import itertools
import json
import logging
import os
import re
import uuid
from pathlib import Path
from textwrap import dedent
from typing import Dict, List, Optional, Tuple
from unittest import mock

import pytest
from pip._vendor import requests
from pip._vendor.packaging.requirements import Requirement

from pip._internal.exceptions import NetworkConnectionError
from pip._internal.index.collector import (
    IndexContent,
    LinkCollector,
    _get_index_content,
    _get_simple_response,
    _make_index_content,
    _NotAPIContent,
    _NotHTTP,
    parse_links,
)
from pip._internal.index.sources import _FlatDirectorySource, _IndexDirectorySource
from pip._internal.models.candidate import InstallationCandidate
from pip._internal.models.index import PyPI
from pip._internal.models.link import (
    Link,
    LinkHash,
    MetadataFile,
    _clean_url_path,
    _ensure_quoted_url,
)
from pip._internal.network.session import PipSession
from tests.lib import TestData, make_test_link_collector

ACCEPT = ", ".join(
    [
        "application/vnd.pypi.simple.v1+json",
        "application/vnd.pypi.simple.v1+html; q=0.1",
        "text/html; q=0.01",
    ]
)


@pytest.mark.parametrize(
    "url",
    [
        "ftp://python.org/python-3.7.1.zip",
        "file:///opt/data/pip-18.0.tar.gz",
    ],
)
def test_get_simple_response_archive_to_naive_scheme(url: str) -> None:
    """
    `_get_simple_response()` should error on an archive-like URL if the scheme
    does not allow "poking" without getting data.
    """
    with pytest.raises(_NotHTTP):
        _get_simple_response(url, session=mock.Mock(PipSession))


@pytest.mark.parametrize(
    "url, content_type",
    [
        ("http://python.org/python-3.7.1.zip", "application/zip"),
        ("https://pypi.org/pip-18.0.tar.gz", "application/gzip"),
    ],
)
@mock.patch("pip._internal.index.collector.raise_for_status")
def test_get_simple_response_archive_to_http_scheme(
    mock_raise_for_status: mock.Mock, url: str, content_type: str
) -> None:
    """
    `_get_simple_response()` should send a HEAD request on an archive-like URL
    if the scheme supports it, and raise `_NotAPIContent` if the response isn't HTML.
    """
    session = mock.Mock(PipSession)
    session.head.return_value = mock.Mock(
        **{
            "request.method": "HEAD",
            "headers": {"Content-Type": content_type},
        }
    )

    with pytest.raises(_NotAPIContent) as ctx:
        _get_simple_response(url, session=session)

    session.assert_has_calls(
        [
            mock.call.head(url, allow_redirects=True),
        ]
    )
    mock_raise_for_status.assert_called_once_with(session.head.return_value)
    assert ctx.value.args == (content_type, "HEAD")


@pytest.mark.parametrize(
    "url",
    [
        ("ftp://python.org/python-3.7.1.zip"),
        ("file:///opt/data/pip-18.0.tar.gz"),
    ],
)
def test_get_index_content_invalid_content_type_archive(
    caplog: pytest.LogCaptureFixture, url: str
) -> None:
    """`_get_index_content()` should warn if an archive URL is not HTML
    and therefore cannot be used for a HEAD request.
    """
    caplog.set_level(logging.WARNING)
    link = Link(url)

    session = mock.Mock(PipSession)

    assert _get_index_content(link, session=session) is None
    assert (
        "pip._internal.index.collector",
        logging.WARNING,
        f"Skipping page {url} because it looks like an archive, and cannot "
        "be checked by a HTTP HEAD request.",
    ) in caplog.record_tuples


@pytest.mark.parametrize(
    "url",
    [
        "http://python.org/python-3.7.1.zip",
        "https://pypi.org/pip-18.0.tar.gz",
    ],
)
@mock.patch("pip._internal.index.collector.raise_for_status")
def test_get_simple_response_archive_to_http_scheme_is_html(
    mock_raise_for_status: mock.Mock, url: str
) -> None:
    """
    `_get_simple_response()` should work with archive-like URLs if the HEAD
    request is responded with text/html.
    """
    session = mock.Mock(PipSession)
    session.head.return_value = mock.Mock(
        **{
            "request.method": "HEAD",
            "headers": {"Content-Type": "text/html"},
        }
    )
    session.get.return_value = mock.Mock(headers={"Content-Type": "text/html"})

    resp = _get_simple_response(url, session=session)

    assert resp is not None
    assert session.mock_calls == [
        mock.call.head(url, allow_redirects=True),
        mock.call.get(
            url,
            headers={
                "Accept": ACCEPT,
                "Cache-Control": "max-age=0",
            },
        ),
    ]
    assert mock_raise_for_status.mock_calls == [
        mock.call(session.head.return_value),
        mock.call(resp),
    ]


