fm-dx-webserver/web/js/main.js

var hostParts = window.location.host.split(':');
var hostname = hostParts[0]; // Extract the hostname
var port = hostParts[1] || '8080'; // Extract the port or use a default (e.g., 8080)
var socketAddress = 'ws://' + hostname + ':' + port + '/text'; // Use 'wss' for secure WebSocket connections (recommended for external access)
var socket = new WebSocket(socketAddress);
var parsedData;
    
const europe_programmes = [
    "No PTY", "News", "Current Affairs", "Info",
    "Sport", "Education", "Drama", "Culture", "Science", "Varied",
    "Pop M", "Rock M", "Easy Listening", "Light Classical",
    "Serious Classical", "Other Music", "Weather", "Finance",
    "Children's Programmes", "Social Affairs", "Religion", "Phone-in",
    "Travel", "Leisure", "Jazz Music", "Country Music", "National Music",
    "Oldies Music", "Folk Music", "Documentary", "Alarm Test"
];

$(document).ready(function() {
    var dataContainer = $('#data-container');
    var canvas = $('#signal-canvas')[0];
    var context = canvas.getContext('2d');
    
    var signalToggle = $("#signal-units-toggle");
    
    canvas.width = canvas.parentElement.clientWidth;
    
    var data = [];
    var maxDataPoints = 300;
    var pointWidth = (canvas.width - 80) / maxDataPoints;
    
    getInitialSettings();
    // Start updating the canvas
    updateCanvas();
    
    function updateCanvas() {
        const color2 = getComputedStyle(document.documentElement).getPropertyValue('--color-2').trim();
        const color4 = getComputedStyle(document.documentElement).getPropertyValue('--color-4').trim();
    
        while (data.length >= maxDataPoints) {
            data.shift();
        }
    
        // Modify the WebSocket onmessage callback
        socket.onmessage = (event) => {
            parsedData = JSON.parse(event.data);
            
            updatePanels(parsedData);
            // Push the new signal data to the array
            data.push(parsedData.signal);
            const actualLowestValue = Math.min(...data);
            const actualHighestValue = Math.max(...data);
            zoomMinValue = actualLowestValue - ((actualHighestValue - actualLowestValue) / 2);
            zoomMaxValue = actualHighestValue + ((actualHighestValue - actualLowestValue) / 2);
            zoomAvgValue = (zoomMaxValue - zoomMinValue) / 2 + zoomMinValue;
    
            // Clear the canvas
            context.clearRect(0, 0, canvas.width, canvas.height);
    
            // Draw the signal graph with zoom
            context.beginPath();
            
            // Start drawing from the rightmost point
            const startingIndex = Math.max(0, data.length - maxDataPoints);
            context.moveTo(canvas.width - 40 - (data.length - startingIndex) * pointWidth, canvas.height - (data[startingIndex] - zoomMinValue) * (canvas.height / (zoomMaxValue - zoomMinValue)));
    
            for (let i = startingIndex + 1; i < data.length; i++) {
                const x = canvas.width - (data.length - i) * pointWidth - 40;
                const y = canvas.height - (data[i] - zoomMinValue) * (canvas.height / (zoomMaxValue - zoomMinValue));
                context.lineTo(x, y);
            }
    
            context.strokeStyle = color4;
            context.lineWidth = 1;
            context.stroke();
    
            // Draw horizontal lines for lowest, highest, and average values
            context.strokeStyle = color2; // Set line color
            context.lineWidth = 1;
    
            // Draw the lowest value line
            const lowestY = canvas.height - (zoomMinValue - zoomMinValue) * (canvas.height / (zoomMaxValue - zoomMinValue));
            context.beginPath();
            context.moveTo(40, lowestY - 18);
            context.lineTo(canvas.width - 40, lowestY - 18);
            context.stroke();
    
            // Draw the highest value line
            const highestY = canvas.height - (zoomMaxValue - zoomMinValue) * (canvas.height / (zoomMaxValue - zoomMinValue));
            context.beginPath();
            context.moveTo(40, highestY + 10);
            context.lineTo(canvas.width - 40, highestY + 10);
            context.stroke();
    
            const avgY = canvas.height / 2;
            context.beginPath();
            context.moveTo(40, avgY - 7);
            context.lineTo(canvas.width - 40, avgY - 7);
            context.stroke();
    
