
    }
}