"""saved_chats: owner-saved chat conversations

Revision ID: 0008
Revises: 0007
Create Date: 2026-08-29

Phase 50 (save-and-view-chat-history story, A13 — one additive,
reversible table, no other schema change):

* ``saved_chats`` — one row per conversation the owner explicitly
  Saves (the A10 extension, owner permission 2026-08-29):
  ``/api/chat`` stays stateless and nothing is stored about a
  conversation that was not saved. ``title`` (the API-side auto-title —
  first question) is plain String(500) so a future rename needs no
  migration; ``messages`` is JSONB holding the exact ``bor.chat.v1``
  localStorage record shape (phase 14) so a saved chat restores
  pixel-identical through the existing ``renderStoredMessage`` path;
  ``created_at``/``updated_at`` are stamped server-side (``updated_at``
  additionally bumps on every row update via the ORM ``onupdate``).
  No share-related columns — phase 51 adds ``share_token`` in ``0009``.
"""
from __future__ import annotations

import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

from alembic import op

revision = "0008"
down_revision = "0007"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.create_table(
        "saved_chats",
        sa.Column("id", postgresql.UUID(as_uuid=True), primary_key=True),
        sa.Column("title", sa.String(500), nullable=False),
        sa.Column("messages", postgresql.JSONB(), nullable=False),
        sa.Column(
            "created_at",
            sa.DateTime(timezone=True),
            server_default=sa.func.now(),
            nullable=False,
        ),
        sa.Column(
            "updated_at",
            sa.DateTime(timezone=True),
            server_default=sa.func.now(),
            nullable=False,
        ),
    )


def downgrade() -> None:
    op.drop_table("saved_chats")