// Copyright 2024 Redpanda Data, Inc.
//
// Licensed as a Redpanda Enterprise file under the Redpanda Community
// License (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// https://github.com/redpanda-data/connect/v4/blob/main/licenses/rcl.md

package pglogicalstream

import (
	"database/sql"
	"fmt"
	"regexp"
	"strconv"
)

var re = regexp.MustCompile(`^(\d+)`)

func openPgConnectionFromConfig(dbDSN string) (*sql.DB, error) {
	return sql.Open("postgres", dbDSN)
}

func getPostgresVersion(dbDSN string) (int, error) {
	conn, err := openPgConnectionFromConfig(dbDSN)
	if err != nil {
		return 0, fmt.Errorf("failed to connect to the database: %w", err)
	}
	defer conn.Close()

	var versionString string
	err = conn.QueryRow("SHOW server_version").Scan(&versionString)
	if err != nil {
		return 0, fmt.Errorf("failed to execute query: %w", err)
	}

	match := re.FindStringSubmatch(versionString)
	if len(match) < 2 {
		return 0, fmt.Errorf("failed to parse version string: %s", versionString)
	}

	majorVersion, err := strconv.Atoi(match[1])
	if err != nil {
		return 0, fmt.Errorf("failed to convert version to integer: %w", err)
	}

	return majorVersion, nil
}