package lockserver

import (
	"bufio"
	"fmt"
	"net"
	"net/url"

	// "os"
	"strings"
	"time"

	log "github.com/sirupsen/logrus"
)

var (
	LockserverUrl string
)

func InitializeServerConnection() (net.Conn, error) {
	const funcName = "InitializeServerConnection"
	// Parse the URL to extract host and port
	parsedUrl, err := url.Parse(LockserverUrl)
	if err != nil {
		return nil, fmt.Errorf("[%s] failed to parse LockserverUrl: %v", funcName, err)
	}

	// Remove any leading/trailing slashes just in case
	address := strings.Trim(parsedUrl.Host, "/")

	// Establish a TCP connection to the Visionline server
	conn, err := net.Dial("tcp", address)
	if err != nil {
		return nil, fmt.Errorf("failed to connect to Visionline server: %v", err)
	}
	return conn, nil
}

func SendHeartbeatToServer(conn net.Conn) (string, error) {
	const funcName = "SendHeartbeatToServer"
	// Write the check command to the server
	heartbeat := "CCC;EAHEARTBEAT;AM1;\r\n"
	log.Printf("Sending headrbeat: %q", heartbeat)
	_, err := conn.Write([]byte(heartbeat))
	if err != nil {
		return "", fmt.Errorf("failed to send Heartbeat command: %v", err)
	}

	// set a read timeout to avoid indefinite blocking
	conn.SetReadDeadline(time.Now().Add(10 * time.Second))

	// Read the response from the server. Visionline returns the response as ASCII text terminated by CRLF.
	reader := bufio.NewReader(conn)
	response, err := reader.ReadString('\n')
	if err != nil {
		return "", fmt.Errorf("error reading response: %v", err)
	}

	substr := "RC"
	response = strings.ReplaceAll(response, "\r\n", "") // Remove CRLF from the response
	num := strings.Index(response, substr)              // Find the index of the response code
	responseCode := response[num+2 : len(response)-1]   // Extract the result code from the response
	if responseCode != "0" {
		return "", fmt.Errorf("negative Heartbeat response code: %s", responseCode)
	}

	return "Success: " + response, nil
}

func RequestEncoding(conn net.Conn, command string) (string, error) {
	const funcName = "RequestEncoding"
	// Write the command to the connection
	log.Printf("Sending Encoding request: %q", command)
	_, err := conn.Write([]byte(command))
	if err != nil {
		return "", fmt.Errorf("failed to send Encoding request: %v", err)
	}

	// Optional: set a read timeout to avoid indefinite blocking
	conn.SetReadDeadline(time.Now().Add(10 * time.Second))

	// Read the response from the server. Visionline returns the response as ASCII text terminated by CRLF.
	reader := bufio.NewReader(conn)
	response, err := reader.ReadString('\n')
	if err != nil {
		return "", fmt.Errorf("error reading response: %v", err)
	}

	substr := "RC"
	response = strings.ReplaceAll(response, "\r\n", "") // Remove CRLF from the response
	num := strings.Index(response, substr)              // Find the index of the response code
	responseCode := response[num+2 : len(response)-1]   // Extract the result code from the response
	if responseCode != "0" {
		return "", fmt.Errorf("negative lock server response code: %s", responseCode)
	}

	return "Success: " + response, nil
}