import os
import re
import shutil
import textwrap
import uuid
from dataclasses import dataclass
from enum import Enum
from hashlib import sha256
from pathlib import Path
from textwrap import dedent
from typing import Callable, Dict, List, Tuple

import pytest

from pip._internal.cli.status_codes import ERROR
from pip._internal.utils.urls import path_to_url
from tests.lib import (
    PipTestEnvironment,
    ScriptFactory,
    TestData,
    TestPipResult,
    create_basic_sdist_for_package,
    create_really_basic_wheel,
)
from tests.lib.server import MockServer, file_response


def fake_wheel(data: TestData, wheel_path: str) -> None:
    wheel_name = os.path.basename(wheel_path)
    name, version, rest = wheel_name.split("-", 2)
    wheel_data = create_really_basic_wheel(name, version)
    data.packages.joinpath(wheel_path).write_bytes(wheel_data)


@pytest.mark.network
def test_download_if_requested(script: PipTestEnvironment) -> None:
    """
    It should download (in the scratch path) and not install if requested.
    """
    result = script.pip("download", "-d", "pip_downloads", "INITools==0.1")
    result.did_create(Path("scratch") / "pip_downloads" / "INITools-0.1.tar.gz")
    result.did_not_create(script.site_packages / "initools")


@pytest.mark.network
def test_basic_download_setuptools(script: PipTestEnvironment) -> None:
    """
    It should download (in the scratch path) and not install if requested.
    """
    result = script.pip("download", "setuptools")
    setuptools_prefix = str(Path("scratch") / "setuptools")
    assert any(os.fspath(p).startswith(setuptools_prefix) for p in result.files_created)


def test_download_wheel(script: PipTestEnvironment, data: TestData) -> None:
    """
    Test using "pip download" to download a *.whl archive.
    """
    result = script.pip(
        "download", "--no-index", "-f", data.packages, "-d", ".", "meta"
    )
    result.did_create(Path("scratch") / "meta-1.0-py2.py3-none-any.whl")
    result.did_not_create(script.site_packages / "piptestpackage")


@pytest.mark.network
def test_single_download_from_requirements_file(script: PipTestEnvironment) -> None:
    """
    It should support download (in the scratch path) from PyPI from a
    requirements file
    """
    script.scratch_path.joinpath("test-req.txt").write_text(
        textwrap.dedent(
            """
        INITools==0.1
        """
        )
    )
    result = script.pip(
        "download",
        "-r",
        script.scratch_path / "test-req.txt",
        "-d",
        ".",
    )
    result.did_create(Path("scratch") / "INITools-0.1.tar.gz")
    result.did_not_create(script.site_packages / "initools")


@pytest.mark.network
def test_basic_download_should_download_dependencies(
    script: PipTestEnvironment,
) -> None:
    """
    It should download dependencies (in the scratch path)
    """
    result = script.pip("download", "Paste[openid]==1.7.5.1", "-d", ".")
    result.did_create(Path("scratch") / "Paste-1.7.5.1.tar.gz")
    openid_tarball_prefix = str(Path("scratch") / "python-openid-")
    assert any(
        os.fspath(path).startswith(openid_tarball_prefix)
        for path in result.files_created
    )
    result.did_not_create(script.site_packages / "openid")


def test_download_wheel_archive(script: PipTestEnvironment, data: TestData) -> None:
    """
    It should download a wheel archive path
    """
    wheel_filename = "colander-0.9.9-py2.py3-none-any.whl"
    wheel_path = "/".join((data.find_links, wheel_filename))
    result = script.pip("download", wheel_path, "-d", ".", "--no-deps")
    result.did_create(Path("scratch") / wheel_filename)


def test_download_should_download_wheel_deps(
    script: PipTestEnvironment, data: TestData
) -> None:
    """
    It should download dependencies for wheels(in the scratch path)
    """
    wheel_filename = "colander-0.9.9-py2.py3-none-any.whl"
    dep_filename = "translationstring-1.1.tar.gz"
    wheel_path = "/".join((data.find_links, wheel_filename))
    result = script.pip(
        "download", wheel_path, "-d", ".", "--find-links", data.find_links, "--no-index"
    )
    result.did_create(Path("scratch") / wheel_filename)
    result.did_create(Path("scratch") / dep_filename)


