import httpx
import pytest
from django.test import override_settings

from apps.sources.services.fetcher import (
    ContentRejectedError,
    FetchError,
    FetchTimeoutError,
    RateLimitedError,
    PolicyBlockedError,
    fetch_url,
)
from apps.sources.services.url_security import ValidatedUrl

PUBLIC_DNS = [(None, None, None, None, ("93.184.216.34", 443))]


def _patch_dns(monkeypatch):
    monkeypatch.setattr(
        "apps.sources.services.url_security.socket.getaddrinfo",
        lambda *args, **kwargs: PUBLIC_DNS,
    )
    # validate_public_url captured the default resolver at definition time, so patch call site too.
    original = __import__(
        "apps.sources.services.url_security", fromlist=["validate_public_url"]
    ).validate_public_url

    def validate(url, **kwargs):
        return original(url, resolver=lambda *a, **k: PUBLIC_DNS, **kwargs)

    monkeypatch.setattr("apps.sources.services.fetcher.validate_public_url", validate)


def test_fetcher_success_redirect_304_and_hash(monkeypatch):
    _patch_dns(monkeypatch)

    def handler(request: httpx.Request) -> httpx.Response:
        if request.url.path == "/start":
            return httpx.Response(302, headers={"location": "/job"})
        return httpx.Response(
            200,
            headers={"content-type": "text/html; charset=utf-8"},
            content=b"Vacature",
        )

    client = httpx.Client(transport=httpx.MockTransport(handler))
    document = fetch_url("https://example.org/start", client=client)
    assert document.final_url == "https://example.org/job"
    assert document.text == "Vacature"
    assert len(document.sha256) == 64
    client.close()

    client = httpx.Client(
        transport=httpx.MockTransport(lambda request: httpx.Response(304, headers={"etag": "x"}))
    )
    unchanged = fetch_url("https://example.org/job", client=client)
    assert unchanged.status_code == 304
    assert unchanged.content == b""
    client.close()


def test_fetcher_respects_rate_limit_and_retry_after(monkeypatch):
    _patch_dns(monkeypatch)
    client = httpx.Client(
        transport=httpx.MockTransport(
            lambda request: httpx.Response(
                429, headers={"retry-after": "45"}, content=b"too many requests"
            )
        )
    )
    with pytest.raises(RateLimitedError) as exc:
        fetch_url("https://example.org/too-fast", client=client)
    assert exc.value.retry_after_seconds == 45
    client.close()


def test_fetcher_rejects_dns_rebinding(monkeypatch):
    _patch_dns(monkeypatch)

    def validate(url: str, **kwargs):
        if "/final" in url:
            return ValidatedUrl(url=url, hostname="example.org", port=443, addresses=("198.51.100.12",))
        return ValidatedUrl(url=url, hostname="example.org", port=443, addresses=("93.184.216.34",))

    monkeypatch.setattr("apps.sources.services.fetcher.validate_public_url", validate)

    def handler(request: httpx.Request) -> httpx.Response:
        if request.url.path == "/start":
            return httpx.Response(302, headers={"location": "/final"})
        return httpx.Response(
            200,
            headers={"content-type": "text/html; charset=utf-8"},
            content=b"Vacature",
        )

    client = httpx.Client(transport=httpx.MockTransport(handler))
    with pytest.raises(FetchError, match="DNS-rebindcontrole"):
        fetch_url("https://example.org/start", client=client)
    client.close()


def test_fetcher_rejects_policy_content_size_and_http(monkeypatch):
    _patch_dns(monkeypatch)
    with pytest.raises(PolicyBlockedError):
        fetch_url("https://linkedin.com/jobs", client=httpx.Client())

    client = httpx.Client(
        transport=httpx.MockTransport(
            lambda request: httpx.Response(200, headers={"content-type": "image/png"}, content=b"x")
        )
    )
    with pytest.raises(ContentRejectedError):
        fetch_url("https://example.org/image", client=client)
    client.close()

    with override_settings(FETCHER_MAX_BYTES=2):
        client = httpx.Client(
            transport=httpx.MockTransport(
                lambda request: httpx.Response(
                    200, headers={"content-type": "text/plain"}, content=b"long"
                )
            )
        )
        with pytest.raises(ContentRejectedError):
            fetch_url("https://example.org/large", client=client)
        client.close()

    client = httpx.Client(
        transport=httpx.MockTransport(lambda request: httpx.Response(500, content=b"error"))
    )
    with pytest.raises(FetchError, match="HTTP 500"):
        fetch_url("https://example.org/error", client=client)
    client.close()

    client = httpx.Client(
        transport=httpx.MockTransport(lambda request: (_ for _ in ()).throw(httpx.TimeoutException("timeout")))
    )
    with pytest.raises(FetchTimeoutError):
        fetch_url("https://example.org/slow", client=client)
    client.close()


def test_fetcher_rejects_redirect_without_location(monkeypatch):
    _patch_dns(monkeypatch)
    client = httpx.Client(transport=httpx.MockTransport(lambda request: httpx.Response(302)))
    with pytest.raises(FetchError, match="Location"):
        fetch_url("https://example.org/start", client=client)
    client.close()