Aug 17 - Update forms will be assigned per contract

migrations/versions/phase52_template_contracts.py

@@ -0,0 +1,61 @@
+"""phase52 — restrict forms to specific contracts
+
+Creates `template_contracts`: one row = "this inspection template is available
+on this contract". Backs per-customer forms — a customer's bespoke form must
+not be visible to, or startable against, another customer's facilities.
+
+**No rows for a template means SHARED (available on every contract)**, not
+"available nowhere". That convention is why this migration needs no backfill
+and cannot change behaviour on deploy: every template that exists today has no
+rows and therefore stays available everywhere, exactly as before. A form only
+becomes customer-specific once an admin attaches it to at least one contract.
+
+Inverting that default later would silently hide every shared form from every
+contract, so it is enforced in one place — InspectionTemplate.available_query()
+— which the pickers, their POST validation, and the mobile API all use.
+
+Table-existence check — safe to re-run.
+"""
+
+revision      = 'phase52_template_contracts'
+down_revision = 'phase51_user_notif_matrix'
+branch_labels = None
+depends_on    = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def _has_table(conn, name):
+    return conn.execute(sa.text(
+        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES "
+        "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :t"
+    ), {'t': name}).scalar() > 0
+
+
+def upgrade():
+    conn = op.get_bind()
+    if _has_table(conn, 'template_contracts'):
+        return
+
+    op.create_table(
+        'template_contracts',
+        sa.Column('id', sa.Integer, primary_key=True),
+        sa.Column('template_id', sa.Integer,
+                  sa.ForeignKey('inspection_templates.id', ondelete='CASCADE'),
+                  nullable=False, index=True),
+        sa.Column('project_id', sa.Integer,
+                  sa.ForeignKey('projects.id', ondelete='CASCADE'),
+                  nullable=False, index=True),
+        sa.Column('created_at', sa.DateTime, nullable=False,
+                  server_default=sa.func.now()),
+        sa.UniqueConstraint('template_id', 'project_id', name='uq_template_contract'),
+    )
+
+
+def downgrade():
+    conn = op.get_bind()
+    if _has_table(conn, 'template_contracts'):
+        # Dropping the table returns every form to shared — no form becomes
+        # unusable, they just stop being restricted.
+        op.drop_table('template_contracts')