@pytest.mark.network
def test_download_should_skip_existing_files(script: PipTestEnvironment) -> None:
    """
    It should not download files already existing in the scratch dir
    """
    script.scratch_path.joinpath("test-req.txt").write_text(
        textwrap.dedent(
            """
        INITools==0.1
        """
        )
    )

    result = script.pip(
        "download",
        "-r",
        script.scratch_path / "test-req.txt",
        "-d",
        ".",
    )
    result.did_create(Path("scratch") / "INITools-0.1.tar.gz")
    result.did_not_create(script.site_packages / "initools")

    # adding second package to test-req.txt
    script.scratch_path.joinpath("test-req.txt").write_text(
        textwrap.dedent(
            """
        INITools==0.1
        python-openid==2.2.5
        """
        )
    )

    # only the second package should be downloaded
    result = script.pip(
        "download",
        "-r",
        script.scratch_path / "test-req.txt",
        "-d",
        ".",
    )
    openid_tarball_prefix = str(Path("scratch") / "python-openid-")
    assert any(
        os.fspath(path).startswith(openid_tarball_prefix)
        for path in result.files_created
    )
    result.did_not_create(Path("scratch") / "INITools-0.1.tar.gz")
    result.did_not_create(script.site_packages / "initools")
    result.did_not_create(script.site_packages / "openid")


@pytest.mark.network
def test_download_vcs_link(script: PipTestEnvironment) -> None:
    """
    It should allow -d flag for vcs links, regression test for issue #798.
    """
    result = script.pip(
        "download", "-d", ".", "git+https://github.com/pypa/pip-test-package.git"
    )
    result.did_create(Path("scratch") / "pip-test-package-0.1.1.zip")
    result.did_not_create(script.site_packages / "piptestpackage")


def test_only_binary_set_then_download_specific_platform(
    script: PipTestEnvironment, data: TestData
) -> None:
    """
    Confirm that specifying an interpreter/platform constraint
    is allowed when ``--only-binary=:all:`` is set.
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "linux_x86_64",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-any.whl")


def test_no_deps_set_then_download_specific_platform(
    script: PipTestEnvironment, data: TestData
) -> None:
    """
    Confirm that specifying an interpreter/platform constraint
    is allowed when ``--no-deps`` is set.
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--no-deps",
        "--dest",
        ".",
        "--platform",
        "linux_x86_64",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-any.whl")


def test_download_specific_platform_fails(
    script: PipTestEnvironment, data: TestData
) -> None:
    """
    Confirm that specifying an interpreter/platform constraint
    enforces that ``--no-deps`` or ``--only-binary=:all:`` is set.
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--dest",
        ".",
        "--platform",
        "linux_x86_64",
        "fake",
        expect_error=True,
    )
    assert "--only-binary=:all:" in result.stderr


def test_no_binary_set_then_download_specific_platform_fails(
    script: PipTestEnvironment, data: TestData
) -> None:
    """
    Confirm that specifying an interpreter/platform constraint
    enforces that ``--only-binary=:all:`` is set without ``--no-binary``.
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--no-binary=fake",
        "--dest",
        ".",
        "--platform",
        "linux_x86_64",
        "fake",
        expect_error=True,
    )
    assert "--only-binary=:all:" in result.stderr


def test_download_specify_platform(script: PipTestEnvironment, data: TestData) -> None:
    """
    Test using "pip download --platform" to download a .whl archive
    supported for a specific platform
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")

    # Confirm that universal wheels are returned even for specific
    # platforms.
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "linux_x86_64",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "macosx_10_9_x86_64",
        "fake",
    )

    data.reset()
    fake_wheel(data, "fake-1.0-py2.py3-none-macosx_10_9_x86_64.whl")
    fake_wheel(data, "fake-2.0-py2.py3-none-linux_x86_64.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "macosx_10_10_x86_64",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-macosx_10_9_x86_64.whl")

    # OSX platform wheels are not backward-compatible.
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "macosx_10_8_x86_64",
        "fake",
        expect_error=True,
    )

    # No linux wheel provided for this version.
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "linux_x86_64",
        "fake==1",
        expect_error=True,
    )

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "linux_x86_64",
        "fake==2",
    )
    result.did_create(Path("scratch") / "fake-2.0-py2.py3-none-linux_x86_64.whl")

