"""task dependencies

Revision ID: 3c6a2d3df4a1
Revises: 1d844b04ee06
Create Date: 2026-02-06
"""

from __future__ import annotations

from alembic import op
import sqlalchemy as sa

# revision identifiers, used by Alembic.
revision = "3c6a2d3df4a1"
down_revision = "1d844b04ee06"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.create_table(
        "task_dependencies",
        sa.Column("id", sa.Uuid(), nullable=False),
        sa.Column("board_id", sa.Uuid(), nullable=False),
        sa.Column("task_id", sa.Uuid(), nullable=False),
        sa.Column("depends_on_task_id", sa.Uuid(), nullable=False),
        sa.Column("created_at", sa.DateTime(), nullable=False),
        sa.ForeignKeyConstraint(
            ["board_id"],
            ["boards.id"],
            ondelete="CASCADE",
        ),
        sa.ForeignKeyConstraint(
            ["task_id"],
            ["tasks.id"],
            ondelete="CASCADE",
        ),
        sa.ForeignKeyConstraint(
            ["depends_on_task_id"],
            ["tasks.id"],
            ondelete="CASCADE",
        ),
        sa.PrimaryKeyConstraint("id"),
        sa.UniqueConstraint(
            "task_id",
            "depends_on_task_id",
            name="uq_task_dependencies_task_id_depends_on_task_id",
        ),
        sa.CheckConstraint(
            "task_id <> depends_on_task_id",
            name="ck_task_dependencies_no_self",
        ),
    )

    op.create_index(
        "ix_task_dependencies_board_id",
        "task_dependencies",
        ["board_id"],
        unique=False,
    )
    op.create_index(
        "ix_task_dependencies_task_id",
        "task_dependencies",
        ["task_id"],
        unique=False,
    )
    op.create_index(
        "ix_task_dependencies_depends_on_task_id",
        "task_dependencies",
        ["depends_on_task_id"],
        unique=False,
    )


def downgrade() -> None:
    op.drop_index("ix_task_dependencies_depends_on_task_id", table_name="task_dependencies")
    op.drop_index("ix_task_dependencies_task_id", table_name="task_dependencies")
    op.drop_index("ix_task_dependencies_board_id", table_name="task_dependencies")
    op.drop_table("task_dependencies")