/**
 * Copyright (c) Tiny Technologies, Inc. All rights reserved.
 * Licensed under the LGPL or a commercial license.
 * For LGPL see License.txt in the project root for license information.
 * For commercial licenses see https://www.tiny.cloud/
 */

import { Adt, Arr, Fun, Optional, Type } from '@ephox/katamari';
import { Insert, InsertAll, SugarElement, Traverse } from '@ephox/sugar';
import DOMUtils from '../api/dom/DOMUtils';
import DomTreeWalker from '../api/dom/TreeWalker';
import Editor from '../api/Editor';
import * as Settings from '../api/Settings';
import Tools from '../api/util/Tools';
import * as Bookmarks from '../bookmark/Bookmarks';
import * as NodeType from '../dom/NodeType';
import { RangeLikeObject } from '../selection/RangeTypes';
import * as RangeWalk from '../selection/RangeWalk';
import * as SelectionUtils from '../selection/SelectionUtils';
import * as SplitRange from '../selection/SplitRange';
import * as TableCellSelection from '../selection/TableCellSelection';
import * as CaretFormat from './CaretFormat';
import * as ExpandRange from './ExpandRange';
import { FormatAttrOrStyleValue, FormatVars, RemoveFormatPartial } from './FormatTypes';
import * as FormatUtils from './FormatUtils';
import * as MatchFormat from './MatchFormat';
import { mergeSiblings } from './MergeUtils';

interface RemoveFormatAdt {
  fold: <T> (
    keep: () => T,
    rename: (name: string) => T,
    removed: () => T
  ) => T;
  match: <T>(branches: {
    keep: () => T;
    rename: (name: string) => T;
    removed: () => T;
  }) => T;
  log: (label: string) => void;
}

const removeResult: {
  keep: () => RemoveFormatAdt;
  rename: (name: string) => RemoveFormatAdt;
  removed: () => RemoveFormatAdt;
} = Adt.generate([
  { keep: [] },
  { rename: [ 'name' ] },
  { removed: [] }
]);

const MCE_ATTR_RE = /^(src|href|style)$/;
const each = Tools.each;
const isEq = FormatUtils.isEq;

const isTableCellOrRow = (node: Node) => /^(TR|TH|TD)$/.test(node.nodeName);

const isChildOfInlineParent = (dom: DOMUtils, node: Node, parent: Node): boolean => dom.isChildOf(node, parent) && node !== parent && !dom.isBlock(parent);

const getContainer = (ed: Editor, rng: RangeLikeObject, start?: boolean) => {
  let container: Node, offset: number;

  container = rng[start ? 'startContainer' : 'endContainer'];
  offset = rng[start ? 'startOffset' : 'endOffset'];

  if (NodeType.isElement(container)) {
    const lastIdx = container.childNodes.length - 1;

    if (!start && offset) {
      offset--;
    }

    container = container.childNodes[offset > lastIdx ? lastIdx : offset];
  }

  // If start text node is excluded then walk to the next node
  if (NodeType.isText(container) && start && offset >= container.nodeValue.length) {
    container = new DomTreeWalker(container, ed.getBody()).next() || container;
  }

  // If end text node is excluded then walk to the previous node
  if (NodeType.isText(container) && !start && offset === 0) {
    container = new DomTreeWalker(container, ed.getBody()).prev() || container;
  }

  return container;
};

const normalizeTableSelection = (node: Node, start: boolean) => {
  const prop = start ? 'firstChild' : 'lastChild';
  if (isTableCellOrRow(node) && node[prop]) {
    const childNode = node[prop];
    if (node.nodeName === 'TR') {
      return childNode[prop] || childNode;
    } else {
      return childNode;
    }
  }

  return node;
};

const wrap = (dom: DOMUtils, node: Node, name: string, attrs?: Record<string, string>) => {
  const wrapper = dom.create(name, attrs);

  node.parentNode.insertBefore(wrapper, node);
  wrapper.appendChild(node);

  return wrapper;
};

const wrapWithSiblings = (dom: DOMUtils, node: Node, next: boolean, name: string, attrs?: Record<string, string>): Node => {
  const start = SugarElement.fromDom(node);
  const wrapper = SugarElement.fromDom(dom.create(name, attrs));
  const siblings = next ? Traverse.nextSiblings(start) : Traverse.prevSiblings(start);

