refac: shared chat

Author: tjbck

backend/open_webui/migrations/versions/c1d2e3f4a5b6_add_shared_chat_table.py

@@ -0,0 +1,164 @@
+"""Add shared_chat table and migrate existing shares
+
+Revision ID: c1d2e3f4a5b6
+Revises: e1f2a3b4c5d6
+Create Date: 2026-04-16 23:00:00.000000
+
+"""
+
+import time
+import uuid
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = 'c1d2e3f4a5b6'
+down_revision = 'e1f2a3b4c5d6'
+branch_labels = None
+depends_on = None
+
+# Lightweight table references for data migration (no ORM models needed)
+chat_t = sa.table(
+    'chat',
+    sa.column('id', sa.Text),
+    sa.column('user_id', sa.Text),
+    sa.column('title', sa.Text),
+    sa.column('chat', sa.JSON),
+    sa.column('share_id', sa.Text),
+    sa.column('created_at', sa.BigInteger),
+    sa.column('updated_at', sa.BigInteger),
+    sa.column('archived', sa.Boolean),
+    sa.column('meta', sa.JSON),
+)
+
+shared_chat_t = sa.table(
+    'shared_chat',
+    sa.column('id', sa.Text),
+    sa.column('chat_id', sa.Text),
+    sa.column('user_id', sa.Text),
+    sa.column('title', sa.Text),
+    sa.column('chat', sa.JSON),
+    sa.column('created_at', sa.BigInteger),
+    sa.column('updated_at', sa.BigInteger),
+)
+
+chat_message_t = sa.table(
+    'chat_message',
+    sa.column('chat_id', sa.Text),
+)
+
+access_grant_t = sa.table(
+    'access_grant',
+    sa.column('id', sa.Text),
+    sa.column('resource_type', sa.Text),
+    sa.column('resource_id', sa.Text),
+    sa.column('principal_type', sa.Text),
+    sa.column('principal_id', sa.Text),
+    sa.column('permission', sa.Text),
+    sa.column('created_at', sa.BigInteger),
+)
+
+
+def upgrade():
+    conn = op.get_bind()
+
+    # 1. Create shared_chat table
+    op.create_table(
+        'shared_chat',
+        sa.Column('id', sa.Text(), primary_key=True),
+        sa.Column('chat_id', sa.Text(), sa.ForeignKey('chat.id', ondelete='CASCADE'), nullable=False),
+        sa.Column('user_id', sa.Text(), nullable=False),
+        sa.Column('title', sa.Text(), nullable=True),
+        sa.Column('chat', sa.JSON(), nullable=True),
+        sa.Column('created_at', sa.BigInteger(), nullable=True),
+        sa.Column('updated_at', sa.BigInteger(), nullable=True),
+    )
+
+    # 2. Migrate existing shared-* rows
+    shared_rows = conn.execute(
+        sa.select(
+            chat_t.c.id,
+            chat_t.c.user_id,
+            chat_t.c.title,
+            chat_t.c.chat,
+            chat_t.c.created_at,
+            chat_t.c.updated_at,
+        ).where(chat_t.c.user_id.like('shared-%'))
+    ).fetchall()
+
+    for row in shared_rows:
+        share_token = row.id
+        original_chat_id = row.user_id.replace('shared-', '', 1)
+
+        # Verify original chat still exists
+        original = conn.execute(
+            sa.select(chat_t.c.user_id).where(chat_t.c.id == original_chat_id)
+        ).fetchone()
+
+        if not original:
+            continue
+
+        # Insert snapshot into shared_chat
+        conn.execute(shared_chat_t.insert().values(
+            id=share_token,
+            chat_id=original_chat_id,
+            user_id=original.user_id,
+            title=row.title,
+            chat=row.chat,
+            created_at=row.created_at,
+            updated_at=row.updated_at,
+        ))
+
+        # Create user:*:read grant for backward compat
+        conn.execute(access_grant_t.insert().values(
+            id=str(uuid.uuid4()),
+            resource_type='shared_chat',
+            resource_id=original_chat_id,
+            principal_type='user',
+            principal_id='*',
+            permission='read',
+            created_at=row.created_at or int(time.time()),
+        ))
+
+    # 3. Clean up old phantom rows
+    conn.execute(
+        chat_message_t.delete().where(
+            chat_message_t.c.chat_id.in_(
+                sa.select(chat_t.c.id).where(chat_t.c.user_id.like('shared-%'))
+            )
+        )
+    )
+    conn.execute(chat_t.delete().where(chat_t.c.user_id.like('shared-%')))
+
+
+def downgrade():
+    conn = op.get_bind()
+
+    shared_rows = conn.execute(
+        sa.select(
+            shared_chat_t.c.id,
+            shared_chat_t.c.chat_id,
+            shared_chat_t.c.user_id,
+            shared_chat_t.c.title,
+            shared_chat_t.c.chat,
+            shared_chat_t.c.created_at,
+            shared_chat_t.c.updated_at,
+        )
+    ).fetchall()
+
+    for row in shared_rows:
+        conn.execute(chat_t.insert().values(
+            id=row.id,
+            user_id=f'shared-{row.chat_id}',
+            title=row.title,
+            chat=row.chat,
+            created_at=row.created_at,
+            updated_at=row.updated_at,
+            archived=False,
+            meta={},
+        ))
+
+    conn.execute(
+        access_grant_t.delete().where(access_grant_t.c.resource_type == 'shared_chat')
+    )
+    op.drop_table('shared_chat')