(function () {
  "use strict";

  function normalizeSequenceState(sequence) {
    return {
      total: Math.max(0, Number(sequence?.total) || 0),
      currentIndex: Number.isFinite(Number(sequence?.currentIndex)) ? Number(sequence.currentIndex) : -1,
      previousKey: String(sequence?.previousKey ?? sequence?.previousId ?? "").trim(),
      nextKey: String(sequence?.nextKey ?? sequence?.nextId ?? "").trim()
    };
  }

  function isEditableKeyTarget(target) {
    if (!(target instanceof HTMLElement)) {
      return false;
    }

    return target instanceof HTMLInputElement
      || target instanceof HTMLTextAreaElement
      || target instanceof HTMLSelectElement
      || target.isContentEditable
      || Boolean(target.closest("[contenteditable='true']"));
  }

  function hasOpenModalDialog() {
    return Boolean(document.querySelector("[role='dialog'][aria-modal='true'][aria-hidden='false']"));
  }

  function createSequenceNavigator(config = {}) {
    const getElements = typeof config.getElements === "function"
      ? config.getElements
      : () => ({});

    let buttonsBound = false;
    let keyboardBound = false;

    function getSequenceState() {
      return normalizeSequenceState(
        typeof config.getSequenceState === "function"
          ? config.getSequenceState()
          : null
      );
    }

    function getPrevButton(elements) {
      return typeof config.getPrevButton === "function" ? config.getPrevButton(elements) : null;
    }

    function getNextButton(elements) {
      return typeof config.getNextButton === "function" ? config.getNextButton(elements) : null;
    }

    function getPositionEl(elements) {
      return typeof config.getPositionEl === "function" ? config.getPositionEl(elements) : null;
    }

    function isActive(elements) {
      return typeof config.isActive === "function" ? config.isActive(elements) !== false : true;
    }

    function getTargetKey(sequence, offset) {
      return offset < 0 ? sequence.previousKey : sequence.nextKey;
    }

    function formatPositionText(sequence, elements) {
      return typeof config.formatPositionText === "function"
        ? String(config.formatPositionText(sequence, elements) || "")
        : "";
    }

    function selectTarget(targetKey, elements, offset) {
      if (!targetKey || typeof config.selectTarget !== "function") {
        return false;
      }

      return config.selectTarget(targetKey, elements, offset) !== false;
    }

    function afterSelect(targetKey, elements, offset) {
      if (typeof config.afterSelect === "function") {
        config.afterSelect(targetKey, elements, offset);
      }
    }

    function shouldHandleKeyEvent(event, elements) {
      if (!isActive(elements)) {
        return false;
      }

      if (event.defaultPrevented || event.altKey || event.ctrlKey || event.metaKey || event.shiftKey) {
        return false;
      }

      if (event.key !== "ArrowLeft" && event.key !== "ArrowRight") {
        return false;
      }

      if (hasOpenModalDialog()) {
        return false;
      }

      return !isEditableKeyTarget(event.target);
    }

    function sync(elements = getElements()) {
      const sequence = getSequenceState();
      const previousKey = getTargetKey(sequence, -1);
      const nextKey = getTargetKey(sequence, 1);
      const prevButton = getPrevButton(elements);
      const nextButton = getNextButton(elements);
      const positionEl = getPositionEl(elements);

      if (prevButton) {
        prevButton.disabled = !previousKey;
      }

      if (nextButton) {
        nextButton.disabled = !nextKey;
      }

      if (positionEl) {
        positionEl.textContent = formatPositionText(sequence, elements);
      }
    }

    function step(offset, elements = getElements()) {
      const sequence = getSequenceState();
      const targetKey = getTargetKey(sequence, offset);
      if (!targetKey) {
        return false;
      }

      const didSelect = selectTarget(targetKey, elements, offset);
      if (didSelect) {
        afterSelect(targetKey, elements, offset);
      }

      return didSelect;
    }

    function bind(elements = getElements()) {
      if (!buttonsBound) {
        getPrevButton(elements)?.addEventListener("click", () => {
          step(-1, getElements());
        });

        getNextButton(elements)?.addEventListener("click", () => {
          step(1, getElements());
        });

        buttonsBound = true;
      }

      if (!keyboardBound) {
        document.addEventListener("keydown", (event) => {
          const latestElements = getElements();
          if (!shouldHandleKeyEvent(event, latestElements)) {
            return;
          }

          const offset = event.key === "ArrowRight" ? 1 : -1;
          const sequence = getSequenceState();
          if (!getTargetKey(sequence, offset)) {
            return;
          }

          event.preventDefault();
          step(offset, latestElements);
        });

        keyboardBound = true;
      }

      sync(elements);
    }

    return {
      bind,
      step,
      sync,
      getSequenceState
    };
  }

  window.TarotSequenceNav = {
    ...(window.TarotSequenceNav || {}),
    createSequenceNavigator
  };
})();