Add textwrap import to support multiline string handling

app.py

@@ -8,6 +8,7 @@ import numpy as np
 import torch
 import importlib
 import requests
+import textwrap
 
 # Optional PDF reporting: import reportlab safely and set a flag.
 # REPORTLAB_AVAILABLE will be used by _write_pdf to select the PDF code path.
@@ -250,73 +251,137 @@ def _write_pdf(path: str, title: str, narrative: str, frames):
     if REPORTLAB_AVAILABLE:
         c = canvas.Canvas(path, pagesize=A4)
         width, height = A4
-        margin = 40
+        # Increase margins and reduce font sizes to fit more content per page
+        margin = 50
         y = height - margin
-        c.setFont("Helvetica-Bold", 16)
-        c.drawString(margin, y, title)
-        y -= 30
-        c.setFont("Helvetica", 11)
-        for line in (narrative or "").splitlines():
-            if y < margin + 50:
+
+        # Fonts and sizes
+        title_font = "Helvetica-Bold"
+        body_font = "Helvetica"
+        small_font = "Helvetica"
+        title_size = 14
+        body_size = 10
+        small_size = 9
+        line_height = body_size * 1.15
+        small_line_height = small_size * 1.12
+
+        # Helper: simple wrapper using textwrap with estimated chars per line
+        def wrap_text(text, font_size, max_width):
+            approx_char_width = font_size * 0.55
+            max_chars = max(40, int(max_width / approx_char_width))
+            out = []
+            for para in str(text or "").splitlines():
+                wrapped = textwrap.wrap(para, width=max_chars)
+                out.extend(wrapped if wrapped else [""])
+            return out
+
+        # Title
+        c.setFont(title_font, title_size)
+        for tline in wrap_text(title, title_size, width - 2 * margin):
+            if y < margin + title_size * 1.5:
+                c.showPage()
+                y = height - margin
+                c.setFont(title_font, title_size)
+            c.drawString(margin, y, tline)
+            y -= title_size * 1.3
+
+        y -= 6
+        # Narrative
+        c.setFont(body_font, body_size)
+        for line in wrap_text(narrative or "", body_size, width - 2 * margin):
+            if y < margin + line_height:
                 c.showPage()
                 y = height - margin
-                c.setFont("Helvetica", 11)
+                c.setFont(body_font, body_size)
             c.drawString(margin, y, line)
-            y -= 16
-        y -= 10
+            y -= line_height
+
+        y -= 8
         c.setFont("Helvetica-Bold", 12)
+        if y < margin + 30:
+            c.showPage()
+            y = height - margin
+            c.setFont("Helvetica-Bold", 12)
         c.drawString(margin, y, "Per-frame detections:")
-        y -= 18
-        c.setFont("Helvetica", 10)
+        y -= 14
+        c.setFont(small_font, small_size)
 
         # Iterate frames and list detections; include cropped images where available.
         for f in frames:
-            if y < margin + 120:
+            if y < margin + 100:
                 c.showPage()
                 y = height - margin
-                c.setFont("Helvetica", 10)
+                c.setFont(small_font, small_size)
             c.drawString(margin, y, f"Frame {f.get('frame_index')}:")
-            y -= 14
+            y -= small_line_height
             dets = f.get("detections", [])
             if not dets:
+                if y < margin + small_line_height:
+                    c.showPage()
+                    y = height - margin
+                    c.setFont(small_font, small_size)
                 c.drawString(margin + 12, y, "No detections")
-                y -= 12
+                y -= small_line_height
             else:
                 for d in dets:
-                    line = f"- {d.get('label')} | conf={d.get('confidence')} | bbox={d.get('bbox')}"
-                    c.drawString(margin + 12, y, line)
-                    y -= 12
-
-                    # If there is a cropped image for this detection, embed it in the PDF.
+                    det_text = f"- {d.get('label')} | conf={d.get('confidence')} | bbox={d.get('bbox')}"
+                    # Wrap det_text leaving room for images (if present)
+                    text_max_width = width - 2 * margin - 150
+                    for dl in wrap_text(det_text, small_size, text_max_width):
+                        if y < margin + small_line_height:
+                            c.showPage()
+                            y = height - margin
+                            c.setFont(small_font, small_size)
+                        c.drawString(margin + 12, y, dl)
+                        y -= small_line_height
+
+                    # If there is a cropped image for this detection, embed it in the PDF (smaller)
                     try:
                         img_path = d.get("image")
                         if img_path and os.path.exists(img_path):
-                            # Desired image size in PDF points
-                            img_w = 140
-                            img_h = 80
-                            # If not enough vertical space, start a new page
+                            img_w = 120
+                            img_h = 70
                             if y < margin + img_h + 20:
                                 c.showPage()
                                 y = height - margin
-                                c.setFont("Helvetica", 10)
-                            # Draw image at the right side of the page
+                                c.setFont(small_font, small_size)
                             x_img = width - margin - img_w
                             y_img = y - img_h + 6
                             c.drawImage(img_path, x_img, y_img, width=img_w, height=img_h, preserveAspectRatio=True, mask='auto')
-                            # Optionally add a short caption / crop description under the image if available
+                            # Crop visual description under image
                             crop_desc = None
                             if isinstance(d.get("crop_visual"), dict):
                                 crop_desc = d["crop_visual"].get("description")
                             if crop_desc:
-                                # Split long lines
-                                for line_part in (crop_desc or "").splitlines():
-                                    if y_img - 12 < margin:
+                                cd_lines = wrap_text(crop_desc, small_size, img_w)
+                                text_y = y_img - 12
+                                for cd in cd_lines:
+                                    if text_y < margin + 20:
                                         c.showPage()
-                                        y_img = height - margin - img_h - 12
-                                        c.setFont("Helvetica", 10)
-                                    c.drawString(x_img, y_img - 12, line_part[:200])
-                                    y_img -= 12
-                            # Move vertical cursor below the image area
+                                        y = height - margin
+                                        text_y = y - img_h - 12
+                                        c.setFont(small_font, small_size)
+                                    c.drawString(x_img, text_y, cd)
+                                    text_y -= small_line_height
+                            # Move cursor below image
+                            y = y - img_h - 10
+                    except Exception:
+                        pass
+        c.save()
+    else:
+        # Fallback: plain text file (saved with .pdf extension)
+        with open(path, "w", encoding="utf-8") as f:
+            f.write(title + "\n\n")
+            f.write((narrative or "") + "\n\n")
+            f.write("Per-frame detections:\n")
+            for fr in frames:
+                f.write(f"Frame {fr.get('frame_index')}:\n")
+                dets = fr.get("detections", [])
+                if not dets:
+                    f.write("  No detections\n")
+                else:
+                    for d in dets:
+                        f.write(f"  - {d}\n")
                             y = y - img_h - 10
                     except Exception:
                         # If embedding fails, continue without stopping report generation