  InsertAll.append(wrapper, siblings);
  if (next) {
    Insert.before(start, wrapper);
    Insert.prepend(wrapper, start);
  } else {
    Insert.after(start, wrapper);
    Insert.append(wrapper, start);
  }

  return wrapper.dom;
};

/**
 * Checks if the specified nodes name matches the format inline/block or selector.
 *
 * @private
 * @param {Node} node Node to match against the specified format.
 * @param {Object} format Format object o match with.
 * @return {boolean} true/false if the format matches.
 */
const matchName = (dom: DOMUtils, node: Node, format: RemoveFormatPartial) => {
  // Check for inline match
  if (isEq(node, format.inline)) {
    return true;
  }

  // Check for block match
  if (isEq(node, format.block)) {
    return true;
  }

  // Check for selector match
  if (format.selector) {
    return NodeType.isElement(node) && dom.is(node, format.selector);
  }
};

const isColorFormatAndAnchor = (node: Node, format: RemoveFormatPartial) => format.links && node.nodeName === 'A';

const find = (dom: DOMUtils, node: Node, next: boolean, inc?: boolean) => {
  node = FormatUtils.getNonWhiteSpaceSibling(node, next, inc);
  return !node || (node.nodeName === 'BR' || dom.isBlock(node));
};

/**
 * Removes the node and wrap it's children in paragraphs before doing so or
 * appends BR elements to the beginning/end of the block element if forcedRootBlocks is disabled.
 *
 * If the div in the node below gets removed:
 *  text<div>text</div>text
 *
 * Output becomes:
 *  text<div><br />text<br /></div>text
 *
 * So when the div is removed the result is:
 *  text<br />text<br />text
 *
 * @private
 * @param {Node} node Node to remove + apply BR/P elements to.
 * @param {Object} format Format rule.
 * @return {Node} Input node.
 */
const removeNode = (ed: Editor, node: Node, format: RemoveFormatPartial) => {
  const parentNode = node.parentNode;
  let rootBlockElm;
  const dom = ed.dom, forcedRootBlock = Settings.getForcedRootBlock(ed);

  if (format.block) {
    if (!forcedRootBlock) {
      // Append BR elements if needed before we remove the block
      if (dom.isBlock(node) && !dom.isBlock(parentNode)) {
        if (!find(dom, node, false) && !find(dom, node.firstChild, true, true)) {
          node.insertBefore(dom.create('br'), node.firstChild);
        }

        if (!find(dom, node, true) && !find(dom, node.lastChild, false, true)) {
          node.appendChild(dom.create('br'));
        }
      }
    } else {
      // Wrap the block in a forcedRootBlock if we are at the root of document
      if (parentNode === dom.getRoot()) {
        if (!format.list_block || !isEq(node, format.list_block)) {
          Arr.each(Arr.from(node.childNodes), (node) => {
            if (FormatUtils.isValid(ed, forcedRootBlock, node.nodeName.toLowerCase())) {
              if (!rootBlockElm) {
                rootBlockElm = wrap(dom, node, forcedRootBlock);
                dom.setAttribs(rootBlockElm, ed.settings.forced_root_block_attrs);
              } else {
                rootBlockElm.appendChild(node);
              }
            } else {
              rootBlockElm = 0;
            }
          });
        }
      }
    }
  }

  // Never remove nodes that isn't the specified inline element if a selector is specified too
  if (format.selector && format.inline && !isEq(format.inline, node)) {
    return;
  }

  dom.remove(node, true);
};

const removeFormatInternal = (ed: Editor, format: RemoveFormatPartial, vars?: FormatVars, node?: Node, compareNode?: Node): RemoveFormatAdt => {
  let stylesModified: boolean;
  const dom = ed.dom;

