"""invitations: users invite friends, even while sign-up is closed

An administrator switch lets every user send a few single-use invitation links
by email; a link opens sign-up for the person it was sent to even when public
registration is off. The email is built from a template the administrator
uploads (or the built-in one) and sent from the instance's own address.

Revision ID: 0027
Revises: 0026
Create Date: 2026-10-14
"""

from __future__ import annotations

from collections.abc import Sequence

from alembic import op

revision: str = "0027"
down_revision: str | None = "0026"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    op.execute(
        """
        ALTER TABLE app_settings
          ADD COLUMN invitations_enabled boolean NOT NULL DEFAULT false,
          ADD COLUMN invite_from text NOT NULL DEFAULT '',
          ADD COLUMN invite_subject text NOT NULL DEFAULT '',
          ADD COLUMN invite_template text NOT NULL DEFAULT ''
        """
    )
    op.execute(
        """
        CREATE TABLE invitations (
          id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
          inviter_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE,
          token_hash text NOT NULL UNIQUE,
          invitee_name text NOT NULL,
          invitee_email text NOT NULL,
          created_at timestamptz NOT NULL DEFAULT now(),
          expires_at timestamptz NOT NULL,
          used_at timestamptz,
          used_by uuid REFERENCES users(id) ON DELETE SET NULL
        )
        """
    )
    op.execute("CREATE INDEX ix_invitations_inviter ON invitations (inviter_id)")


def downgrade() -> None:
    op.execute("DROP TABLE IF EXISTS invitations")
    op.execute(
        """
        ALTER TABLE app_settings
          DROP COLUMN IF EXISTS invitations_enabled,
          DROP COLUMN IF EXISTS invite_from,
          DROP COLUMN IF EXISTS invite_subject,
          DROP COLUMN IF EXISTS invite_template
        """
    )