document.addEventListener("DOMContentLoaded", function () {
  // Function to load a script into the DOM
  function loadScript(url, integrity, crossorigin) {
    return new Promise((resolve, reject) => {
      const script = document.createElement("script");
      script.src = url;
      script.integrity = integrity;
      script.crossOrigin = crossorigin;
      script.onload = () => resolve(script);
      script.onerror = () => reject(new Error(`Failed to load script: ${url}`));
      document.head.appendChild(script);
    });
  }

  // Function to get URL parameters
  function getUrlParameter(name) {
    const url = document.location.href;
    const urlobj = new URL(url);
    return urlobj.searchParams.get(name);
  }

  // Function to wait until a global variable is defined
  function waitForGlobalVariable(variableName) {
    return new Promise((resolve) => {
      const checkVariable = setInterval(() => {
        if (window[variableName]) {
          clearInterval(checkVariable);
          resolve();
        }
      }, 100);
    });
  }

  // Check if the 'embed' parameter is set to '1'
  if (getUrlParameter("embed") === "1") {
    // Apply custom CSS to hide Moodle interface elements
    const style = document.createElement("style");
    style.innerHTML = `
      body.path-mod {
        #header, #footer, .breadcrumb, .navbar, .side-pre, .side-post, .drawer, .drawer-toggler, .footer-popover, .navigation {
          display: none !important;
        }
        #region-main {
          margin: 0;
          padding: 0;
        }
      }
    `;
    document.head.appendChild(style);

    // Load jQuery if not already defined
    const jQueryPromise = window.jQuery
      ? Promise.resolve()
      : loadScript(
        "https://code.jquery.com/jquery-3.7.1.min.js",
        "sha256-/JqT3SQfawRcv/BIHPThkBvs0OEvtFFmqPF/lYI/Cxo=",
        "anonymous"
      ).then(() => waitForGlobalVariable("$"));

    jQueryPromise
      .then(() => {
        console.log("jQuery loaded successfully");

        // Load Bootstrap if not already defined
        const bootstrapPromise = window.bootstrap
          ? Promise.resolve()
          : loadScript(
            "https://stackpath.bootstrapcdn.com/bootstrap/5.3.3/js/bootstrap.bundle.min.js",
            "sha384-YvpcrYf0tY3lHB60NNkmXc5s9fDVZLESaAA55NDzOxhy9GkcIdslK1eN7N6jIeHz",
            "anonymous"
          ).then(() => waitForGlobalVariable("bootstrap"));

        return bootstrapPromise;
      })
      .then(() => {
        console.log("Bootstrap loaded successfully");

        $(document).ready(function () {
          $(".btn-secondary:contains('Back')").hide();

          const embedded = getUrlParameter("embed");
          const inModal = getUrlParameter("modal");
          const page = getUrlParameter("page") ? getUrlParameter("page") : 0;

          // Set required attribute on inputs associated with labels containing <i title="Required field">
          $('label:has(i[title="Required field"])').each(function () {
            const inputId = $(this).attr("for");
            $("#" + inputId).attr("required", "required");
          });

          // Hide the modal if the 'cancel' button is clicked
          $("[name=cancel]").click(function () {
            hideContent();
          });

          $("form").each(function () {
            const form = $(this);

            // Check if the form has a button where the text contains "Finish attempt"
            let isLast = false;
            const finishButton = form.find('input[type="submit"][value*="Finish attempt"]');
            if (finishButton.length) {
              isLast = true;
            }

            form.submit(function (event) {
              event.preventDefault(); // Prevent the default form submission

              // Check if the form is valid
              if (!form[0].checkValidity()) {
                form[0].reportValidity();
                return;
              }

              // Serialize the form data
              let formData = form.serialize();

              // Add the submit button's data to formData
              const submitButton = form.find(
                'input[type="submit"][name="savevalues"]'
              );
              if (submitButton.length) {
                formData +=
                  "&" +
                  encodeURIComponent(submitButton.attr("name")) +
                  "=" +
                  encodeURIComponent(submitButton.val());
              }

              const sesskey = form.find('input[name=sesskey]').val();
              const attempt = form.find('input[name=attempt]').val();

              // Perform the AJAX request
              $.ajax({
                url: form.attr("action"), // Use the form's action attribute
                type: form.attr("method"), // Use the form's method attribute
                data: formData,
                success: function (response, status, xhr) {
                  if (form.attr("action").includes("/quiz/")) {
                    // Check if the quiz has a next page by calling the attempt.php page
                    let nextUrl = form.attr("action").replace("processattempt", "attempt");
                    nextUrl += "&page=" + (parseInt(page) + 1) + "&attempt=" + attempt + "&sesskey=" + sesskey;

                    if (isLast) {
                      nextUrl = "https://invalid.invalid";
                    }

                    $.get(nextUrl, function (response) {
                      console.log(nextUrl + " seems to be a valid URL, redirecting...");
                      nextUrl = nextUrl + "&embed=1";

                      if (inModal === "1") {
                        nextUrl += "&modal=1";
                      }

                      document.location.href = nextUrl;

                      return;
                    })
                      .fail(function () {
                        console.log("No next page found at " + nextUrl + ", finalizing attempt...");

                        const finalize = "/mod/quiz/processattempt.php";
                        const data = {
                          attempt: attempt,
                          finishattempt: 1,
                          sesskey: sesskey,
                        };
                        $.post(finalize, data, function (response) {
                          console.log(response);
                          // Close the modal if `modal=1` is set
                          if (inModal === "1") {
                            window.top.closeQuizModal();
                          } else {
                            // Else call the nextContent function
                            window.top.nextContent();
                          }
                        });
                      });

                  } else {
                    // Close the modal if `modal=1` is set
                    if (inModal === "1") {
                      window.top.closeQuizModal();
                    } else {
                      // Else call the nextContent function
                      window.top.nextContent();
                    }
                  }
                },
                error: function (xhr, status, error) {
                  // Handle any errors that occur during the AJAX request
                  console.error(
                    "Form submission failed: " + status + " - " + error
                  );
                },
              });
            });
          });
        });
      })
      .catch((error) => {
        console.error(error.message);
      });
  }
});