            // Label the lines with their values
            context.fillStyle = color4;
            context.font = '12px Titillium Web';
    
            const offset = signalToggle.prop('checked') ? 11.25 : 0;
            context.textAlign = 'right';
            context.fillText(`${(zoomMinValue - offset).toFixed(1)}`, 35, lowestY - 14);
            context.fillText(`${(zoomMaxValue - offset).toFixed(1)}`, 35, highestY + 14);
            context.fillText(`${(zoomAvgValue - offset).toFixed(1)}`, 35, avgY - 3);
    
            context.textAlign = 'left';
            context.fillText(`${(zoomMinValue - offset).toFixed(1)}`, canvas.width - 35, lowestY - 14);
            context.fillText(`${(zoomMaxValue - offset).toFixed(1)}`, canvas.width - 35, highestY + 14);
            context.fillText(`${(zoomAvgValue - offset).toFixed(1)}`, canvas.width - 35, avgY - 3);
    
            // Update the data container with the latest data
            dataContainer.html(event.data + '<br>');
        };
        requestAnimationFrame(updateCanvas);
    }    
    
    signalToggle.on("change", function() {
        const signalText = localStorage.getItem('signalUnit');

        if (signalText == 'dbuv') {
            signalText.text('dBµV');
        } else if (signalText == 'dbf') {
            signalText.text('dBf');
        } else {
            signalText.text('dBm');
        }
    });    
    
    const textInput = $('#commandinput');
    
    textInput.on('change', function (event) {
        const inputValue = textInput.val();
        // Check if the user agent contains 'iPhone'
        if (/iPhone/i.test(navigator.userAgent) && socket.readyState === WebSocket.OPEN) {
            socket.send("T" + (inputValue * 1000));
            // Clear the input field if needed
            textInput.val('');
        }
    });
    
    textInput.on('keyup', function (event) {
        if (event.key !== 'Backspace') {
            let inputValue = textInput.val();
            inputValue = inputValue.replace(/[^0-9.]/g, '');
            
            if (inputValue.includes("..")) {
                inputValue = inputValue.slice(0, inputValue.lastIndexOf('.')) + inputValue.slice(inputValue.lastIndexOf('.') + 1);
                textInput.val(inputValue);
            }
            
            if (!inputValue.includes(".")) {
                if (inputValue.startsWith('10') && inputValue.length > 2) {
                    inputValue = inputValue.slice(0, 3) + '.' + inputValue.slice(3);
                    textInput.val(inputValue);
                } else if (inputValue.length > 2) {
                    inputValue = inputValue.slice(0, 2) + '.' + inputValue.slice(2);
                    textInput.val(inputValue);
                }
            }
        }
        if (event.key === 'Enter') {
            const inputValue = textInput.val();
            if (socket.readyState === WebSocket.OPEN) {
                socket.send("T" + (inputValue * 1000));
            }
            textInput.val('');
        }
    });
    
    document.onkeydown = checkKey;

    $(window).on('wheel', function(e) {
        var delta = e.originalEvent.deltaY;
    
        // Check if the scroll event originated from #af-list
        if ($(e.target).closest('#af-list').length === 0) {
            if (delta > 0) {
                tuneDown();
            } else {
                tuneUp();
            }
            return false;
        }
    });    
    
    var freqUpButton = $('#freq-up')[0];
    var freqDownButton = $('#freq-down')[0];
    var psContainer = $('#ps-container')[0];
    var rtContainer = $('#rt-container')[0];
    var piCodeContainer = $('#pi-code-container')[0];
    var freqContainer = $('#freq-container')[0];
    
    $("#data-eq").click(function () {
        toggleButtonState("eq");
    });

    $("#data-ims").click(function () {
        toggleButtonState("ims");
    });

    $(freqUpButton).on("click", tuneUp);
    $(freqDownButton).on("click", tuneDown);
    $(psContainer).on("click", copyPs);
    $(rtContainer).on("click", copyRt);
    $(piCodeContainer).on("click", findOnMaps);
    $(freqContainer).on("click", function() {
        textInput.focus();
    });
});

function getInitialSettings() {
    $.ajax({
        url: '/static_data',
        dataType: 'json',
        success: function(data) {
            // Use the received data (data.qthLatitude, data.qthLongitude) as needed
            localStorage.setItem('qthLatitude', data.qthLatitude);
            localStorage.setItem('qthLongitude', data.qthLongitude);
            localStorage.setItem('webServerName', data.webServerName);
            localStorage.setItem('audioPort', data.audioPort);
            localStorage.setItem('streamEnabled', data.streamEnabled);
            
