Administration day

function solve() {

  const findTagFromParent = (parent, tag, text) => {
    const parents = document.getElementsByClassName(parent);

    for (parent of parents) {
      const descendants = parent.getElementsByTagName(tag);
      if (descendants.length) {
        const button = descendants[0];
        if (button.innerHTML === text) {
          return button;
        }
      }
    }

    return undefined;
  };




  const el = (tag, content, attributes) => {
    const element = document.createElement(tag);
    if (attributes) {
      //Ако са подадени атрибути (ID, className, etc.) ги закачаме към елемента
      Object.assign(element, attributes);
    }
    if (Array.isArray(content)) {
      //Ако създаваме например Div, в който трябва да има други елементи - p, span, etc., ги закачаме като масив
      content.forEach(appendEl);
    } else {
      //Ако не е масив, просто закачаме текста или числото, което сме подали
      appendEl(content);
    }

    function appendEl(node) {
      if (typeof node == "string" || typeof node == "number") {
        node = document.createTextNode(node);
      }
      element.appendChild(node);
    }

    return element;
  };

  const validateAndAdd = (e) => {
    const lectureName = document.getElementsByName("lecture-name")[0].value;
    const lectureDate = document.getElementsByName("lecture-date")[0].value;
    const lectureModule = document.getElementsByName("lecture-module")[0].value;

    if (
      lectureName === "" ||
      lectureDate === "" ||
      lectureModule === "Select module"
    )
      return;

    const title = `${lectureModule.toUpperCase()}-MODULE`;

    const chosenDate = new Date(lectureDate);

    gayFormatDate =
      chosenDate.getFullYear() +
      "/" +
      ("0" + chosenDate.getDate()).slice(-2) +
      "/" +
      ("0" + (chosenDate.getMonth() + 1)).slice(-2) +
      " - " +
      chosenDate.getHours() +
      ":" +
      ("0" + chosenDate.getMinutes()).slice(-2);
    const date = gayFormatDate;

    const module = findTagFromParent("module", "h3", title);

    const h4 = el("h4", `${lectureName} - ${date}`);
    const button = el("button", "Del", { className: "red" });
    const li = el("li", [h4, button], { className: "flex" });

    let ul;

    if (!module) {
      const modules = document.getElementsByClassName("modules")[0];
      const h3 = el("h3", title);
      ul = el("ul", li);

      const newModule = el("div", [h3, ul], { className: "module" });
      modules.appendChild(newModule);
    } else {
      ul = module.parentNode.getElementsByTagName("ul")[0];

      ul.appendChild(li);
    }

    e.preventDefault();
  };


  const addButton = findTagFromParent("form-control", "button", "Add");

  if (!addButton) {
    return;
  }
  addButton.addEventListener("click", validateAndAdd);



}