@pytest.mark.parametrize(
    "url",
    [
        "https://pypi.org/simple/pip",
        "https://pypi.org/simple/pip/",
        "https://python.org/sitemap.xml",
    ],
)
@mock.patch("pip._internal.index.collector.raise_for_status")
def test_get_simple_response_no_head(
    mock_raise_for_status: mock.Mock, url: str
) -> None:
    """
    `_get_simple_response()` shouldn't send a HEAD request if the URL does not
    look like an archive, only the GET request that retrieves data.
    """
    session = mock.Mock(PipSession)

    # Mock the headers dict to ensure it is accessed.
    session.get.return_value = mock.Mock(
        headers=mock.Mock(
            **{
                "get.return_value": "text/html",
            }
        )
    )

    resp = _get_simple_response(url, session=session)

    assert resp is not None
    assert session.head.call_count == 0
    assert session.get.mock_calls == [
        mock.call(
            url,
            headers={
                "Accept": ACCEPT,
                "Cache-Control": "max-age=0",
            },
        ),
        mock.call().headers.get("Content-Type", "Unknown"),
        mock.call().headers.get("Content-Type", "Unknown"),
    ]
    mock_raise_for_status.assert_called_once_with(resp)


@mock.patch("pip._internal.index.collector.raise_for_status")
def test_get_simple_response_dont_log_clear_text_password(
    mock_raise_for_status: mock.Mock, caplog: pytest.LogCaptureFixture
) -> None:
    """
    `_get_simple_response()` should redact the password from the index URL
    in its DEBUG log message.
    """
    session = mock.Mock(PipSession)

    # Mock the headers dict to ensure it is accessed.
    session.get.return_value = mock.Mock(
        headers=mock.Mock(
            **{
                "get.return_value": "text/html",
            }
        )
    )

    caplog.set_level(logging.DEBUG)

    resp = _get_simple_response(
        "https://user:my_password@example.com/simple/", session=session
    )

    assert resp is not None
    mock_raise_for_status.assert_called_once_with(resp)

    assert len(caplog.records) == 2
    record = caplog.records[0]
    assert record.levelname == "DEBUG"
    assert record.message.splitlines() == [
        "Getting page https://user:****@example.com/simple/",
    ]
    record = caplog.records[1]
    assert record.levelname == "DEBUG"
    assert record.message.splitlines() == [
        "Fetched page https://user:****@example.com/simple/ as text/html",
    ]


@pytest.mark.parametrize(
    ("path", "expected"),
    [
        # Test a character that needs quoting.
        ("a b", "a%20b"),
        # Test an unquoted "@".
        ("a @ b", "a%20@%20b"),
        # Test multiple unquoted "@".
        ("a @ @ b", "a%20@%20@%20b"),
        # Test a quoted "@".
        ("a %40 b", "a%20%40%20b"),
        # Test a quoted "@" before an unquoted "@".
        ("a %40b@ c", "a%20%40b@%20c"),
        # Test a quoted "@" after an unquoted "@".
        ("a @b%40 c", "a%20@b%40%20c"),
        # Test alternating quoted and unquoted "@".
        ("a %40@b %40@c %40", "a%20%40@b%20%40@c%20%40"),
        # Test an unquoted "/".
        ("a / b", "a%20/%20b"),
        # Test multiple unquoted "/".
        ("a / / b", "a%20/%20/%20b"),
        # Test a quoted "/".
        ("a %2F b", "a%20%2F%20b"),
        # Test a quoted "/" before an unquoted "/".
        ("a %2Fb/ c", "a%20%2Fb/%20c"),
        # Test a quoted "/" after an unquoted "/".
        ("a /b%2F c", "a%20/b%2F%20c"),
        # Test alternating quoted and unquoted "/".
        ("a %2F/b %2F/c %2F", "a%20%2F/b%20%2F/c%20%2F"),
        # Test normalizing non-reserved quoted characters "[" and "]"
        ("a %5b %5d b", "a%20%5B%20%5D%20b"),
        # Test normalizing a reserved quoted "/"
        ("a %2f b", "a%20%2F%20b"),
    ],
)
@pytest.mark.parametrize("is_local_path", [True, False])
def test_clean_url_path(path: str, expected: str, is_local_path: bool) -> None:
    assert _clean_url_path(path, is_local_path=is_local_path) == expected


@pytest.mark.parametrize(
    ("path", "expected"),
    [
        # Test a VCS path with a Windows drive letter and revision.
        pytest.param(
            "/T:/with space/repo.git@1.0",
            "///T:/with%20space/repo.git@1.0",
            marks=pytest.mark.skipif("sys.platform != 'win32'"),
        ),
        # Test a VCS path with a Windows drive letter and revision,
        # running on non-windows platform.
        pytest.param(
            "/T:/with space/repo.git@1.0",
            "/T%3A/with%20space/repo.git@1.0",
            marks=pytest.mark.skipif("sys.platform == 'win32'"),
        ),
    ],
)
def test_clean_url_path_with_local_path(path: str, expected: str) -> None:
    actual = _clean_url_path(path, is_local_path=True)
    assert actual == expected


