First commit of claude's rework in django + vanillajs fronted

apps/tools/analyzer/pdf_report.py

@@ -0,0 +1,95 @@
+import base64
+import io
+from datetime import datetime
+
+from fpdf import FPDF
+
+_COL_LABEL = 80
+_COL_VALUE = 50
+_ROW_H = 7
+
+
+def generate_pdf(overall: dict, group_stats: list, charts: list, overview_chart: str) -> bytes:
+    pdf = FPDF()
+    pdf.set_auto_page_break(auto=True, margin=15)
+
+    pdf.add_page()
+    _title_block(pdf)
+    _overall_section(pdf, overall, overview_chart)
+
+    for stat, chart_b64 in zip(group_stats, charts):
+        _group_section(pdf, stat, chart_b64)
+
+    return bytes(pdf.output())
+
+
+# ---------------------------------------------------------------------------
+
+def _title_block(pdf: FPDF):
+    pdf.set_font("Helvetica", "B", 18)
+    pdf.cell(0, 12, "Ballistic Analysis Report", new_x="LMARGIN", new_y="NEXT", align="C")
+    pdf.set_font("Helvetica", "", 9)
+    pdf.cell(
+        0, 5,
+        f"Generated: {datetime.now().strftime('%Y-%m-%d  %H:%M')}",
+        new_x="LMARGIN", new_y="NEXT", align="C",
+    )
+    pdf.ln(8)
+
+
+def _overall_section(pdf: FPDF, overall: dict, overview_chart: str):
+    _section_heading(pdf, "Overall Statistics")
+    rows = [
+        ("Total shots",    str(overall["count"])),
+        ("Min speed",      f"{overall['min_speed']:.4f}"),
+        ("Max speed",      f"{overall['max_speed']:.4f}"),
+        ("Mean speed",     f"{overall['mean_speed']:.4f}"),
+        ("Std dev (speed)", f"{overall['std_speed']:.4f}" if overall["std_speed"] is not None else "n/a"),
+    ]
+    _table(pdf, rows)
+    img_bytes = base64.b64decode(overview_chart)
+    pdf.image(io.BytesIO(img_bytes), x=pdf.l_margin, w=min(140, pdf.epw))
+    pdf.ln(4)
+
+
+def _group_section(pdf: FPDF, stat: dict, chart_b64: str):
+    pdf.ln(4)
+    heading = (
+        f"Group {stat['group_index']}  -  "
+        f"{stat['time_start']} to {stat['time_end']}  "
+        f"({stat['count']} shot(s))"
+    )
+    _section_heading(pdf, heading)
+
+    rows = [
+        ("Min speed",      f"{stat['min_speed']:.4f}"),
+        ("Max speed",      f"{stat['max_speed']:.4f}"),
+        ("Mean speed",     f"{stat['mean_speed']:.4f}"),
+        ("Std dev (speed)", f"{stat['std_speed']:.4f}" if stat["std_speed"] is not None else "n/a"),
+    ]
+    _table(pdf, rows)
+
+    img_bytes = base64.b64decode(chart_b64)
+    # Check remaining page space; add new page if chart won't fit
+    if pdf.get_y() + 75 > pdf.page_break_trigger:
+        pdf.add_page()
+    pdf.image(io.BytesIO(img_bytes), x=pdf.l_margin, w=pdf.epw)
+    pdf.ln(4)
+
+
+def _section_heading(pdf: FPDF, text: str):
+    pdf.set_font("Helvetica", "B", 12)
+    pdf.set_fill_color(230, 236, 255)
+    pdf.cell(0, 8, text, new_x="LMARGIN", new_y="NEXT", fill=True)
+    pdf.ln(2)
+
+
+def _table(pdf: FPDF, rows: list):
+    for i, (label, value) in enumerate(rows):
+        fill = i % 2 == 0
+        pdf.set_fill_color(248, 249, 252) if fill else pdf.set_fill_color(255, 255, 255)
+        pdf.set_font("Helvetica", "", 10)
+        pdf.cell(_COL_LABEL, _ROW_H, label, border=0, fill=fill)
+        pdf.set_font("Helvetica", "B", 10)
+        pdf.cell(_COL_VALUE, _ROW_H, value, border=0, fill=fill, new_x="LMARGIN", new_y="NEXT")
+    pdf.ln(3)