const scriptLocation = "/usr/local/echopilot/";
const confLocation = "/etc/wifibroadcast.cfg";
const encryptionFileLocation = "/etc/drone.key"; // Destination for encryption key

// Elements
const version = document.getElementById("version");
const file_location = document.getElementById("file_location");
const wifiChannel = document.getElementById("wifiChannel");
const wifiRegion = document.getElementById("wifiRegion");
const wifiTxPower = document.getElementById("wifiTxPower");
const tempInterval = document.getElementById("tempInterval");
const tempWarning = document.getElementById("tempWarning");
const droneMavlinkFwmark = document.getElementById("droneMavlinkFwmark");
const droneMavlinkType = document.getElementById("droneMavlinkType");
const droneMavlinkIP = document.getElementById("droneMavlinkIP");
const droneMavlinkPort = document.getElementById("droneMavlinkPort");
const droneVideoFwmark = document.getElementById("droneVideoFwmark");
const droneVideoType = document.getElementById("droneVideoType");
const droneVideoIP = document.getElementById("droneVideoIP");
const droneVideoPort = document.getElementById("droneVideoPort");
const injectRssi = document.getElementById("injectRssi");
const mavlinkSysId = document.getElementById("mavlinkSysId");
const mavlinkCompId = document.getElementById("mavlinkCompId");
const mavlinkTcpPort = document.getElementById("mavlinkTcpPort");

const spiriLinkForm = document.getElementById("spiriLinkForm");
const output = document.getElementById("output");

const wifiChannels = [
    // 2.4 GHz Channels
    ["1", "1 (2.412 GHz)"], ["2", "2 (2.417 GHz)"], ["3", "3 (2.422 GHz)"],
    ["4", "4 (2.427 GHz)"], ["5", "5 (2.432 GHz)"], ["6", "6 (2.437 GHz)"],
    ["7", "7 (2.442 GHz)"], ["8", "8 (2.447 GHz)"], ["9", "9 (2.452 GHz)"],
    ["10", "10 (2.457 GHz)"], ["11", "11 (2.462 GHz)"], ["12", "12 (2.467 GHz)"],
    ["13", "13 (2.472 GHz)"], ["14", "14 (2.484 GHz, Japan only)"],
    // 5 GHz Channels
    ["36", "36 (5.180 GHz)"], ["40", "40 (5.200 GHz)"], ["44", "44 (5.220 GHz)"],
    ["48", "48 (5.240 GHz)"], ["52", "52 (5.260 GHz)"], ["56", "56 (5.280 GHz)"],
    ["60", "60 (5.300 GHz)"], ["64", "64 (5.320 GHz)"], ["100", "100 (5.500 GHz)"],
    ["104", "104 (5.520 GHz)"], ["108", "108 (5.540 GHz)"], ["112", "112 (5.560 GHz)"],
    ["116", "116 (5.580 GHz)"], ["120", "120 (5.600 GHz)"], ["124", "124 (5.620 GHz)"],
    ["128", "128 (5.640 GHz)"], ["132", "132 (5.660 GHz)"], ["136", "136 (5.680 GHz)"],
    ["140", "140 (5.700 GHz)"], ["149", "149 (5.745 GHz)"], ["153", "153 (5.765 GHz)"],
    ["157", "157 (5.785 GHz)"], ["161", "161 (5.805 GHz)"], ["165", "165 (5.825 GHz)"]
]

const wifiRegions = [
    ["BO", "BO (Max TX)"],
    ["US", "US (United States)"],
    ["EU", "EU (Europe)"],
    ["JP", "JP (Japan)"],
    ["AU", "AU (Australia, Max TX)"],
    ["CA", "CA (Canada)"],
    ["CN", "CN (China)"],
    ["IN", "IN (India)"],
    ["ZA", "ZA (South Africa)"],
    ["KR", "KR (South Korea)"]
]

const connectionTypes = [
    ["listen", "Listen"],
    ["connect", "Connect"]
]

// Load initial settings
document.onload = initPage();
// Save file button
document.getElementById("save").addEventListener("click", saveSettings);
// Apply encryption file button
document.getElementById("applyEncryptionFile").addEventListener("click", applyEncryptionFile);

// Function to initialize the page
function initPage() {
    file_location.innerHTML = confLocation;

    const inputs = document.querySelectorAll("input, select, textarea");
    inputs.forEach(input => {
        input.addEventListener("focus", resetForm);
    });

    cockpit.file(confLocation)
        .read().then((content) => successReadFile(content))
        .catch(error => failureReadFile(error));
}

// Load configuration values from the configuration file
function successReadFile(content) {
    try {
        
        // WiFi Configuration
        // Remove surrounding quotes from wifi_region value if present
        const currentWifiChannel = getValueByKey(content, "common", "wifi_channel");
        const currentWifiRegion = getValueByKey(content, "common", "wifi_region").replace(/^['"]|['"]$/g, "");
        const txPowerValue = getValueByKey(content, "common", "wifi_txpower");

        addDropDown(wifiChannel, wifiChannels, currentWifiChannel);
        addDropDown(wifiRegion, wifiRegions, currentWifiRegion);
        wifiTxPower.value = txPowerValue === "None" ? "" : txPowerValue; // None should result in an empty string
        
