added more info and how-to about ODA

README.md

@@ -150,6 +150,38 @@ If you only need the core tools, install the minimal set:
 pip install Flask Pillow PyMuPDF "qrcode[pil]" markdown reportlab img2pdf python-docx
 ```
 
+### Enabling DWG support (ODA File Converter)
+
+DXF files work out of the box once you install `ezdxf` and `matplotlib`. For **DWG** files, the app shells out to the free **ODA File Converter** (by Open Design Alliance) to convert DWG → DXF, then renders the DXF. There is no reliable pure-Python library that reads DWG, so this extra step is necessary.
+
+1. **Download** the installer for your OS from [opendesign.com](https://www.opendesign.com/guestfiles/oda_file_converter). It's a free guest download — no account required.
+2. **Run the installer.** Defaults are fine.
+3. **Add it to your PATH** so the Flask app can find it. The app looks for a binary named `ODAFileConverter` or `oda_file_converter` using `shutil.which()`.
+
+   - **Windows** — add the install folder (contains `ODAFileConverter.exe`) to your `Path`:
+     - Press `Win + R` → `sysdm.cpl` → *Advanced* tab → *Environment Variables*
+     - Under *System variables*, select `Path` → *Edit* → *New* → paste the folder, e.g.:
+       ```
+       C:\Program Files\ODA\ODAFileConverter 26.4.0
+       ```
+     - Click OK, open a **new** terminal, run `where ODAFileConverter` to verify.
+
+   - **macOS** — symlink the binary into `/usr/local/bin`:
+     ```bash
+     sudo ln -s /Applications/ODAFileConverter.app/Contents/MacOS/ODAFileConverter /usr/local/bin/ODAFileConverter
+     ```
+     Verify with `which ODAFileConverter`.
+
+   - **Linux** — the `.deb` / `.rpm` package usually installs the binary on `PATH` automatically. If not:
+     ```bash
+     sudo ln -s /opt/ODAFileConverter_QT5*/ODAFileConverter /usr/local/bin/ODAFileConverter
+     ```
+     Verify with `which ODAFileConverter`.
+
+4. **Restart the Flask server.** PATH is read once at startup, so a running server won't see the new entry. After restart, the CAD tool page will show a green *"DWG support is enabled"* banner.
+
+**No ODA, no problem:** if you can't install it (e.g. on a restricted machine), open your DWG in free tools like [Autodesk Viewer](https://viewer.autodesk.com/), LibreCAD, or QCAD, export as DXF, then upload the DXF here.
+
 ---
 
 ## Project Structure

routes/convert_tools.py

@@ -134,12 +134,43 @@ def ocr_pdf_page():
 
 @bp.route("/cad-to-pdf")
 def cad_to_pdf_page():
-    desc = "Convert DXF (or DWG with ODA File Converter) drawings to PDF or PNG"
-    if not ODA_CONVERTER:
-        desc += " — DWG requires ODA File Converter on PATH"
+    if ODA_CONVERTER:
+        notes = (
+            '<p><i class="bi bi-check-circle-fill" style="color:#2ec4b6"></i> '
+            '<strong>DWG support is enabled.</strong> ODA File Converter was detected at '
+            f'<code>{ODA_CONVERTER}</code>.</p>'
+            '<p>DXF files are rendered directly. DWG files are auto-converted to DXF first.</p>'
+        )
+    else:
+        notes = (
+            '<p><strong>DXF works out of the box.</strong> DWG files need the free '
+            '<a href="https://www.opendesign.com/guestfiles/oda_file_converter" target="_blank" rel="noopener">'
+            'ODA File Converter</a> installed and available on your system <code>PATH</code>.</p>'
+            '<details>'
+            '<summary>How to install ODA File Converter</summary>'
+            '<ol>'
+            '<li>Download the installer for your OS from '
+            '<a href="https://www.opendesign.com/guestfiles/oda_file_converter" target="_blank" rel="noopener">opendesign.com</a> '
+            '(free, guest download — no account required).</li>'
+            '<li>Run the installer. Defaults are fine.</li>'
+            '<li><strong>Add it to your PATH so this app can find it:</strong>'
+            '<ul>'
+            '<li><strong>Windows:</strong> add <code>C:\\Program Files\\ODA\\ODAFileConverter_title_version</code> '
+            '(the folder containing <code>ODAFileConverter.exe</code>) to your <em>System Environment Variables</em> &rarr; <code>Path</code>.</li>'
+            '<li><strong>macOS:</strong> <code>ln -s /Applications/ODAFileConverter.app/Contents/MacOS/ODAFileConverter /usr/local/bin/ODAFileConverter</code></li>'
+            '<li><strong>Linux:</strong> the <code>.deb</code>/<code>.rpm</code> package installs <code>ODAFileConverter</code> on PATH automatically. Otherwise symlink the binary into <code>/usr/local/bin</code>.</li>'
+            '</ul></li>'
+            '<li>Open a new terminal and verify: <code>ODAFileConverter</code> (should launch the tool GUI, or exit silently).</li>'
+            '<li><strong>Restart this Flask server</strong> so it picks up the updated PATH.</li>'
+            '</ol>'
+            '<p style="margin-top:.4rem">Alternative: open your DWG in free tools like <a href="https://www.autodesk.com/viewers" target="_blank" rel="noopener">Autodesk Viewer</a>, LibreCAD, or QCAD and export it as DXF, then upload the DXF here.</p>'
+            '</details>'
+        )
+
     return render_template("upload_tool.html",
         title="CAD to PDF/Image",
-        description=desc,
+        description="Convert DXF drawings to PDF or PNG. DWG is supported when ODA File Converter is installed.",
+        notes=notes,
         endpoint="/convert/cad-to-pdf",
         accept=".dxf,.dwg",
         multiple=False,

static/css/style.css

@@ -224,6 +224,35 @@ a { color: var(--primary); text-decoration: none; }
 .tool-header h1 { font-size: 1.5rem; margin-bottom: .3rem; }
 .tool-header p { color: var(--text-light); }
 
+.tool-notes {
+    background: #fff8e1;
+    border-left: 3px solid #f5b700;
+    border-radius: 4px;
+    padding: .75rem 1rem;
+    margin-bottom: 1.25rem;
+    font-size: .88rem;
+    line-height: 1.5;
+    color: #5a4200;
+}
+.tool-notes p { margin: 0 0 .5rem; }
+.tool-notes p:last-child { margin-bottom: 0; }
+.tool-notes code {
+    background: rgba(0,0,0,.06);
+    padding: .1rem .35rem;
+    border-radius: 3px;
+    font-size: .82rem;
+}
+.tool-notes details { margin-top: .5rem; }
+.tool-notes details > summary {
+    cursor: pointer;
+    font-weight: 600;
+    color: #8a6300;
+}
+.tool-notes details[open] > summary { margin-bottom: .5rem; }
+.tool-notes ol, .tool-notes ul { margin: .25rem 0 .5rem 1.2rem; padding: 0; }
+.tool-notes li { margin-bottom: .2rem; }
+.tool-notes a { color: #b26f00; }
+
 /* ── Upload Zone ──────────────────────────────── */
 .upload-zone {
     border: 2px dashed var(--border);

templates/upload_tool.html

@@ -9,6 +9,12 @@
         <p>{{ description }}</p>
     </div>
 
+    {% if notes %}
+    <div class="tool-notes">
+        {{ notes|safe }}
+    </div>
+    {% endif %}
+
     <form id="tool-form" data-endpoint="{{ endpoint }}">
         {% if text_input %}
         <div class="form-group">