"""Жизненный цикл партии: статус, тайминг, длительность, причина победы; place → nullable.

Идемпотентна: на свежей БД (0001 создаёт схему из актуальных моделей через create_all)
столбцы уже есть → no-op; на существующей БД (ревизия 0002, старая схема) — добавляет
столбцы и делает place nullable. render_as_batch включён в env.py (нужен для SQLite).

Revision ID: 0003_match_lifecycle
Revises: 0002_seed_reference
Create Date: 2026-06-15
"""
from typing import Sequence, Union

import sqlalchemy as sa
from sqlalchemy import inspect

from alembic import op

revision: str = "0003_match_lifecycle"
down_revision: Union[str, None] = "0002_seed_reference"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    bind = op.get_bind()
    insp = inspect(bind)

    match_cols = {c["name"] for c in insp.get_columns("matches")}
    add = []
    if "status" not in match_cols:
        add.append(sa.Column("status", sa.String(16), nullable=False, server_default="finished"))
    if "started_at" not in match_cols:
        add.append(sa.Column("started_at", sa.DateTime(), nullable=True))
    if "finished_at" not in match_cols:
        add.append(sa.Column("finished_at", sa.DateTime(), nullable=True))
    if "duration_minutes" not in match_cols:
        add.append(sa.Column("duration_minutes", sa.Integer(), nullable=True))
    if "win_reason" not in match_cols:
        add.append(sa.Column("win_reason", sa.String(16), nullable=True))

    if add:
        with op.batch_alter_table("matches") as b:
            for col in add:
                b.add_column(col)
        # Бэкфилл для существующих (уже завершённых) партий.
        op.execute("UPDATE matches SET status = 'finished' WHERE status IS NULL")
        op.execute("UPDATE matches SET started_at = created_at WHERE started_at IS NULL")
        op.execute("UPDATE matches SET finished_at = created_at WHERE finished_at IS NULL")

    # place → nullable, если ещё NOT NULL.
    place_col = next(c for c in insp.get_columns("match_participants") if c["name"] == "place")
    if not place_col["nullable"]:
        with op.batch_alter_table("match_participants") as b:
            b.alter_column("place", existing_type=sa.Integer(), nullable=True)


def downgrade() -> None:
    with op.batch_alter_table("matches") as b:
        for name in ("win_reason", "duration_minutes", "finished_at", "started_at", "status"):
            try:
                b.drop_column(name)
            except Exception:  # noqa: BLE001
                pass