        // Temperature Configuration
        tempInterval.value = getValueByKey(content, "common", "temp_measurement_interval");
        tempWarning.value = getValueByKey(content, "common", "temp_overheat_warning");

        // Drone Video Configuration
        droneVideoFwmark.value = getValueByKey(content, "drone_video", "fwmark");
        const droneVideoPeer = getValueByKey(content, "drone_video", "peer");
        if (droneVideoPeer) {
            const peer = parsePeer(droneVideoPeer);
            addDropDown(droneVideoType, connectionTypes, droneVideoType.value);
            droneVideoIP.value = peer.ip;
            droneVideoPort.value = peer.port;
        }

        // Drone MAVLink Configuration
        droneMavlinkFwmark.value = getValueByKey(content, "drone_mavlink", "fwmark");        
        const droneMavlinkPeer = getValueByKey(content, "drone_mavlink", "peer");
        if (droneMavlinkPeer) {
            const peer = parsePeer(droneMavlinkPeer);
            addDropDown(droneMavlinkType, connectionTypes, peer.type);
            droneMavlinkIP.value = peer.ip;
            droneMavlinkPort.value = peer.port;
        }  

        // MAVLink Settings
        injectRssi.checked = getValueByKey(content, "mavlink", "inject_rssi") === "True";
        mavlinkSysId.value = getValueByKey(content, "mavlink", "mavlink_sys_id");
        mavlinkCompId.value = getValueByKey(content, "mavlink", "mavlink_comp_id");
        const tcpPortValue = getValueByKey(content, "mavlink", "mavlink_tcp_port");
        mavlinkTcpPort.value = tcpPortValue === "None" ? "" : tcpPortValue;

    } catch (e) {
        failureReadFile(e);
    }
}

// Log error message and display it
// TODO: Add more error handling for failed file reads
function failureReadFile(error) {
    console.error("Error : " + error.message);
    displayFail(error.message)
}

// Validate the form using non-standard input validation conditions.
// Additional checks for IP, port, and system/component ID fields
// Returns true if all fields are valid, false otherwise
function validateSpiriLinkForm(form) {
    const ipformat = /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
    const portformat = /^([1-9][0-9]{0,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5])$/;
    let isValid = true;
    
    defaultValidation = form.checkValidity();

    const inputs = form.querySelectorAll("input, select, textarea");
    inputs.forEach(input => {
        if (input.value === "") {
            isValid = !input.hasAttribute("required");
            setValidationVisuals(input, isValid);
        } else {
            if (input.id === "droneMavlinkIP" || input.id === "droneVideoIP") {
                isValid = input.value.match(ipformat);
                setValidationVisuals(input, isValid);
            } 
            else if (input.id === "droneMavlinkPort" || input.id === "droneVideoPort" || input.id === "mavlinkTcpPort") {
                isValid = input.value.match(portformat);
                setValidationVisuals(input, isValid);
            } 
            else if (input.id === "mavlinkSysId" || input.id === "mavlinkCompId") {
                isValid = input.value > 1 || input.value < 255;
                setValidationVisuals(input, isValid);
            }
        }
    });

    form.classList.add("was-validated");
    if (!isValid || !defaultValidation) return false;
    return true;
}

// Set validation visuals for input fields
// Adds or removes is-invalid class based on the validity of the input
// The setCustomValidity function triggers the actual field visuals. 
//      Giving it an empty string assumes the input is valid.
function setValidationVisuals(input, isValid) {
    if (isValid) {
        input.classList.remove("is-invalid");
        input.setCustomValidity("");
    } else {
        input.classList.add("is-invalid");
        input.setCustomValidity("Invalid input");
    }
}

// Save configuration values to the configuration file
function saveSettings() {

    const dataIsValid = validateSpiriLinkForm(spiriLinkForm);
    if (!dataIsValid) return;

    try {
        cockpit.file(confLocation)
            .read()
            .then((content) => {
                // WiFi & Temperature Configuration
                content = setValueByKey(content, "[common]", "wifi_channel", wifiChannel.value);
                content = setValueByKey(content, "[common]", "wifi_region", wifiRegion.value);
                content = setValueByKey(content, "[common]", "wifi_txpower", wifiTxPower.value === "" ? "None" : wifiTxPower.value);
                content = setValueByKey(content, "[common]", "temp_measurement_interval", tempInterval.value);
                content = setValueByKey(content, "[common]", "temp_overheat_warning", tempWarning.value);
                
                // Drone Video Configuration
                const droneVideoPeer = `${droneVideoType.value}://${droneVideoIP.value}:${droneVideoPort.value}`;
                content = setValueByKey(content, "[drone_video]", "fwmark", droneVideoFwmark.value);
                content = setValueByKey(content, "[drone_video]", "peer", droneVideoPeer);

                // Drone MAVLink Configuration
                const droneMavlinkPeer = `${droneMavlinkType.value}://${droneMavlinkIP.value}:${droneMavlinkPort.value}`;
                content = setValueByKey(content, "[drone_mavlink]", "fwmark", droneMavlinkFwmark.value);
                content = setValueByKey(content, "[drone_mavlink]", "peer", droneMavlinkPeer);

