"""Re-enable RLS fail-closed on all tenant tables.

This migration reverses the RLS disabling from migrations 0078-0081.
RLS is re-enabled with FORCE and fail-closed policies:

- Tenant context set (app.current_tenant_id): only own tenant rows visible
- Tenant context missing: NO rows visible (fail-closed, not fail-open)

Global tables (users, tenants, user_tenants, sessions, plugins) remain
without RLS — they are accessed via a separate bootstrap/auth connection
and filtered at the application layer.

Bootstrap and startup must use:
  1. A separate connection (crm_auth/crm_bootstrap) for global tables
  2. Per-tenant initialization with explicit tenant context:
     SELECT set_config('app.current_tenant_id', :tenant_id, true);

Revision ID: 0084
Revises: 0083
"""

from alembic import op
from sqlalchemy import text

revision = "0084"
down_revision = "0083"
branch_labels = None
depends_on = None

# Tables WITH tenant_id column — get fail-closed RLS
TENANT_TABLES = [
    "groups", "roles", "system_settings", "currencies", "tax_rates", "sequences",
    "saved_filters", "saved_views", "webhooks", "workspaces", "workspace_modules",
    "workspace_users", "workspace_widgets", "user_preferences", "custom_field_definitions",
    "backups", "share_links", "entity_links", "entity_history",
    "contact_folder_permissions", "contact_folders", "guest_users", "guest_invitations",
    "permission_delegations", "permission_templates", "entity_permissions", "entity_policies",
    "entity_attachments", "files", "folders", "tags", "tag_assignments", "tasks", "subtasks",
    "notification_preferences", "audit_log",
    "automation_cron_jobs", "automation_definitions",
    "automation_runs", "automation_versions", "automation_agent_definitions",
    "automation_agent_runs", "automation_agent_versions",
    "report_templates", "report_instances",
    "consumer_inbox", "event_outbox", "outbox_deliveries",
]


def upgrade() -> None:
    conn = op.get_bind()

    for table in TENANT_TABLES:
        # Check if table exists
        exists = conn.execute(
            text(f"SELECT 1 FROM information_schema.tables WHERE table_name = '{table}'")
        ).fetchone() is not None
        if not exists:
            continue

        # Check if table has tenant_id column
        has_tenant_id = conn.execute(
            text(f"SELECT 1 FROM information_schema.columns WHERE table_name = '{table}' AND column_name = 'tenant_id'")
        ).fetchone() is not None
        if not has_tenant_id:
            continue

        # Drop any existing policies
        policies = conn.execute(text(
            f"SELECT policyname FROM pg_policies WHERE tablename = '{table}'"
        )).fetchall()
        for (policyname,) in policies:
            conn.execute(text(f"DROP POLICY IF EXISTS {policyname} ON {table}"))

        # Enable RLS and FORCE it (table owner cannot bypass)
        conn.execute(text(f"ALTER TABLE {table} ENABLE ROW LEVEL SECURITY"))
        conn.execute(text(f"ALTER TABLE {table} FORCE ROW LEVEL SECURITY"))

        # Fail-closed tenant isolation policy
        # NULLIF converts empty string to NULL -> comparison yields NULL -> no rows returned
        # This is fail-closed: missing tenant context = no access
        policy_sql = (
            "CREATE POLICY " + table + "_tenant_isolation "
            "ON " + table + " "
            "AS PERMISSIVE "
            "FOR ALL "
            "TO crm_api "
            "USING ("
            "tenant_id = NULLIF(current_setting('app.current_tenant_id', true), '')::uuid"
            ") "
            "WITH CHECK ("
            "tenant_id = NULLIF(current_setting('app.current_tenant_id', true), '')::uuid"
            ")"
        )
        conn.execute(text(policy_sql))


def downgrade() -> None:
    conn = op.get_bind()
    for table in TENANT_TABLES:
        exists = conn.execute(
            text(f"SELECT 1 FROM information_schema.tables WHERE table_name = '{table}'")
        ).fetchone() is not None
        if not exists:
            continue
        conn.execute(text(f"DROP POLICY IF EXISTS {table}_tenant_isolation ON {table}"))
        conn.execute(text(f"ALTER TABLE {table} NO FORCE ROW LEVEL SECURITY"))
        conn.execute(text(f"ALTER TABLE {table} DISABLE ROW LEVEL SECURITY"))