"""Drop the ``cmdb_cloud_scopes.is_ai_dedicated`` column.

Revision ID: 153
Revises: 152
Create Date: 2026-05-12

Why
---
``is_ai_dedicated`` was a tenant-level boolean ("this entire Azure
subscription / AWS account is 100% AI-purpose") used to bucket a
scope's full billing into the AI Spending dashboard. The model
collapsed three real states into one:

1. A subscription whose ONLY workload is AI (e.g. "PingCAP Azure
   OpenAI"). is_ai_dedicated=true sent its entire daily total to
   the AI bucket — correct.
2. A subscription with mixed workloads where AI is a minority
   (e.g. azure-azure-digital-bi-dev). is_ai_dedicated=true would
   send the full subscription total to AI even though most of it is
   Microsoft Fabric / storage / network — wrong, over-counts AI.
3. A subscription where some AI services are billed alongside other
   infrastructure. is_ai_dedicated=false caused those AI lines to
   silently drop from the AI bucket — wrong, under-counts AI.

PR #253 (Phase 2) replaces the flag with service-level classification:
any ``cmdb_cost_facts`` row whose ``service`` matches the configurable
``ai_spending.service_whitelist`` is AI; everything else isn't,
regardless of which scope it lives in. This handles all three states
correctly without admin-managed flags.

Downgrade
---------
Re-adds the column with default 0. Re-population is NOT attempted —
the autogrant flow that previously set the flag (Azure OpenAI / AWS
Bedrock) is also removed in this PR, so even a downgraded schema
won't have a writer.

Pre-deploy invariant
--------------------
Code references to ``CmdbCloudScope.is_ai_dedicated`` must be removed
in the same PR. Migration runs at startup before the app imports the
ORM models; a model with a non-existent column raises only when a
query refers to that column, not on import — but every production
query path has been pruned. See the PR's commit chain for the
mechanical changes in ``cmdb/models.py``,
``cmdb/admin_overview_service.py``,
``apikey/azure_openai_autogrant.py``, and the frontend i18n keys.
"""
from __future__ import annotations

import sqlalchemy as sa

from alembic import op

revision = "153"
down_revision = "152"
branch_labels = None
depends_on = None


TABLE = "cmdb_cloud_scopes"
COLUMN = "is_ai_dedicated"


def _column_exists(bind, table: str, name: str) -> bool:
    return bind.execute(
        sa.text(
            "SELECT 1 FROM information_schema.COLUMNS "
            "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :t "
            "AND COLUMN_NAME = :c"
        ),
        {"t": table, "c": name},
    ).scalar() is not None


def upgrade() -> None:
    bind = op.get_bind()
    if _column_exists(bind, TABLE, COLUMN):
        op.drop_column(TABLE, COLUMN)


def downgrade() -> None:
    bind = op.get_bind()
    if _column_exists(bind, TABLE, COLUMN):
        return
    op.add_column(
        TABLE,
        sa.Column(
            COLUMN,
            sa.Boolean(),
            nullable=False,
            server_default=sa.text("0"),
        ),
    )