"""Add photo fields to Item and Box models.

Revision ID: 001_add_photo_fields
Revises: None
Create Date: 2026-04-20

This migration adds three photo-related columns to both Item and Box tables:
- photo_path: String, nullable (original photo filename/path)
- photo_thumbnail_path: String, nullable (thumbnail photo filename/path)
- photo_upload_date: DateTime, nullable (when photo was uploaded)

These fields support the Phase 1 Image System implementation.
All fields are nullable to maintain backward compatibility with existing items/boxes.
"""

from alembic import op
import sqlalchemy as sa


# revision identifiers, used by Alembic.
revision = '001_add_photo_fields'
down_revision = None
branch_labels = None
depends_on = None


def upgrade():
    """Add photo fields to items table."""
    # Add photo_path column to items table
    op.add_column('items', sa.Column('photo_path', sa.String(), nullable=True))

    # Add photo_thumbnail_path column to items table
    op.add_column('items', sa.Column('photo_thumbnail_path', sa.String(), nullable=True))

    # Add photo_upload_date column to items table
    op.add_column('items', sa.Column('photo_upload_date', sa.DateTime(), nullable=True))

    # Create boxes table with photo fields
    op.create_table(
        'boxes',
        sa.Column('id', sa.Integer(), nullable=False),
        sa.Column('box_label', sa.String(), nullable=False),
        sa.Column('description', sa.String(), nullable=True),
        sa.Column('photo_path', sa.String(), nullable=True),
        sa.Column('photo_thumbnail_path', sa.String(), nullable=True),
        sa.Column('photo_upload_date', sa.DateTime(), nullable=True),
        sa.PrimaryKeyConstraint('id'),
        sa.UniqueConstraint('box_label', name='unique_box_label')
    )

    # Create index on box_label for fast lookups
    op.create_index('ix_boxes_box_label', 'boxes', ['box_label'], unique=True)


def downgrade():
    """Remove photo fields from items table and drop boxes table."""
    # Drop boxes table
    op.drop_table('boxes')

    # Remove photo columns from items table
    op.drop_column('items', 'photo_upload_date')
    op.drop_column('items', 'photo_thumbnail_path')
    op.drop_column('items', 'photo_path')