"""Добавить public_id в таблицу tasks.

Revision ID: 002
Revises: 001
Create Date: 2026-05-24
"""

import secrets

from alembic import op
import sqlalchemy as sa
from sqlalchemy import text

revision = "002"
down_revision = "001"
branch_labels = None
depends_on = None


def upgrade() -> None:
    # Добавляем колонку как nullable — сначала заполним данными, потом сделаем NOT NULL
    op.add_column(
        "tasks",
        sa.Column("public_id", sa.String(32), nullable=True),
    )

    # Заполняем существующие строки уникальными public_id
    conn = op.get_bind()
    tasks = conn.execute(text("SELECT id FROM tasks")).fetchall()
    for (task_id,) in tasks:
        conn.execute(
            text("UPDATE tasks SET public_id = :pid WHERE id = :id"),
            {"pid": secrets.token_urlsafe(16), "id": task_id},
        )

    # Делаем NOT NULL и добавляем уникальный индекс
    op.alter_column("tasks", "public_id", nullable=False)
    op.create_unique_constraint("uq_tasks_public_id", "tasks", ["public_id"])
    op.create_index("ix_tasks_public_id", "tasks", ["public_id"], unique=True)


def downgrade() -> None:
    op.drop_index("ix_tasks_public_id", table_name="tasks")
    op.drop_constraint("uq_tasks_public_id", "tasks", type_="unique")
    op.drop_column("tasks", "public_id")