/*
 *    Copyright [2015] [wisemapping]
 *
 *   Licensed under WiseMapping Public License, Version 1.0 (the "License").
 *   It is basically the Apache License, Version 2.0 (the "License") plus the
 *   "powered by wisemapping" text requirement on every single page;
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the license at
 *
 *       http://www.wisemapping.org/license
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
const AbstractBasicSorter = require('./AbstractBasicSorter').default;

const SymmetricSorter = new Class(
  /** @lends SymmetricSorter */ {
    Extends: AbstractBasicSorter,
    /**
         * @constructs
         * @extends mindplot.layout.AbstractBasicSorter
         */
    initialize() {},

    /**
         * Predict the order and position of a dragged node.
         *
         * @param graph The tree set
         * @param parent The parent of the node
         * @param node The node
         * @param position The position of the drag
         * @param free Free drag or not
         * @return {*}
         */
    predict(graph, parent, node, position, free) {
      const self = this;
      const rootNode = graph.getRootNode(parent);

      // If its a free node...
      if (free) {
        $assert(
          $defined(position),
          'position cannot be null for predict in free positioning',
        );
        $assert($defined(node), 'node cannot be null for predict in free positioning');

        const direction = this._getRelativeDirection(
          rootNode.getPosition(),
          parent.getPosition(),
        );
        const limitXPos = parent.getPosition().x
                    + direction
                        * (parent.getSize().width / 2
                            + node.getSize().width / 2
                            + SymmetricSorter.INTERNODE_HORIZONTAL_PADDING);

        const xPos = direction > 0
          ? position.x >= limitXPos
            ? position.x
            : limitXPos
          : position.x <= limitXPos
            ? position.x
            : limitXPos;

        return [0, { x: xPos, y: position.y }];
      }

      // Its not a dragged node (it is being added)
      if (!node) {
        const parentDirection = self._getRelativeDirection(
          rootNode.getPosition(),
          parent.getPosition(),
        );

        var position = {
          x:
                        parent.getPosition().x
                        + parentDirection
                            * (parent.getSize().width + SymmetricSorter.INTERNODE_HORIZONTAL_PADDING),
          y: parent.getPosition().y,
        };
        return [graph.getChildren(parent).length, position];
      }

      // If it is a dragged node...
      $assert($defined(position), 'position cannot be null for predict in dragging');
      const nodeDirection = this._getRelativeDirection(
        rootNode.getPosition(),
        node.getPosition(),
      );
      const positionDirection = this._getRelativeDirection(rootNode.getPosition(), position);
      const siblings = graph.getSiblings(node);

      // node has no siblings and its trying to reconnect to its own parent
      const sameParent = parent == graph.getParent(node);
      if (siblings.length == 0 && nodeDirection == positionDirection && sameParent) {
        return [node.getOrder(), node.getPosition()];
      }

      const parentChildren = graph.getChildren(parent);

      if (parentChildren.length == 0) {
        // Fit as a child of the parent node...
        var position = {
          x:
                        parent.getPosition().x
                        + positionDirection
                            * (parent.getSize().width + SymmetricSorter.INTERNODE_HORIZONTAL_PADDING),
          y: parent.getPosition().y,
        };
        return [0, position];
      }
      // Try to fit within ...
      const result = null;
      const last = parentChildren.getLast();
      for (let i = 0; i < parentChildren.length; i++) {
        const parentChild = parentChildren[i];
        const nodeAfter = i + 1 == parentChild.length ? null : parentChildren[i + 1];

        // Fit at the bottom
        if (!nodeAfter && position.y > parentChild.getPosition().y) {
          var order = graph.getParent(node) && graph.getParent(node).getId() == parent.getId()
            ? last.getOrder()
            : last.getOrder() + 1;
          var position = {
            x: parentChild.getPosition().x,
            y:
                                parentChild.getPosition().y
                                + parentChild.getSize().height
                                + SymmetricSorter.INTERNODE_VERTICAL_PADDING * 2,
          };
          return [order, position];
        }

        // Fit after this node
        if (
          nodeAfter
                        && position.y > parentChild.getPosition().y
                        && position.y < nodeAfter.getPosition().y
        ) {
          if (
            nodeAfter.getId() == node.getId()
                            || parentChild.getId() == node.getId()
          ) {
            return [node.getOrder(), node.getPosition()];
          }
          var order = position.y > node.getPosition().y
            ? nodeAfter.getOrder() - 1
            : parentChild.getOrder() + 1;
          var position = {
            x: parentChild.getPosition().x,
            y:
                                    parentChild.getPosition().y
                                    + (nodeAfter.getPosition().y - parentChild.getPosition().y) / 2,
          };
          return [order, position];
        }
      }

