<?php

class MysqliDb
{
    /** @var mysqli */
    private $conn;

    public function __construct(array $config)
    {
        $host = $config['host'] ?? '127.0.0.1';
        $user = $config['username'] ?? 'root';
        $pass = $config['password'] ?? '';
        $db = $config['db'] ?? '';
        $port = $config['port'] ?? null;
        $socket = $config['socket'] ?? null;
        $charset = $config['charset'] ?? 'utf8mb4';

        $this->conn = @new mysqli($host, $user, $pass, $db, $port ?? ini_get("mysqli.default_port"), $socket);
        if ($this->conn->connect_errno) {
            throw new Exception('MySQL connection error: ' . $this->conn->connect_error);
        }
        $this->conn->set_charset($charset);
    }

    /**
     * @return array|bool
     */
    public function rawQuery(string $sql, array $params = [])
    {
        if (empty($params)) {
            $result = $this->conn->query($sql);
            if ($result === false) {
                throw new Exception('Query error: ' . $this->conn->error);
            }
            if ($result === true) {
                return true;
            }
            $data = $result->fetch_all(MYSQLI_ASSOC);
            $result->free();
            return $data;
        }

        $stmt = $this->prepareAndBind($sql, $params);
        if (!$stmt->execute()) {
            throw new Exception('Query error: ' . $stmt->error);
        }
        $res = $stmt->get_result();
        $rows = $res ? $res->fetch_all(MYSQLI_ASSOC) : [];
        $stmt->close();
        return $rows;
    }

    /**
     * @return array|bool
     */
    public function query(string $sql, array $params = [])
    {
        return $this->rawQuery($sql, $params);
    }

    /**
     * @return array|null
     */
    public function getOne(string $sql, array $params = [])
    {
        $rows = $this->rawQuery($sql, $params);
        return $rows[0] ?? null;
    }

    public function getValue(string $sql, array $params = [])
    {
        $row = $this->getOne($sql, $params);
        if (!$row) {
            return null;
        }
        return array_shift($row);
    }

    public function insert(string $table, array $data): int
    {
        $cols = array_keys($data);
        $placeholders = implode(',', array_fill(0, count($cols), '?'));
        $colList = '`' . implode('`,`', $cols) . '`';
        $sql = "INSERT INTO `$table` ($colList) VALUES ($placeholders)";
        $stmt = $this->prepareAndBind($sql, array_values($data));
        if (!$stmt->execute()) {
            throw new Exception('Insert error: ' . $stmt->error);
        }
        $id = $stmt->insert_id ?: $this->conn->insert_id;
        $stmt->close();
        return (int) $id;
    }

    public function deleteById(string $table, int $id): bool
    {
        $stmt = $this->prepareAndBind("DELETE FROM `$table` WHERE id = ?", [$id]);
        $ok = $stmt->execute();
        $stmt->close();
        return $ok;
    }

    public function update(string $table, array $data, string $where, array $params = []): bool
    {
        $sets = [];
        $values = [];
        foreach ($data as $col => $val) {
            $sets[] = "`$col` = ?";
            $values[] = $val;
        }
        $sql = "UPDATE `$table` SET " . implode(',', $sets) . " WHERE $where";
        $bind = array_merge($values, $params);
        $stmt = $this->prepareAndBind($sql, $bind);
        $ok = $stmt->execute();
        $stmt->close();
        return $ok;
    }

    private function prepareAndBind(string $sql, array $params): mysqli_stmt
    {
        $stmt = $this->conn->prepare($sql);
        if (!$stmt) {
            throw new Exception('Prepare failed: ' . $this->conn->error);
        }
        if (!empty($params)) {
            $types = '';
            $refs = [];
            foreach ($params as $param) {
                $types .= is_int($param) ? 'i' : (is_float($param) ? 'd' : 's');
            }
            $refs[] = &$types;
            foreach ($params as $k => $v) {
                $refs[] = &$params[$k];
            }
            $stmt->bind_param(...$refs);
        }
        return $stmt;
    }
}