const serialResultsDiv = document.getElementById("serialResults");

// Buffer for accumulating received data before logging
let receivedDataBuffer = '';

// Function to log communication to API
async function logCommunication(data, direction) {
    // Only log if debug mode is enabled
    if (typeof DEBUG === 'undefined' || !DEBUG) {
        return;
    }
    
    // Log all communication including connection/disconnection events
    try {
        // Get service token for API authentication
        const serviceToken = document.getElementById("servicetoken")?.innerHTML || '';

        // Get serial number if available
        let serialNumber = '';
        if (typeof serial !== 'undefined' && serial) {
            serialNumber = serial;
        }

        const logData = {
            data: data,
            direction: direction, // 'sent', 'received', 'connected', 'disconnected', 'handshake'
            timestamp: new Date().toISOString(),
            serial_number: serialNumber,
            maintenance_run: 0 // Not used in scripts.js, set to 0
        };

        // Get base URL for API calls (assuming 'link' variable is defined globally)
        const url = link + '/v2/com_log/log';

        const bearer = 'Bearer ' + serviceToken;

        const response = await fetch(url, {
            method: 'POST',
            withCredentials: true,
            credentials: 'include',
            headers: {
                'Authorization': bearer,
                'Content-Type': 'application/json'
            },
            body: JSON.stringify(logData)
        });

        if (!response.ok) {
            console.warn('Failed to log communication:', response.status);
        }
    } catch (error) {
        console.warn('Error logging communication:', error);
    }
}

function progressBar(percentage, message, color){
    var readbar = document.getElementById("readBar");
    readBar.style.background = color;
    readBar.style.width = percentage +"%";
    readBar.innerHTML = message;
}

async function connectDevice() {

        //clear input
        readBar.innerHTML = '';
        serialResultsDiv.innerHTML = '';
        // Reset received data buffer for new connection
        receivedDataBuffer = '';

        //set prgress bar
        progressBar("1", "", "");

    try {
        // Prompt user to select any serial port.
        const filters = [{ usbVendorId: 1027, usbProductId: 24597 }];
        port = await navigator.serial.requestPort({ filters });
        
        // Log selected port details
        const portInfo = port.getInfo();
        const portDetails = {
            processStep: 'Firmware',
            usbVendorId: portInfo.usbVendorId,
            usbProductId: portInfo.usbProductId,
            readable: !!port.readable,
            writable: !!port.writable,
            opened: port.readable !== null && port.writable !== null
        };
        await logCommunication(`Selected USB device - ${JSON.stringify(portDetails)}`, 'connected');
        
        await port.open({ 
            baudRate: 56700,
            dataBits: 8,
            stopBits: 1,
            parity: 'none',
            flowControl: 'none'
        });
        progressBar("10", "Connecting", "#04AA6D");

        // Log successful connection with details
        const portInfoSuccess = port.getInfo();
        const portDetailsSuccess = {
            processStep: 'Firmware',
            usbVendorId: portInfoSuccess.usbVendorId,
            usbProductId: portInfoSuccess.usbProductId,
            readable: !!port.readable,
            writable: !!port.writable,
            opened: port.readable !== null && port.writable !== null
        };
        await logCommunication(`Serial port opened successfully (baudRate: 56700) - ${JSON.stringify(portDetailsSuccess)}`, 'connected');

        listenToPort();

        textEncoder = new TextEncoderStream();
        writableStreamClosed = textEncoder.readable.pipeTo(port.writable);

        writer = textEncoder.writable.getWriter();
    } catch (error) {
        // Log connection failure details
        await logCommunication(`Serial connection failed: ${error.message || 'Unknown error'}`, 'disconnected');
        
        // Check for specific "No port selected" error and show user-friendly message
        if (error.message && error.message.includes('No port selected by the user')) {
            progressBar("100", "No device selected, please try again", "#ff6666");
        } else if (openPort = 1){
          closePort();
          console.log("Closing port");
          alert("System is still trying to close the serial port. If this message continues to come up please refresh this page.");
        }
        else{
          alert("Your browser does not support this functionality. Please use latest Chrome or Edge browser.");
          }
      }
}

async function listenToPort() {
    const textDecoder = new TextDecoderStream();
    readableStreamClosed = port.readable.pipeTo(textDecoder.writable);
    reader = textDecoder.readable.getReader();
    openPort = 1;

