# -*- coding: utf-8 -*-
# Copyright (c) 2025 relakkes@gmail.com
#
# This file is part of MediaCrawler project.
# Repository: https://github.com/NanmiCoder/MediaCrawler/blob/main/api/monitor/runner.py
# GitHub: https://github.com/NanmiCoder
# Licensed under NON-COMMERCIAL LEARNING LICENSE 1.1
#
# 声明：本代码仅供学习和研究目的使用。使用者应遵守以下原则：
# 1. 不得用于任何商业用途。
# 2. 使用时应遵守目标平台的使用条款和robots.txt规则。
# 3. 不得进行大规模爬取或对平台造成运营干扰。
# 4. 应合理控制请求频率，避免给目标平台带来不必要的负担。
# 5. 不得用于任何非法或不当的用途。
#
# 详细许可条款请参阅项目根目录下的LICENSE文件。
# 使用本代码即表示您同意遵守上述原则和LICENSE中的所有条款。

"""Execute a single monitoring run: build the command, wait, then ingest.

Runs reuse ``CrawlerManager`` so that monitor crawls share the existing
single-subprocess guarantee and their logs stream to the existing Terminal
component over the existing log WebSocket.
"""

import asyncio
import os
from pathlib import Path
from typing import Iterable, List, Optional

from tools.time_util import get_current_timestamp

from ..schemas import (
    CrawlerStartRequest,
    CrawlerTypeEnum,
    LoginTypeEnum,
    PlatformEnum,
    SaveDataOptionEnum,
)
from ..services import crawler_manager
from . import adapters, app_settings, covers, notify
from .db import get_session
from .ingest import IngestResult, diagnose_failure, ingest_run
from .models import (
    MODE_CREATOR,
    RUN_FAILED,
    RUN_PENDING,
    RUN_RUNNING,
    RUN_TIMEOUT,
    MonitorRun,
    MonitorTarget,
    MonitorTask,
)
from .settings import get_cookie, mark_cookie_ok

PROJECT_ROOT = Path(__file__).parent.parent.parent
MONITOR_RUNS_DIR = PROJECT_ROOT / "data" / "monitor_runs"

# Monitor platform ids align with PlatformEnum's values, but mapping explicitly
# beats relying on that coincidence.
_PLATFORM_ENUM = {
    "xhs": PlatformEnum.XHS,
    "dy": PlatformEnum.DOUYIN,
    "ks": PlatformEnum.KUAISHOU,
    "bili": PlatformEnum.BILIBILI,
    "wb": PlatformEnum.WEIBO,
    "tieba": PlatformEnum.TIEBA,
    "zhihu": PlatformEnum.ZHIHU,
}

# Timeout used when the caller does not care; tasks carry their own.
DEFAULT_RUN_TIMEOUT_SECONDS = 3600


def build_target_url(value: str, kind: str, platform: str) -> str:
    """Turn a stored target into a URL the crawler's parser accepts.

    Always emits a full URL rather than a bare id: both platforms' parsers accept
    a bare id only in a narrower form, so the URL is the safer universal input.
    The shape itself is platform-specific and comes from ``adapters``.
    """
    spec = adapters.adapter(platform)
    path = spec.creator_path if kind == MODE_CREATOR else spec.note_path
    return f"{spec.web_base}{path}/{value}"


def build_target_urls(
    mode: str, targets: Iterable[MonitorTarget], platform: str
) -> List[str]:
    """存储的目标 -> 爬虫接受的 URL。

    ``xsec_token`` 只有小红书有，而且是会过期的刷新令牌 —— 有就带上，没有就算了。
    抖音恒为空，所以这一段对它是天然的 no-op，不需要平台分支。
    """
    urls = []
    for target in targets:
        url = build_target_url(target.external_id, target.kind, platform)
        if target.xsec_token:
            url = f"{url}?xsec_token={target.xsec_token}"
            if target.xsec_source:
                url = f"{url}&xsec_source={target.xsec_source}"
        urls.append(url)
    return urls


async def _strategy_settings(session, platform: str) -> dict:
    """Crawl-strategy and proxy settings for one platform.

