import type { Instance } from "@webstudio-is/sdk";
import { idAttribute, selectorIdAttribute } from "@webstudio-is/react-sdk";
import type { InstanceSelector } from "@webstudio-is/project-build/runtime";
import { getIsVisuallyHidden } from "./visually-hidden";

export const getInstanceIdFromElement = (
  element: Element
): Instance["id"] | undefined => {
  return element.getAttribute(idAttribute) ?? undefined;
};

// traverse dom to the root and find all instances
export const getInstanceSelectorFromElement = (element: Element) => {
  // Change logic to support Portals
  const matched: undefined | Element =
    element.closest(`[${idAttribute}]`) ?? undefined;

  const instanceSelector: InstanceSelector =
    matched?.getAttribute(selectorIdAttribute)?.split(",") ?? [];

  if (instanceSelector.length === 0) {
    return;
  }
  return instanceSelector;
};

export const getElementByInstanceSelector = (
  instanceSelector: InstanceSelector | Readonly<InstanceSelector>
) => {
  return (
    document.querySelector<HTMLElement>(
      `[${selectorIdAttribute}="${instanceSelector.join(",")}"]`
    ) ?? undefined
  );
};

// Determine if the element is detached, or lacks visual layout.
// We want to exclude elements that are display: none, option tags, or are not in the DOM
const hasLayout = (element: HTMLElement) => {
  // Detached element
  if (false === document.documentElement.contains(element)) {
    return false;
  }

  if (element.tagName.toLowerCase() === "option") {
    return false;
  }

  // Display none
  if (getComputedStyle(element)?.display?.toLowerCase() === "none") {
    return false;
  }

  return true;
};

export const getVisibleElementsByInstanceSelector = (
  instanceSelector: InstanceSelector | Readonly<InstanceSelector>
) => {
  return getElementsByInstanceSelector(instanceSelector, true);
};

export const getAllElementsByInstanceSelector = (
  instanceSelector: InstanceSelector | Readonly<InstanceSelector>
) => {
  return getElementsByInstanceSelector(instanceSelector, false);
};

/**
 * Get root visible elements, even if instance
 **/
const getElementsByInstanceSelector = (
  instanceSelector: InstanceSelector | Readonly<InstanceSelector>,
  skipHidden: boolean
) => {
  const descendantsOrSelf = [
    ...document.querySelectorAll<HTMLElement>(
      `[${selectorIdAttribute}$="${instanceSelector.join(",")}"]`
    ),
  ].filter((element) =>
    skipHidden ? getIsVisuallyHidden(element) === false : true
  );

  const visibleIdSelectors = descendantsOrSelf.map(
    (element) => element.getAttribute(selectorIdAttribute) ?? ""
  );

  // Find root selectors (i.e. selectors that are not descendants of other selectors)
  let rootSelectors = [...visibleIdSelectors];
  const isDescendant = (testSelector: string, selector: string) =>
    testSelector.endsWith(`,${selector}`);

  for (const selector of visibleIdSelectors) {
    rootSelectors = rootSelectors.filter(
      (rootSelector) => isDescendant(rootSelector, selector) === false
    );
  }

  const rootSelectorSet = new Set(rootSelectors);

  const rootElements = descendantsOrSelf.filter((element) =>
    rootSelectorSet.has(element.getAttribute(selectorIdAttribute) ?? "")
  );

  return rootElements.map((element) => {
    let elementResult: HTMLElement = element;

    while (
      skipHidden &&
      false === hasLayout(elementResult) &&
      elementResult.parentElement !== null
    ) {
      elementResult = elementResult.parentElement;
    }

    return elementResult;
  });
};

type Rect = {
  top: number;
  right: number;
  bottom: number;
  left: number;
};

const sumRects = (first: Rect, second: Rect) => {
  return {
    top: Math.min(first.top, second.top),
    right: Math.max(first.right, second.right),
    bottom: Math.max(first.bottom, second.bottom),
    left: Math.min(first.left, second.left),
  };
};

type BoundingBoxOptions = {
  fallbackToParent?: boolean;
};

const getElementsBoundingBox = (
  elements: Element[],
  options: BoundingBoxOptions,
  depth: number
): DOMRect => {
  const rects: Rect[] = [];

  if (elements.length === 0) {
    return DOMRect.fromRect({ width: 0, height: 0, x: 0, y: 0 });
  }

  for (const element of elements) {
    const rect = element.getBoundingClientRect();