    // Log starting to listen to port
    await logCommunication('Starting to listen to serial port', 'connected');

    while (true) {
        const { value, done } = await reader.read();
        if (done) {
            reader.releaseLock();
            break;
        }
        progressBar("40", "Reading", "#04AA6D");

        appendToTerminal(value);

        var item = serialResultsDiv.innerHTML;
        x = Array.from(new Set(item.split(";"))).toString();
        if (x.indexOf("SN=") > 0 && x.indexOf("HW=") > 0 && x.indexOf("FW=") >0 && x.indexOf("STATE=") > 0)
        {
          progressBar("60", "Reading device completed", "#04AA6D");
          // Log combined received data when device identification is complete
          await logCommunication(`Device identification data received: ${receivedDataBuffer.trim()}`, 'handshake');
          // Reset buffer for next connection
          receivedDataBuffer = '';
          setTimeout(getDeviceData, 4000);
          return;
        }
    }

}

async function appendToTerminal(newStuff) {
    serialResultsDiv.innerHTML += newStuff;

    // Log received data
    await logCommunication(newStuff.trim(), 'received');
}

async function getServiceID(){
    var data = document.getElementById("servicetoken").innerHTML;
    return data
}

async function getDeviceData(){
  var item = serialResultsDiv.innerHTML;
  x = Array.from(new Set(item.split(";"))).toString();

  //Check if Serialnumber is retrieved from device
  if (x.indexOf("SN=") > 0){
    var a = x.indexOf("SN=");
    var b = a + 3;
    var c = b + 8;
    serial = x.substring(b,c);
    progressBar("65", "Retrieving device data", "#04AA6D");
    console.log(serial);
    // Log serial number retrieval
    await logCommunication(`Serial number retrieved: ${serial}`, 'handshake');
  
    if (x.indexOf("FW=") > 0){
      var a = x.indexOf("FW=");
      var b = a + 3;
      var c = b + 8;
      fw = x.substring(b,c);
      fw = fw.replace(/^0+/, '');
      // Log firmware version
      await logCommunication(`Firmware version retrieved: ${fw}`, 'handshake');
    }

    //Check if HW is retrieved from device
    if (x.indexOf("HW=") > 0 && x.indexOf("FW=") >0){
      var a = x.indexOf("HW=");
      var b = a + 3;
      var c = b + 8;
      var d = x.substring(b,c);
      var e = d.slice(-1);

      if (e.toLowerCase() !== e.toUpperCase()){
        var f = d.slice(d.length - 3)
        hw = 'R'+f;
        sw = 'R'+f;
      }
        else {
        var f = d.slice(d.length - 2)
        hw = 'R'+f;
        sw = 'R'+f;
      }

    //GET THE COMMITCODE
    commitCode = compareCommitCodes("",fw);
    // Log hardware version and commit code
    await logCommunication(`Hardware version retrieved: ${hw}, Commit code: ${commitCode}`, 'handshake');
        
    getServiceID().then(firmwareUpdate);
    progressBar("80", "checking for available firmware", "#04AA6D");
    setTimeout(checkAvailableFirmware, 5000);
    }
    else {
      progressBar("80", "Reading of device not successful, please try again", "#ff6666");
      console.log('Reading of device not successful');
      // Log failure to read device data
      await logCommunication('Failed to retrieve complete device data (HW and FW)', 'disconnected');
    } 
  }
}

function firmwareUpdate(data){

    var serialnumber = serial;
    var action = '/v2/products_software/sn='+serialnumber+'&version='+commitCode+'&hw_version='+hw;
    var url = link+action;
  
    var bearer = 'Bearer ' + data;
  
    // Log firmware update request
    logCommunication(`Requesting firmware update for SN: ${serialnumber}, Version: ${commitCode}, HW: ${hw}`, 'sent');

    fetch(url, {
            method: 'GET',
            withCredentials: true,
            credentials: 'include',
            headers: {
                'Authorization': bearer,
                'Content-Type': 'application/json'
            }
        })
        .then(response => response.json())
        .then(firmware=> {
                firmwarelocation = './firmware/'+firmware['software'];
                upgraded_version = firmware['version'];
                // Log firmware response
                logCommunication(`Firmware update response: ${firmware['software']}, Version: ${firmware['version']}`, 'received');
                return firmwarelocation;
                    })
  
            .catch(error => {
             console.log(error)
             // Log firmware fetch error
             logCommunication(`Firmware update fetch error: ${error.message}`, 'disconnected');
            })
  