    Per-platform because the values genuinely differ: what is a safe request
    interval on one site is a rate limit on another. Read per run rather than
    cached, so a change takes effect on the next scheduled run.
    """
    return {
        "enable_sub_comments": bool(
            await app_settings.get_value(session, "enable_sub_comments", platform, False)
        ),
        "crawl_sleep_sec": int(
            await app_settings.get_value(session, "crawl_sleep_sec", platform, 2)
        ),
        "enable_ip_proxy": bool(
            await app_settings.get_value(session, "enable_ip_proxy", platform, False)
        ),
        "proxy_provider": await app_settings.get_value(
            session, "proxy_provider", platform, "kuaidaili"
        ),
        "proxy_pool_count": int(
            await app_settings.get_value(session, "proxy_pool_count", platform, 2)
        ),
        "static_proxy_url": await app_settings.get_value(
            session, "static_proxy_url", platform, ""
        ),
    }


def _write_cookie_file(path: Path, cookie: str) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(cookie, encoding="utf-8")


def _remove_cookie_file(path: Path) -> None:
    """Best-effort removal; the cookie is a credential, do not leave it around."""
    try:
        os.remove(path)
    except OSError:
        pass


async def execute_task(task_id: int, trigger: str = "manual") -> IngestResult:
    """Run one monitoring cycle for ``task_id`` and ingest its output.

    Split into three phases with separate short-lived DB sessions so no
    transaction is held open across the multi-minute subprocess run.
    """
    # --- Phase 1: book the run and work out where its output goes -------------
    async with get_session() as session:
        task = await session.get(MonitorTask, task_id)
        if task is None:
            raise ValueError(f"Monitor task {task_id} not found")

        targets = [target for target in task.targets if target.enabled]
        if not targets:
            raise ValueError(f"Monitor task {task_id} has no enabled targets")

        platform = task.platform
        urls = build_target_urls(task.mode, targets, platform)
        cookie = await get_cookie(session, platform)
        strategy = await _strategy_settings(session, platform)
        # System-wide switch. On a headless server the crawler must attach to the
        # Chrome already listening on the debug port -- that browser is where the
        # operator scanned the login QR, so its profile is the login. Default False
        # keeps desktop runs launching a private browser exactly as before.
        cdp_enabled = await app_settings.get_value(session, "cdp_enabled", fallback=False)

        run = MonitorRun(
            task_id=task.id,
            trigger=trigger,
            status=RUN_PENDING,
            phase=task.mode,
            save_data_path="",
            queued_at=get_current_timestamp(),
            not_before=0,
            max_comments_count=task.max_comments_count if task.enable_comments else 0,
        )
        session.add(run)
        await session.flush()

        run_id = run.id
        out_dir = MONITOR_RUNS_DIR / str(task.id) / str(run_id)
        run.save_data_path = str(out_dir)

        # Snapshot the values the subprocess needs; `task` is detached after commit.
        mode = task.mode
        enable_comments = task.enable_comments
        max_notes_count = task.max_notes_count
        max_comments_count = task.max_comments_count
        timeout_seconds = task.run_timeout_seconds

    # --- Phase 2: run the crawler outside any transaction ---------------------
    cookie_file = out_dir / ".cookies"
    _write_cookie_file(cookie_file, cookie)

