1 files changed, 309 insertions, 0 deletions

diff --git a/subprojects/frontend/src/graph/dotSource.ts b/subprojects/frontend/src/graph/dotSource.ts
new file mode 100644
index 00000000..bf45d303
--- /dev/null
+++ b/subprojects/frontend/src/graph/dotSource.ts
@@ -0,0 +1,309 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+import type {
+  NodeMetadata,
+  RelationMetadata,
+} from '../xtext/xtextServiceResults';
+
+import type GraphStore from './GraphStore';
+
+const EDGE_WEIGHT = 1;
+const CONTAINMENT_WEIGHT = 5;
+const UNKNOWN_WEIGHT_FACTOR = 0.5;
+
+function nodeName({ simpleName, kind }: NodeMetadata): string {
+  switch (kind) {
+    case 'INDIVIDUAL':
+      return `<b>${simpleName}</b>`;
+    case 'NEW':
+      return `<i>${simpleName}</i>`;
+    default:
+      return simpleName;
+  }
+}
+
+function relationName({ simpleName, detail }: RelationMetadata): string {
+  if (detail.type === 'class' && detail.abstractClass) {
+    return `<i>${simpleName}</i>`;
+  }
+  if (detail.type === 'reference' && detail.containment) {
+    return `<b>${simpleName}</b>`;
+  }
+  return simpleName;
+}
+
+interface NodeData {
+  exists: string;
+  equalsSelf: string;
+  unaryPredicates: Map<RelationMetadata, string>;
+}
+
+function computeNodeData(graph: GraphStore): NodeData[] {
+  const {
+    semantics: { nodes, relations, partialInterpretation },
+  } = graph;
+
+  const nodeData = Array.from(Array(nodes.length)).map(() => ({
+    exists: 'FALSE',
+    equalsSelf: 'FALSE',
+    unaryPredicates: new Map(),
+  }));
+
+  relations.forEach((relation) => {
+    if (relation.arity !== 1) {
+      return;
+    }
+    const visibility = graph.getVisiblity(relation.name);
+    if (visibility === 'none') {
+      return;
+    }
+    const interpretation = partialInterpretation[relation.name] ?? [];
+    interpretation.forEach(([index, value]) => {
+      if (
+        typeof index === 'number' &&
+        typeof value === 'string' &&
+        (visibility === 'all' || value !== 'UNKNOWN')
+      ) {
+        nodeData[index]?.unaryPredicates?.set(relation, value);
+      }
+    });
+  });
+
+  partialInterpretation['builtin::exists']?.forEach(([index, value]) => {
+    if (typeof index === 'number' && typeof value === 'string') {
+      const data = nodeData[index];
+      if (data !== undefined) {
+        data.exists = value;
+      }
+    }
+  });
+
+  partialInterpretation['builtin::equals']?.forEach(([index, other, value]) => {
+    if (
+      typeof index === 'number' &&
+      index === other &&
+      typeof value === 'string'
+    ) {
+      const data = nodeData[index];
+      if (data !== undefined) {
+        data.equalsSelf = value;
+      }
+    }
+  });
+
+  return nodeData;
+}
+
+function createNodes(graph: GraphStore, lines: string[]): void {
+  const nodeData = computeNodeData(graph);
+  const {
+    semantics: { nodes },
+  } = graph;
+
+  nodes.forEach((node, i) => {
+    const data = nodeData[i];
+    if (data === undefined) {
+      return;
+    }
+    const classes = [
+      `node-${node.kind} node-exists-${data.exists} node-equalsSelf-${data.equalsSelf}`,
+    ].join(' ');
+    const name = nodeName(node);
+    const border = node.kind === 'INDIVIDUAL' ? 2 : 1;
+    lines.push(`n${i} [id="${node.name}", class="${classes}", label=<
+        <table border="${border}" cellborder="0" cellspacing="0" style="rounded" bgcolor="white">
+          <tr><td cellpadding="4.5" width="32" bgcolor="green">${name}</td></tr>`);
+    if (data.unaryPredicates.size > 0) {
+      lines.push(
+        '<hr/><tr><td cellpadding="4.5"><table fixedsize="TRUE" align="left" border="0" cellborder="0" cellspacing="0" cellpadding="1.5">',
+      );
+      data.unaryPredicates.forEach((value, relation) => {
+        lines.push(
+          `<tr>
+              <td><img src="#${value}"/></td>
+              <td width="1.5"></td>
+              <td align="left" href="#${value}" id="${node.name},${
+                relation.name
+              },label">${relationName(relation)}</td>
+            </tr>`,
+        );
+      });
+      lines.push('</table></td></tr>');
+    }
+    lines.push('</table>>]');
+  });
+}
+
+function compare(
+  a: readonly (number | string)[],
+  b: readonly number[],
+): number {
+  if (a.length !== b.length + 1) {
+    throw new Error('Tuple length mismatch');
+  }
+  for (let i = 0; i < b.length; i += 1) {
+    const aItem = a[i];