@pytest.mark.parametrize(
    ("url", "clean_url"),
    [
        # URL with hostname and port. Port separator should not be quoted.
        (
            "https://localhost.localdomain:8181/path/with space/",
            "https://localhost.localdomain:8181/path/with%20space/",
        ),
        # URL that is already properly quoted. The quoting `%`
        # characters should not be quoted again.
        (
            "https://localhost.localdomain:8181/path/with%20quoted%20space/",
            "https://localhost.localdomain:8181/path/with%20quoted%20space/",
        ),
        # URL with IPv4 address and port.
        (
            "https://127.0.0.1:8181/path/with space/",
            "https://127.0.0.1:8181/path/with%20space/",
        ),
        # URL with IPv6 address and port. The `[]` brackets around the
        # IPv6 address should not be quoted.
        (
            "https://[fd00:0:0:236::100]:8181/path/with space/",
            "https://[fd00:0:0:236::100]:8181/path/with%20space/",
        ),
        # URL with query. The leading `?` should not be quoted.
        (
            "https://localhost.localdomain:8181/path/with/query?request=test",
            "https://localhost.localdomain:8181/path/with/query?request=test",
        ),
        # URL with colon in the path portion.
        (
            "https://localhost.localdomain:8181/path:/with:/colon",
            "https://localhost.localdomain:8181/path%3A/with%3A/colon",
        ),
        # URL with something that looks like a drive letter, but is
        # not. The `:` should be quoted.
        (
            "https://localhost.localdomain/T:/path/",
            "https://localhost.localdomain/T%3A/path/",
        ),
        # URL with a quoted "/" in the path portion.
        (
            "https://example.com/access%2Ftoken/path/",
            "https://example.com/access%2Ftoken/path/",
        ),
        # VCS URL containing revision string.
        (
            "git+ssh://example.com/path to/repo.git@1.0#egg=my-package-1.0",
            "git+ssh://example.com/path%20to/repo.git@1.0#egg=my-package-1.0",
        ),
        # VCS URL with a quoted "#" in the revision string.
        (
            "git+https://example.com/repo.git@hash%23symbol#egg=my-package-1.0",
            "git+https://example.com/repo.git@hash%23symbol#egg=my-package-1.0",
        ),
        # VCS URL with a quoted "@" in the revision string.
        (
            "git+https://example.com/repo.git@at%40 space#egg=my-package-1.0",
            "git+https://example.com/repo.git@at%40%20space#egg=my-package-1.0",
        ),
        # URL with Windows drive letter. The `:` after the drive
        # letter should not be quoted. The trailing `/` should be
        # removed.
        pytest.param(
            "file:///T:/path/with spaces/",
            "file:///T:/path/with%20spaces",
            marks=pytest.mark.skipif("sys.platform != 'win32'"),
        ),
        # URL with Windows drive letter, running on non-windows
        # platform. The `:` after the drive should be quoted.
        pytest.param(
            "file:///T:/path/with spaces/",
            "file:///T%3A/path/with%20spaces/",
            marks=pytest.mark.skipif("sys.platform == 'win32'"),
        ),
        # Test a VCS URL with a Windows drive letter and revision.
        pytest.param(
            "git+file:///T:/with space/repo.git@1.0#egg=my-package-1.0",
            "git+file:///T:/with%20space/repo.git@1.0#egg=my-package-1.0",
            marks=pytest.mark.skipif("sys.platform != 'win32'"),
        ),
        # Test a VCS URL with a Windows drive letter and revision,
        # running on non-windows platform.
        pytest.param(
            "git+file:///T:/with space/repo.git@1.0#egg=my-package-1.0",
            "git+file:/T%3A/with%20space/repo.git@1.0#egg=my-package-1.0",
            marks=pytest.mark.skipif("sys.platform == 'win32'"),
        ),
    ],
)
def test_ensure_quoted_url(url: str, clean_url: str) -> None:
    assert _ensure_quoted_url(url) == clean_url


def _test_parse_links_data_attribute(
    anchor_html: str, attr: str, expected: Optional[str]
) -> Link:
    html = (
        "<!DOCTYPE html>"
        '<html><head><meta charset="utf-8"><head>'
        f"<body>{anchor_html}</body></html>"
    )
    html_bytes = html.encode("utf-8")
    page = IndexContent(
        html_bytes,
        "text/html",
        encoding=None,
        # parse_links() is cached by url, so we inject a random uuid to ensure
        # the page content isn't cached.
        url=f"https://example.com/simple-{uuid.uuid4()}/",
    )
    links = list(parse_links(page))
    (link,) = links
    actual = getattr(link, attr)
    assert actual == expected
    return link


