"""Mermaid diagram generation for codemap graphs.
Produces deterministic Mermaid flowcharts from ``CodemapGraph`` instances,
with subgraphs per file, color-coded node classes (entry/cross-file/leaf),
and optional click handlers for source navigation.
"""
from __future__ import annotations
import re
from collections import defaultdict
from pathlib import Path
from local_deepwiki.generators.codemap_models import (
CodemapFocus,
CodemapGraph,
CodemapNode,
)
def generate_codemap_diagram(
graph: CodemapGraph, focus: CodemapFocus, repo_path: Path | None = None
) -> str:
"""Generate a deterministic Mermaid flowchart from *graph*."""
try:
from local_deepwiki.generators.diagrams import (
sanitize_mermaid_name as _sanitize,
)
except ImportError: # pragma: no cover
def _sanitize(name: str) -> str:
return re.sub(r"[^a-zA-Z0-9_]", "_", name)
sanitize_mermaid_name = _sanitize
if not graph.nodes:
return 'flowchart TD\n empty["No code paths found for this query"]'
# Deterministic ordering: sort nodes by (file, qualified_name)
sorted_nodes = sorted(
graph.nodes.values(), key=lambda n: (n.file_path, n.qualified_name)
)
# Assign stable IDs
node_ids: dict[str, str] = {}
for idx, node in enumerate(sorted_nodes):
node_ids[node.qualified_name] = f"N{idx}"
# Group by file
files_to_nodes: dict[str, list[CodemapNode]] = defaultdict(list)
for node in sorted_nodes:
files_to_nodes[node.file_path].append(node)
# Determine node classes
cross_file_targets: set[str] = {
e.target for e in graph.edges if e.source_file != e.target_file
}
nodes_with_outgoing: set[str] = {e.source for e in graph.edges}
lines: list[str] = ["flowchart TD"]
for file_path in sorted(files_to_nodes):
safe_subgraph = sanitize_mermaid_name(file_path)
lines.append(f' subgraph {safe_subgraph}["{file_path}"]')
for node in files_to_nodes[file_path]:
nid = node_ids[node.qualified_name]
label = f"{node.name}\\n:{node.start_line}-{node.end_line}"
lines.append(f' {nid}["{label}"]')
lines.append(" end")
# Edges (sorted for determinism)
sorted_edges = sorted(
graph.edges,
key=lambda e: (e.source, e.target),
)
seen_edges: set[tuple[str, str]] = set()
for edge in sorted_edges:
src_id = node_ids.get(edge.source)
tgt_id = node_ids.get(edge.target)
if src_id is None or tgt_id is None:
continue
pair = (src_id, tgt_id)
if pair in seen_edges:
continue
seen_edges.add(pair)
arrow = "-.->" if edge.source_file != edge.target_file else "-->"
if focus == CodemapFocus.DATA_FLOW and edge.edge_type != "calls":
safe_label = edge.edge_type.replace('"', "'")
lines.append(f' {src_id} {arrow}|"{safe_label}"| {tgt_id}')
else:
lines.append(f" {src_id} {arrow} {tgt_id}")
# Class definitions
lines.append("")
lines.append(" classDef entry fill:#2d6a4f,color:#fff")
lines.append(" classDef crossfile fill:#1d3557,color:#fff")
lines.append(" classDef leaf fill:#6c757d,color:#fff")
# Apply classes
if graph.entry_point and graph.entry_point in node_ids:
lines.append(f" class {node_ids[graph.entry_point]} entry")
crossfile_ids = [
node_ids[qn]
for qn in cross_file_targets
if qn in node_ids and qn != graph.entry_point
]
if crossfile_ids:
lines.append(f" class {','.join(sorted(crossfile_ids))} crossfile")
leaf_ids = [
node_ids[n.qualified_name]
for n in sorted_nodes
if n.qualified_name not in nodes_with_outgoing
and n.qualified_name != graph.entry_point
and n.qualified_name not in cross_file_targets
]
if leaf_ids:
lines.append(f" class {','.join(sorted(leaf_ids))} leaf")
# Click handlers for source navigation
if repo_path is not None:
for node in sorted_nodes:
nid = node_ids[node.qualified_name]
try:
rel = str(Path(node.file_path).relative_to(repo_path))
except (ValueError, TypeError):
rel = node.file_path
lines.append(f' click {nid} "files/{rel}" _blank')
return "\n".join(lines)