  // Check if node matches format
  if (!matchName(dom, node, format) && !isColorFormatAndAnchor(node, format)) {
    return removeResult.keep();
  }

  // "matchName" will made sure we're dealing with an element, so cast as one
  const elm = node as Element;

  // Applies to styling elements like strong, em, i, u, etc. so that if they have styling attributes, the attributes can be kept but the styling element is removed
  if (format.inline && format.remove === 'all' && Type.isArray(format.preserve_attributes)) {
    // Remove all attributes except for the attributes specified in preserve_attributes
    const attrsToPreserve = Arr.filter(dom.getAttribs(elm), (attr) => Arr.contains(format.preserve_attributes, attr.name.toLowerCase()));
    dom.removeAllAttribs(elm);
    Arr.each(attrsToPreserve, (attr) => dom.setAttrib(elm, attr.name, attr.value));
    // Note: If there are no attributes left, the element will be removed as normal at the end of the function
    if (attrsToPreserve.length > 0) {
      // Convert inline element to span if necessary
      return removeResult.rename('span');
    }
  }

  // Should we compare with format attribs and styles
  if (format.remove !== 'all') {
    // Remove styles
    each(format.styles as any, (value: FormatAttrOrStyleValue, name: string | number) => {
      value = FormatUtils.normalizeStyleValue(dom, FormatUtils.replaceVars(value, vars), name + '');

      // Indexed array
      if (Type.isNumber(name)) {
        name = value;
        compareNode = null;
      }

      if (format.remove_similar || (!compareNode || isEq(FormatUtils.getStyle(dom, compareNode, name), value))) {
        dom.setStyle(elm, name, '');
      }

      stylesModified = true;
    });

    // Remove style attribute if it's empty
    if (stylesModified && dom.getAttrib(elm, 'style') === '') {
      elm.removeAttribute('style');
      elm.removeAttribute('data-mce-style');
    }

    // Remove attributes
    each(format.attributes as any, (value: FormatAttrOrStyleValue, name: string | number) => {
      let valueOut: string;

      value = FormatUtils.replaceVars(value, vars);

      // Indexed array
      if (Type.isNumber(name)) {
        name = value;
        compareNode = null;
      }

      if (format.remove_similar || (!compareNode || isEq(dom.getAttrib(compareNode, name), value))) {
        // Keep internal classes
        if (name === 'class') {
          value = dom.getAttrib(elm, name);
          if (value) {
            // Build new class value where everything is removed except the internal prefixed classes
            valueOut = '';
            Arr.each(value.split(/\s+/), (cls) => {
              if (/mce\-\w+/.test(cls)) {
                valueOut += (valueOut ? ' ' : '') + cls;
              }
            });

            // We got some internal classes left
            if (valueOut) {
              dom.setAttrib(elm, name, valueOut);
              return;
            }
          }
        }

        // Remove mce prefixed attributes (must clean before short circuit operations)
        if (MCE_ATTR_RE.test(name)) {
          elm.removeAttribute('data-mce-' + name);
        }

        // keep style="list-style-type: none" on <li>s
        if (name === 'style' && NodeType.matchNodeNames([ 'li' ])(elm) && dom.getStyle(elm, 'list-style-type') === 'none') {
          elm.removeAttribute(name);
          dom.setStyle(elm, 'list-style-type', 'none');
          return;
        }

        // IE6 has a bug where the attribute doesn't get removed correctly
        if (name === 'class') {
          elm.removeAttribute('className');
        }

        elm.removeAttribute(name);
      }
    });

    // Remove classes
    each(format.classes, (value) => {
      value = FormatUtils.replaceVars(value, vars);

      if (!compareNode || dom.hasClass(compareNode, value)) {
        dom.removeClass(elm, value);
      }
    });

