/**
 * Internal dependencies
 */

import { toTree } from './to-tree';
import { createElement } from './create-element';
import { isRangeEqual } from './is-range-equal';

/** @typedef {import('./types').RichTextValue} RichTextValue */

/**
 * Creates a path as an array of indices from the given root node to the given
 * node.
 *
 * @param {Node}        node     Node to find the path of.
 * @param {HTMLElement} rootNode Root node to find the path from.
 * @param {Array}       path     Initial path to build on.
 *
 * @return {Array} The path from the root node to the node.
 */
function createPathToNode(node, rootNode, path) {
  const parentNode = node.parentNode;
  let i = 0;
  while (node = node.previousSibling) {
    i++;
  }
  path = [i, ...path];
  if (parentNode !== rootNode) {
    path = createPathToNode(parentNode, rootNode, path);
  }
  return path;
}

/**
 * Gets a node given a path (array of indices) from the given node.
 *
 * @param {HTMLElement} node Root node to find the wanted node in.
 * @param {Array}       path Path (indices) to the wanted node.
 *
 * @return {Object} Object with the found node and the remaining offset (if any).
 */
function getNodeByPath(node, path) {
  path = [...path];
  while (node && path.length > 1) {
    node = node.childNodes[path.shift()];
  }
  return {
    node,
    offset: path[0]
  };
}
function append(element, child) {
  if (child.html !== undefined) {
    return element.innerHTML += child.html;
  }
  if (typeof child === 'string') {
    child = element.ownerDocument.createTextNode(child);
  }
  const {
    type,
    attributes
  } = child;
  if (type) {
    child = element.ownerDocument.createElement(type);
    for (const key in attributes) {
      child.setAttribute(key, attributes[key]);
    }
  }
  return element.appendChild(child);
}
function appendText(node, text) {
  node.appendData(text);
}
function getLastChild({
  lastChild
}) {
  return lastChild;
}
function getParent({
  parentNode
}) {
  return parentNode;
}
function isText(node) {
  return node.nodeType === node.TEXT_NODE;
}
function getText({
  nodeValue
}) {
  return nodeValue;
}
function remove(node) {
  return node.parentNode.removeChild(node);
}
export function toDom({
  value,
  prepareEditableTree,
  isEditableTree = true,
  placeholder,
  doc = document
}) {
  let startPath = [];
  let endPath = [];
  if (prepareEditableTree) {
    value = {
      ...value,
      formats: prepareEditableTree(value)
    };
  }

  /**
   * Returns a new instance of a DOM tree upon which RichText operations can be
   * applied.
   *
   * Note: The current implementation will return a shared reference, reset on
   * each call to `createEmpty`. Therefore, you should not hold a reference to
   * the value to operate upon asynchronously, as it may have unexpected results.
   *
   * @return {Object} RichText tree.
   */
  const createEmpty = () => createElement(doc, '');
  const tree = toTree({
    value,
    createEmpty,
    append,
    getLastChild,
    getParent,
    isText,
    getText,
    remove,
    appendText,
    onStartIndex(body, pointer) {
      startPath = createPathToNode(pointer, body, [pointer.nodeValue.length]);
    },
    onEndIndex(body, pointer) {
      endPath = createPathToNode(pointer, body, [pointer.nodeValue.length]);
    },
    isEditableTree,
    placeholder
  });
  return {
    body: tree,
    selection: {
      startPath,
      endPath
    }
  };
}

/**
 * Create an `Element` tree from a Rich Text value and applies the difference to
 * the `Element` tree contained by `current`.
 *
 * @param {Object}        $1                       Named arguments.
 * @param {RichTextValue} $1.value                 Value to apply.
 * @param {HTMLElement}   $1.current               The live root node to apply the element tree to.
 * @param {Function}      [$1.prepareEditableTree] Function to filter editorable formats.
 * @param {boolean}       [$1.__unstableDomOnly]   Only apply elements, no selection.
 * @param {string}        [$1.placeholder]         Placeholder text.
 */
export function apply({
  value,
  current,
  prepareEditableTree,
  __unstableDomOnly,
  placeholder
}) {
  // Construct a new element tree in memory.
  const {
    body,
    selection
  } = toDom({
    value,
    prepareEditableTree,
    placeholder,
    doc: current.ownerDocument
  });
  applyValue(body, current);
  if (value.start !== undefined && !__unstableDomOnly) {
    applySelection(selection, current);
  }
}
export function applyValue(future, current) {
  let i = 0;
  let futureChild;
  while (futureChild = future.firstChild) {
    const currentChild = current.childNodes[i];
    if (!currentChild) {
      current.appendChild(futureChild);
    } else if (!currentChild.isEqualNode(futureChild)) {
      if (currentChild.nodeName !== futureChild.nodeName || currentChild.nodeType === currentChild.TEXT_NODE && currentChild.data !== futureChild.data) {
        current.replaceChild(futureChild, currentChild);
      } else {
        const currentAttributes = currentChild.attributes;
        const futureAttributes = futureChild.attributes;
        if (currentAttributes) {
          let ii = currentAttributes.length;

          // Reverse loop because `removeAttribute` on `currentChild`
          // changes `currentAttributes`.
          while (ii--) {
            const {
              name
            } = currentAttributes[ii];
            if (!futureChild.getAttribute(name)) {
              currentChild.removeAttribute(name);
            }
          }
        }
        if (futureAttributes) {
          for (let ii = 0; ii < futureAttributes.length; ii++) {
            const {
              name,
              value
            } = futureAttributes[ii];
            if (currentChild.getAttribute(name) !== value) {
              currentChild.setAttribute(name, value);
            }
          }
        }
        applyValue(futureChild, currentChild);
        future.removeChild(futureChild);
      }
    } else {
      future.removeChild(futureChild);
    }
    i++;
  }
  while (current.childNodes[i]) {
    current.removeChild(current.childNodes[i]);
  }
}
export function applySelection({
  startPath,
  endPath
}, current) {
  const {
    node: startContainer,
    offset: startOffset
  } = getNodeByPath(current, startPath);
  const {
    node: endContainer,
    offset: endOffset
  } = getNodeByPath(current, endPath);
  const {
    ownerDocument
  } = current;
  const {
    defaultView
  } = ownerDocument;
  const selection = defaultView.getSelection();
  const range = ownerDocument.createRange();
  range.setStart(startContainer, startOffset);
  range.setEnd(endContainer, endOffset);
  const {
    activeElement
  } = ownerDocument;
  if (selection.rangeCount > 0) {
    // If the to be added range and the live range are the same, there's no
    // need to remove the live range and add the equivalent range.
    if (isRangeEqual(range, selection.getRangeAt(0))) {
      return;
    }
    selection.removeAllRanges();
  }
  selection.addRange(range);

  // This function is not intended to cause a shift in focus. Since the above
  // selection manipulations may shift focus, ensure that focus is restored to
  // its previous state.
  if (activeElement !== ownerDocument.activeElement) {
    // The `instanceof` checks protect against edge cases where the focused
    // element is not of the interface HTMLElement (does not have a `focus`
    // or `blur` property).
    //
    // See: https://github.com/Microsoft/TypeScript/issues/5901#issuecomment-431649653
    if (activeElement instanceof defaultView.HTMLElement) {
      activeElement.focus();
    }
  }
}
//# sourceMappingURL=to-dom.js.map