"""Record which model produced each stored embedding.

Without this a model change silently mixes vectors from different embedding
spaces, and cosine distance between them is meaningless.

Revision ID: r0d1e2f3a475
Revises: q9c0d1e2f364
"""
from alembic import op

revision = "r0d1e2f3a475"
down_revision = "q9c0d1e2f364"
branch_labels = None
depends_on = None


def upgrade():
    op.execute("ALTER TABLE questions ADD COLUMN IF NOT EXISTS embedding_model VARCHAR(120)")
    op.execute("ALTER TABLE questions ADD COLUMN IF NOT EXISTS embedded_at TIMESTAMP")
    op.execute("CREATE INDEX IF NOT EXISTS ix_questions_embedding_model ON questions(embedding_model)")


def downgrade():
    op.execute("DROP INDEX IF EXISTS ix_questions_embedding_model")
    op.execute("ALTER TABLE questions DROP COLUMN IF EXISTS embedded_at")
    op.execute("ALTER TABLE questions DROP COLUMN IF EXISTS embedding_model")