    // Check for non internal attributes
    const attrs = dom.getAttribs(elm);
    for (let i = 0; i < attrs.length; i++) {
      const attrName = attrs[i].nodeName;
      if (attrName.indexOf('_') !== 0 && attrName.indexOf('data-') !== 0) {
        return removeResult.keep();
      }
    }
  }

  // Remove the inline child if it's empty for example <b> or <span>
  if (format.remove !== 'none') {
    removeNode(ed, elm, format);
    return removeResult.removed();
  }

  return removeResult.keep();
};

/**
 * Removes the specified format for the specified node. It will also remove the node if it doesn't have
 * any attributes if the format specifies it to do so.
 *
 * @private
 * @param {Object} format Format object with items to remove from node.
 * @param {Object} vars Name/value object with variables to apply to format.
 * @param {Node} node Node to remove the format styles on.
 * @param {Node} compareNode Optional compare node, if specified the styles will be compared to that node.
 * @return {Boolean} True/false if the node was removed or not.
 */
const removeFormat = (ed: Editor, format: RemoveFormatPartial, vars?: FormatVars, node?: Node, compareNode?: Node): boolean =>
  removeFormatInternal(ed, format, vars, node, compareNode).fold(
    Fun.never,
    (newName) => {
      // If renaming we are guaranteed this is a Element, so cast
      ed.dom.rename(node as Element, newName);
      return true;
    },
    Fun.always
  );

const findFormatRoot = (editor: Editor, container: Node, name: string, vars: FormatVars, similar: boolean) => {
  let formatRoot: Node;

  // Find format root
  Arr.each(FormatUtils.getParents(editor.dom, container.parentNode).reverse(), (parent) => {
    // Find format root element
    if (!formatRoot && parent.id !== '_start' && parent.id !== '_end') {
      // Is the node matching the format we are looking for
      const format = MatchFormat.matchNode(editor, parent, name, vars, similar);
      if (format && format.split !== false) {
        formatRoot = parent;
      }
    }
  });

  return formatRoot;
};

const removeFormatFromClone = (editor: Editor, format: RemoveFormatPartial, vars: FormatVars, clone: Node) =>
  removeFormatInternal(editor, format, vars, clone, clone).fold(
    Fun.constant(clone),
    (newName) => {
      // To rename a node, it needs to be a child of another node
      const fragment = editor.dom.createFragment();
      fragment.appendChild(clone);
      // If renaming we are guaranteed this is a Element, so cast
      return editor.dom.rename(clone as Element, newName);
    },
    Fun.constant(null)
  );

const wrapAndSplit = (editor: Editor, formatList: RemoveFormatPartial[], formatRoot: Node, container: Node, target: Node, split: boolean, format: RemoveFormatPartial, vars: FormatVars) => {
  let clone: Node | null, lastClone: Node, firstClone: Node;
  const dom = editor.dom;

  // Format root found then clone formats and split it
  if (formatRoot) {
    const formatRootParent = formatRoot.parentNode;

    for (let parent = container.parentNode; parent && parent !== formatRootParent; parent = parent.parentNode) {
      clone = dom.clone(parent, false);

      for (let i = 0; i < formatList.length; i++) {
        clone = removeFormatFromClone(editor, formatList[i], vars, clone);
        if (clone === null) {
          break;
        }
      }

      // Build wrapper node
      if (clone) {
        if (lastClone) {
          clone.appendChild(lastClone);
        }

        if (!firstClone) {
          firstClone = clone;
        }

        lastClone = clone;
      }
    }

    // Never split block elements if the format is mixed
    if (split && (!format.mixed || !dom.isBlock(formatRoot))) {
      container = dom.split(formatRoot, container);
    }

    // Wrap container in cloned formats
    if (lastClone) {
      target.parentNode.insertBefore(lastClone, target);
      firstClone.appendChild(target);