@pytest.mark.parametrize(
    "anchor_html, expected",
    [
        # Test not present.
        ('<a href="/pkg-1.0.tar.gz"></a>', None),
        # Test present with no value.
        ('<a href="/pkg-1.0.tar.gz" data-requires-python></a>', None),
        # Test a value with an escaped character.
        (
            '<a href="/pkg-1.0.tar.gz" data-requires-python="&gt;=3.6"></a>',
            ">=3.6",
        ),
        # Test requires python is unescaped once.
        (
            '<a href="/pkg-1.0.tar.gz" data-requires-python="&amp;gt;=3.6"></a>',
            "&gt;=3.6",
        ),
    ],
)
def test_parse_links__requires_python(
    anchor_html: str, expected: Optional[str]
) -> None:
    _test_parse_links_data_attribute(anchor_html, "requires_python", expected)


# TODO: this test generates its own examples to validate the json client implementation
# instead of sharing those examples with the html client testing. We expect this won't
# hide any bugs because operations like resolving PEP 658 metadata should use the same
# code for both types of indices, but it might be nice to explicitly have all our tests
# in test_download.py execute over both html and json indices with
# a pytest.mark.parameterize decorator to ensure nothing slips through the cracks.
def test_parse_links_json() -> None:
    json_bytes = json.dumps(
        {
            "meta": {"api-version": "1.0"},
            "name": "holygrail",
            "files": [
                {
                    "filename": "holygrail-1.0.tar.gz",
                    "url": "https://example.com/files/holygrail-1.0.tar.gz",
                    "hashes": {"sha256": "sha256 hash", "blake2b": "blake2b hash"},
                    "requires-python": ">=3.7",
                    "yanked": "Had a vulnerability",
                },
                {
                    "filename": "holygrail-1.0-py3-none-any.whl",
                    "url": "/files/holygrail-1.0-py3-none-any.whl",
                    "hashes": {"sha256": "sha256 hash", "blake2b": "blake2b hash"},
                    "requires-python": ">=3.7",
                    "dist-info-metadata": False,
                },
                # Same as above, but parsing core-metadata.
                {
                    "filename": "holygrail-1.0-py3-none-any.whl",
                    "url": "/files/holygrail-1.0-py3-none-any.whl",
                    "hashes": {"sha256": "sha256 hash", "blake2b": "blake2b hash"},
                    "requires-python": ">=3.7",
                    "core-metadata": {"sha512": "aabdd41"},
                },
                # Ensure fallback to dist-info-metadata works
                {
                    "filename": "holygrail-1.0-py3-none-any.whl",
                    "url": "/files/holygrail-1.0-py3-none-any.whl",
                    "hashes": {"sha256": "sha256 hash", "blake2b": "blake2b hash"},
                    "requires-python": ">=3.7",
                    "dist-info-metadata": {"sha512": "aabdd41"},
                },
                # Ensure that core-metadata gets priority.
                {
                    "filename": "holygrail-1.0-py3-none-any.whl",
                    "url": "/files/holygrail-1.0-py3-none-any.whl",
                    "hashes": {"sha256": "sha256 hash", "blake2b": "blake2b hash"},
                    "requires-python": ">=3.7",
                    "core-metadata": {"sha512": "aabdd41"},
                    "dist-info-metadata": {"sha512": "this_is_wrong"},
                },
            ],
        }
    ).encode("utf8")
    page = IndexContent(
        json_bytes,
        "application/vnd.pypi.simple.v1+json",
        encoding=None,
        # parse_links() is cached by url, so we inject a random uuid to ensure
        # the page content isn't cached.
        url=f"https://example.com/simple-{uuid.uuid4()}/",
    )
    links = list(parse_links(page))

    assert links == [
        Link(
            "https://example.com/files/holygrail-1.0.tar.gz",
            comes_from=page.url,
            requires_python=">=3.7",
            yanked_reason="Had a vulnerability",
            hashes={"sha256": "sha256 hash", "blake2b": "blake2b hash"},
        ),
        Link(
            "https://example.com/files/holygrail-1.0-py3-none-any.whl",
            comes_from=page.url,
            requires_python=">=3.7",
            yanked_reason=None,
            hashes={"sha256": "sha256 hash", "blake2b": "blake2b hash"},
        ),
        Link(
            "https://example.com/files/holygrail-1.0-py3-none-any.whl",
            comes_from=page.url,
            requires_python=">=3.7",
            yanked_reason=None,
            hashes={"sha256": "sha256 hash", "blake2b": "blake2b hash"},
            metadata_file_data=MetadataFile({"sha512": "aabdd41"}),
        ),
        Link(
            "https://example.com/files/holygrail-1.0-py3-none-any.whl",
            comes_from=page.url,
            requires_python=">=3.7",
            yanked_reason=None,
            hashes={"sha256": "sha256 hash", "blake2b": "blake2b hash"},
            metadata_file_data=MetadataFile({"sha512": "aabdd41"}),
        ),
        Link(
            "https://example.com/files/holygrail-1.0-py3-none-any.whl",
            comes_from=page.url,
            requires_python=">=3.7",
            yanked_reason=None,
            hashes={"sha256": "sha256 hash", "blake2b": "blake2b hash"},
            metadata_file_data=MetadataFile({"sha512": "aabdd41"}),
        ),
    ]

