"""Narrative engine (consolidation step 4): the current arc, trends, callbacks.

Where the profile is timeless ("who Brian is"), the narrative is time-aware
("what's going on lately, where things are trending"). It distills the profile
plus the most recent monthly era digests into the current story — recent focus,
notable trends or changes, mood/arc, and a few specific callbacks worth
referencing. Injected into chat so Lyra follows along like a friend who's been
paying attention. Runs on the consolidation backend (MI50 in steady state).
"""
from __future__ import annotations


from lyra import config, llm, logbus, memory
from lyra.llm import Backend, Message

RECENT_ERAS = 4

_PROMPT = """You are distilling the CURRENT narrative about Brian — what a close \
friend who has been following along would keep in mind right now. From his profile \
and recent monthly digests below, write: what he's been focused on lately, any \
notable trends or changes (improving, slipping, new patterns), his current arc and \
mood, and 2-4 specific things worth referencing back to him ("remember when…"). \
Third person, referring to him as "Brian". 6-10 sentences. This is a memory note, \
not a reply. No preamble."""


def rebuild_narrative(backend: Backend | None = None) -> str | None:
    """(Re)derive the current narrative from the profile + recent era digests."""
    backend = backend or config.load().summary_backend
    profile = memory.get_profile()
    eras = memory.list_eras()
    if not profile and not eras:
        return None

    parts = []
    if profile:
        parts.append("PROFILE (timeless):\n" + profile)
    recent = eras[-RECENT_ERAS:]
    if recent:
        parts.append(
            "RECENT MONTHS (oldest first):\n"
            + "\n\n".join(f"[{e.month}]\n{e.content}" for e in recent)
        )
    body = "\n\n".join(parts)

    messages: list[Message] = [
        {"role": "system", "content": _PROMPT},
        {"role": "user", "content": body},
    ]
    narrative = llm.complete(messages, backend=backend)
    memory.set_narrative(narrative)
    logbus.log("info", "narrative rebuilt", chars=len(narrative), eras=len(recent))
    return narrative


def main() -> int:
    narrative = rebuild_narrative()
    if narrative is None:
        print("Need a profile and/or eras first — run lyra-profile and lyra-era.")
        return 1
    print(narrative)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())