"""Seed default render positions (3/4 Front + 3/4 Rear) for all existing products.

Revision ID: 029
Revises: 028
Create Date: 2026-03-04
"""
from alembic import op

revision = "029"
down_revision = "028"
branch_labels = None
depends_on = None


def upgrade():
    # Insert two default positions for every product that currently has none.
    # The CTE guarantees both rows are inserted for the same set of products.
    op.execute("""
        WITH products_without_positions AS (
            SELECT p.id AS product_id
            FROM products p
            WHERE NOT EXISTS (
                SELECT 1 FROM product_render_positions rp WHERE rp.product_id = p.id
            )
        )
        INSERT INTO product_render_positions
            (id, product_id, name, rotation_x, rotation_y, rotation_z,
             is_default, sort_order, created_at, updated_at)
        SELECT gen_random_uuid(), product_id,
               '3/4 Front', -15.0, 45.0, 0.0, true,  0, NOW(), NOW()
        FROM products_without_positions
        UNION ALL
        SELECT gen_random_uuid(), product_id,
               '3/4 Rear',  -15.0, -135.0, 0.0, false, 1, NOW(), NOW()
        FROM products_without_positions
    """)


def downgrade():
    # Remove positions named exactly '3/4 Front' or '3/4 Rear'
    # where they are the only two positions on that product (i.e. seeded ones).
    op.execute("""
        DELETE FROM product_render_positions
        WHERE name IN ('3/4 Front', '3/4 Rear')
          AND product_id IN (
              SELECT product_id
              FROM product_render_positions
              GROUP BY product_id
              HAVING COUNT(*) = 2
                 AND bool_or(name = '3/4 Front')
                 AND bool_or(name = '3/4 Rear')
          )
    """)