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*/

;(function(){ 'use strict';

  // registers the extension on a cytoscape lib ref

  var register = function( cytoscape, dagre ){

    if( !cytoscape || !dagre ){ return; } // can't register if cytoscape unspecified

    var isFunction = function(o){ return typeof o === 'function'; };

    // default layout options

    var defaults = {

      // dagre algo options, uses default value on undefined

      nodeSep: undefined, // the separation between adjacent nodes in the same rank

      edgeSep: undefined, // the separation between adjacent edges in the same rank

      rankSep: undefined, // the separation between adjacent nodes in the same rank

      rankDir: undefined, // 'TB' for top to bottom flow, 'LR' for left to right

      minLen: function( edge ){ return 1; }, // number of ranks to keep between the source and target of the edge

      edgeWeight: function( edge ){ return 1; }, // higher weight edges are generally made shorter and straighter than lower weight edges

      // general layout options

      fit: true, // whether to fit to viewport

      padding: 30, // fit padding

      animate: false, // whether to transition the node positions

      animationDuration: 500, // duration of animation in ms if enabled

      animationEasing: undefined, // easing of animation if enabled

      boundingBox: undefined, // constrain layout bounds; { x1, y1, x2, y2 } or { x1, y1, w, h }

      ready: function(){}, // on layoutready

      stop: function(){} // on layoutstop

    };

    // constructor

    // options : object containing layout options

    function DagreLayout( options ){

      var opts = this.options = {};

      for( var i in defaults ){ opts[i] = defaults[i]; }

      for( var i in options ){ opts[i] = options[i]; }

    }

    // runs the layout

    DagreLayout.prototype.run = function(){

      var options = this.options;

      var layout = this;

      var cy = options.cy; // cy is automatically populated for us in the constructor

      var eles = options.eles;

      var getVal = function( ele, val ){

        return isFunction(val) ? val.apply( ele, [ ele ] ) : val;

      };

      var bb = options.boundingBox || { x1: 0, y1: 0, w: cy.width(), h: cy.height() };

      if( bb.x2 === undefined ){ bb.x2 = bb.x1 + bb.w; }

      if( bb.w === undefined ){ bb.w = bb.x2 - bb.x1; }

      if( bb.y2 === undefined ){ bb.y2 = bb.y1 + bb.h; }

      if( bb.h === undefined ){ bb.h = bb.y2 - bb.y1; }

      var g = new dagre.graphlib.Graph({

        multigraph: true,

        compound: true

      });

      var gObj = {};

      var setGObj = function( name, val ){

        if( val != null ){

          gObj[ name ] = val;

        }

      };

      setGObj( 'nodesep', options.nodeSep );

      setGObj( 'edgesep', options.edgeSep );

      setGObj( 'ranksep', options.rankSep );

      setGObj( 'rankdir', options.rankDir );

      g.setGraph( gObj );

      g.setDefaultEdgeLabel(function() { return {}; });

      g.setDefaultNodeLabel(function() { return {}; });

      // add nodes to dagre

      var nodes = eles.nodes();

      for( var i = 0; i < nodes.length; i++ ){

        var node = nodes[i];

        var nbb = node.boundingBox();

        g.setNode( node.id(), {

          width: nbb.w,

          height: nbb.h,

          name: node.id()

        } );

        // console.log( g.node(node.id()) );

      }

      // set compound parents

      for( var i = 0; i < nodes.length; i++ ){

        var node = nodes[i];

        if( node.isChild() ){

          g.setParent( node.id(), node.parent().id() );

        }

      }

      // add edges to dagre

      var edges = eles.edges().stdFilter(function( edge ){

        return !edge.source().isParent() && !edge.target().isParent(); // dagre can't handle edges on compound nodes

      });

      for( var i = 0; i < edges.length; i++ ){

        var edge = edges[i];

        g.setEdge( edge.source().id(), edge.target().id(), {

          minlen: getVal( edge, options.minLen ),

          weight: getVal( edge, options.edgeWeight ),

          name: edge.id()

        }, edge.id() );

        // console.log( g.edge(edge.source().id(), edge.target().id(), edge.id()) );

      }

      dagre.layout( g );

      var gNodeIds = g.nodes();

      for( var i = 0; i < gNodeIds.length; i++ ){

        var id = gNodeIds[i];

        var n = g.node( id );

        cy.getElementById(id).scratch().dagre = n;

      }

      var dagreBB;

      if( options.boundingBox ){

        dagreBB = { x1: Infinity, x2: -Infinity, y1: Infinity, y2: -Infinity };

        nodes.forEach(function( node ){

          var dModel = node.scratch().dagre;

          dagreBB.x1 = Math.min( dagreBB.x1, dModel.x );

          dagreBB.x2 = Math.max( dagreBB.x2, dModel.x );

          dagreBB.y1 = Math.min( dagreBB.y1, dModel.y );

          dagreBB.y2 = Math.max( dagreBB.y2, dModel.y );

        });

        dagreBB.w = dagreBB.x2 - dagreBB.x1;

        dagreBB.h = dagreBB.y2 - dagreBB.y1;

      } else {

        dagreBB = bb;

      }

      var constrainPos = function( p ){

        if( options.boundingBox ){

          var xPct = dagreBB.w === 0 ? 0 : (p.x - dagreBB.x1) / dagreBB.w;

          var yPct = dagreBB.h === 0 ? 0 : (p.y - dagreBB.y1) / dagreBB.h;

          return {

            x: bb.x1 + xPct * bb.w,

            y: bb.y1 + yPct * bb.h

          };

        } else {

          return p;

        }

      };

      nodes.layoutPositions(layout, options, function( ele ){

        ele = typeof ele === "object" ? ele : this;

        var dModel = ele.scratch().dagre;

        return constrainPos({

          x: dModel.x,

          y: dModel.y

        });

      });

      return this; // chaining

    };

    cytoscape('layout', 'dagre', DagreLayout);

  };

  if( typeof module !== 'undefined' && module.exports ){ // expose as a commonjs module

    module.exports = function( cytoscape, dagre ){

      register( cytoscape, dagre || require('dagre') );

    };

  } else if( typeof define !== 'undefined' && define.amd ){ // expose as an amd/requirejs module

    define('cytoscape-dagre', function(){

      return register;

    });

  }

  if( typeof cytoscape !== 'undefined' && typeof dagre !== 'undefined' ){ // expose to global cytoscape (i.e. window.cytoscape)

    register( cytoscape, dagre );

  }

})();