            document.title = 'FM-DX Webserver [' + data.webServerName + ']';
        },
        error: function(error) {
            console.error('Error:', error);
        }
    });
}
    
function compareNumbers(a, b) {
    return a - b;
}

function escapeHTML(unsafeText) {
    let div = document.createElement('div');
    div.innerText = unsafeText;
    return div.innerHTML.replace(' ', '&nbsp;');
}

function processString(string, errors) {
    var output = '';
    const max_alpha = 70;
    const alpha_range = 50;
    const max_error = 10;
    errors = errors?.split(',');
    
    for (let i = 0; i < string.length; i++) {
        alpha = parseInt(errors[i]) * (alpha_range / (max_error + 1));
        if (alpha) {
            output += "<span style='opacity: " + (max_alpha - alpha) + "%'>" + escapeHTML(string[i]) + "</span>";
        } else {
            output += escapeHTML(string[i]);
        }
    }
    
    return output;
}

function getCurrentFreq() {
    currentFreq = $('#data-frequency').text();
    currentFreq = parseFloat(currentFreq).toFixed(3);
    currentFreq = parseFloat(currentFreq);
    
    return currentFreq;
}

function checkKey(e) {
    e = e || window.event;
    
    getCurrentFreq();
    
    if (socket.readyState === WebSocket.OPEN) {
        if (e.keyCode == '38') {
            socket.send("T" + ((currentFreq + 0.01).toFixed(2) * 1000));
        }
        else if (e.keyCode == '40') {
            socket.send("T" + ((currentFreq - 0.01).toFixed(2) * 1000));
        }
        else if (e.keyCode == '37') {
            socket.send("T" + ((currentFreq - 0.10).toFixed(1) * 1000));
        }
        else if (e.keyCode == '39') {
            socket.send("T" + ((currentFreq + 0.10).toFixed(1) * 1000));
        }
    }
}

function tuneUp() {
    if (socket.readyState === WebSocket.OPEN) {
        getCurrentFreq();
        socket.send("T" + ((currentFreq + 0.10).toFixed(1) * 1000));
    }
}

function tuneDown() {
    if (socket.readyState === WebSocket.OPEN) {
        getCurrentFreq();
        socket.send("T" + ((currentFreq - 0.10).toFixed(1) * 1000));
    }
}

function tuneTo(freq) {
    if (socket.readyState === WebSocket.OPEN) {
        socket.send("T" + ((freq).toFixed(1) * 1000));
    }
}

async function copyPs() {
    var frequency = $('#data-frequency').text();
    var pi = $('#data-pi').text();
    var ps = $('#data-ps').text();
    var signal = $('#data-signal').text();
    var signalDecimal = $('#data-signal-decimal').text();
    var signalUnit = $('#signal-units').text();
    
    try {
        await copyToClipboard(frequency + " - " + pi + " | " + ps +  " [" + signal + signalDecimal + " " + signalUnit + "]");
    } catch(error) {
        console.error(error);
    }
}

async function copyRt() {
    var rt0 = $('#data-rt0').text();
    var rt1 = $('#data-rt1').text();
    
    try {
        await copyToClipboard("[0] RT: " + rt0 + "\n[1] RT: " + rt1);
    } catch(error) {
        console.error(error);
    }
}

function copyToClipboard(textToCopy) {
    // Navigator clipboard api needs a secure context (https)
    if (navigator.clipboard && window.isSecureContext) {
        navigator.clipboard.writeText(textToCopy)
        .catch(function(err) {
            console.error('Error:', err);
        });
    } else {
        var textArea = $('<textarea></textarea>');
        textArea.val(textToCopy);
        textArea.css({
            'position': 'absolute',
            'left': '-999999px'
        });
        
