backend/graph/state.py

from typing import Annotated, Literal, TypedDict

from langgraph.graph.message import add_messages


class InterviewState(TypedDict):
    # Static — set once at session start
    topic_name: str
    session_id: str
    student_id: str
    questions_remaining: list[dict]        # [{"question_text": str, "difficulty": str}]
    past_best_score: int | None
    past_weak_areas: list[str]

    # Dynamic — mutates during session
    messages: Annotated[list, add_messages]  # appended via reducer
    conversation_summary: str
    questions_asked: list[str]
    student_weak_areas: list[str]
    turn_count: int
    awaiting_counter_response: bool
    counter_questions_asked: int          # global cap — max 2 per interview
    last_verdict: str | None               # "strong" | "shallow" | "wrong" | None

    # Terminal — set once at end
    status: Literal["active", "complete"]
    score: int | None
    feedback: dict | None