package commands

import (
	"fmt"
	"os"

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

func ResolvePort(host string) string {

	if len(host) > 0 {
		hasPort := false
		for i := len(host) - 1; i >= 0; i-- {
			if host[i] == ':' {
				hasPort = true
				break
			}
			if host[i] == ']' {
				break
			}
		}
		if !hasPort {
			host = host + ":22"
		}
	}

	return host

}

func GetSigner(private_key_file string) ssh.Signer {

	key_bytes, err := os.ReadFile(private_key_file)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error reading private key: %v\n", err)
		os.Exit(1)
	}

	signer, err := ssh.ParsePrivateKey(key_bytes)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error parsing private key: %v\n", err)
		os.Exit(1)
	}

	return signer

}

func GetClient(private_key_file, username, host string) *ssh.Client {

	signer := GetSigner(private_key_file)

	config := &ssh.ClientConfig{
		User: username,
		Auth: []ssh.AuthMethod{
			ssh.PublicKeys(signer),
		},
		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
	}

	addr := ResolvePort(host)

	client, err := ssh.Dial("tcp", addr, config)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error connecting to server: %v\n", err)
		os.Exit(1)
	}

	return client
}

type RunCommandArgs struct {
	Command string `json:"command"`
	RemoteCommand string `json:"remote_command"`
	PrivateKeyFile string `json:"private_key_file"`
	Username string `json:"username"`
	Host string `json:"host"`
}

func (rca *RunCommandArgs) ReadArgs() {

	if len(os.Args) != 6 {
		fmt.Fprintf(os.Stderr, "Usage: %s run_command <remote-command> <private-key> <username> <host>\n", os.Args[0])
		os.Exit(1)
	}

	rca.Command = os.Args[1]
	rca.RemoteCommand = os.Args[2]
	rca.PrivateKeyFile = os.Args[3]
	rca.Username = os.Args[4]
	rca.Host = os.Args[5]

}

func RunCommand() {

	args := RunCommandArgs{} 
	args.ReadArgs()

	client := GetClient(args.PrivateKeyFile, args.Username, args.Host)
	defer client.Close()

	session, err := client.NewSession()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error creating SSH session: %v\n", err)
		os.Exit(1)
	}
	defer session.Close()

	session.Stdout = os.Stdout
	session.Stderr = os.Stderr
	if err := session.Run(args.RemoteCommand); err != nil {
		fmt.Fprintf(os.Stderr, "Error running command: %v\n", err)
		os.Exit(1)
	}
	return

}