    # Ensure the metadata info can be parsed into the correct link.
    metadata_link = links[2].metadata_link()
    assert metadata_link is not None
    assert (
        metadata_link.url
        == "https://example.com/files/holygrail-1.0-py3-none-any.whl.metadata"
    )
    assert metadata_link._hashes == {"sha512": "aabdd41"}


@pytest.mark.parametrize(
    "anchor_html, expected",
    [
        # Test not present.
        ('<a href="/pkg1-1.0.tar.gz"></a>', None),
        # Test present with no value.
        ('<a href="/pkg2-1.0.tar.gz" data-yanked></a>', None),
        # Test the empty string.
        ('<a href="/pkg3-1.0.tar.gz" data-yanked=""></a>', ""),
        # Test a non-empty string.
        ('<a href="/pkg4-1.0.tar.gz" data-yanked="error"></a>', "error"),
        # Test a value with an escaped character.
        ('<a href="/pkg4-1.0.tar.gz" data-yanked="version &lt 1"></a>', "version < 1"),
        # Test a yanked reason with a non-ascii character.
        (
            '<a href="/pkg-1.0.tar.gz" data-yanked="curlyquote \u2018"></a>',
            "curlyquote \u2018",
        ),
        # Test yanked reason is unescaped once.
        (
            '<a href="/pkg-1.0.tar.gz" data-yanked="version &amp;lt; 1"></a>',
            "version &lt; 1",
        ),
    ],
)
def test_parse_links__yanked_reason(anchor_html: str, expected: Optional[str]) -> None:
    _test_parse_links_data_attribute(anchor_html, "yanked_reason", expected)


# Requirement objects do not == each other unless they point to the same instance!
_pkg1_requirement = Requirement("pkg1==1.0")


@pytest.mark.parametrize(
    "anchor_html, expected, hashes",
    [
        # Test not present.
        (
            '<a href="/pkg1-1.0.tar.gz"></a>',
            None,
            {},
        ),
        # Test with value "true".
        (
            '<a href="/pkg1-1.0.tar.gz" data-core-metadata="true"></a>',
            MetadataFile(None),
            {},
        ),
        # Test with a provided hash value.
        (
            '<a href="/pkg1-1.0.tar.gz" data-core-metadata="sha256=aa113592bbe"></a>',
            MetadataFile({"sha256": "aa113592bbe"}),
            {},
        ),
        # Test with a provided hash value for both the requirement as well as metadata.
        (
            '<a href="/pkg1-1.0.tar.gz#sha512=abc132409cb" data-core-metadata="sha256=aa113592bbe"></a>',  # noqa: E501
            MetadataFile({"sha256": "aa113592bbe"}),
            {"sha512": "abc132409cb"},
        ),
        # Ensure the fallback to the old name works.
        (
            '<a href="/pkg1-1.0.tar.gz" data-dist-info-metadata="sha256=aa113592bbe"></a>',  # noqa: E501
            MetadataFile({"sha256": "aa113592bbe"}),
            {},
        ),
        # Ensure that the data-core-metadata name gets priority.
        (
            '<a href="/pkg1-1.0.tar.gz" data-core-metadata="sha256=aa113592bbe" data-dist-info-metadata="sha256=invalid_value"></a>',  # noqa: E501
            MetadataFile({"sha256": "aa113592bbe"}),
            {},
        ),
    ],
)
def test_parse_links__metadata_file_data(
    anchor_html: str,
    expected: Optional[str],
    hashes: Dict[str, str],
) -> None:
    link = _test_parse_links_data_attribute(anchor_html, "metadata_file_data", expected)
    assert link._hashes == hashes


def test_parse_links_caches_same_page_by_url() -> None:
    html = (
        "<!DOCTYPE html>"
        '<html><head><meta charset="utf-8"><head>'
        '<body><a href="/pkg1-1.0.tar.gz"></a></body></html>'
    )
    html_bytes = html.encode("utf-8")

    url = "https://example.com/simple/"

    page_1 = IndexContent(
        html_bytes,
        "text/html",
        encoding=None,
        url=url,
    )
    # Make a second page with zero content, to ensure that it's not accessed,
    # because the page was cached by url.
    page_2 = IndexContent(
        b"",
        "text/html",
        encoding=None,
        url=url,
    )
    # Make a third page which represents an index url, which should not be
    # cached, even for the same url. We modify the page content slightly to
    # verify that the result is not cached.
    page_3 = IndexContent(
        re.sub(b"pkg1", b"pkg2", html_bytes),
        "text/html",
        encoding=None,
        url=url,
        cache_link_parsing=False,
    )

    parsed_links_1 = list(parse_links(page_1))
    assert len(parsed_links_1) == 1
    assert "pkg1" in parsed_links_1[0].url

    parsed_links_2 = list(parse_links(page_2))
    assert parsed_links_2 == parsed_links_1

    parsed_links_3 = list(parse_links(page_3))
    assert len(parsed_links_3) == 1
    assert parsed_links_3 != parsed_links_1
    assert "pkg2" in parsed_links_3[0].url


