package lockserver

import (
	"fmt"
	"net"
	"time"
	"strings"
	
	log "github.com/sirupsen/logrus"
)

// Build key encoding request command for the Assa Abloy lock server.
func (lock *AssaLockServer) BuildCommand(doorReq DoorCardRequest, checkIn, checkOut time.Time) error {
	ci := checkIn.Format("200601021504")
	co := checkOut.Format("200601021504")

	lock.command = fmt.Sprintf("CCA;EA%s;GR%s;CO%s;CI%s;AM1;\r\n", lock.encoderAddr, doorReq.RoomField, co, ci)
	return nil
}

// Checks heart beat of the Assa Abloy lock server and perform key encoding
func (lock *AssaLockServer) LockSequence(conn net.Conn) error {
	const funcName = "AssaLockServer.LockSequence"
	resp, err := sendHeartbeatToServer(conn)
	if err != nil {
		return fmt.Errorf("[%s] heartbeat failed: %v", funcName, err)
	}
	log.Infof("Heartbeat response: %s", resp)

	resp, err = requestEncoding(conn, lock.command)
	if err != nil {
		return fmt.Errorf("[%s] request encoding failed: %v", funcName, err)
	}
	log.Infof("Encoding response: %s", resp)
	return nil
}

func sendHeartbeatToServer(conn net.Conn) (string, error) {
	const heartbeatRegister = "CCC;EAHEARTBEAT;AM1;\r\n"

	raw, err := sendAndReceive(conn, []byte(heartbeatRegister))
	if err != nil {
		return "", fmt.Errorf("failed to send Heartbeat command: %v", err)
	}

	return parseAssaResponse(raw)
}

func requestEncoding(conn net.Conn, command string) (string, error) {
	raw, err := sendAndReceive(conn, []byte(command))
	if err != nil {
		return "", fmt.Errorf("failed to send Encoding request: %v", err)
	}

	return parseAssaResponse(raw)
}

func parseAssaResponse(raw string) (string, error) {
	clean := strings.ReplaceAll(raw, "\r\n", "")
	idx := strings.Index(clean, "RC")
	code := clean[idx+2 : idx+3] // Extract the response code
	if code != "0" {
		return "", fmt.Errorf("negative response code: %s", clean)
	}
	return "Success: " + clean, nil
}