import tempfile

import pytest
import queuelib

from scrapy.http.request import Request
from scrapy.pqueues import DownloaderAwarePriorityQueue, ScrapyPriorityQueue
from scrapy.spiders import Spider
from scrapy.squeues import FifoMemoryQueue
from scrapy.utils.test import get_crawler
from tests.test_scheduler import MockDownloader, MockEngine


class TestPriorityQueue:
    def setup_method(self):
        self.crawler = get_crawler(Spider)
        self.spider = self.crawler._create_spider("foo")

    def test_queue_push_pop_one(self):
        temp_dir = tempfile.mkdtemp()
        queue = ScrapyPriorityQueue.from_crawler(
            self.crawler, FifoMemoryQueue, temp_dir
        )
        assert queue.pop() is None
        assert len(queue) == 0
        req1 = Request("https://example.org/1", priority=1)
        queue.push(req1)
        assert len(queue) == 1
        dequeued = queue.pop()
        assert len(queue) == 0
        assert dequeued.url == req1.url
        assert dequeued.priority == req1.priority
        assert not queue.close()

    def test_no_peek_raises(self):
        if hasattr(queuelib.queue.FifoMemoryQueue, "peek"):
            pytest.skip("queuelib.queue.FifoMemoryQueue.peek is defined")
        temp_dir = tempfile.mkdtemp()
        queue = ScrapyPriorityQueue.from_crawler(
            self.crawler, FifoMemoryQueue, temp_dir
        )
        queue.push(Request("https://example.org"))
        with pytest.raises(
            NotImplementedError,
            match="The underlying queue class does not implement 'peek'",
        ):
            queue.peek()
        queue.close()

    def test_peek(self):
        if not hasattr(queuelib.queue.FifoMemoryQueue, "peek"):
            pytest.skip("queuelib.queue.FifoMemoryQueue.peek is undefined")
        temp_dir = tempfile.mkdtemp()
        queue = ScrapyPriorityQueue.from_crawler(
            self.crawler, FifoMemoryQueue, temp_dir
        )
        assert len(queue) == 0
        assert queue.peek() is None
        req1 = Request("https://example.org/1")
        req2 = Request("https://example.org/2")
        req3 = Request("https://example.org/3")
        queue.push(req1)
        queue.push(req2)
        queue.push(req3)
        assert len(queue) == 3
        assert queue.peek().url == req1.url
        assert queue.pop().url == req1.url
        assert len(queue) == 2
        assert queue.peek().url == req2.url
        assert queue.pop().url == req2.url
        assert len(queue) == 1
        assert queue.peek().url == req3.url
        assert queue.pop().url == req3.url
        assert not queue.close()

    def test_queue_push_pop_priorities(self):
        temp_dir = tempfile.mkdtemp()
        queue = ScrapyPriorityQueue.from_crawler(
            self.crawler, FifoMemoryQueue, temp_dir, [-1, -2, -3]
        )
        assert queue.pop() is None
        assert len(queue) == 0
        req1 = Request("https://example.org/1", priority=1)
        req2 = Request("https://example.org/2", priority=2)
        req3 = Request("https://example.org/3", priority=3)
        queue.push(req1)
        queue.push(req2)
        queue.push(req3)
        assert len(queue) == 3
        dequeued = queue.pop()
        assert len(queue) == 2
        assert dequeued.url == req3.url
        assert dequeued.priority == req3.priority
        assert queue.close() == [-1, -2]


class TestDownloaderAwarePriorityQueue:
    def setup_method(self):
        crawler = get_crawler(Spider)
        crawler.engine = MockEngine(downloader=MockDownloader())
        self.queue = DownloaderAwarePriorityQueue.from_crawler(
            crawler=crawler,
            downstream_queue_cls=FifoMemoryQueue,
            key="foo/bar",
        )

    def teardown_method(self):
        self.queue.close()

    def test_push_pop(self):
        assert len(self.queue) == 0
        assert self.queue.pop() is None
        req1 = Request("http://www.example.com/1")
        req2 = Request("http://www.example.com/2")
        req3 = Request("http://www.example.com/3")
        self.queue.push(req1)
        self.queue.push(req2)
        self.queue.push(req3)
        assert len(self.queue) == 3
        assert self.queue.pop().url == req1.url
        assert len(self.queue) == 2
        assert self.queue.pop().url == req2.url
        assert len(self.queue) == 1
        assert self.queue.pop().url == req3.url
        assert len(self.queue) == 0
        assert self.queue.pop() is None

    def test_no_peek_raises(self):
        if hasattr(queuelib.queue.FifoMemoryQueue, "peek"):
            pytest.skip("queuelib.queue.FifoMemoryQueue.peek is defined")
        self.queue.push(Request("https://example.org"))
        with pytest.raises(
            NotImplementedError,
            match="The underlying queue class does not implement 'peek'",
        ):
            self.queue.peek()

    def test_peek(self):
        if not hasattr(queuelib.queue.FifoMemoryQueue, "peek"):
            pytest.skip("queuelib.queue.FifoMemoryQueue.peek is undefined")
        assert len(self.queue) == 0
        req1 = Request("https://example.org/1")
        req2 = Request("https://example.org/2")
        req3 = Request("https://example.org/3")
        self.queue.push(req1)
        self.queue.push(req2)
        self.queue.push(req3)
        assert len(self.queue) == 3
        assert self.queue.peek().url == req1.url
        assert self.queue.pop().url == req1.url
        assert len(self.queue) == 2
        assert self.queue.peek().url == req2.url
        assert self.queue.pop().url == req2.url
        assert len(self.queue) == 1
        assert self.queue.peek().url == req3.url
        assert self.queue.pop().url == req3.url
        assert self.queue.peek() is None