"""change_proposals (AI propose-then-confirm)

Revision ID: a1b2c3d4e5f6
Revises: d4a9c1e7b2f3
Create Date: 2026-06-09

"""
from collections.abc import Sequence

import sqlalchemy as sa
from alembic import op
from sqlalchemy.dialects import postgresql

revision: str = "a1b2c3d4e5f6"
down_revision: str | None = "d4a9c1e7b2f3"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    op.create_table(
        "change_proposals",
        sa.Column("id", sa.Uuid(), nullable=False),
        sa.Column("tree_id", sa.Uuid(), nullable=False),
        sa.Column(
            "status",
            sa.Enum("pending", "applied", "rejected", name="change_proposal_status"),
            server_default="pending",
            nullable=False,
        ),
        sa.Column(
            "origin",
            sa.Enum("assistant", "contributor", name="change_proposal_origin"),
            server_default="assistant",
            nullable=False,
        ),
        sa.Column("created_by_user_id", sa.Uuid(), nullable=True),
        sa.Column("summary", sa.String(length=512), nullable=False),
        sa.Column("rationale", sa.Text(), nullable=True),
        sa.Column("operations", postgresql.JSONB(astext_type=sa.Text()), nullable=False),
        sa.Column("reviewed_by_user_id", sa.Uuid(), nullable=True),
        sa.Column("reviewed_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("review_note", sa.String(length=512), nullable=True),
        sa.Column("apply_error", sa.Text(), nullable=True),
        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
        sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True),
        sa.ForeignKeyConstraint(["tree_id"], ["trees.id"], ondelete="CASCADE"),
        sa.ForeignKeyConstraint(["created_by_user_id"], ["users.id"], ondelete="SET NULL"),
        sa.ForeignKeyConstraint(["reviewed_by_user_id"], ["users.id"], ondelete="SET NULL"),
        sa.PrimaryKeyConstraint("id"),
    )
    op.create_index("ix_change_proposals_tree_id", "change_proposals", ["tree_id"])
    op.create_index("ix_change_proposals_status", "change_proposals", ["status"])


def downgrade() -> None:
    op.drop_index("ix_change_proposals_status", table_name="change_proposals")
    op.drop_index("ix_change_proposals_tree_id", table_name="change_proposals")
    op.drop_table("change_proposals")
    sa.Enum(name="change_proposal_status").drop(op.get_bind())
    sa.Enum(name="change_proposal_origin").drop(op.get_bind())