      // After splitting the nodes may match with other siblings so we need to attempt to merge them
      // Note: We can't use MergeFormats, as that'd create a circular dependency
      if (format.inline) {
        mergeSiblings(dom, format, vars, lastClone);
      }
    }
  }

  return container;
};

const remove = (ed: Editor, name: string, vars?: FormatVars, node?: Node | Range, similar?: boolean) => {
  const formatList = ed.formatter.get(name) as RemoveFormatPartial[];
  const format = formatList[0];
  let contentEditable = true;
  const dom = ed.dom;
  const selection = ed.selection;

  const splitToFormatRoot = (container: Node) => {
    const formatRoot = findFormatRoot(ed, container, name, vars, similar);
    return wrapAndSplit(ed, formatList, formatRoot, container, container, true, format, vars);
  };

  // Make sure to only check for bookmarks created here (eg _start or _end)
  // as there maybe nested bookmarks
  const isRemoveBookmarkNode = (node: Node) => Bookmarks.isBookmarkNode(node) && NodeType.isElement(node) && (node.id === '_start' || node.id === '_end');

  // Merges the styles for each node
  const process = (node: Node) => {
    let lastContentEditable: boolean, hasContentEditableState: boolean;

    // TINY-6567 Include the last node in the selection
    const parentNode = node.parentNode;
    if (NodeType.isText(node) && FormatUtils.hasBlockChildren(dom, parentNode)) {
      removeFormat(ed, format, vars, parentNode, parentNode);
    }

    // Node has a contentEditable value
    if (NodeType.isElement(node) && dom.getContentEditable(node)) {
      lastContentEditable = contentEditable;
      contentEditable = dom.getContentEditable(node) === 'true';
      hasContentEditableState = true; // We don't want to wrap the container only it's children
    }

    // Grab the children first since the nodelist might be changed
    const children = Arr.from(node.childNodes);

    // Process current node
    if (contentEditable && !hasContentEditableState) {
      for (let i = 0; i < formatList.length; i++) {
        if (removeFormat(ed, formatList[i], vars, node, node)) {
          break;
        }
      }
    }

    // Process the children
    if (format.deep) {
      if (children.length) {
        for (let i = 0; i < children.length; i++) {
          process(children[i]);
        }

        if (hasContentEditableState) {
          contentEditable = lastContentEditable; // Restore last contentEditable state from stack
        }
      }
    }
  };

  const unwrap = (start?: boolean) => {
    const node = dom.get(start ? '_start' : '_end');
    let out = node[start ? 'firstChild' : 'lastChild'];

    // If the end is placed within the start the result will be removed
    // So this checks if the out node is a bookmark node if it is it
    // checks for another more suitable node
    if (isRemoveBookmarkNode(out)) {
      out = out[start ? 'firstChild' : 'lastChild'];
    }

    // Since dom.remove removes empty text nodes then we need to try to find a better node
    if (NodeType.isText(out) && out.data.length === 0) {
      out = start ? node.previousSibling || node.nextSibling : node.nextSibling || node.previousSibling;
    }

    dom.remove(node, true);

    return out;
  };

  const removeRngStyle = (rng: Range) => {
    let startContainer: Node, endContainer: Node;

    let expandedRng = ExpandRange.expandRng(ed, rng, formatList, rng.collapsed);

    if (format.split) {
      // Split text nodes
      expandedRng = SplitRange.split(expandedRng);

      startContainer = getContainer(ed, expandedRng, true);
      endContainer = getContainer(ed, expandedRng);

      if (startContainer !== endContainer) {
        // WebKit will render the table incorrectly if we wrap a TH or TD in a SPAN
        // so let's see if we can use the first/last child instead
        // This will happen if you triple click a table cell and use remove formatting
        startContainer = normalizeTableSelection(startContainer, true);
        endContainer = normalizeTableSelection(endContainer, false);

        // Wrap and split if nested
        if (isChildOfInlineParent(dom, startContainer, endContainer)) {
          const marker = Optional.from(startContainer.firstChild).getOr(startContainer);
          splitToFormatRoot(wrapWithSiblings(dom, marker, true, 'span', { 'id': '_start', 'data-mce-type': 'bookmark' }));
          unwrap(true);
          return;
        }

