"""Lab reference article deep links and card associations.

Revision ID: i2d3e4f5a607
Revises: h1c2d3e4f506
"""
from alembic import op

revision = "i2d3e4f5a607"
down_revision = "h1c2d3e4f506"
branch_labels = None
depends_on = None


def upgrade():
    op.execute("ALTER TABLE lab_reference_values ADD COLUMN IF NOT EXISTS article_id INTEGER REFERENCES articles(id) ON DELETE SET NULL")
    op.execute("ALTER TABLE lab_reference_values ADD COLUMN IF NOT EXISTS article_section_id VARCHAR(64)")
    op.execute("""
    CREATE TABLE IF NOT EXISTS lab_reference_card_links (
        id SERIAL PRIMARY KEY,
        lab_reference_id INTEGER NOT NULL REFERENCES lab_reference_values(id) ON DELETE CASCADE,
        flashcard_id INTEGER NOT NULL REFERENCES flashcards(id) ON DELETE CASCADE,
        CONSTRAINT uq_lab_card_link UNIQUE (lab_reference_id, flashcard_id)
    )""")
    op.execute("CREATE INDEX IF NOT EXISTS ix_lab_reference_card_links_lab ON lab_reference_card_links (lab_reference_id)")


def downgrade():
    op.execute("DROP TABLE IF EXISTS lab_reference_card_links")
    op.execute("ALTER TABLE lab_reference_values DROP COLUMN IF EXISTS article_section_id")
    op.execute("ALTER TABLE lab_reference_values DROP COLUMN IF EXISTS article_id")