"""Documents Generator tables (Phase L1): letterheads, print_templates,
document_assets.

Revision ID: 0143
Revises: 0142
Create Date: 2026-08-29

Dual-path convergence (Gate B): on plugin-first installs the report_generator
plugin migration 0003 has already created these tables — skip instead of
failing. Both paths converge to the identical schema (see
app/plugins/builtins/report_generator/migrations/0003_documents_generator.sql).
"""

import sqlalchemy as sa
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.dialects.postgresql import UUID as PGUUID

from alembic import op

revision = "0143"
down_revision = "0142"
branch_labels = None
depends_on = None


def _table_exists(conn, table_name: str) -> bool:
    row = conn.execute(
        sa.text("SELECT to_regclass(:tname) IS NOT NULL"),
        {"tname": f"public.{table_name}"},
    ).scalar()
    return bool(row)


def _rls(table: str) -> None:
    op.execute(f"ALTER TABLE {table} ENABLE ROW LEVEL SECURITY")
    op.execute(f"ALTER TABLE {table} FORCE ROW LEVEL SECURITY")
    op.execute(f"DROP POLICY IF EXISTS {table}_tenant_isolation ON {table}")
    op.execute(
        f"CREATE POLICY {table}_tenant_isolation ON {table} AS PERMISSIVE "
        f"FOR ALL TO crm_api "
        f"USING (tenant_id = NULLIF(current_setting('app.current_tenant_id', true), '')::uuid) "
        f"WITH CHECK (tenant_id = NULLIF(current_setting('app.current_tenant_id', true), '')::uuid)"
    )


def upgrade() -> None:
    conn = op.get_bind()
    if _table_exists(conn, "letterheads"):
        return

    op.create_table(
        "letterheads",
        sa.Column("id", PGUUID(as_uuid=True), primary_key=True),
        sa.Column("name", sa.String(255), nullable=False),
        sa.Column("description", sa.Text(), nullable=False, server_default=""),
        sa.Column("config", JSONB(), nullable=False, server_default=sa.text("'{}'::jsonb")),
        sa.Column("is_default", sa.Boolean(), nullable=False, server_default=sa.false()),
        sa.Column("tenant_id", PGUUID(as_uuid=True), nullable=False),
        sa.Column("owner_id", PGUUID(as_uuid=True), sa.ForeignKey("users.id", ondelete="SET NULL"), nullable=True),
        sa.Column("deleted_at", sa.DateTime(timezone=True)),
        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
        sa.Column("created_by", PGUUID(as_uuid=True), nullable=False),
    )
    op.create_index("ix_letterheads_tenant", "letterheads", ["tenant_id"])
    op.create_index("ix_letterheads_name", "letterheads", ["name"])

    op.create_table(
        "print_templates",
        sa.Column("id", PGUUID(as_uuid=True), primary_key=True),
        sa.Column("name", sa.String(255), nullable=False),
        sa.Column("description", sa.Text(), nullable=False, server_default=""),
        sa.Column("letterhead_id", PGUUID(as_uuid=True), sa.ForeignKey("letterheads.id", ondelete="SET NULL"), nullable=True),
        sa.Column("entity_type", sa.String(100), nullable=False, server_default="contact"),
        sa.Column("blocks", JSONB(), nullable=False, server_default=sa.text("'[]'::jsonb")),
        sa.Column("output_format", sa.String(20), nullable=False, server_default="pdf"),
        sa.Column("tenant_id", PGUUID(as_uuid=True), nullable=False),
        sa.Column("owner_id", PGUUID(as_uuid=True), sa.ForeignKey("users.id", ondelete="SET NULL"), nullable=True),
        sa.Column("deleted_at", sa.DateTime(timezone=True)),
        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
        sa.Column("created_by", PGUUID(as_uuid=True), nullable=False),
    )
    op.create_index("ix_print_templates_tenant", "print_templates", ["tenant_id"])
    op.create_index("ix_print_templates_name", "print_templates", ["name"])

    op.create_table(
        "document_assets",
        sa.Column("id", PGUUID(as_uuid=True), primary_key=True),
        sa.Column("letterhead_id", PGUUID(as_uuid=True), sa.ForeignKey("letterheads.id", ondelete="CASCADE"), nullable=True),
        sa.Column("filename", sa.String(255), nullable=False),
        sa.Column("mime_type", sa.String(100), nullable=False),
        sa.Column("size_bytes", sa.Integer(), nullable=False, server_default="0"),
        sa.Column("storage_path", sa.String(1024), nullable=False),
        sa.Column("tenant_id", PGUUID(as_uuid=True), nullable=False),
        sa.Column("owner_id", PGUUID(as_uuid=True), sa.ForeignKey("users.id", ondelete="SET NULL"), nullable=True),
        sa.Column("deleted_at", sa.DateTime(timezone=True)),
        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
        sa.Column("created_by", PGUUID(as_uuid=True), nullable=False),
    )
    op.create_index("ix_document_assets_tenant", "document_assets", ["tenant_id"])
    op.create_index("ix_document_assets_letterhead", "document_assets", ["letterhead_id"])

    for table in ("letterheads", "print_templates", "document_assets"):
        _rls(table)


def downgrade() -> None:
    conn = op.get_bind()
    if not _table_exists(conn, "letterheads"):
        return
    for table in ("document_assets", "print_templates", "letterheads"):
        op.execute(f"DROP POLICY IF EXISTS {table}_tenant_isolation ON {table}")
        op.drop_table(table)