    # Test with multiple supported platforms specified.
    data.reset()
    fake_wheel(data, "fake-3.0-py2.py3-none-linux_x86_64.whl")
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--platform",
        "manylinux1_x86_64",
        "--platform",
        "linux_x86_64",
        "--platform",
        "any",
        "fake==3",
    )
    result.did_create(Path("scratch") / "fake-3.0-py2.py3-none-linux_x86_64.whl")


class TestDownloadPlatformManylinuxes:
    """
    "pip download --platform" downloads a .whl archive supported for
    manylinux platforms.
    """

    @pytest.mark.parametrize(
        "platform",
        [
            "linux_x86_64",
            "manylinux1_x86_64",
            "manylinux2010_x86_64",
            "manylinux2014_x86_64",
        ],
    )
    def test_download_universal(
        self, platform: str, script: PipTestEnvironment, data: TestData
    ) -> None:
        """
        Universal wheels are returned even for specific platforms.
        """
        fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")
        result = script.pip(
            "download",
            "--no-index",
            "--find-links",
            data.find_links,
            "--only-binary=:all:",
            "--dest",
            ".",
            "--platform",
            platform,
            "fake",
        )
        result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-any.whl")

    @pytest.mark.parametrize(
        "wheel_abi,platform",
        [
            ("manylinux1_x86_64", "manylinux1_x86_64"),
            ("manylinux1_x86_64", "manylinux2010_x86_64"),
            ("manylinux2010_x86_64", "manylinux2010_x86_64"),
            ("manylinux1_x86_64", "manylinux2014_x86_64"),
            ("manylinux2010_x86_64", "manylinux2014_x86_64"),
            ("manylinux2014_x86_64", "manylinux2014_x86_64"),
        ],
    )
    def test_download_compatible_manylinuxes(
        self,
        wheel_abi: str,
        platform: str,
        script: PipTestEnvironment,
        data: TestData,
    ) -> None:
        """
        Earlier manylinuxes are compatible with later manylinuxes.
        """
        wheel = f"fake-1.0-py2.py3-none-{wheel_abi}.whl"
        fake_wheel(data, wheel)
        result = script.pip(
            "download",
            "--no-index",
            "--find-links",
            data.find_links,
            "--only-binary=:all:",
            "--dest",
            ".",
            "--platform",
            platform,
            "fake",
        )
        result.did_create(Path("scratch") / wheel)

    def test_explicit_platform_only(
        self, data: TestData, script: PipTestEnvironment
    ) -> None:
        """
        When specifying the platform, manylinux1 needs to be the
        explicit platform--it won't ever be added to the compatible
        tags.
        """
        fake_wheel(data, "fake-1.0-py2.py3-none-linux_x86_64.whl")
        script.pip(
            "download",
            "--no-index",
            "--find-links",
            data.find_links,
            "--only-binary=:all:",
            "--dest",
            ".",
            "--platform",
            "linux_x86_64",
            "fake",
        )


def test_download__python_version(script: PipTestEnvironment, data: TestData) -> None:
    """
    Test using "pip download --python-version" to download a .whl archive
    supported for a specific interpreter
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "2",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "3",
        "fake",
    )

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "27",
        "fake",
    )

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "33",
        "fake",
    )

    data.reset()
    fake_wheel(data, "fake-1.0-py2-none-any.whl")
    fake_wheel(data, "fake-2.0-py3-none-any.whl")

    # No py3 provided for version 1.
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "3",
        "fake==1.0",
        expect_error=True,
    )

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "2",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "26",
        "fake",
    )

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "3",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-2.0-py3-none-any.whl")


def make_wheel_with_python_requires(
    script: PipTestEnvironment, package_name: str, python_requires: str
) -> Path:
    """
    Create a wheel using the given python_requires.

    :return: the path to the wheel file.
    """
    package_dir = script.scratch_path / package_name
    package_dir.mkdir()

    text = textwrap.dedent(
        """\
    from setuptools import setup
    setup(name='{}',
          python_requires='{}',
          version='1.0')
    """
    ).format(package_name, python_requires)
    package_dir.joinpath("setup.py").write_text(text)
    script.run(
        "python",
        "setup.py",
        "bdist_wheel",
        "--universal",
        cwd=package_dir,
    )

    file_name = f"{package_name}-1.0-py2.py3-none-any.whl"
    return package_dir / "dist" / file_name


def test_download__python_version_used_for_python_requires(
    script: PipTestEnvironment, data: TestData
) -> None:
    """
    Test that --python-version is used for the Requires-Python check.
    """
    wheel_path = make_wheel_with_python_requires(
        script,
        "mypackage",
        python_requires="==3.2",
    )
    wheel_dir = os.path.dirname(wheel_path)

