"""add_email_verification

Add email_hash blind index to users (for uniqueness without decryption),
and the email_verifications table for registration, email change, and
invitation codes.

Revision ID: d4e5f6a7b8c9
Revises: c3d4e5f6a7b8
Create Date: 2026-08-31 14:00:00.000000

"""
from collections.abc import Sequence

import sqlalchemy as sa
from alembic import op

revision: str = 'd4e5f6a7b8c9'
down_revision: str | Sequence[str] | None = 'c3d4e5f6a7b8'
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    op.add_column('users',
        sa.Column('email_hash', sa.String(64), nullable=True))
    op.create_index('ix_users_email_hash', 'users', ['email_hash'], unique=True)

    op.create_table('email_verifications',
        sa.Column('id', sa.String(36), nullable=False),
        sa.Column('email_hash', sa.String(64), nullable=False),
        sa.Column('email_encrypted', sa.String(256), nullable=True),
        sa.Column('code', sa.String(16), nullable=False),
        sa.Column('purpose', sa.String(16), nullable=False),
        sa.Column('user_id', sa.String(36), sa.ForeignKey('users.id'), nullable=True),
        sa.Column('group_id', sa.String(36), sa.ForeignKey('groups.id'), nullable=True),
        # `sa.func.now()`, as every other migration in this chain uses: the
        # dialect running it renders it. Written out as PostgreSQL's
        # `(now() at time zone 'utc')`, this was a syntax error on SQLite — so
        # the chain could not reach head on the database the suite and the
        # local-hub workflow both use, and the two newest migrations had been
        # run by exactly one thing: a production deploy.
        sa.Column('created_at', sa.DateTime(timezone=True),
                  server_default=sa.func.now()),
        sa.Column('expires_at', sa.DateTime(timezone=True), nullable=False),
        sa.Column('verified_at', sa.DateTime(timezone=True), nullable=True),
        sa.Column('attempts', sa.Integer, server_default='0'),
        sa.PrimaryKeyConstraint('id'),
    )
    op.create_index('ix_email_verif_hash', 'email_verifications', ['email_hash'])
    op.create_index('ix_email_verif_user', 'email_verifications', ['user_id'])


def downgrade() -> None:
    op.drop_index('ix_email_verif_user')
    op.drop_index('ix_email_verif_hash')
    op.drop_table('email_verifications')
    op.drop_index('ix_users_email_hash', table_name='users')
    op.drop_column('users', 'email_hash')