@mock.patch("pip._internal.index.collector.raise_for_status")
def test_request_http_error(
    mock_raise_for_status: mock.Mock, caplog: pytest.LogCaptureFixture
) -> None:
    caplog.set_level(logging.DEBUG)
    link = Link("http://localhost")
    session = mock.Mock(PipSession)
    session.get.return_value = mock.Mock()
    mock_raise_for_status.side_effect = NetworkConnectionError("Http error")
    assert _get_index_content(link, session=session) is None
    assert "Could not fetch URL http://localhost: Http error - skipping" in caplog.text


def test_request_retries(caplog: pytest.LogCaptureFixture) -> None:
    caplog.set_level(logging.DEBUG)
    link = Link("http://localhost")
    session = mock.Mock(PipSession)
    session.get.side_effect = requests.exceptions.RetryError("Retry error")
    assert _get_index_content(link, session=session) is None
    assert "Could not fetch URL http://localhost: Retry error - skipping" in caplog.text


def test_make_index_content() -> None:
    headers = {"Content-Type": "text/html; charset=UTF-8"}
    response = mock.Mock(
        content=b"<content>",
        url="https://example.com/index.html",
        headers=headers,
    )

    actual = _make_index_content(response)
    assert actual.content == b"<content>"
    assert actual.encoding == "UTF-8"
    assert actual.url == "https://example.com/index.html"


@pytest.mark.parametrize(
    "url, vcs_scheme",
    [
        ("svn+http://pypi.org/something", "svn"),
        ("git+https://github.com/pypa/pip.git", "git"),
    ],
)
def test_get_index_content_invalid_scheme(
    caplog: pytest.LogCaptureFixture, url: str, vcs_scheme: str
) -> None:
    """`_get_index_content()` should error if an invalid scheme is given.

    Only file:, http:, https:, and ftp: are allowed.
    """
    with caplog.at_level(logging.WARNING):
        page = _get_index_content(Link(url), session=mock.Mock(PipSession))

    assert page is None
    assert caplog.record_tuples == [
        (
            "pip._internal.index.collector",
            logging.WARNING,
            f"Cannot look at {vcs_scheme} URL {url} because it does not support "
            "lookup as web pages.",
        ),
    ]


@pytest.mark.parametrize(
    "content_type",
    [
        "application/xhtml+xml",
        "application/json",
    ],
)
@mock.patch("pip._internal.index.collector.raise_for_status")
def test_get_index_content_invalid_content_type(
    mock_raise_for_status: mock.Mock,
    caplog: pytest.LogCaptureFixture,
    content_type: str,
) -> None:
    """`_get_index_content()` should warn if an invalid content-type is given.
    Only text/html is allowed.
    """
    caplog.set_level(logging.DEBUG)
    url = "https://pypi.org/simple/pip"
    link = Link(url)

    session = mock.Mock(PipSession)
    session.get.return_value = mock.Mock(
        **{
            "request.method": "GET",
            "headers": {"Content-Type": content_type},
        }
    )
    assert _get_index_content(link, session=session) is None
    mock_raise_for_status.assert_called_once_with(session.get.return_value)
    assert (
        "pip._internal.index.collector",
        logging.WARNING,
        "Skipping page {} because the GET request got Content-Type: {}. "
        "The only supported Content-Types are application/vnd.pypi.simple.v1+json, "
        "application/vnd.pypi.simple.v1+html, and text/html".format(url, content_type),
    ) in caplog.record_tuples


def make_fake_html_response(url: str) -> mock.Mock:
    """
    Create a fake requests.Response object.
    """
    html = dedent(
        """\
    <html><head><meta name="api-version" value="2" /></head>
    <body>
    <a href="/abc-1.0.tar.gz#md5=000000000">abc-1.0.tar.gz</a>
    </body></html>
    """
    )
    content = html.encode("utf-8")
    return mock.Mock(content=content, url=url, headers={"Content-Type": "text/html"})


def test_get_index_content_directory_append_index(tmpdir: Path) -> None:
    """`_get_index_content()` should append "index.html" to a directory URL."""
    dirpath = tmpdir / "something"
    dirpath.mkdir()
    dir_url = dirpath.as_uri()
    expected_url = "{}/index.html".format(dir_url.rstrip("/"))

    session = mock.Mock(PipSession)
    fake_response = make_fake_html_response(expected_url)
    mock_func = mock.patch("pip._internal.index.collector._get_simple_response")
    with mock_func as mock_func:
        mock_func.return_value = fake_response
        actual = _get_index_content(Link(dir_url), session=session)
        assert mock_func.mock_calls == [
            mock.call(expected_url, session=session),
        ], f"actual calls: {mock_func.mock_calls}"

        assert actual is not None
        assert actual.content == fake_response.content
        assert actual.encoding is None
        assert actual.url == expected_url


