"""由已抽取事实生成时间线事件（LLM + JSON）。"""

from __future__ import annotations

import json
from typing import Any

from app.core.langchain_llm import ainvoke_json_object, invoke_json_object
from app.core.logging import get_logger
from app.features.memory.llm_schemas import (
    TimelineEventsPayload,
    parse_json_payload,
    timeline_payload_to_dicts,
)

logger = get_logger(__name__)

MAX_FACTS_JSON = 20000


def build_timeline_events_from_facts_sync(llm: Any, facts: list[dict]) -> list[dict]:
    """facts 须含 id 字段（已落库）。"""
    if not llm or not facts:
        return []
    payload = json.dumps(facts, ensure_ascii=False)[:MAX_FACTS_JSON]
    prompt = (
        "根据下列事实（含 id）生成时间线事件，用于回忆录展示。\n"
        "每条含 event_year（整数或 null）、event_date（可选）、title、description、"
        "source_fact_ids（必须来自输入中的 id 列表）。\n"
        '只输出 JSON：{"events":[...]}，无事件则 {"events":[]}。最多 15 条。\n\n'
        f"{payload}"
    )
    try:
        raw = invoke_json_object(
            llm, prompt, max_tokens=4096, agent="memory.timeline_events_sync"
        )
        parsed = parse_json_payload(raw, TimelineEventsPayload)
        if parsed is None:
            return []
        return timeline_payload_to_dicts(parsed)
    except (TypeError, ValueError) as e:
        logger.warning("build_timeline_events_from_facts_sync 失败: {}", e)
        return []


async def build_timeline_events_from_facts_async(
    llm: Any, facts: list[dict]
) -> list[dict]:
    if not llm or not facts:
        return []
    payload = json.dumps(facts, ensure_ascii=False)[:MAX_FACTS_JSON]
    prompt = (
        "根据下列事实（含 id）生成时间线事件。\n"
        "每条含 event_year、event_date、title、description、source_fact_ids（来自输入 id）。\n"
        '只输出 JSON：{"events":[...]}。\n\n'
        f"{payload}"
    )
    try:
        raw = await ainvoke_json_object(
            llm, prompt, max_tokens=4096, agent="memory.timeline_events_async"
        )
        parsed = parse_json_payload(raw, TimelineEventsPayload)
        if parsed is None:
            return []
        return timeline_payload_to_dicts(parsed)
    except (TypeError, ValueError) as e:
        logger.warning("build_timeline_events_from_facts_async 失败: {}", e)
        return []


async def build_timeline_events(facts: list[dict]) -> list[dict]:
    """兼容旧接口。"""
    from app.core.dependencies import get_llm_provider_fast

    llm = get_llm_provider_fast().langchain_llm
    return await build_timeline_events_from_facts_async(llm, facts)