"""add signal planner fields

Revision ID: add_signal_planner_fields
Revises: expand_user_workload_ratio_precision
Create Date: 2026-03-12
"""

from __future__ import annotations

from alembic import op
import sqlalchemy as sa


revision = "add_signal_planner_fields"
down_revision = "expand_user_workload_ratio_precision"
branch_labels = None
depends_on = None


def _table_exists(bind, table_name: str) -> bool:
    return sa.inspect(bind).has_table(table_name)


def _column_exists(bind, table_name: str, column_name: str) -> bool:
    inspector = sa.inspect(bind)
    if not inspector.has_table(table_name):
        return False
    for column in inspector.get_columns(table_name):
        if str(column.get("name") or "") == column_name:
            return True
    return False


def _index_exists(bind, table_name: str, index_name: str) -> bool:
    inspector = sa.inspect(bind)
    if not inspector.has_table(table_name):
        return False
    return any(str(item.get("name") or "") == index_name for item in inspector.get_indexes(table_name))


def upgrade() -> None:
    bind = op.get_bind()
    if not _table_exists(bind, "signals"):
        return

    with op.batch_alter_table("signals") as batch_op:
        if not _column_exists(bind, "signals", "planner_status"):
            batch_op.add_column(
                sa.Column(
                    "planner_status",
                    sa.String(length=20),
                    nullable=False,
                    server_default="pending",
                )
            )
        if not _column_exists(bind, "signals", "planner_analyzed_at"):
            batch_op.add_column(sa.Column("planner_analyzed_at", sa.TIMESTAMP(), nullable=True))
        if not _column_exists(bind, "signals", "planner_assignee_user_id"):
            batch_op.add_column(sa.Column("planner_assignee_user_id", sa.BigInteger(), nullable=True))

    if not _index_exists(bind, "signals", "ix_signals_planner_status"):
        op.create_index("ix_signals_planner_status", "signals", ["planner_status"])



def downgrade() -> None:
    bind = op.get_bind()
    if not _table_exists(bind, "signals"):
        return

    if _index_exists(bind, "signals", "ix_signals_planner_status"):
        op.drop_index("ix_signals_planner_status", table_name="signals")

    with op.batch_alter_table("signals") as batch_op:
        if _column_exists(bind, "signals", "planner_assignee_user_id"):
            batch_op.drop_column("planner_assignee_user_id")
        if _column_exists(bind, "signals", "planner_analyzed_at"):
            batch_op.drop_column("planner_analyzed_at")
        if _column_exists(bind, "signals", "planner_status"):
            batch_op.drop_column("planner_status")