"""create dataset_review_sessions table

Previously this table was created at runtime by init_db() →
Base.metadata.create_all(). Migration f0e9d8c7b6a5 references it
(altering the environment_id FK to add ondelete='CASCADE'), so the
table must exist when that migration runs.

This migration creates dataset_review_sessions with the FK already
having ondelete='CASCADE' (matching the model). On fresh databases,
f0e9d8c7b6a5's drop+recreate of this FK is a no-op. On databases
upgraded from before the FK had CASCADE, f0e9d8c7b6a5 still applies
the change.

Revision ID: e1f2a3b4c5d6
Revises: a5b6c7d8e9f0
Create Date: 2026-06-11 17:10:00.000000

"""
from collections.abc import Sequence

import sqlalchemy as sa
from alembic import op

# revision identifiers, used by Alembic.
revision: str = 'e1f2a3b4c5d6'
down_revision: str | Sequence[str] | None = 'a5b6c7d8e9f0'
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    """Create dataset_review_sessions table."""
    op.create_table(
        'dataset_review_sessions',
        sa.Column('session_id', sa.String(), nullable=False),
        sa.Column('user_id', sa.String(), nullable=False),
        sa.Column('environment_id', sa.String(), nullable=False),
        sa.Column('source_kind', sa.String(), nullable=False),
        sa.Column('source_input', sa.String(), nullable=False),
        sa.Column('dataset_ref', sa.String(), nullable=False),
        sa.Column('dataset_id', sa.Integer(), nullable=True),
        sa.Column('dashboard_id', sa.Integer(), nullable=True),
        sa.Column('readiness_state', sa.Enum(
            'empty', 'importing', 'review_ready', 'semantic_source_review_needed',
            'clarification_needed', 'clarification_active', 'mapping_review_needed',
            'compiled_preview_ready', 'partially_ready', 'run_ready',
            'run_in_progress', 'completed', 'recovery_required',
            name='readinessstate', create_type=False,
        ), nullable=False),
        sa.Column('recommended_action', sa.Enum(
            'import_from_superset', 'review_documentation', 'apply_semantic_source',
            'start_clarification', 'answer_next_question', 'approve_mapping',
            'generate_sql_preview', 'complete_required_values', 'launch_dataset',
            'resume_session', 'export_outputs',
            name='recommendedaction', create_type=False,
        ), nullable=False),
        sa.Column('version', sa.Integer(), nullable=False, server_default=sa.text('0')),
        sa.Column('status', sa.Enum(
            'active', 'paused', 'completed', 'archived', 'cancelled',
            name='sessionstatus', create_type=False,
        ), nullable=False),
        sa.Column('current_phase', sa.Enum(
            'intake', 'recovery', 'review', 'semantic_review', 'clarification',
            'mapping_review', 'preview', 'launch', 'post_run',
            name='sessionphase', create_type=False,
        ), nullable=False),
        sa.Column('active_task_id', sa.String(), nullable=True),
        sa.Column('last_preview_id', sa.String(), nullable=True),
        sa.Column('last_run_context_id', sa.String(), nullable=True),
        sa.Column('created_at', sa.DateTime(), nullable=False),
        sa.Column('updated_at', sa.DateTime(), nullable=False),
        sa.Column('last_activity_at', sa.DateTime(), nullable=False),
        sa.Column('closed_at', sa.DateTime(), nullable=True),
        sa.ForeignKeyConstraint(
            ['environment_id'], ['environments.id'],
            ondelete='CASCADE', name='dataset_review_sessions_environment_id_fkey',
        ),
        sa.ForeignKeyConstraint(
            ['user_id'], ['users.id'],
            name='dataset_review_sessions_user_id_fkey',
        ),
        sa.PrimaryKeyConstraint('session_id'),
    )


def downgrade() -> None:
    """Drop dataset_review_sessions table."""
    op.drop_table('dataset_review_sessions')
    op.execute('DROP TYPE IF EXISTS readinessstate')
    op.execute('DROP TYPE IF EXISTS recommendedaction')
    op.execute('DROP TYPE IF EXISTS sessionstatus')
    op.execute('DROP TYPE IF EXISTS sessionphase')