Initial commit: Busbar Designer

Web tool for designing nickel/copper busbars over cylindrical-cell battery
packs (21700, 18650) in hex holders. Flask + build123d backend exports
STEP/DXF/SVG; vanilla JS frontend with live preview, multi-project SQLite
persistence, snapshot history.

Deploy scripts in deploy/ (proxmox-lxc.sh, install.sh, update.sh).

app.py

@@ -0,0 +1,194 @@
+"""Flask entrypoint for Busbar Designer.
+
+Serves the static frontend, the /api/export/<fmt> CAD endpoints (build123d →
+STEP/DXF/SVG), and the /api/projects, /api/presets, /api/snapshots persistence
+endpoints (SQLite via storage.py).
+
+Run:
+    python app.py
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import traceback
+
+from flask import Flask, Response, jsonify, request, send_from_directory
+
+from busbar_export import WRITERS
+import storage
+
+APP_DIR = os.path.dirname(os.path.abspath(__file__))
+STATIC_DIR = os.path.join(APP_DIR, "static")
+
+app = Flask(__name__, static_folder=STATIC_DIR, static_url_path="")
+
+storage.init_db()
+
+
+# ---------------------------------------------------------------------------
+# Static + health
+# ---------------------------------------------------------------------------
+
+
+@app.get("/")
+def index():
+    return send_from_directory(STATIC_DIR, "index.html")
+
+
+@app.get("/api/health")
+def health():
+    return jsonify({"status": "ok"})
+
+
+# ---------------------------------------------------------------------------
+# CAD export (unchanged contract)
+# ---------------------------------------------------------------------------
+
+
+@app.post("/api/export/<fmt>")
+def export(fmt: str):
+    fmt = fmt.lower()
+    if fmt not in WRITERS:
+        return jsonify({"error": f"unsupported format: {fmt}"}), 400
+
+    payload = request.get_json(silent=True) or {}
+    writer, mimetype, ext = WRITERS[fmt]
+    try:
+        data = writer(payload)
+    except ValueError as e:
+        return jsonify({"error": str(e)}), 400
+    except Exception as e:
+        traceback.print_exc()
+        return jsonify({"error": f"{type(e).__name__}: {e}"}), 500
+
+    filename = f"busbars.{ext}"
+    return Response(
+        data,
+        mimetype=mimetype,
+        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
+    )
+
+
+# ---------------------------------------------------------------------------
+# Projects
+# ---------------------------------------------------------------------------
+
+
+@app.get("/api/projects")
+def projects_index():
+    return jsonify(storage.list_projects())
+
+
+@app.post("/api/projects")
+def projects_create():
+    body = request.get_json(silent=True) or {}
+    name = (body.get("name") or "Untitled").strip() or "Untitled"
+    data = body.get("data") or {}
+    pid = storage.create_project(name, data)
+    return jsonify({"id": pid, "name": name})
+
+
+@app.get("/api/projects/<int:pid>")
+def projects_show(pid: int):
+    p = storage.get_project(pid)
+    if p is None:
+        return jsonify({"error": "not found"}), 404
+    return jsonify(p)
+
+
+@app.put("/api/projects/<int:pid>")
+def projects_update(pid: int):
+    body = request.get_json(silent=True) or {}
+    ok = storage.update_project(
+        pid,
+        name=body.get("name"),
+        data=body.get("data"),
+        snapshot=bool(body.get("snapshot", False)),
+        note=body.get("note"),
+    )
+    if not ok:
+        return jsonify({"error": "not found"}), 404
+    return jsonify({"ok": True})
+
+
+@app.delete("/api/projects/<int:pid>")
+def projects_delete(pid: int):
+    storage.delete_project(pid)
+    return jsonify({"ok": True})
+
+
+# ---------------------------------------------------------------------------
+# Snapshots
+# ---------------------------------------------------------------------------
+
+
+@app.get("/api/projects/<int:pid>/snapshots")
+def snapshots_index(pid: int):
+    return jsonify(storage.list_snapshots(pid))
+
+
+@app.get("/api/snapshots/<int:sid>")
+def snapshot_show(sid: int):
+    snap = storage.get_snapshot(sid)
+    if snap is None:
+        return jsonify({"error": "not found"}), 404
+    return jsonify(snap)
+
+
+@app.post("/api/snapshots/<int:sid>/restore")
+def snapshot_restore(sid: int):
+    if not storage.restore_snapshot(sid):
+        return jsonify({"error": "not found"}), 404
+    return jsonify({"ok": True})
+
+
+# ---------------------------------------------------------------------------
+# Presets
+# ---------------------------------------------------------------------------
+
+
+@app.get("/api/presets")
+def presets_index():
+    return jsonify(storage.list_presets())
+
+
+@app.post("/api/presets")
+def presets_create():
+    body = request.get_json(silent=True) or {}
+    name = (body.get("name") or "").strip()
+    if not name:
+        return jsonify({"error": "name required"}), 400
+    pid = storage.create_preset(name, body.get("params") or {})
+    if pid is None:
+        return jsonify({"error": "name already in use"}), 409
+    return jsonify({"id": pid, "name": name})
+
+
+@app.put("/api/presets/<int:pid>")
+def presets_update(pid: int):
+    body = request.get_json(silent=True) or {}
+    ok = storage.update_preset(pid, name=body.get("name"), params=body.get("params"))
+    if not ok:
+        return jsonify({"error": "not found or name conflict"}), 404
+    return jsonify({"ok": True})
+
+
+@app.delete("/api/presets/<int:pid>")
+def presets_delete(pid: int):
+    storage.delete_preset(pid)
+    return jsonify({"ok": True})
+
+
+# ---------------------------------------------------------------------------
+# Boot
+# ---------------------------------------------------------------------------
+
+
+if __name__ == "__main__":
+    port = int(os.environ.get("PORT", 5000))
+    host = os.environ.get("HOST", "127.0.0.1")
+    debug = os.environ.get("FLASK_DEBUG", "1") == "1"
+    print(f" * Busbar Designer running on http://{host}:{port}", file=sys.stderr)
+    app.run(host=host, port=port, debug=debug)