"""problem correlation fields

Revision ID: 003
Revises: 002
"""

from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op

revision: str = "003"
down_revision: Union[str, None] = "002"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.add_column("problems", sa.Column("fingerprint", sa.String(length=128), nullable=True))
    op.add_column(
        "problems",
        sa.Column("event_count", sa.Integer(), nullable=False, server_default="1"),
    )
    op.add_column("problems", sa.Column("last_seen_at", sa.DateTime(timezone=True), nullable=True))
    op.create_index("ix_problems_fingerprint", "problems", ["fingerprint"])
    op.create_index("ix_problems_last_seen_at", "problems", ["last_seen_at"])

    op.execute(
        sa.text(
            """
            UPDATE problems p SET
                fingerprint = 'h' || COALESCE(p.host_id::text, '0') || chr(58) || 'r'
                    || COALESCE(p.rule_id, 'unknown'),
                event_count = COALESCE(
                    (SELECT COUNT(*)::int FROM problem_events pe WHERE pe.problem_id = p.id),
                    1
                ),
                last_seen_at = COALESCE(p.updated_at, p.created_at)
            """
        )
    )

    op.alter_column("problems", "fingerprint", nullable=False)
    op.alter_column("problems", "last_seen_at", nullable=False)


def downgrade() -> None:
    op.drop_index("ix_problems_last_seen_at", table_name="problems")
    op.drop_index("ix_problems_fingerprint", table_name="problems")
    op.drop_column("problems", "last_seen_at")
    op.drop_column("problems", "event_count")
    op.drop_column("problems", "fingerprint")