"""Storage contract for the durable, user-owned session workflow state."""

from __future__ import annotations

from typing import Protocol, Sequence

from tht.decisions import DecisionInput, DecisionRecord
from tht.session.models import PrincipalContext, SessionManifest, SessionSnapshot


class SessionRepository(Protocol):
    """Persistence boundary shared by local files and the server database adapter."""

    principal: PrincipalContext

    def create(self, manifest: SessionManifest) -> SessionSnapshot: ...

    def get(self, session_id: str) -> SessionSnapshot: ...

    def save_manifest(self, manifest: SessionManifest) -> SessionSnapshot: ...

    def read_artifact(self, session_id: str, key: str) -> str | None: ...

    def write_artifact(self, session_id: str, key: str, content: str) -> None: ...

    def append_decisions(
        self, session_id: str, decisions: Sequence[DecisionInput | dict]
    ) -> list[DecisionRecord]: ...

    def get_preferences(self) -> dict: ...

    def set_preferences(self, preferences: dict) -> None: ...

    def delete(self, session_id: str) -> None: ...


def build_session_repository(config, principal: PrincipalContext, *, home=None) -> SessionRepository:
    """Build the configured private session persistence adapter."""
    session_storage = getattr(config, "session_storage", None)
    if session_storage is not None:
        from tht.session.postgres_repository import PostgresSessionRepository

        return PostgresSessionRepository.from_config(session_storage.connection, principal)

    from tht.config import local_tht_home
    from tht.session.filesystem_repository import FilesystemSessionRepository

    workspace = getattr(config, "_workspace_id", "default")
    return FilesystemSessionRepository(home or local_tht_home(), workspace, principal)