/*
 *    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: function () {},

        /**
         * 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: function (graph, parent, node, position, free) {
            var self = this;
            var 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');

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

                var 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) {
                var 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');
            var nodeDirection = this._getRelativeDirection(
                rootNode.getPosition(),
                node.getPosition()
            );
            var positionDirection = this._getRelativeDirection(rootNode.getPosition(), position);
            var siblings = graph.getSiblings(node);

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

            var 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];
            } else {
                // Try to fit within ...
                var result = null;
                var last = parentChildren.getLast();
                for (var i = 0; i < parentChildren.length; i++) {
                    var parentChild = parentChildren[i];
                    var 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()];
                        } else {
                            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
            var 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: function (treeSet, parent, child, order) {
            var 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 (var i = order; i < children.length; i++) {
                var 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: function (treeSet, node) {
            var parent = treeSet.getParent(node);
            var children = this._getSortedChildren(treeSet, parent);
            var order = node.getOrder();
            $assert(children[order] === node, 'Node seems not to be in the right position');

            // Shift all the nodes ...
            for (var i = node.getOrder() + 1; i < children.length; i++) {
                var 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: function (treeSet, node) {
            $assert(treeSet, 'treeSet can no be null.');
            $assert(node, 'node can no be null.');

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

            // Compute heights ...
            var 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 ...
            var totalHeight = 0;
            _.each(heights, function (elem) {
                totalHeight += elem.height;
            });
            var ysum = totalHeight / 2;

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

                var yOffset = ysum + heights[i].height / 2;
                var 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: function (treeSet, node) {
            // Check that all is consistent ...
            var children = this._getSortedChildren(treeSet, node);

            for (var 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: function (treeSet, child) {
            $assert(treeSet, 'treeSet can no be null.');
            $assert(treeSet.getParent(child), 'This should not happen');

            var result;
            var 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 ...
                var parent = treeSet.getParent(child);
                var grandParent = treeSet.getParent(parent);
                var sorter = grandParent.getSorter();
                result = sorter.getChildDirection(treeSet, parent);
            }
            return result;
        },

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

        _getVerticalPadding: function () {
            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;