                // MAVLink Configuration
                content = setValueByKey(content, "[mavlink]", "inject_rssi", injectRssi.checked ? "True" : "False");
                content = setValueByKey(content, "[mavlink]", "mavlink_sys_id", mavlinkSysId.value);
                content = setValueByKey(content, "[mavlink]", "mavlink_comp_id", mavlinkCompId.value);
                content = setValueByKey(content, "[mavlink]", "mavlink_tcp_port", mavlinkTcpPort.value === "" ? "None" : mavlinkTcpPort.value);

                cockpit.file(confLocation, { superuser: "try" }).replace(content)
                    .then(() => {
                        restartWifibroadcastService();
                        displaySuccess("Configuration saved successfully.");
                    })
                    .catch((error) => {
                        displayFail("Failed to save configuration: " + error.message);
                    });
            })
            .catch(error => {
                displayFail("Failed to save configuration: " + error.message);
            });
    } catch (e) {
        console.error("Error during save operation:", e);
        failureReadFile(e);
    }
}

// Apply encryption file from base station
function applyEncryptionFile() {
    const command = `
        /usr/bin/sshpass -p 'spirifriend' scp -o StrictHostKeyChecking=no spiri@spiri-base.local:/home/spiri/drone.key /tmp/drone.key &&
        /usr/bin/sudo /bin/mv /tmp/drone.key ${encryptionFileLocation} &&
        /usr/bin/sudo /bin/systemctl restart wifibroadcast@drone
    `;
    
    cockpit.spawn(["bash", "-c", command], { superuser: "require" })
        .then(() => {
            displaySuccess("Encryption key applied and wifibroadcast service restarted.");
        })
        .catch((error) => {
            console.error("Failed to apply encryption key or restart service:", error);
            displayFail("Failed to apply encryption key or restart service: " + error);
        });
}

// Restart wifibroadcast service
function restartWifibroadcastService() {
    cockpit.spawn(["systemctl", "restart", "wifibroadcast@drone"], { superuser: "require" })
        .then(() => {
            displaySuccess("wifibroadcast@drone service restarted.");
        })
        .catch((error) => {
            console.error("Failed to restart wifibroadcast@drone service:", error);
            displayFail("Failed to restart wifibroadcast@drone service: " + error);
        });
}

// Display Success result
function displaySuccess(msg) {
    result.style.color = "green";
    if (result.innerHTML === "")
        result.innerHTML = msg;
    else
        result.innerHTML += "<br>" + msg;

    // setTimeout(() => result.innerHTML = "", 5000);
}

// Display failure message
function displayFail(error) {
    result.style.color = "red";
    result.innerHTML = "Error : " + error;
}

// Reset & clear form data
function resetForm() {
    result.innerHTML = "";
    const inputs = spiriLinkForm.querySelectorAll("input, select, textarea");
    inputs.forEach(input => {
        input.setCustomValidity("");
        input.classList.remove("is-invalid");
        input.classList.remove("is-valid");
    });

    spiriLinkForm.classList.remove("was-validated");
    spiriLinkForm.classList.add("needs-validation");
}

function addDropDown(box, pairs, defaultValue) {
    try {
        for(let i = 0; i < pairs.length; i++){
            if (pairs[i].length == 0 || pairs[i][0] === "" || pairs[i][1] === "") continue;
            const option = document.createElement("option");
            option.value = pairs[i][0];
            option.text = pairs[i][1];
            box.add(option);
            if (defaultValue === option.value) {
                box.value = option.value;
            }
        }
    }
    catch(e) {
        displayFail(e)
    }
}

// Parse Peer configuration (type, IP, port)
function parsePeer(peerString) {
    const peer = { type: "", ip: "", port: "" };
    
    if (!peerString) return peer;

    const regex = /(listen|connect):\/\/([\d.]+):(\d+)/;
    const match = peerString.match(regex);
    if (match) {
        peer.type = match[1];
        peer.ip = match[2];
        peer.port = match[3];
    }

    return peer;
}

// Get value by key from configuration content
function getValueByKey(content, section, key) {
    const sectionRegex = new RegExp(`\\[${section}\\][\\s\\S]*?^${key}\\s*=\\s*(.*)`, "m");
    const match = content.match(sectionRegex);
    if (match) {
        const value = match[1].trim();
        return value;
    } else {
        return "";
    }
}

// Set value by key in configuration content
function setValueByKey(content, section, key, value) {
    const regex = new RegExp(`(${section}[\\s\\S]*?)(${key}\\s*=\\s*)(.*)`, "m");
    if (content.match(regex)) {
        return content.replace(regex, `$1$2${value}`);
    } else {
        // Add key if not found
        const sectionRegex = new RegExp(`(${section}[\\s\\S]*?)\\n`, "m");
        return content.match(sectionRegex)
            ? content.replace(sectionRegex, `$1\n${key} = ${value}\n`)
            : `${content}\n${section}\n${key} = ${value}\n`;
    }
}