  
  }

function findShortGitCommitHash(string) {
  // Step 1: Find all hexadecimal sequences
  const hexSequencePattern = /[0-9a-f]+/gi;
  const allHexMatches = string.match(hexSequencePattern) || [];
  
  // Step 2: Filter to only include those with exactly 6 or 7 characters
  const commitHashes = allHexMatches.filter(match => match.length === 6 || match.length === 7);
  
  return commitHashes;
}
  
function compareCommitCodes(stringA, stringB) {
  // Get commit codes from both strings
  const commitCodesA = findShortGitCommitHash(stringA);
  const commitCodesB = findShortGitCommitHash(stringB);
  
  // Case 1: Check if there are matching commit codes between A and B
  for (const codeA of commitCodesA) {
    if (commitCodesB.includes(codeA)) {
      return codeA; // Return the first matching commit code
    }
  }
  
  // Case 2: If A has commit code but B doesn't
  if (commitCodesA.length > 0 && commitCodesB.length === 0) {
    return commitCodesA[0]; // Return the first commit code from A
  }
  
  // Case 3: If A has no commit code but B does
  if (commitCodesA.length === 0 && commitCodesB.length > 0) {
    return commitCodesB[0]; // Return the first commit code from B
  }
  
  // Case 4: Neither has commit code
  return "";
}

function checkAvailableFirmware(){

  if (typeof firmwarelocation !== 'undefined') {
    progressBar("90", "Validating firmware retrieved", "#04AA6D");
    hex_fw = firmwarelocation.split("/firmware/").pop();
    console.log(hex_fw)

        if (hex_fw == 'null' || hex_fw == ''){
          //document.getElementById("updateAvailabe").style.display = "none";
          progressBar("100", "No firmware found for this device", "#ff6666");
          // Log no firmware found
          logCommunication('No firmware found for this device', 'disconnected');
        }
        else {
          var element = document.getElementById("Device_output");
    
          //COMPARE commitCODE from DEVICE with RETURNED CODE FROM API
          if (commitCode.toUpperCase() == upgraded_version.toUpperCase()){
              readBar.innerHTML = 'Latest Firmware already on device';
              // Log firmware up to date
              logCommunication(`Firmware is up to date: ${commitCode}`, 'received');

              if (typeof(element) != 'undefined' && element != null)
              {
                document.getElementById("Device_output").style.display = "none";
              }
            }
            else {
              readBar.innerHTML = 'Firmware available';
              // Log firmware available
              logCommunication(`Firmware update available: Current ${commitCode}, Available ${upgraded_version}`, 'received');
              
              if (typeof(element) != 'undefined' && element != null){
                document.getElementById("Device_output").style.display = "block";
              }       
          }
        }
  }
  else{
    document.getElementById("updateAvailabe").style.display = "none";
    readBar.innerHTML = 'No firmware found for this device';
    // Log no firmware location
    logCommunication('No firmware location available', 'disconnected');
  }
  closePort();
}

async function closePort(){
        
        try {
            // Log port closure start
            const portInfo = port.getInfo();
            const portDetails = {
                processStep: 'Firmware',
                usbVendorId: portInfo.usbVendorId,
                usbProductId: portInfo.usbProductId,
                readable: !!port.readable,
                writable: !!port.writable,
                opened: port.readable !== null && port.writable !== null
            };
            await logCommunication(`Starting port closure - ${JSON.stringify(portDetails)}`, 'disconnected');
            
            reader.cancel();
            await readableStreamClosed.catch(() => { /* Ignore the error */ });
            writer.close();
            await writableStreamClosed;
            console.log('Device connection closed');
            await port.close();

            // Log successful port closure
            await logCommunication(`Serial port closed successfully - VendorID: ${portInfo.usbVendorId}, ProductID: ${portInfo.usbProductId}`, 'disconnected');
        } catch (error) {
            // Log port closure failure
            await logCommunication(`Serial port closure failed: ${error.message || 'Unknown error'}`, 'disconnected');
        }

        openPort = 0;
        readBar.style.width = "100%";
}

function checkFormUpdateFirmware() {
    let buttonfirmware = document.getElementById("updateFirmware")
  
    if (document.getElementById("action_firmware").checked)
      {updateFirmware.disabled = false;
        buttonfirmware.style.display = "block";
      }
      else {
        buttonfirmware.disabled = "disabled";
        buttonfirmware.style.display = "none";
      }
  }