"""phase30 — device_registrations table for iOS device tracking

Revision ID: phase30_device_registry
Down revision: phase29_broadcasts
"""

revision      = 'phase30_device_registry'
down_revision = 'phase29_broadcasts'

from alembic import op
import sqlalchemy as sa


def upgrade():
    # Guard: skip if table already exists (safe to re-run)
    conn = op.get_bind()
    exists = conn.execute(sa.text(
        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES "
        "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'device_registrations'"
    )).scalar()
    if exists:
        return

    op.create_table(
        'device_registrations',
        sa.Column('id',            sa.Integer(),     primary_key=True),
        sa.Column('device_id',     sa.String(64),    nullable=False),
        sa.Column('user_id',       sa.Integer(),     sa.ForeignKey('users.id'), nullable=False),
        sa.Column('device_name',   sa.String(255),   nullable=False, server_default=''),
        sa.Column('app_version',   sa.String(32),    nullable=False, server_default=''),
        sa.Column('ios_version',   sa.String(32),    nullable=False, server_default=''),
        sa.Column('registered_at', sa.DateTime(),    nullable=False),
        sa.Column('last_seen_at',  sa.DateTime(),    nullable=False),
    )

    op.create_index('uq_device_id', 'device_registrations', ['device_id'], unique=True)
    op.create_index('ix_device_registrations_user_id', 'device_registrations', ['user_id'])


def downgrade():
    op.drop_table('device_registrations')