(function (Drupal) {
  "use strict";

  Drupal.behaviors.nouisliderYearFormat = {
    // Weight needs to be higher than the module's behavior so we run after it.
    // Drupal behaviors don't have explicit weight in this API, but attaching
    // after DOM ready is fine since once() ensures the module ran first.
    attach: function (context, settings) {
      const sliderEl = context.querySelector("#year.noUi-target");

      if (!sliderEl || !sliderEl.noUiSlider) return;
      if (sliderEl.dataset.yearFormatApplied) return;
      sliderEl.dataset.yearFormatApplied = "true";

      const inputFrom = document.getElementById("nouislider-input-from");
      const inputTo = document.getElementById("nouislider-input-to");

      // The module's update listener gives inputs the raw float (e.g. 1971.00)
      // because no top-level format is set on the slider. We add our own
      // update listener that overwrites the input value with a rounded integer.
      // 'update' fires on drag but does NOT trigger navigation — only 'set' does.
      sliderEl.noUiSlider.on("update", function (values, handle) {
        const rounded = Math.round(parseFloat(values[handle]));
        if (handle === 0 && inputFrom) inputFrom.value = rounded;
        if (handle === 1 && inputTo) inputTo.value = rounded;
      });

      // Fix the current displayed values in the inputs immediately
      const current = sliderEl.noUiSlider.get();
      if (inputFrom) inputFrom.value = Math.round(parseFloat(current[0]));
      if (inputTo) inputTo.value = Math.round(parseFloat(current[1]));
    },
  };
})(Drupal);