From 3afc8ed3d895dfb106f4a8f6076adb97e9e3a7f8 Mon Sep 17 00:00:00 2001
From: Pouzor <remy.jardinet@gmail.com>
Date: Wed, 8 Apr 2026 23:31:53 +0200
Subject: [PATCH] fix: persist edge waypoints in backend

Add waypoints JSON column to edges table, include it in all edge
schemas (EdgeBase, EdgeUpdate, canvas CanvasEdge) and add the
idempotent ALTER TABLE migration so existing databases are upgraded
on next startup.
---
 backend/app/db/database.py    | 2 ++
 backend/app/db/models.py      | 1 +
 backend/app/schemas/canvas.py | 1 +
 backend/app/schemas/edges.py  | 2 ++
 4 files changed, 6 insertions(+)

diff --git a/backend/app/db/database.py b/backend/app/db/database.py
index 6717f45..955adb5 100644
--- a/backend/app/db/database.py
+++ b/backend/app/db/database.py
@@ -61,6 +61,8 @@ async def init_db() -> None:
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN bottom_handles INTEGER NOT NULL DEFAULT 1")
         with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE pending_devices ADD COLUMN discovery_source TEXT")
+        with suppress(OperationalError):
+            await conn.exec_driver_sql("ALTER TABLE edges ADD COLUMN waypoints JSON")
         # Migrate animated column from boolean (0/1) to string ('none'/'snake')
         with suppress(OperationalError):
             await conn.exec_driver_sql("UPDATE edges SET animated = 'snake' WHERE animated = '1' OR animated = 1")
diff --git a/backend/app/db/models.py b/backend/app/db/models.py
index 0aac1b0..903dbc6 100644
--- a/backend/app/db/models.py
+++ b/backend/app/db/models.py
@@ -69,6 +69,7 @@ class Edge(Base):
     animated: Mapped[str] = mapped_column(String, nullable=False, default='none')
     source_handle: Mapped[str | None] = mapped_column(String)
     target_handle: Mapped[str | None] = mapped_column(String)
+    waypoints: Mapped[list | None] = mapped_column(JSON, nullable=True)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_now)
 
 
diff --git a/backend/app/schemas/canvas.py b/backend/app/schemas/canvas.py
index 5f1e5d4..ea2ec7d 100644
--- a/backend/app/schemas/canvas.py
+++ b/backend/app/schemas/canvas.py
@@ -49,6 +49,7 @@ class EdgeSave(BaseModel):
     animated: str = 'none'
     source_handle: str | None = None
     target_handle: str | None = None
+    waypoints: list | None = None
 
     @field_validator('animated', mode='before')
     @classmethod
diff --git a/backend/app/schemas/edges.py b/backend/app/schemas/edges.py
index a663806..9c83d8a 100644
--- a/backend/app/schemas/edges.py
+++ b/backend/app/schemas/edges.py
@@ -17,6 +17,7 @@ class EdgeBase(BaseModel):
     animated: str = 'none'
     source_handle: str | None = None
     target_handle: str | None = None
+    waypoints: list | None = None
 
     @field_validator('animated', mode='before')
     @classmethod
@@ -38,6 +39,7 @@ class EdgeUpdate(BaseModel):
     animated: str | None = None
     source_handle: str | None = None
     target_handle: str | None = None
+    waypoints: list | None = None
 
     @field_validator('animated', mode='before')
     @classmethod