"""phase31 — device_registrations table (re-issue of phase30)

phase30 used op.get_bind() + op.create_table() which is unreliable with
Flask-Migrate and left the table uncreated even though alembic_version
recorded phase30 as applied.  This migration re-creates the table using
the same raw-SQL pattern used by every other migration in this project.
CREATE TABLE IF NOT EXISTS is idempotent — safe whether or not the table
was partially created by the broken phase30.
"""

from alembic import op

revision      = 'phase31_device_registry'
down_revision = 'phase30_device_registry'
branch_labels = None
depends_on    = None


def upgrade():
    op.execute("""
        CREATE TABLE IF NOT EXISTS device_registrations (
            id            INT          NOT NULL AUTO_INCREMENT PRIMARY KEY,
            device_id     VARCHAR(64)  NOT NULL,
            user_id       INT          NOT NULL,
            device_name   VARCHAR(255) NOT NULL DEFAULT '',
            app_version   VARCHAR(32)  NOT NULL DEFAULT '',
            ios_version   VARCHAR(32)  NOT NULL DEFAULT '',
            registered_at DATETIME     NOT NULL,
            last_seen_at  DATETIME     NOT NULL,
            CONSTRAINT uq_device_id UNIQUE (device_id),
            CONSTRAINT fk_device_reg_user
                FOREIGN KEY (user_id) REFERENCES users(id)
                ON DELETE CASCADE
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
    """)


def downgrade():
    op.execute("DROP TABLE IF EXISTS device_registrations")