    request = CrawlerStartRequest(
        platform=_PLATFORM_ENUM[platform],
        login_type=LoginTypeEnum.COOKIE,
        crawler_type=CrawlerTypeEnum.CREATOR if mode == MODE_CREATOR else CrawlerTypeEnum.DETAIL,
        creator_ids=",".join(urls) if mode == MODE_CREATOR else "",
        specified_ids=",".join(urls) if mode != MODE_CREATOR else "",
        start_page=1,
        enable_comments=enable_comments,
        enable_sub_comments=strategy["enable_sub_comments"],
        enable_media=False,
        save_option=SaveDataOptionEnum.JSONL,
        cookies="",
        headless=True,
        max_notes_count=max_notes_count,
        max_comments_count=max_comments_count,
        # Isolate this run's output: the crawler names files by date only, so
        # otherwise same-day runs would append into one shared file.
        save_data_path=str(out_dir),
        # Attach to the browser already running on CDP_DEBUG_PORT when the
        # operator enabled it; otherwise launch a private, throwaway browser.
        enable_cdp_mode=cdp_enabled,
        # Only injecting web_session is not enough to sign requests from a cold
        # browser profile.
        inject_all_cookies=True,
        save_login_state=True,
        cookies_file=str(cookie_file),
        max_concurrency_num=1,
        # Strategy + proxy, surfaced on the Settings page.
        crawler_max_sleep_sec=strategy["crawl_sleep_sec"],
        enable_ip_proxy=strategy["enable_ip_proxy"],
        ip_proxy_pool_count=strategy["proxy_pool_count"],
        ip_proxy_provider_name=strategy["proxy_provider"],
        static_proxy_url=strategy["static_proxy_url"] or None,
    )

    async with get_session() as session:
        run = await session.get(MonitorRun, run_id)
        if run is not None:
            run.status = RUN_RUNNING
            run.started_at = get_current_timestamp()

    try:
        exit_code = await crawler_manager.run_and_wait(request, timeout=timeout_seconds)
    finally:
        _remove_cookie_file(cookie_file)

    # --- Phase 3: ingest ------------------------------------------------------
    async with get_session() as session:
        run = await session.get(MonitorRun, run_id)
        task = await session.get(MonitorTask, task_id)
        if run is None or task is None:
            raise ValueError(f"Run {run_id} or task {task_id} vanished during execution")

        # 目录名按平台解析 —— 抖音的平台 id 是 dy 而产物目录是 douyin，写死就永远判不准。
        if exit_code == -1 and not (out_dir / adapters.artifact_dir(task.platform)).exists():
            # run_and_wait returns -1 when the process could not start or timed out.
            run.status = RUN_TIMEOUT
            run.finished_at = get_current_timestamp()
            run.exit_code = exit_code
            run.error_message = "Run was killed by timeout or failed to start"
            # -1 同时代表「超时」和「根本没起来」，两者要查的东西完全不同。输出尾巴里
            # 有异常就带上它，否则运行历史里只能看到这句没有信息量的话。
            cause = diagnose_failure(crawler_manager.get_output_tail())
            if cause:
                run.error_message = f"{run.error_message}；原因：{cause}"
            result = IngestResult(status=RUN_TIMEOUT, error=run.error_message)
        else:
            run.exit_code = exit_code
            run.finished_at = get_current_timestamp()
            # 把爬虫输出的尾巴交给 ingest：退出码本身说明不了问题，运行历史里要显示的
            # 是真正的报错（比如抖音的 DataFetchError: account blocked）。
            result = await ingest_run(
                session, run, task, out_dir, output_tail=crawler_manager.get_output_tail()
            )

        # A run that authenticated fine is the only useful signal that the
        # stored cookie still works.
        if result.notes_fetched > 0:
            await mark_cookie_ok(session, task.platform)

        task.last_run_at = run.finished_at
        task.last_status = result.status
        task.last_error = result.error

    # --- Phase 4: notify ------------------------------------------------------
    # Runs after the ingest transaction has committed, in its own session. A push
    # failure must never roll back collected data, and notify_run() swallows its
    # own errors for the same reason.
    async with get_session() as session:
        task = await session.get(MonitorTask, task_id)
        run = await session.get(MonitorRun, run_id)
        if task is not None and run is not None:
            await notify.notify_run(session, task, run)

    # --- Phase 5: 封面落盘 ------------------------------------------------------
    # 也放在事务之外。封面地址带签名、会过期（实测隔天即 403），落盘之后才与签名无关。
    # 下载慢且可能失败，占着一个入库事务是不合适的；失败也不影响本轮数据。
    try:
        async with get_session() as session:
            saved = await covers.cache_pending(session, task_id)
            if saved:
                print(f"[monitor.runner] 缓存了 {saved} 张作品封面")
    except Exception as exc:  # noqa: BLE001 - 封面拿不到不该让整轮失败
        print(f"[monitor.runner] 封面缓存失败：{exc}")

    return result