      // Position wasn't below any node, so it must be fitted above the first
      const first = parentChildren[0];
      var position = {
        x: first.getPosition().x,
        y:
                    first.getPosition().y
                    - first.getSize().height
                    - SymmetricSorter.INTERNODE_VERTICAL_PADDING * 2,
      };
      return [0, position];
    },

    /**
         * @param treeSet
         * @param parent
         * @param child
         * @param order
         * @throws will throw an error if the order is not strictly continuous
         */
    insert(treeSet, parent, child, order) {
      const children = this._getSortedChildren(treeSet, parent);
      $assert(
        order <= children.length,
        `Order must be continues and can not have holes. Order:${order}`,
      );

      // Shift all the elements in one .
      for (let i = order; i < children.length; i++) {
        const node = children[i];
        node.setOrder(i + 1);
      }
      child.setOrder(order);
    },

    /**
         * @param treeSet
         * @param node
         * @throws will throw an error if the node is in the wrong position */
    detach(treeSet, node) {
      const parent = treeSet.getParent(node);
      const children = this._getSortedChildren(treeSet, parent);
      const order = node.getOrder();
      $assert(children[order] === node, 'Node seems not to be in the right position');

      // Shift all the nodes ...
      for (let i = node.getOrder() + 1; i < children.length; i++) {
        const child = children[i];
        child.setOrder(child.getOrder() - 1);
      }
      node.setOrder(0);
    },

    /**
         * @param treeSet
         * @param node
         * @throws will throw an error if treeSet is null or undefined
         * @throws will throw an error if node is null or undefined
         * @throws will throw an error if the calculated x offset cannot be converted to a numeric
         * value, is null or undefined
         * @throws will throw an error if the calculated y offset cannot be converted to a numeric
         * value, is null or undefined
         * @return offsets
         */
    computeOffsets(treeSet, node) {
      $assert(treeSet, 'treeSet can no be null.');
      $assert(node, 'node can no be null.');

      const children = this._getSortedChildren(treeSet, node);

      // Compute heights ...
      const heights = children
        .map(function (child) {
          return {
            id: child.getId(),
            order: child.getOrder(),
            position: child.getPosition(),
            width: child.getSize().width,
            height: this._computeChildrenHeight(treeSet, child),
          };
        }, this)
        .reverse();

      // Compute the center of the branch ...
      let totalHeight = 0;
      _.each(heights, (elem) => {
        totalHeight += elem.height;
      });
      let ysum = totalHeight / 2;

      // Calculate the offsets ...
      const result = {};
      for (let i = 0; i < heights.length; i++) {
        ysum -= heights[i].height;
        const childNode = treeSet.find(heights[i].id);
        const direction = this.getChildDirection(treeSet, childNode);

        const yOffset = ysum + heights[i].height / 2;
        const xOffset = direction
                    * (heights[i].width / 2
                        + node.getSize().width / 2
                        + SymmetricSorter.INTERNODE_HORIZONTAL_PADDING);

        $assert(!isNaN(xOffset), 'xOffset can not be null');
        $assert(!isNaN(yOffset), 'yOffset can not be null');

        result[heights[i].id] = { x: xOffset, y: yOffset };
      }
      return result;
    },

    /**
         * @param treeSet
         * @param node
         * @throws will throw an error if order elements are missing
         */
    verify(treeSet, node) {
      // Check that all is consistent ...
      const children = this._getSortedChildren(treeSet, node);

      for (let i = 0; i < children.length; i++) {
        $assert(children[i].getOrder() == i, 'missing order elements');
      }
    },

    /**
         * @param treeSet
         * @param child
         * @return direction of the given child from its parent or from the root node, if isolated */
    getChildDirection(treeSet, child) {
      $assert(treeSet, 'treeSet can no be null.');
      $assert(treeSet.getParent(child), 'This should not happen');

      let result;
      const rootNode = treeSet.getRootNode(child);
      if (treeSet.getParent(child) == rootNode) {
        // This is the case of a isolated child ... In this case, the directions is based on the root.
        result = Math.sign(rootNode.getPosition().x);
      } else {
        // if this is not the case, honor the direction of the parent ...
        const parent = treeSet.getParent(child);
        const grandParent = treeSet.getParent(parent);
        const sorter = grandParent.getSorter();
        result = sorter.getChildDirection(treeSet, parent);
      }
      return result;
    },

    /** @return {String} the print name of this class */
    toString() {
      return 'Symmetric Sorter';
    },

    _getVerticalPadding() {
      return SymmetricSorter.INTERNODE_VERTICAL_PADDING;
    },
  },
);

/**
 * @constant
 * @type {Number}
 * @default
 */
SymmetricSorter.INTERNODE_VERTICAL_PADDING = 5;
/**
 * @constant
 * @type {Number}
 * @default
 */
SymmetricSorter.INTERNODE_HORIZONTAL_PADDING = 30;

export default SymmetricSorter;