"""Add channel SKU mapping table (master SKU ↔ channel-specific SKU).

Revision ID: 0032_add_channel_sku_mapping
Revises: 0031_add_master_product_relation
Create Date: 2026-06-12 18:00:00.000000
"""

from __future__ import annotations

from alembic import op
import sqlalchemy as sa

revision = "0032_add_channel_sku_mapping"
down_revision = "0031_add_master_product_relation"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.create_table(
        "channel_sku_mapping",
        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
        sa.Column("master_sku", sa.String(128), nullable=False),
        sa.Column("channel_code", sa.String(32), nullable=False),
        sa.Column("channel_sku", sa.String(128), nullable=False),
        sa.Column("remote_id", sa.String(255), nullable=True),
        sa.Column("mapping_status", sa.String(32), nullable=False, server_default="active"),
        sa.Column("match_source", sa.String(64), nullable=True),
        sa.Column("notes", sa.Text(), nullable=True),
        sa.Column(
            "updated_at",
            sa.DateTime(timezone=True),
            nullable=False,
            server_default=sa.func.now(),
        ),
        sa.UniqueConstraint(
            "master_sku",
            "channel_code",
            name="uq_channel_sku_mapping_master_channel",
        ),
        sa.UniqueConstraint(
            "channel_code",
            "channel_sku",
            name="uq_channel_sku_mapping_channel_sku",
        ),
    )
    op.create_index("ix_channel_sku_mapping_master_sku", "channel_sku_mapping", ["master_sku"])
    op.create_index("ix_channel_sku_mapping_channel_code", "channel_sku_mapping", ["channel_code"])
    op.create_index("ix_channel_sku_mapping_channel_sku", "channel_sku_mapping", ["channel_sku"])


def downgrade() -> None:
    op.drop_index("ix_channel_sku_mapping_channel_sku", table_name="channel_sku_mapping")
    op.drop_index("ix_channel_sku_mapping_channel_code", table_name="channel_sku_mapping")
    op.drop_index("ix_channel_sku_mapping_master_sku", table_name="channel_sku_mapping")
    op.drop_table("channel_sku_mapping")