<div id="compatAlert" class="alert alert-warning text-center d-none" role="alert">
    Your browser is not supported. Please update or switch to a modern browser.
</div>

<script>
    // Checks if the users browser supports ES2022 features.
    //
    // Required because blazor.web.js targets ES2022 and so won't work on a browser that doesn't support it
    // (e.g. any iPhone on a version less than 16.4)
    // NOTE: THIS DID NOT CORRECTLY IDENTIFY DEVICES THAT WOULD HAVE ISSUES SO NOT USING IT
    window.es2022Support = {
        check: function () {
        
            // 1) Check static class fields:
            // Attempt to parse a class with a static field. If the browser doesn't
            // support static fields, this will throw a SyntaxError.
            try {
                new Function("class Test { static x = 42; }")();
            } catch (e) {
                return false;
            }

            // 2) If `.at()` doesn't exist on Array (ES2022),
            // then we declare "no" for modern support.
            if (typeof Array.prototype.at !== "function") {
                return false;
            }

            return true;
        }
    };

    window.iOSVersionInfo = {
        getVersion: function () {
            
            //alert(navigator.platform);
            //alert(navigator.appVersion);

            // Quick exit if it's not iOS.
            //if (!/iP(hone|od|ad)/.test(navigator.platform)) {
            //    return null;
            //}

            // The user agent may look like: "CPU OS 16_4 like Mac OS X" or "CPU iPhone OS 15_2 like Mac OS X"
            // We'll try to extract 'major.minor' or 'major.minor.patch'.
            let appVersion = navigator.appVersion;
            const match = appVersion.match(/OS (\d+)_(\d+)_?(\d+)?/);
            if (!match) {
                return null; // If we don’t find what we need, return null or handle differently.
            }

            const major = parseInt(match[1], 10) || 0;
            const minor = parseInt(match[2], 10) || 0;
            // Patch is optional—some iOS user agents may show it, some may not.
            const patch = parseInt(match[3] || "0", 10);

            return {
                major: major,
                minor: minor,
                patch: patch
            };
        }
    };

    (function () {
        // On page load check if the user's browser is compatible with ES2022 features otherwise
        // display a warning.

        let showAlert = false;

        //if (!es2022Support.check()) {
          //showAlert = true;
        //}

        let version = iOSVersionInfo.getVersion();

        if (version !== null)
        {
            // If iOS < 16.4 => show the alert
            // We'll compare major.minor to 16.4.
            // For example, iOS 16.3 => major=16, minor=3, patch=?.
            const detectedVersion = version.major + (version.minor / 10.0);

            if (detectedVersion < 16.4)
            {
                showAlert = true;
            }
        }

        if (showAlert) {
            // Reveal the alert (removing Bootstrap’s .d-none)
            let alertEl = document.getElementById("compatAlert");
            if (alertEl) {
                alertEl.classList.remove("d-none");
            }
        }
    })();
</script>