"""流水线服务 — crawl → summarize → cleanup 的共享编排逻辑。

供 admin 手动触发和 scheduler 定时调度共用。
"""

from __future__ import annotations

import logging
from datetime import date as date_type

from sqlalchemy.exc import IntegrityError
from sqlalchemy.orm import Session

from app.config import settings
from app.models import CrawlLog, TaskLock
from app.services.cleaner import cleanup_tmp
from app.services.crawler import crawl_daily
from app.services.summarizer import summarize_batch
from app.utils import release_lock, truncate_error, utc_now, yesterday_str

logger = logging.getLogger(__name__)


def acquire_lock(db: Session, task: str, lock_key: str, owner: str) -> TaskLock:
    """获取 TaskLock，锁冲突时抛出 RuntimeError。

    供需要防重入的操作（crawl、pipeline 等）统一调用。
    """
    lock = TaskLock(
        task=task,
        lock_key=lock_key,
        status="running",
        owner=owner,
        acquired_at=utc_now(),
    )
    try:
        db.add(lock)
        db.commit()
    except IntegrityError:
        db.rollback()
        raise RuntimeError(f"{task} already running for {lock_key}")
    return lock


async def run_crawl(db: Session, target_date: str, owner: str = "admin_crawl") -> dict:
    """执行单次抓取（带防重入锁）。

    Args:
        db: 数据库 session
        target_date: 目标日期 YYYY-MM-DD
        owner: 调用者标识

    Returns:
        crawl_daily() 的原始返回值
    """
    lock = acquire_lock(db, "crawl", target_date, owner)
    try:
        return await crawl_daily(db, target_date)
    finally:
        release_lock(db, lock)


async def run_pipeline(db: Session, target_date: str, owner: str) -> dict:
    """执行完整流水线：crawl → summarize → cleanup。

    使用 task_locks 防重入，写入 CrawlLog 记录。

    Args:
        db: 数据库 session
        target_date: 目标日期 YYYY-MM-DD
        owner: 调用者标识（如 "admin_trigger" / "daily_pipeline"）

    Returns:
        {"status": "success"|"failed", "error": str|None, ...}
    """
    now = utc_now()
    lock_key = f"pipeline-{target_date}"

    # ── 获取锁 ──────────────────────────────────────────────────────────
    lock = TaskLock(
        task="scheduler",
        lock_key=lock_key,
        status="running",
        owner=owner,
        acquired_at=now,
    )
    try:
        db.add(lock)
        db.commit()
    except IntegrityError:
        db.rollback()
        raise RuntimeError(f"Pipeline already running for {target_date}")

    # ── 写调度日志 ──────────────────────────────────────────────────────
    log_entry = CrawlLog(
        task="scheduler",
        status="running",
        date=date_type.fromisoformat(target_date),
        started_at=now,
    )
    db.add(log_entry)
    db.commit()

    error_msg = None
    crawl_result: dict = {}
    try:
        # Step 1: 抓取（先试今天，无数据则回退昨天）
        crawl_result = await crawl_daily(db, target_date)
        logger.info(
            "Pipeline [%s]: crawl %s, found=%d new=%d",
            owner,
            target_date,
            crawl_result.get("found", 0),
            crawl_result.get("new", 0),
        )

        if crawl_result.get("status") == "success" and crawl_result.get("found") == 0:
            yesterday = yesterday_str()
            logger.info("Pipeline [%s]: falling back to %s", owner, yesterday)
            crawl_result = await crawl_daily(db, yesterday)

        # Step 2: 总结
        summarize_result = await summarize_batch(db, pdf_mode=settings.SUMMARY_PDF_MODE)
        logger.info("Pipeline [%s]: summarize done, result=%s", owner, summarize_result)

        # Step 3: 清理
        cleanup_result = cleanup_tmp()
        logger.info(
            "Pipeline [%s]: cleanup done, removed=%d",
            owner,
            cleanup_result.get("removed", 0),
        )

        log_entry.status = "success"
        log_entry.papers_found = crawl_result.get("found", 0)
        log_entry.papers_new = crawl_result.get("new", 0)

    except Exception as exc:
        logger.exception("Pipeline [%s] failed", owner)
        log_entry.status = "failed"
        error_msg = truncate_error(exc, limit=2000)

    finally:
        log_entry.completed_at = utc_now()
        if error_msg:
            log_entry.error = error_msg
        db.commit()

        release_lock(db, lock)

    if error_msg:
        return {"status": "failed", "error": error_msg}
    return {"status": "success", "message": "Pipeline completed"}