feat: implement annotation rendering functions for text highlighting and layout creation

src/utils/annotation_rendering.py

@@ -0,0 +1,83 @@
+from collections import defaultdict
+
+
+def get_sections_and_text(chunks):
+    text = "".join(chunk["page_content"] for chunk in chunks["chunks"])
+    sections = [
+        {
+            "start": chunk["metadata"]["start_index"],
+            "end": chunk["metadata"]["start_index"] + len(chunk["page_content"]),
+            "text": chunk["page_content"],
+        }
+        for chunk in chunks["chunks"]
+    ]
+    return sections, text
+
+
+def calculate_coverage(selection):
+    coverage = defaultdict(int)
+    for s in selection:
+        for i in range(s["start"], s["end"]):
+            coverage[i] += 1
+    return coverage
+
+
+def create_end_markers(selection):
+    end_markers = defaultdict(list)
+    for i, s in enumerate(selection, 1):
+        end_markers[s["end"]].append(i)
+    return end_markers
+
+
+def highlight_text(text, coverage, end_markers):
+    output = []
+    buffer = []
+
+    def flush_buffer():
+        if buffer:
+            output.append("".join(buffer))
+            buffer.clear()
+
+    for i, ch in enumerate(text):
+        if coverage.get(i, 0) > 0:
+            # flush normal markdown
+            flush_buffer()
+
+            opacity = min(0.3 + 0.2 * coverage[i], 0.8)
+            output.append(
+                f"<span style='background: rgba(255, 230, 150, {opacity});'>"
+                f"{ch}</span>"
+            )
+        else:
+            buffer.append(ch)
+
+        if i + 1 in end_markers:
+            flush_buffer()
+            if ch.isalnum():
+                output.append(" ")
+            for m in end_markers[i + 1]:
+                output.append(f"[^{m}]")
+
+    flush_buffer()
+    return "".join(output)
+
+
+def create_layout(annotated_text, sections):
+    annotations = []
+    for i, s in enumerate(sections, 1):
+        annotations.append(f"[^{i}]: Section {i} {s['rebuttal']}")
+
+    markdown = (
+        f"{annotated_text}\n\n" f"---\n\n" f"### Annotations\n" + "\n".join(annotations)
+    )
+
+    return markdown
+
+
+def render_annotated_text(chunks):
+    sections, text = get_sections_and_text(chunks)
+    coverage = calculate_coverage(sections)
+    end_markers = create_end_markers(sections)
+    annotated_text = highlight_text(text, coverage, end_markers)
+    layout = create_layout(annotated_text, sections)
+    return layout