"""Classify snapshots whose sole Alpha failure is the unopened PPAC theme."""

import sqlalchemy as sa
from alembic import op

revision = "0022"
down_revision = "0021"
branch_labels = None
depends_on = None


def upgrade():
    # Reuse the indexed check_type column; preserve all raw evidence and check stages.
    table = sa.table("alphas", sa.column("id", sa.String()), sa.column("checks", sa.JSON()),
                     sa.column("check_type", sa.String(20)))
    connection = op.get_bind()
    last_id = None
    while True:
        query = sa.select(table.c.id, table.c.checks).order_by(table.c.id).limit(500)
        if last_id is not None:
            query = query.where(table.c.id > last_id)
        rows = connection.execute(query).mappings().all()
        if not rows:
            break
        candidates = []
        for row in rows:
            # Freeze the current interpretation instead of importing application code.
            checks = row["checks"] if isinstance(row["checks"], list) else []
            failures = [check for check in checks if isinstance(check, dict)
                        and check.get("name") != "REGULAR_SUBMISSION"
                        and isinstance(check.get("result"), str) and check["result"].upper() == "FAIL"]
            if len(failures) == 1 and failures[0].get("name") == "PURE_POWER_POOL_THEME":
                candidates.append(row["id"])
        if candidates:
            connection.execute(table.update().where(table.c.id.in_(candidates)).values(check_type="PPAC_CANDIDATE"))
        last_id = rows[-1]["id"]


def downgrade():
    table = sa.table("alphas", sa.column("check_type", sa.String(20)))
    op.execute(table.update().where(table.c.check_type == "PPAC_CANDIDATE").values(check_type="FAIL_1"))