def test_collect_sources__file_expand_dir(data: TestData) -> None:
    """
    Test that a file:// dir from --find-links becomes _FlatDirectorySource
    """
    collector = LinkCollector.create(
        session=mock.Mock(is_secure_origin=None),  # Shouldn't be used.
        options=mock.Mock(
            index_url="ignored-by-no-index",
            extra_index_urls=[],
            no_index=True,
            find_links=[data.find_links],
        ),
    )
    sources = collector.collect_sources(
        # Shouldn't be used.
        project_name=None,  # type: ignore[arg-type]
        candidates_from_page=None,  # type: ignore[arg-type]
    )
    assert (
        not sources.index_urls
        and len(sources.find_links) == 1
        and isinstance(sources.find_links[0], _FlatDirectorySource)
    ), (
        "Directory source should have been found "
        f"at find-links url: {data.find_links}"
    )


def test_collect_sources__file_not_find_link(data: TestData) -> None:
    """
    Test that a file:// dir from --index-url doesn't become _FlatDirectorySource
    run
    """
    collector = LinkCollector.create(
        session=mock.Mock(is_secure_origin=None),  # Shouldn't be used.
        options=mock.Mock(
            index_url=data.index_url("empty_with_pkg"),
            extra_index_urls=[],
            no_index=False,
            find_links=[],
        ),
    )
    sources = collector.collect_sources(
        project_name="",
        # Shouldn't be used.
        candidates_from_page=None,  # type: ignore[arg-type]
    )
    assert (
        not sources.find_links
        and len(sources.index_urls) == 1
        and isinstance(sources.index_urls[0], _IndexDirectorySource)
    ), "Directory specified as index should be treated as a page"


def test_collect_sources__non_existing_path() -> None:
    """
    Test that a non-existing path is ignored.
    """
    collector = LinkCollector.create(
        session=mock.Mock(is_secure_origin=None),  # Shouldn't be used.
        options=mock.Mock(
            index_url="ignored-by-no-index",
            extra_index_urls=[],
            no_index=True,
            find_links=[os.path.join("this", "doesnt", "exist")],
        ),
    )
    sources = collector.collect_sources(
        # Shouldn't be used.
        project_name=None,  # type: ignore[arg-type]
        candidates_from_page=None,  # type: ignore[arg-type]
    )
    assert not sources.index_urls and sources.find_links == [
        None
    ], "Nothing should have been found"


def check_links_include(links: List[Link], names: List[str]) -> None:
    """
    Assert that the given list of Link objects includes, for each of the
    given names, a link whose URL has a base name matching that name.
    """
    for name in names:
        assert any(
            link.url.endswith(name) for link in links
        ), f"name {name!r} not among links: {links}"


class TestLinkCollector:
    @mock.patch("pip._internal.index.collector._get_simple_response")
    def test_fetch_response(self, mock_get_simple_response: mock.Mock) -> None:
        url = "https://pypi.org/simple/twine/"

        fake_response = make_fake_html_response(url)
        mock_get_simple_response.return_value = fake_response

        location = Link(url, cache_link_parsing=False)
        link_collector = make_test_link_collector()
        actual = link_collector.fetch_response(location)

        assert actual is not None
        assert actual.content == fake_response.content
        assert actual.encoding is None
        assert actual.url == url
        assert actual.cache_link_parsing == location.cache_link_parsing

        # Also check that the right session object was passed to
        # _get_simple_response().
        mock_get_simple_response.assert_called_once_with(
            url,
            session=link_collector.session,
        )

    def test_collect_sources(
        self, caplog: pytest.LogCaptureFixture, data: TestData
    ) -> None:
        caplog.set_level(logging.DEBUG)

        link_collector = make_test_link_collector(
            find_links=[data.find_links],
            # Include two copies of the URL to check that the second one
            # is skipped.
            index_urls=[PyPI.simple_url, PyPI.simple_url],
        )
        collected_sources = link_collector.collect_sources(
            "twine",
            candidates_from_page=lambda link: [
                InstallationCandidate("twine", "1.0", link)
            ],
        )

        files_it = itertools.chain.from_iterable(
            source.file_links()
            for sources in collected_sources
            for source in sources
            if source is not None
        )
        pages_it = itertools.chain.from_iterable(
            source.page_candidates()
            for sources in collected_sources
            for source in sources
            if source is not None
        )
        files = list(files_it)
        pages = list(pages_it)

        # Spot-check the returned sources.
        assert len(files) > 20
        check_links_include(files, names=["simple-1.0.tar.gz"])

        assert [page.link for page in pages] == [Link("https://pypi.org/simple/twine/")]
        # Check that index URLs are marked as *un*cacheable.
        assert not pages[0].link.cache_link_parsing

        expected_message = dedent(
            """\
        1 location(s) to search for versions of twine:
        * https://pypi.org/simple/twine/"""
        )
        assert caplog.record_tuples == [
            ("pip._internal.index.collector", logging.DEBUG, expected_message),
        ]


