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import { addBorderNode, addDummyNode } from './util';
/*
* A nesting graph creates dummy nodes for the tops and bottoms of subgraphs,
* adds appropriate edges to ensure that all cluster nodes are placed between
* these boundries, and ensures that the graph is connected.
*
* In addition we ensure, through the use of the minlen property, that nodes
* and subgraph border nodes to not end up on the same rank.
*
* Preconditions:
*
* 1. Input graph is a DAG
* 2. Nodes in the input graph has a minlen attribute
*
* Postconditions:
*
* 1. Input graph is connected.
* 2. Dummy nodes are added for the tops and bottoms of subgraphs.
* 3. The minlen attribute for nodes is adjusted to ensure nodes do not
* get placed on the same rank as subgraph border nodes.
*
* The nesting graph idea comes from Sander, "Layout of Compound Directed
* Graphs."
*/
const run = (g) => {
const root = addDummyNode(g, 'root', {}, '_root');
const depths = treeDepths(g);
let maxDepth = Math.max(...Object.values(depths));
if (Math.abs(maxDepth) === Infinity) {
maxDepth = 1;
}
const height = maxDepth - 1; // Note: depths is an Object not an array
const nodeSep = 2 * height + 1;
// g.graph().nestingRoot = root;
// Multiply minlen by nodeSep to align nodes on non-border ranks.
g.getAllEdges().forEach((e) => {
e.data.minlen *= nodeSep;
});
// Calculate a weight that is sufficient to keep subgraphs vertically compact
const weight = sumWeights(g) + 1;
// Create border nodes and link them up
// g.children()?.forEach((child) => {
// dfs(g, root, nodeSep, weight, height, depths, child);
// });
g.getRoots().forEach((child) => {
dfs(g, root, nodeSep, weight, height, depths, child.id);
});
// Save the multiplier for node layers for later removal of empty border
// layers.
// g.graph().nodeRankFactor = nodeSep;
return {
nestingRoot: root,
nodeRankFactor: nodeSep,
};
};
const dfs = (g, root, nodeSep, weight, height, depths, v) => {
const children = g.getChildren(v);
if (!(children === null || children === void 0 ? void 0 : children.length)) {
if (v !== root) {
// g.setEdge(root, v, { weight: 0, minlen: nodeSep });
g.addEdge({
id: `e${Math.random()}`,
source: root,
target: v,
data: { weight: 0, minlen: nodeSep },
});
}
return;
}
const top = addBorderNode(g, '_bt');
const bottom = addBorderNode(g, '_bb');
const label = g.getNode(v);
g.setParent(top, v);
label.data.borderTop = top;
g.setParent(bottom, v);
label.data.borderBottom = bottom;
children === null || children === void 0 ? void 0 : children.forEach((childNode) => {
dfs(g, root, nodeSep, weight, height, depths, childNode.id);
const childTop = childNode.data.borderTop
? childNode.data.borderTop
: childNode.id;
const childBottom = childNode.data.borderBottom
? childNode.data.borderBottom
: childNode.id;
const thisWeight = childNode.data.borderTop ? weight : 2 * weight;
const minlen = childTop !== childBottom ? 1 : height - depths[v] + 1;
g.addEdge({
id: `e${Math.random()}`,
source: top,
target: childTop,
data: {
minlen,
weight: thisWeight,
nestingEdge: true,
},
});
g.addEdge({
id: `e${Math.random()}`,
source: childBottom,
target: bottom,
data: {
minlen,
weight: thisWeight,
nestingEdge: true,
},
});
});
if (!g.getParent(v)) {
g.addEdge({
id: `e${Math.random()}`,
source: root,
target: top,
data: {
weight: 0,
minlen: height + depths[v],
},
});
}
};
const treeDepths = (g) => {
const depths = {};
const dfs = (v, depth) => {
const children = g.getChildren(v);
children === null || children === void 0 ? void 0 : children.forEach((child) => dfs(child.id, depth + 1));
depths[v] = depth;
};
// g.children()?.forEach((v) => dfs(v, 1));
g.getRoots().forEach((v) => dfs(v.id, 1));
return depths;
};
const sumWeights = (g) => {
let result = 0;
g.getAllEdges().forEach((e) => {
result += e.data.weight;
});
return result;
};
const cleanup = (g, nestingRoot) => {
// const graphLabel = g.graph();
// graphLabel.nestingRoot && g.removeNode(graphLabel.nestingRoot);
// delete graphLabel.nestingRoot;
if (nestingRoot) {
g.removeNode(nestingRoot);
}
g.getAllEdges().forEach((e) => {
if (e.data.nestingEdge) {
g.removeEdge(e.id);
}
});
};
export { run, cleanup };
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