    // possible display: contents
    if (rect.width !== 0 || rect.height !== 0) {
      rects.push(rect);
      continue;
    }

    if (element.children.length === 0) {
      const textNode = element.firstChild;

      if (textNode?.nodeType === Node.TEXT_NODE) {
        // Create a range object
        const range = document.createRange();
        // Set the range to encompass the text node
        range.selectNodeContents(textNode);
        // Get the bounding rectangle
        const rect = range.getBoundingClientRect();

        if (rect.width !== 0 || rect.height !== 0) {
          rects.push(rect);
          range.detach();
          continue;
        }
        range.detach();
      }
    }

    if (element.children.length > 0) {
      const childRect = getElementsBoundingBox(
        [...element.children],
        options,
        depth + 1
      );
      if (childRect.width !== 0 || childRect.height !== 0) {
        const { top, right, bottom, left } = childRect;
        rects.push({ top, right, bottom, left });
        continue;
      }
    }

    if (depth > 0 || options.fallbackToParent === false) {
      continue;
    }

    // We here, let's try ancestor size
    const parentElement = element.parentElement;
    if (parentElement === null) {
      continue;
    }
    const parentRect = getElementsBoundingBox([parentElement], {}, 0);

    if (parentRect.width !== 0 || parentRect.height !== 0) {
      const { top, right, bottom, left } = parentRect;
      rects.push({ top, right, bottom, left });
      continue;
    }
  }

  if (rects.length === 0) {
    // To preserve position even if width/height is 0
    return elements[0].getBoundingClientRect();
  }

  const { top, right, bottom, left } = rects.reduce(sumRects);

  return DOMRect.fromRect({
    x: left,
    y: top,
    height: bottom - top,
    width: right - left,
  });
};

export const getAllElementsBoundingBox = (
  elements: Element[],
  options: BoundingBoxOptions = {}
): DOMRect => {
  return getElementsBoundingBox(elements, options, 0);
};

const doNotTrackMutationAttribute = "data-ws-do-not-track-mutation";

export const doNotTrackMutation = (element: Element) => {
  element.setAttribute(doNotTrackMutationAttribute, "true");
};

export const hasDoNotTrackMutationAttribute = (element: Element) => {
  return element.hasAttribute(doNotTrackMutationAttribute);
};

export const hasDoNotTrackMutationRecord = (
  mutationRecords: MutationRecord[]
) => {
  return mutationRecords.some((record) =>
    record.type === "childList"
      ? [...record.addedNodes.values()].some(
          (node) =>
            node instanceof Element &&
            node.hasAttribute(doNotTrackMutationAttribute)
        )
      : false
  );
};

/**
 * Get a DOMMatrix mapping the container's local coords to viewport coords.
 * This uses one test DIV (width=100, height=100) placed at (0,0) in container space.
 */
const getLocalToViewportMatrix = (container: Element): DOMMatrix => {
  const rectSize = 100;

  const testDiv = document.createElement("div");
  Object.assign(testDiv.style, {
    position: "absolute",
    left: "0px",
    top: "0px",
    width: `${rectSize}px`,
    height: `${rectSize}px`,
    pointerEvents: "none",
    background: "transparent",
    visibility: "hidden",
  });
  container.appendChild(testDiv);
  testDiv.setAttribute(doNotTrackMutationAttribute, "true");

  const { left, top, width, height } = testDiv.getBoundingClientRect();
  container.removeChild(testDiv);

  const x1 = left;
  const y1 = top;
  const x2 = left + width;
  const y2 = top;
  const x3 = left;
  const y3 = top + height;

