/*
 *    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 Node = require('./Node').default;
const SymmetricSorter = require('./SymmetricSorter').default;
const BalancedSorter = require('./BalancedSorter').default;

const OriginalLayout = new Class(
  /** @lends OriginalLayout */ {
    /**
         * @constructs
         * @param treeSet
         */
    initialize(treeSet) {
      this._treeSet = treeSet;
    },

    /** */
    createNode(id, size, position, type) {
      $assert($defined(id), 'id can not be null');
      $assert(size, 'size can not be null');
      $assert(position, 'position can not be null');
      $assert(type, 'type can not be null');

      const strategy = type === 'root' ? OriginalLayout.BALANCED_SORTER : OriginalLayout.SYMMETRIC_SORTER;
      return new Node(id, size, position, strategy);
    },

    /** */
    connectNode(parentId, childId, order) {
      const parent = this._treeSet.find(parentId);
      const child = this._treeSet.find(childId);

      // Insert the new node ...
      const sorter = parent.getSorter();
      sorter.insert(this._treeSet, parent, child, order);

      // Connect the new node ...
      this._treeSet.connect(parentId, childId);

      // Fire a basic validation ...
      sorter.verify(this._treeSet, parent);
    },

    /** */
    disconnectNode(nodeId) {
      const node = this._treeSet.find(nodeId);
      const parent = this._treeSet.getParent(node);
      $assert(parent, 'Node already disconnected');

      // Make it fixed
      node.setFree(false);
      node.resetFreeDisplacement();

      // Remove from children list.
      const sorter = parent.getSorter();
      sorter.detach(this._treeSet, node);

      // Disconnect the new node ...
      this._treeSet.disconnect(nodeId);

      // Fire a basic validation ...
      parent.getSorter().verify(this._treeSet, parent);
    },

    /** */
    layout() {
      const roots = this._treeSet.getTreeRoots();
      _.each(
        roots,
        function (node) {
          // Calculate all node heights ...
          const sorter = node.getSorter();

          const heightById = sorter.computeChildrenIdByHeights(this._treeSet, node);

          this._layoutChildren(node, heightById);

          this._fixOverlapping(node, heightById);
        },
        this,
      );
    },

    _layoutChildren(node, heightById) {
      const nodeId = node.getId();
      const children = this._treeSet.getChildren(node);
      const parent = this._treeSet.getParent(node);
      const childrenOrderMoved = children.some((child) => child.hasOrderChanged());
      const childrenSizeChanged = children.some((child) => child.hasSizeChanged());

      // If ether any of the nodes has been changed of position or the height of the children is not
      // the same, children nodes must be repositioned ....
      const newBranchHeight = heightById[nodeId];

      const parentHeightChanged = $defined(parent) ? parent._heightChanged : false;
      const heightChanged = node._branchHeight != newBranchHeight;
      node._heightChanged = heightChanged || parentHeightChanged;

      if (childrenOrderMoved || childrenSizeChanged || heightChanged || parentHeightChanged) {
        const sorter = node.getSorter();
        const offsetById = sorter.computeOffsets(this._treeSet, node);
        const parentPosition = node.getPosition();
        const me = this;
        _.each(children, (child) => {
          const offset = offsetById[child.getId()];

          const childFreeDisplacement = child.getFreeDisplacement();
          const direction = node.getSorter().getChildDirection(me._treeSet, child);

          if (
            (direction > 0 && childFreeDisplacement.x < 0)
                        || (direction < 0 && childFreeDisplacement.x > 0)
          ) {
            child.resetFreeDisplacement();
            child.setFreeDisplacement({
              x: -childFreeDisplacement.x,
              y: childFreeDisplacement.y,
            });
          }

          offset.x += child.getFreeDisplacement().x;
          offset.y += child.getFreeDisplacement().y;

          const parentX = parentPosition.x;
          const parentY = parentPosition.y;

          const newPos = {
            x: parentX + offset.x,
            y: parentY + offset.y + me._calculateAlignOffset(node, child, heightById),
          };
          me._treeSet.updateBranchPosition(child, newPos);
        });

        node._branchHeight = newBranchHeight;
      }

      // Continue reordering the children nodes ...
      _.each(
        children,
        function (child) {
          this._layoutChildren(child, heightById);
        },
        this,
      );
    },