@pytest.mark.parametrize(
    "find_links, no_index, suppress_no_index, expected",
    [
        (["link1"], False, False, (["link1"], ["default_url", "url1", "url2"])),
        (["link1"], False, True, (["link1"], ["default_url", "url1", "url2"])),
        (["link1"], True, False, (["link1"], [])),
        # Passing suppress_no_index=True suppresses no_index=True.
        (["link1"], True, True, (["link1"], ["default_url", "url1", "url2"])),
        # Test options.find_links=False.
        (False, False, False, ([], ["default_url", "url1", "url2"])),
    ],
)
def test_link_collector_create(
    find_links: List[str],
    no_index: bool,
    suppress_no_index: bool,
    expected: Tuple[List[str], List[str]],
) -> None:
    """
    :param expected: the expected (find_links, index_urls) values.
    """
    expected_find_links, expected_index_urls = expected
    session = PipSession()
    options = mock.Mock(
        find_links=find_links,
        index_url="default_url",
        extra_index_urls=["url1", "url2"],
        no_index=no_index,
    )
    link_collector = LinkCollector.create(
        session,
        options=options,
        suppress_no_index=suppress_no_index,
    )

    assert link_collector.session is session

    search_scope = link_collector.search_scope
    assert search_scope.find_links == expected_find_links
    assert search_scope.index_urls == expected_index_urls


@mock.patch("os.path.expanduser")
def test_link_collector_create_find_links_expansion(
    mock_expanduser: mock.Mock, tmpdir: Path
) -> None:
    """
    Test "~" expansion in --find-links paths.
    """

    # This is a mock version of expanduser() that expands "~" to the tmpdir.
    def expand_path(path: str) -> str:
        if path.startswith("~/"):
            path = os.path.join(tmpdir, path[2:])
        return path

    mock_expanduser.side_effect = expand_path

    session = PipSession()
    options = mock.Mock(
        find_links=["~/temp1", "~/temp2"],
        index_url="default_url",
        extra_index_urls=[],
        no_index=False,
    )
    # Only create temp2 and not temp1 to test that "~" expansion only occurs
    # when the directory exists.
    temp2_dir = os.path.join(tmpdir, "temp2")
    os.mkdir(temp2_dir)

    link_collector = LinkCollector.create(session, options=options)

    search_scope = link_collector.search_scope
    # Only ~/temp2 gets expanded. Also, the path is normalized when expanded.
    expected_temp2_dir = os.path.normcase(temp2_dir)
    assert search_scope.find_links == ["~/temp1", expected_temp2_dir]
    assert search_scope.index_urls == ["default_url"]


@pytest.mark.parametrize(
    "url, result",
    [
        (
            "https://pypi.org/pip-18.0.tar.gz#sha256=aa113592bbe",
            LinkHash("sha256", "aa113592bbe"),
        ),
        (
            "https://pypi.org/pip-18.0.tar.gz#sha256=aa113592bbe&subdirectory=setup",
            LinkHash("sha256", "aa113592bbe"),
        ),
        (
            "https://pypi.org/pip-18.0.tar.gz#subdirectory=setup&sha256=aa113592bbe",
            LinkHash("sha256", "aa113592bbe"),
        ),
        # "xsha256" is not a valid algorithm, so we discard it.
        ("https://pypi.org/pip-18.0.tar.gz#xsha256=aa113592bbe", None),
        # Empty hash.
        (
            "https://pypi.org/pip-18.0.tar.gz#sha256=",
            LinkHash("sha256", ""),
        ),
        (
            "https://pypi.org/pip-18.0.tar.gz#md5=aa113592bbe",
            LinkHash("md5", "aa113592bbe"),
        ),
        ("https://pypi.org/pip-18.0.tar.gz", None),
        # We don't recognize the "sha500" algorithm, so we discard it.
        ("https://pypi.org/pip-18.0.tar.gz#sha500=aa113592bbe", None),
    ],
)
def test_link_hash_parsing(url: str, result: Optional[LinkHash]) -> None:
    assert LinkHash.find_hash_url_fragment(url) == result


@pytest.mark.parametrize(
    "metadata_attrib, expected",
    [
        ("sha256=aa113592bbe", MetadataFile({"sha256": "aa113592bbe"})),
        ("sha256=", MetadataFile({"sha256": ""})),
        ("sha500=aa113592bbe", MetadataFile(None)),
        ("true", MetadataFile(None)),
        (None, None),
        # Attribute is present but invalid
        ("", MetadataFile(None)),
        ("aa113592bbe", MetadataFile(None)),
    ],
)
def test_metadata_file_info_parsing_html(
    metadata_attrib: str, expected: Optional[MetadataFile]
) -> None:
    attribs: Dict[str, Optional[str]] = {
        "href": "something",
        "data-dist-info-metadata": metadata_attrib,
    }
    page_url = "dummy_for_comes_from"
    base_url = "https://index.url/simple"
    link = Link.from_element(attribs, page_url, base_url)
    assert link is not None and link.metadata_file_data == expected