        // Wrap and split if nested
        if (isChildOfInlineParent(dom, endContainer, startContainer)) {
          const marker = Optional.from(endContainer.lastChild).getOr(endContainer);
          splitToFormatRoot(wrapWithSiblings(dom, marker, false, 'span', { 'id': '_end', 'data-mce-type': 'bookmark' }));
          unwrap(false);
          return;
        }

        // Wrap start/end nodes in span element since these might be cloned/moved
        startContainer = wrap(dom, startContainer, 'span', { 'id': '_start', 'data-mce-type': 'bookmark' });
        endContainer = wrap(dom, endContainer, 'span', { 'id': '_end', 'data-mce-type': 'bookmark' });

        // Split start/end and anything in between
        const newRng = dom.createRng();
        newRng.setStartAfter(startContainer);
        newRng.setEndBefore(endContainer);
        RangeWalk.walk(dom, newRng, (nodes) => {
          Arr.each(nodes, (n) => {
            if (!Bookmarks.isBookmarkNode(n) && !Bookmarks.isBookmarkNode(n.parentNode)) {
              splitToFormatRoot(n);
            }
          });
        });
        splitToFormatRoot(startContainer);
        splitToFormatRoot(endContainer);

        // Unwrap start/end to get real elements again
        startContainer = unwrap(true);
        endContainer = unwrap();
      } else {
        startContainer = endContainer = splitToFormatRoot(startContainer);
      }

      // Update range positions since they might have changed after the split operations
      expandedRng.startContainer = startContainer.parentNode ? startContainer.parentNode : startContainer;
      expandedRng.startOffset = dom.nodeIndex(startContainer);
      expandedRng.endContainer = endContainer.parentNode ? endContainer.parentNode : endContainer;
      expandedRng.endOffset = dom.nodeIndex(endContainer) + 1;
    }

    // Remove items between start/end
    RangeWalk.walk(dom, expandedRng, (nodes) => {
      Arr.each(nodes, (node) => {
        process(node);

        // Note: Assists with cleaning up any stray text decorations that may been applied when text decorations
        // and text colors were merged together from a applied format
        // Remove child span if it only contains text-decoration and a parent node also has the same text decoration.
        const textDecorations = [ 'underline', 'line-through', 'overline' ];
        Arr.each(textDecorations, (decoration) => {
          if (NodeType.isElement(node) && ed.dom.getStyle(node, 'text-decoration') === decoration &&
            node.parentNode && FormatUtils.getTextDecoration(dom, node.parentNode) === decoration) {
            removeFormat(ed, {
              deep: false,
              exact: true,
              inline: 'span',
              styles: {
                textDecoration: decoration
              }
            }, null, node);
          }
        });
      });
    });
  };

  // Handle node
  if (node) {
    if (FormatUtils.isNode(node)) {
      const rng = dom.createRng();
      rng.setStartBefore(node);
      rng.setEndAfter(node);
      removeRngStyle(rng);
    } else {
      removeRngStyle(node);
    }

    return;
  }

  if (dom.getContentEditable(selection.getNode()) === 'false') {
    node = selection.getNode();
    for (let i = 0; i < formatList.length; i++) {
      if (formatList[i].ceFalseOverride) {
        if (removeFormat(ed, formatList[i], vars, node, node)) {
          break;
        }
      }
    }

    return;
  }

  if (!selection.isCollapsed() || !format.inline || TableCellSelection.getCellsFromEditor(ed).length) {
    // Remove formatting on the selection
    SelectionUtils.preserve(selection, true, () => {
      SelectionUtils.runOnRanges(ed, removeRngStyle);
    });

    // Check if start element still has formatting then we are at: "<b>text|</b>text"
    // and need to move the start into the next text node
    if (format.inline && MatchFormat.match(ed, name, vars, selection.getStart())) {
      FormatUtils.moveStart(dom, selection, selection.getRng());
    }

    ed.nodeChanged();
  } else {
    CaretFormat.removeCaretFormat(ed, name, vars, similar);
  }
};

export {
  removeFormat,
  remove
};
