from __future__ import annotations

import logging
import sys

import pytest
from twisted.internet.defer import inlineCallbacks

from scrapy import signals
from scrapy.extensions.memusage import MemoryUsage
from scrapy.spiders import Spider
from scrapy.utils.test import get_crawler

# memusage relies on the stdlib 'resource' module (not available on Windows)
pytestmark = pytest.mark.skipif(
    sys.platform.startswith("win"),
    reason="MemoryUsage extension not available on Windows",
)


class _LoopSpider(Spider):
    name = "loop-data-spider"

    def __init__(self, url: str, loops: int = 60, **kw):
        super().__init__(**kw)
        self.url = url
        self.loops = loops
        self.start_urls = [url]

    def parse(self, response):
        count = response.meta.get("count", 0)
        if count + 1 < self.loops:
            yield response.follow(
                self.url, callback=self.parse, meta={"count": count + 1}
            )


@inlineCallbacks
def test_memusage_limit_closes_spider_with_reason_and_error_log(caplog, monkeypatch):
    url = "data:,"
    settings = {
        "MEMUSAGE_ENABLED": True,
        "MEMUSAGE_LIMIT_MB": 10,
        "MEMUSAGE_CHECK_INTERVAL_SECONDS": 0.01,
        "LOG_LEVEL": "INFO",
    }

    MB = 1024 * 1024
    state = {"high": False}

    def fake_vsz(self):
        return 250 * MB if state["high"] else 5 * MB

    monkeypatch.setattr(MemoryUsage, "get_virtual_size", fake_vsz)

    crawler = get_crawler(spidercls=_LoopSpider, settings_dict=settings)

    def on_opened(spider):
        state["high"] = True

    crawler.signals.connect(on_opened, signal=signals.spider_opened)

    caplog.set_level(logging.ERROR, logger="scrapy.extensions.memusage")
    yield crawler.crawl(url=url, loops=100)

    assert crawler.stats.get_value("finish_reason") == "memusage_exceeded"
    assert any(
        "memory usage exceeded" in r.getMessage().lower() for r in caplog.records
    )


@inlineCallbacks
def test_memusage_warning_logs_but_allows_normal_finish(caplog, monkeypatch):
    url = "data:,"
    settings = {
        "MEMUSAGE_ENABLED": True,
        "MEMUSAGE_WARNING_MB": 50,
        "MEMUSAGE_LIMIT_MB": 0,  # no hard limit
        "MEMUSAGE_CHECK_INTERVAL_SECONDS": 0.01,
        "LOG_LEVEL": "INFO",
    }

    MB = 1024 * 1024
    monkeypatch.setattr(MemoryUsage, "get_virtual_size", lambda self: 75 * MB)

    crawler = get_crawler(spidercls=_LoopSpider, settings_dict=settings)

    caplog.set_level(logging.WARNING, logger="scrapy.extensions.memusage")
    yield crawler.crawl(url=url, loops=60)

    assert crawler.stats.get_value("finish_reason") == "finished"
    assert any("memory usage reached" in r.getMessage().lower() for r in caplog.records)