#49 feat: servicio genérico de layout por columnas y adaptador cytoscape

src/services/graph/graph-layout.js

@@ -0,0 +1,73 @@
+/**
+ * Servicio genérico de grafos en capas (columnas).
+ *
+ * Provee un layout determinista por columnas (un tipo por columna) y un
+ * adaptador al formato `elements` de cytoscape.js. No conoce el dominio
+ * (provenance, organigrama, etc.), solo el modelo de grafo:
+ *   node: { id, kind, label, image?, entity? }
+ *   edge: { from, to }  (ids de los nodos)
+ */
+
+const DEFAULTS = {
+  columnWidth: 220,
+  rowHeight: 64,
+  padding: 24,
+}
+
+function groupByColumn (nodes, columnOf) {
+  const columns = {}
+  for (const node of nodes) {
+    const column = columnOf(node) ?? 0
+    if (!columns[column]) columns[column] = []
+    columns[column].push(node)
+  }
+  return columns
+}
+
+export function computeColumnLayout (nodes, edges, options = {}) {
+  const { columnOf, columnWidth = DEFAULTS.columnWidth, rowHeight = DEFAULTS.rowHeight, padding = DEFAULTS.padding } = options
+  const columns = groupByColumn(nodes, columnOf)
+  const columnKeys = Object.keys(columns).map(Number)
+  const maxColumn = columnKeys.length > 0 ? Math.max(...columnKeys) : 0
+  const maxRows = columnKeys.length > 0 ? Math.max(...columnKeys.map(c => columns[c].length)) : 0
+
+  const positionedNodes = nodes.map(node => {
+    const column = columnOf(node) ?? 0
+    const index = columns[column].indexOf(node)
+    return {
+      ...node,
+      x: padding + column * columnWidth + columnWidth / 2,
+      y: padding + index * rowHeight + rowHeight / 2,
+    }
+  })
+
+  return {
+    nodes: positionedNodes,
+    edges,
+    width: padding * 2 + (maxColumn + 1) * columnWidth,
+    height: padding * 2 + maxRows * rowHeight,
+  }
+}
+
+export function toCytoscapeElements ({ nodes, edges }) {
+  return [
+    ...nodes.map(node => ({
+      data: {
+        id: node.id,
+        kind: node.kind,
+        label: node.label,
+        image: node.image || null,
+        entity: node.entity || null,
+      },
+      classes: [node.kind],
+      position: { x: node.x, y: node.y },
+    })),
+    ...edges.map(edge => ({
+      data: {
+        id: `edge:${edge.from}:${edge.to}`,
+        source: edge.from,
+        target: edge.to,
+      },
+    })),
+  ]
+}