  const a = (x2 - x1) / rectSize;
  const b = (y2 - y1) / rectSize;
  const c = (x3 - x1) / rectSize;
  const d = (y3 - y1) / rectSize;
  const e = x1;
  const f = y1;

  return new DOMMatrix([a, b, c, d, e, f]);
};

const getViewportToLocalMatrix = (container: Element): DOMMatrix => {
  return getLocalToViewportMatrix(container).inverse();
};

const transformDOMRect = (rect: DOMRect, matrix: DOMMatrix) => {
  const topLeft = new DOMPoint(rect.x, rect.y).matrixTransform(matrix);
  const topRight = new DOMPoint(rect.x + rect.width, rect.y).matrixTransform(
    matrix
  );
  const bottomLeft = new DOMPoint(rect.x, rect.y + rect.height).matrixTransform(
    matrix
  );
  const bottomRight = new DOMPoint(
    rect.x + rect.width,
    rect.y + rect.height
  ).matrixTransform(matrix);

  const xs = [topLeft.x, topRight.x, bottomLeft.x, bottomRight.x];
  const ys = [topLeft.y, topRight.y, bottomLeft.y, bottomRight.y];
  const minX = Math.min(...xs);
  const maxX = Math.max(...xs);
  const minY = Math.min(...ys);
  const maxY = Math.max(...ys);

  return new DOMRect(minX, minY, maxX - minX, maxY - minY);
};

/**
 * `overflow: hidden` can be scrolled
 */
const isScrollable = (
  node: HTMLElement,
  checkForOverflow: boolean
): boolean => {
  if (!node) {
    return false;
  }
  const style = window.getComputedStyle(node);

  let isScrollable = /(auto|scroll|hidden)/.test(
    style.overflow + style.overflowX + style.overflowY
  );

  if (isScrollable && checkForOverflow) {
    isScrollable =
      node.scrollHeight !== node.clientHeight ||
      node.scrollWidth !== node.clientWidth;
  }

  return isScrollable;
};

const getScrollParent = (
  node: HTMLElement,
  checkForOverflow: boolean
): HTMLElement | null => {
  for (
    let scrollableNode = node.parentElement;
    scrollableNode !== null;
    scrollableNode = scrollableNode.parentElement
  ) {
    if (isScrollable(scrollableNode, checkForOverflow)) {
      return scrollableNode;
    }
  }

  return document.documentElement;
};

/**
 * We scroll using rectangle and anchor calculations because `scrollIntoView` does not work
 * reliably for certain elements, such as those with `display: contents`.
 * For these elements, we display a selected or hovered outline on the canvas using the
 * bounding rectangles of their children or the selection range.
 * Here, we ensure scrolling works for these elements as well.
 */
export const scrollIntoView = (anchor: HTMLElement, rect: DOMRect) => {
  const scrollParent = getScrollParent(anchor, true);

  if (false === scrollParent instanceof HTMLElement) {
    return;
  }

  requestAnimationFrame(() => {
    const savedPosition = (scrollParent as HTMLElement).style.position;
    // avoid updating <html> to prevent full page repaint and freeze on big projects
    if (scrollParent.tagName !== "HTML") {
      (scrollParent as HTMLElement).style.position = "relative";
    }

    const matrix = getViewportToLocalMatrix(scrollParent);

    const transformedRect = transformDOMRect(rect, matrix);

    const scrollDiv = document.createElement("div");

    Object.assign(scrollDiv.style, {
      position: "absolute",
      left: `${transformedRect.left}px`,
      top: `${transformedRect.top}px`,
      width: `${transformedRect.width}px`,
      height: `${transformedRect.height}px`,
      pointerEvents: "none",
      background: "transparent",
      scrollMargin: "20px",
    });
    scrollParent.appendChild(scrollDiv);

    scrollDiv.scrollIntoView({ behavior: "smooth", block: "nearest" });

    scrollParent.removeChild(scrollDiv);

    // avoid updating <html> to prevent full page repaint and freeze on big projects
    if (scrollParent.tagName !== "HTML") {
      (scrollParent as HTMLElement).style.position = savedPosition;
    }
  });
};