        $('body').prepend(textArea);
        textArea.select();
        
        try {
            document.execCommand('copy');
        } catch (error) {
            console.error('Error:', error);
        } finally {
            textArea.remove();
        }
    }
}

function findOnMaps() {
    var frequency = $('#data-frequency').text();
    var pi = $('#data-pi').text();
    var latitude = localStorage.getItem('qthLongitude');
    var longitude = localStorage.getItem('qthLatitude');
    frequency = parseFloat(frequency).toFixed(1);
    
    var url = "https://maps.fmdx.pl/#qth=" + longitude + "," + latitude + "&freq=" + frequency + "&pi=" + pi;
    window.open(url, "_blank");
}

function updateSignalUnits(parsedData) {
    const signalUnit = localStorage.getItem('signalUnit');
    let signalText = $('#signal-units');
    let signalValue;

    switch (signalUnit) {
        case 'dbuv':
            signalValue = parsedData.signal - 11.25;
            signalText.text('dBµV');
            break;

        case 'dbm':
            signalValue = parsedData.signal - 120;
            signalText.text('dBm');
            break;

        default:
            signalValue = parsedData.signal;
            signalText.text('dBf');
            break;
    }

    const integerPart = Math.floor(signalValue);
    const decimalPart = (signalValue - integerPart).toFixed(1).slice(1);

    $('#data-signal').text(integerPart);
    $('#data-signal-decimal').text(decimalPart);
}

function updateDataElements(parsedData) {
    $('#data-frequency').text(parsedData.freq);
    $('#data-pi').html(parsedData.pi === '?' ? "<span class='text-gray'>?</span>" : parsedData.pi);
    $('#data-ps').html(parsedData.ps === '?' ? "<span class='text-gray'>?</span>" : processString(parsedData.ps, parsedData.ps_errors));
    $('.data-tp').html(parsedData.tp === false ? "<span class='text-gray'>TP</span>" : "TP");
    $('.data-ta').html(parsedData.ta === 0 ? "<span class='text-gray'>TA</span>" : "TA");
    $('.data-ms').html(parsedData.ms === 0
        ? "<span class='text-gray'>M</span><span class='text-red'>S</span>"
        : (parsedData.ms === -1
            ? "<span class='text-gray'>M</span><span class='text-gray'>S</span>"
            : "<span class='text-red'>M</span><span class='text-gray'>S</span>"
          )
    );        
    $('.data-pty').html(europe_programmes[parsedData.pty]);
    $('.data-st').html(parsedData.st === false ? "<span class='text-gray'>ST</span>" : "ST");
    $('#data-rt0').html(processString(parsedData.rt0, parsedData.rt0_errors));
    $('#data-rt1').html(processString(parsedData.rt1, parsedData.rt1_errors));
    $('.data-flag').html(`<i title="${parsedData.country_name}" class="flag-sm flag-sm-${parsedData.country_iso}"></i>`);
}

let isEventListenerAdded = false;

let updateCounter = 0;

function updatePanels(parsedData) {
    updateCounter++;

    const sortedAf = parsedData.af.sort(compareNumbers);
    const scaledArray = sortedAf.map(element => element / 1000);

    const listContainer = $('#af-list');
    const scrollTop = listContainer.scrollTop();
    let ul = listContainer.find('ul');

    if (!ul.length) {
        ul = $('<ul></ul>');
        listContainer.append(ul);
    }

    if (updateCounter % 3 === 0) {
        
        updateButtonState("data-eq", parsedData.eq);
        updateButtonState("data-ims", parsedData.ims);

        // Only update #af-list on every 3rd call
        ul.html('');
        const listItems = scaledArray.map(createListItem);
        ul.append(listItems);

        // Add the event listener only once
        if (!isEventListenerAdded) {
            ul.on('click', 'a', function () {
                const frequency = parseFloat($(this).text());
                tuneTo(frequency);
            });
            isEventListenerAdded = true;
        }

        listContainer.scrollTop(scrollTop);
    }

    // Update other elements every time
    updateDataElements(parsedData);
    updateSignalUnits(parsedData);
    $('#users-online').text(parsedData.users);
}

function createListItem(element) {
    return $('<li></li>').html(`<a>${element.toFixed(1)}</a>`)[0];
}

function updateButtonState(buttonId, value) {
    var button = $("#" + buttonId);
    if (value === 0) {
        button.addClass("bg-gray");
    } else {
        button.removeClass("bg-gray");
    }
}

function toggleButtonState(buttonId) {
    parsedData[buttonId] = 1 - parsedData[buttonId]; // Toggle between 0 and 1
    updateButtonState(buttonId, parsedData[buttonId]);
    var message = "G";
    message += parsedData.eq ? "1" : "0";
    message += parsedData.ims ? "1" : "0";
    socket.send(message);
}