"""从 transcript 块中抽取结构化事实（LLM + JSON）。"""

from __future__ import annotations

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 (
    FactsExtractionPayload,
    facts_payload_to_dicts,
    parse_json_payload,
)

logger = get_logger(__name__)


def _max_transcript_chars() -> int:
    from app.core.config import settings

    return settings.memory_enrichment_max_chars


def extract_facts_from_transcript_sync(llm: Any, numbered_blocks: str) -> list[dict]:
    """同步：带 chunk_id 标记的文本 → 事实列表。"""
    if not llm or not (numbered_blocks or "").strip():
        return []
    text = numbered_blocks.strip()[: _max_transcript_chars()]
    prompt = (
        "你是回忆录记忆抽取助手。阅读下列带 [chunk_id=...] 的文本块，抽取可核查的事实。\n"
        "每个事实含 fact_type: person|event|relation|place|milestone；subject；predicate；"
        "object_json（可为字符串或对象）；confidence 0..1；source_chunk_id 必须等于某段的 chunk id。\n"
        '只输出 JSON：{"facts":[...]}，无事实则 {"facts":[]}。\n\n'
        f"{text}"
    )
    try:
        raw = invoke_json_object(
            llm,
            prompt,
            max_tokens=4096,
            agent="memory.extract_facts_sync",
        )
        parsed = parse_json_payload(raw, FactsExtractionPayload)
        if parsed is None:
            return []
        return facts_payload_to_dicts(parsed)
    except (TypeError, ValueError) as e:
        logger.warning("extract_facts_from_transcript_sync 解析失败: {}", e)
        return []


async def extract_facts_from_transcript_async(
    llm: Any, numbered_blocks: str
) -> list[dict]:
    """异步版。"""
    if not llm or not (numbered_blocks or "").strip():
        return []
    text = numbered_blocks.strip()[: _max_transcript_chars()]
    prompt = (
        "你是回忆录记忆抽取助手。阅读下列带 [chunk_id=...] 的文本块，抽取可核查的事实。\n"
        "每个事实含 fact_type: person|event|relation|place|milestone；subject；predicate；"
        "object_json；confidence 0..1；source_chunk_id 必须等于某段的 chunk id。\n"
        '只输出 JSON：{"facts":[...]}，无事实则 {"facts":[]}。\n\n'
        f"{text}"
    )
    try:
        raw = await ainvoke_json_object(
            llm,
            prompt,
            max_tokens=4096,
            agent="memory.extract_facts_async",
        )
        parsed = parse_json_payload(raw, FactsExtractionPayload)
        if parsed is None:
            return []
        return facts_payload_to_dicts(parsed)
    except (TypeError, ValueError) as e:
        logger.warning("extract_facts_from_transcript_async 解析失败: {}", e)
        return []


async def extract_facts(chunk_text: str, *, user_id: str) -> list[dict]:
    """兼容旧接口：单块文本（无 chunk id 时传空 source_chunk_id）。"""
    from app.core.dependencies import get_llm_provider_fast

    llm = get_llm_provider_fast().langchain_llm
    blocks = f"[chunk_id=null]\n{chunk_text}"
    facts = await extract_facts_from_transcript_async(llm, blocks)
    for f in facts:
        if f.get("source_chunk_id") in (None, "null", ""):
            f["source_chunk_id"] = None
    return facts