"""doc_drafts: server-side drafts of chat answers saved as docs (phase 59)

Revision ID: 0011
Revises: 0010
Create Date: 2026-09-01

Phase 59 (save chat answers as docs — edit screen → commit + push to the
.env docs branch, owner revision D3 2026-08-31: no PR tooling — one
additive, reversible table, no other schema change, A13):

* ``doc_drafts`` — one row per "Save as doc" action: the long answer
  body must live on the **server**, never in a URL. ``token`` is an
  unguessable 128-bit ``uuid4`` — the edit screen's URL credential
  (``/doc-edit.html?draft=<token>``, the share-token trust model,
  phase 51) — UNIQUE (``ix_doc_drafts_token``) + NOT NULL. Unlike the
  NULLable ``saved_chats.share_token`` there is no "un-drafted" state,
  so no NULLs ever occur; the unique index is the guard against
  duplicate tokens.
* ``title`` / ``path`` / ``body`` — the editable triple (TEXT NOT NULL;
  the body is the answer's raw markdown, never HTML — the
  ``bor.chat.v1`` record shape).
* ``status`` — plain TEXT + server default ``'draft'`` (the
  ``git_sources.kind`` phase-38 precedent — the ``draft`` | ``pushed``
  domain is enforced by the API layer, not a CHECK constraint).
* ``branch`` / ``commit_sha`` — TEXT NULL: set by the push endpoint
  (task 04) when it commits + pushes the file to the ``BOR_DOCS_REPO``
  branch, recording the branch + the pushed branch's new HEAD (the UI's
  branch + sha feedback).
* ``created_at`` / ``updated_at`` — TIMESTAMPTZ NOT NULL, stamped
  server-side (``updated_at`` bumps on every row update via the ORM
  ``onupdate`` — the ``saved_chats`` precedent).
"""
from __future__ import annotations

import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

from alembic import op

revision = "0011"
down_revision = "0010"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.create_table(
        "doc_drafts",
        sa.Column("id", postgresql.UUID(as_uuid=True), primary_key=True),
        sa.Column("token", postgresql.UUID(as_uuid=True), nullable=False),
        sa.Column("title", sa.Text(), nullable=False),
        sa.Column("path", sa.Text(), nullable=False),
        sa.Column("body", sa.Text(), nullable=False),
        sa.Column("status", sa.Text(), nullable=False, server_default=sa.text("'draft'")),
        sa.Column("branch", sa.Text(), nullable=True),
        sa.Column("commit_sha", sa.Text(), nullable=True),
        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,
        ),
    )
    # The token is the URL credential — a unique handle (the
    # saved_chats.share_token unique-index precedent, phase 51).
    op.create_index("ix_doc_drafts_token", "doc_drafts", ["token"], unique=True)


def downgrade() -> None:
    # Safe order: drop the token index first, then the table (A13 —
    # fully reversible, no other schema change).
    op.drop_index("ix_doc_drafts_token", table_name="doc_drafts")
    op.drop_table("doc_drafts")