-- B06 只登记作者控制的有限返修会话、轮任务引用和选择；实际模型任务与候选仍归 S02/B05。
CREATE TABLE public.muse_revision_session (
    session_id uuid PRIMARY KEY,
    author_id text NOT NULL,
    create_command_id text NOT NULL,
    request_hash text NOT NULL CHECK(request_hash ~ '^[0-9a-f]{64}$'),
    work_id text NOT NULL REFERENCES public.muse_work(work_id),
    chapter_id text NOT NULL REFERENCES public.muse_chapter(chapter_id),
    branch_id text NOT NULL,
    original_revision bigint NOT NULL CHECK(original_revision > 0),
    original_document_hash text NOT NULL CHECK(original_document_hash ~ '^[0-9a-f]{64}$'),
    source_kind text NOT NULL CHECK(source_kind IN ('diagnosis','selection')),
    basis_hash text NOT NULL CHECK(basis_hash ~ '^[0-9a-f]{64}$'),
    "authorization" jsonb NOT NULL CHECK(jsonb_typeof("authorization") = 'object'),
    authorization_hash text NOT NULL CHECK(authorization_hash ~ '^[0-9a-f]{64}$'),
    config_id text NOT NULL,
    max_rounds integer NOT NULL CHECK(max_rounds BETWEEN 1 AND 5),
    current_round integer NOT NULL DEFAULT 1 CHECK(current_round BETWEEN 1 AND 5),
    state text NOT NULL CHECK(state IN ('preparing','running','awaiting_author','closed')),
    stop_reason text,
    stop_detail text,
    author_choice text CHECK(author_choice IN ('original','candidate')),
    selected_candidate_id uuid REFERENCES public.muse_writing_candidate(candidate_id),
    created_at timestamptz NOT NULL DEFAULT clock_timestamp(),
    updated_at timestamptz NOT NULL DEFAULT clock_timestamp(),
    UNIQUE(author_id,create_command_id),
    UNIQUE(session_id,author_id),
    CHECK(current_round <= max_rounds),
    CHECK((state = 'closed') = (stop_reason IS NOT NULL)),
    CHECK(
        (author_choice IS NULL AND selected_candidate_id IS NULL)
        OR (author_choice = 'original' AND selected_candidate_id IS NULL)
        OR (author_choice = 'candidate' AND selected_candidate_id IS NOT NULL)
    )
);

CREATE TABLE public.muse_revision_round (
    session_id uuid NOT NULL REFERENCES public.muse_revision_session(session_id),
    round_number integer NOT NULL CHECK(round_number BETWEEN 1 AND 5),
    task_command_id text NOT NULL UNIQUE,
    task_request_hash text NOT NULL CHECK(task_request_hash ~ '^[0-9a-f]{64}$'),
    task_id uuid UNIQUE REFERENCES public.muse_task(task_id),
    state text NOT NULL CHECK(state IN ('preparing','running','candidate','original','rejected')),
    outcome text CHECK(outcome IN ('candidate','original','rejected')),
    candidate_id uuid REFERENCES public.muse_writing_candidate(candidate_id),
    created_at timestamptz NOT NULL DEFAULT clock_timestamp(),
    updated_at timestamptz NOT NULL DEFAULT clock_timestamp(),
    PRIMARY KEY(session_id,round_number),
    CHECK((task_id IS NULL) = (state = 'preparing')),
    CHECK((outcome IS NULL) = (state IN ('preparing','running'))),
    CHECK((outcome = 'candidate') = (candidate_id IS NOT NULL))
);

CREATE TABLE public.muse_revision_session_action (
    action_id uuid PRIMARY KEY,
    session_id uuid NOT NULL REFERENCES public.muse_revision_session(session_id),
    author_id text NOT NULL,
    command_id text NOT NULL,
    expected_round integer NOT NULL CHECK(expected_round BETWEEN 1 AND 5),
    candidate_id uuid NOT NULL REFERENCES public.muse_writing_candidate(candidate_id),
    choice text NOT NULL CHECK(choice IN ('original','candidate','retry')),
    request_hash text NOT NULL CHECK(request_hash ~ '^[0-9a-f]{64}$'),
    created_at timestamptz NOT NULL DEFAULT clock_timestamp(),
    UNIQUE(author_id,command_id),
    FOREIGN KEY(session_id,author_id)
        REFERENCES public.muse_revision_session(session_id,author_id)
);

CREATE TRIGGER muse_revision_session_action_immutable BEFORE UPDATE OR DELETE
    ON public.muse_revision_session_action FOR EACH ROW
    EXECUTE FUNCTION public.muse_guard_literary_history();

REVOKE ALL ON public.muse_revision_session,public.muse_revision_round,
    public.muse_revision_session_action FROM PUBLIC,muse_app,muse_eval;
GRANT SELECT,INSERT ON public.muse_revision_session,public.muse_revision_round TO muse_app;
GRANT UPDATE(current_round,state,stop_reason,stop_detail,author_choice,
    selected_candidate_id,updated_at)
    ON public.muse_revision_session TO muse_app;
GRANT UPDATE(task_id,state,outcome,candidate_id,updated_at)
    ON public.muse_revision_round TO muse_app;
GRANT SELECT,INSERT ON public.muse_revision_session_action TO muse_app;