package ssh

import (
	"fmt"
	"io/ioutil"
	"log"

	"golang.org/x/crypto/ssh"
)

type SSHConfig struct {
	User       string
	Host       string
	Port       string
	Password   string
	PrivateKey string
}

// ConnectSSH handles both key-based and password authentication dynamically.
func ConnectSSH(config SSHConfig) error {
	log.Printf("Attempting SSH connection to %s@%s:%s", config.User, config.Host, config.Port)

	// Build SSH authentication methods
	var authMethods []ssh.AuthMethod

	// Add key-based authentication if a private key is provided
	if config.PrivateKey != "" {
		log.Println("Attempting key-based authentication...")
		key, err := ioutil.ReadFile(config.PrivateKey)
		if err != nil {
			log.Printf("Error reading private key: %v", err)
			return fmt.Errorf("failed to read private key: %w", err)
		}

		signer, err := ssh.ParsePrivateKey(key)
		if err != nil {
			log.Printf("Error parsing private key: %v", err)
			return fmt.Errorf("failed to parse private key: %w", err)
		}

		authMethods = append(authMethods, ssh.PublicKeys(signer))
	}

	// Add password-based authentication if a password is provided
	if config.Password != "" {
		log.Println("Attempting password-based authentication...")
		authMethods = append(authMethods, ssh.Password(config.Password))
	}

	// Ensure at least one authentication method is configured
	if len(authMethods) == 0 {
		return fmt.Errorf("no authentication method provided (password or private key)")
	}

	// Configure SSH client
	clientConfig := &ssh.ClientConfig{
		User:            config.User,
		Auth:            authMethods,
		HostKeyCallback: ssh.InsecureIgnoreHostKey(), // Use a proper host key callback for production!
	}

	// Dial the SSH server
	address := fmt.Sprintf("%s:%s", config.Host, config.Port)
	log.Printf("Connecting to SSH server at %s...", address)

	client, err := ssh.Dial("tcp", address, clientConfig)
	if err != nil {
		log.Printf("Failed to connect to SSH server: %v", err)
		return fmt.Errorf("failed to connect to SSH server: %w", err)
	}
	defer client.Close()

	log.Printf("Successfully connected to %s@%s:%s", config.User, config.Host, config.Port)
	return nil
}