"""messages: drop direct messaging (the owner's decision, 2026-10-04)

Chat — end-to-end encrypted direct messages plus the server's welcome note — was never used: prod held
two welcome notes, no message between people, and one key. Its tables go with its code. The rows are
not migrated anywhere; the nightly backup holds them.

The downgrade restores the schema as it stood (0026 + 0027), empty: a message can't be brought back
from a migration, and the E2EE key blobs were only ever readable by their owner's browser anyway.
"""

import sqlalchemy as sa
from alembic import op

revision: str = "0097_drop_messages"
down_revision: str | None = "0096_videos_sort_indexes"
branch_labels: str | None = None
depends_on: str | None = None


def upgrade() -> None:
    op.drop_table("message_keys")
    op.drop_index("ix_messages_created_at", table_name="messages")
    op.drop_index("ix_messages_recipient_id", table_name="messages")
    op.drop_index("ix_messages_sender_id", table_name="messages")
    op.drop_table("messages")


def downgrade() -> None:
    op.create_table(
        "messages",
        sa.Column("id", sa.Integer(), primary_key=True),
        sa.Column(
            "sender_id", sa.Integer(), sa.ForeignKey("users.id", ondelete="CASCADE"), nullable=True
        ),
        sa.Column(
            "recipient_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column("body", sa.Text(), nullable=True),
        sa.Column("read_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column(
            "created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False
        ),
        sa.Column("kind", sa.String(length=16), nullable=False, server_default="user"),
        sa.Column("ciphertext", sa.Text(), nullable=True),
        sa.Column("iv", sa.String(length=32), nullable=True),
    )
    op.create_index("ix_messages_sender_id", "messages", ["sender_id"])
    op.create_index("ix_messages_recipient_id", "messages", ["recipient_id"])
    op.create_index("ix_messages_created_at", "messages", ["created_at"])
    op.create_table(
        "message_keys",
        sa.Column(
            "user_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            primary_key=True,
        ),
        sa.Column("public_key", sa.Text(), nullable=False),
        sa.Column("wrapped_private_key", sa.Text(), nullable=False),
        sa.Column("salt", sa.String(length=64), nullable=False),
        sa.Column("wrap_iv", sa.String(length=32), nullable=False),
        sa.Column("key_check", sa.Text(), nullable=False),
        sa.Column(
            "created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False
        ),
    )