+    const bItem = b[i];
+    if (typeof aItem !== 'number' || typeof bItem !== 'number') {
+      throw new Error('Invalid tuple');
+    }
+    if (aItem < bItem) {
+      return -1;
+    }
+    if (aItem > bItem) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+function binarySerach(
+  tuples: readonly (readonly (number | string)[])[],
+  key: readonly number[],
+): string | undefined {
+  let lower = 0;
+  let upper = tuples.length - 1;
+  while (lower <= upper) {
+    const middle = Math.floor((lower + upper) / 2);
+    const tuple = tuples[middle];
+    if (tuple === undefined) {
+      throw new Error('Range error');
+    }
+    const result = compare(tuple, key);
+    if (result === 0) {
+      const found = tuple[key.length];
+      if (typeof found !== 'string') {
+        throw new Error('Invalid tuple value');
+      }
+      return found;
+    }
+    if (result < 0) {
+      lower = middle + 1;
+    } else {
+      // result > 0
+      upper = middle - 1;
+    }
+  }
+  return undefined;
+}
+
+function createRelationEdges(
+  graph: GraphStore,
+  relation: RelationMetadata,
+  showUnknown: boolean,
+  lines: string[],
+): void {
+  const {
+    semantics: { nodes, partialInterpretation },
+  } = graph;
+  const { detail } = relation;
+
+  let constraint: 'true' | 'false' = 'true';
+  let weight = EDGE_WEIGHT;
+  let penwidth = 1;
+  let label = `"${relation.simpleName}"`;
+  if (detail.type === 'reference' && detail.containment) {
+    weight = CONTAINMENT_WEIGHT;
+    label = `<<b>${relation.simpleName}</b>>`;
+    penwidth = 2;
+  } else if (
+    detail.type === 'opposite' &&
+    graph.getVisiblity(detail.opposite) !== 'none'
+  ) {
+    constraint = 'false';
+    weight = 0;
+  }
+
+  const tuples = partialInterpretation[relation.name] ?? [];
+  tuples.forEach(([from, to, value]) => {
+    const isUnknown = value === 'UNKNOWN';
+    if (
+      (!showUnknown && isUnknown) ||
+      typeof from !== 'number' ||
+      typeof to !== 'number' ||
+      typeof value !== 'string'
+    ) {
+      return;
+    }
+
+    const fromNode = nodes[from];
+    const toNode = nodes[to];
+    if (fromNode === undefined || toNode === undefined) {
+      return;
+    }
+
+    let dir = 'forward';
+    let edgeConstraint = constraint;
+    let edgeWeight = weight;
+    const opposite = binarySerach(tuples, [to, from]);
+    const oppositeUnknown = opposite === 'UNKNOWN';
+    const oppositeSet = opposite !== undefined;
+    const oppositeVisible = oppositeSet && (showUnknown || !oppositeUnknown);
+    if (opposite === value) {
+      if (to < from) {
+        // We already added this edge in the reverse direction.
+        return;
+      }
+      if (to > from) {
+        dir = 'both';
+      }
+    } else if (oppositeVisible && to < from) {
+      // Let the opposite edge drive the graph layout.
+      edgeConstraint = 'false';
+      edgeWeight = 0;
+    } else if (isUnknown && (!oppositeSet || oppositeUnknown)) {
+      // Only apply the UNKNOWN value penalty if we aren't the opposite
+      // edge driving the graph layout from above, or the penalty would
+      // be applied anyway.
+      edgeWeight *= UNKNOWN_WEIGHT_FACTOR;
+    }
+
+    lines.push(`n${from} -> n${to} [
+      id="${fromNode.name},${toNode.name},${relation.name}",
+      dir="${dir}",
+      constraint=${edgeConstraint},
+      weight=${edgeWeight},
+      xlabel=${label},
+      penwidth=${penwidth},
+      style="${isUnknown ? 'dashed' : 'solid'}",
+      class="edge-${value}"
+    ]`);
+  });
+}
+
+function createEdges(graph: GraphStore, lines: string[]): void {
+  const {
+    semantics: { relations },
+  } = graph;
+  relations.forEach((relation) => {
+    if (relation.arity !== 2) {
+      return;
+    }
+    const visibility = graph.getVisiblity(relation.name);
+    if (visibility !== 'none') {
+      createRelationEdges(graph, relation, visibility === 'all', lines);
+    }
+  });
+}
+
+export default function dotSource(
+  graph: GraphStore | undefined,
+): string | undefined {
+  if (graph === undefined) {
+    return undefined;
+  }
+  const lines = [
+    'digraph {',
+    'graph [bgcolor=transparent];',
+    `node [fontsize=12, shape=plain, fontname="OpenSans"];`,
+    'edge [fontsize=10.5, color=black, fontname="OpenSans"];',
+  ];
+  createNodes(graph, lines);
+  createEdges(graph, lines);
+  lines.push('}');
+  return lines.join('\n');
+}