"""embeddings vector 512 -> 768

Revision ID: 0010_embeddings_768d
Revises: 0009_users_and_auth
Create Date: 2026-04-12

Resize embeddings.vector from Vector(512) to Vector(768) for
SigLIP2 ViT-B/16 embeddings. Drops existing data and HNSW index,
recreates with the new dimension. Existing embeddings will be
regenerated by the vision backfill task.
"""
from typing import Sequence, Union

from alembic import op

revision: str = "0010_embeddings_768d"
down_revision: Union[str, None] = "0009_users_and_auth"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.execute("DROP INDEX IF EXISTS ix_embeddings_vector_hnsw")
    op.execute("DELETE FROM embeddings")
    op.execute("ALTER TABLE embeddings ALTER COLUMN vector TYPE vector(768)")
    op.execute("""
        CREATE INDEX IF NOT EXISTS ix_embeddings_vector_hnsw
        ON embeddings USING hnsw (vector vector_cosine_ops)
    """)


def downgrade() -> None:
    op.execute("DROP INDEX IF EXISTS ix_embeddings_vector_hnsw")
    op.execute("DELETE FROM embeddings")
    op.execute("ALTER TABLE embeddings ALTER COLUMN vector TYPE vector(512)")
    op.execute("""
        CREATE INDEX IF NOT EXISTS ix_embeddings_vector_hnsw
        ON embeddings USING hnsw (vector vector_cosine_ops)
    """)