    _calculateAlignOffset(node, child, heightById) {
      if (child.isFree()) {
        return 0;
      }

      let offset = 0;

      const nodeHeight = node.getSize().height;
      const childHeight = child.getSize().height;

      if (
        this._treeSet.isStartOfSubBranch(child)
                && this._branchIsTaller(child, heightById)
      ) {
        if (this._treeSet.hasSinglePathToSingleLeaf(child)) {
          offset = heightById[child.getId()] / 2
                        - (childHeight + child.getSorter()._getVerticalPadding() * 2) / 2;
        } else {
          offset = this._treeSet.isLeaf(child) ? 0 : -(childHeight - nodeHeight) / 2;
        }
      } else if (nodeHeight > childHeight) {
        if (this._treeSet.getSiblings(child).length > 0) {
          offset = 0;
        } else {
          offset = nodeHeight / 2 - childHeight / 2;
        }
      } else if (childHeight > nodeHeight) {
        if (this._treeSet.getSiblings(child).length > 0) {
          offset = 0;
        } else {
          offset = -(childHeight / 2 - nodeHeight / 2);
        }
      }

      return offset;
    },

    _branchIsTaller(node, heightById) {
      return (
        heightById[node.getId()]
                > node.getSize().height + node.getSorter()._getVerticalPadding() * 2
      );
    },

    _fixOverlapping(node, heightById) {
      const children = this._treeSet.getChildren(node);

      if (node.isFree()) {
        this._shiftBranches(node, heightById);
      }

      _.each(
        children,
        function (child) {
          this._fixOverlapping(child, heightById);
        },
        this,
      );
    },

    _shiftBranches(node, heightById) {
      const shiftedBranches = [node];

      const siblingsToShift = this._treeSet.getSiblingsInVerticalDirection(
        node,
        node.getFreeDisplacement().y,
      );
      let last = node;
      _.each(
        siblingsToShift,
        function (sibling) {
          const overlappingOccurs = shiftedBranches.some(function (shiftedBranch) {
            return this._branchesOverlap(shiftedBranch, sibling, heightById);
          }, this);

          if (!sibling.isFree() || overlappingOccurs) {
            const sAmount = node.getFreeDisplacement().y;
            this._treeSet.shiftBranchPosition(sibling, 0, sAmount);
            shiftedBranches.push(sibling);
          }
        },
        this,
      );

      const branchesToShift = this._treeSet
        .getBranchesInVerticalDirection(node, node.getFreeDisplacement().y)
        .filter((branch) => !shiftedBranches.contains(branch));

      _.each(
        branchesToShift,
        function (branch) {
          const bAmount = node.getFreeDisplacement().y;
          this._treeSet.shiftBranchPosition(branch, 0, bAmount);
          shiftedBranches.push(branch);
          last = branch;
        },
        this,
      );
    },

    _branchesOverlap(branchA, branchB, heightById) {
      // a branch doesn't really overlap with itself
      if (branchA == branchB) {
        return false;
      }

      const topA = branchA.getPosition().y - heightById[branchA.getId()] / 2;
      const bottomA = branchA.getPosition().y + heightById[branchA.getId()] / 2;
      const topB = branchB.getPosition().y - heightById[branchB.getId()] / 2;
      const bottomB = branchB.getPosition().y + heightById[branchB.getId()] / 2;

      return !(topA >= bottomB || bottomA <= topB);
    },
  },
);

/**
 * @type {mindplot.layout.SymmetricSorter}
 */
OriginalLayout.SYMMETRIC_SORTER = new SymmetricSorter();
/**
 * @type {mindplot.layout.BalancedSorter}
 */
OriginalLayout.BALANCED_SORTER = new BalancedSorter();

export default OriginalLayout;