    def make_args(python_version: str) -> List[str]:
        return [
            "download",
            "--no-index",
            "--find-links",
            wheel_dir,
            "--only-binary=:all:",
            "--dest",
            ".",
            "--python-version",
            python_version,
            "mypackage==1.0",
        ]

    args = make_args("33")
    result = script.pip(*args, expect_error=True)
    expected_err = (
        "ERROR: Package 'mypackage' requires a different Python: "
        "3.3.0 not in '==3.2'"
    )
    assert expected_err in result.stderr, f"stderr: {result.stderr}"

    # Now try with a --python-version that satisfies the Requires-Python.
    args = make_args("32")
    script.pip(*args)  # no exception


def test_download_ignore_requires_python_dont_fail_with_wrong_python(
    script: PipTestEnvironment,
) -> None:
    """
    Test that --ignore-requires-python ignores Requires-Python check.
    """
    wheel_path = make_wheel_with_python_requires(
        script,
        "mypackage",
        python_requires="==999",
    )
    wheel_dir = os.path.dirname(wheel_path)

    result = script.pip(
        "download",
        "--ignore-requires-python",
        "--no-index",
        "--find-links",
        wheel_dir,
        "--only-binary=:all:",
        "--dest",
        ".",
        "mypackage==1.0",
    )
    result.did_create(Path("scratch") / "mypackage-1.0-py2.py3-none-any.whl")


def test_download_specify_abi(script: PipTestEnvironment, data: TestData) -> None:
    """
    Test using "pip download --abi" to download a .whl archive
    supported for a specific abi
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--implementation",
        "fk",
        "--abi",
        "fake_abi",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--implementation",
        "fk",
        "--abi",
        "none",
        "fake",
    )

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--abi",
        "cp27m",
        "fake",
    )

    data.reset()
    fake_wheel(data, "fake-1.0-fk2-fakeabi-fake_platform.whl")
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "2",
        "--implementation",
        "fk",
        "--platform",
        "fake_platform",
        "--abi",
        "fakeabi",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-fk2-fakeabi-fake_platform.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--implementation",
        "fk",
        "--platform",
        "fake_platform",
        "--abi",
        "none",
        "fake",
        expect_error=True,
    )

    data.reset()
    fake_wheel(data, "fake-1.0-fk2-otherabi-fake_platform.whl")
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--python-version",
        "2",
        "--implementation",
        "fk",
        "--platform",
        "fake_platform",
        "--abi",
        "fakeabi",
        "--abi",
        "otherabi",
        "--abi",
        "none",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-fk2-otherabi-fake_platform.whl")


def test_download_specify_implementation(
    script: PipTestEnvironment, data: TestData
) -> None:
    """
    Test using "pip download --abi" to download a .whl archive
    supported for a specific abi
    """
    fake_wheel(data, "fake-1.0-py2.py3-none-any.whl")
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--implementation",
        "fk",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-py2.py3-none-any.whl")

    data.reset()
    fake_wheel(data, "fake-1.0-fk3-none-any.whl")
    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--implementation",
        "fk",
        "--python-version",
        "3",
        "fake",
    )
    result.did_create(Path("scratch") / "fake-1.0-fk3-none-any.whl")

    result = script.pip(
        "download",
        "--no-index",
        "--find-links",
        data.find_links,
        "--only-binary=:all:",
        "--dest",
        ".",
        "--implementation",
        "fk",
        "--python-version",
        "2",
        "fake",
        expect_error=True,
    )


def test_download_exit_status_code_when_no_requirements(
    script: PipTestEnvironment,
) -> None:
    """
    Test download exit status code when no requirements specified
    """
    result = script.pip("download", expect_error=True)
    assert "You must give at least one requirement to download" in result.stderr
    assert result.returncode == ERROR


def test_download_exit_status_code_when_blank_requirements_file(
    script: PipTestEnvironment,
) -> None:
    """
    Test download exit status code when blank requirements file specified
    """
    script.scratch_path.joinpath("blank.txt").write_text("\n")
    script.pip("download", "-r", "blank.txt")


def test_download_prefer_binary_when_tarball_higher_than_wheel(
    script: PipTestEnvironment, data: TestData
) -> None:
    fake_wheel(data, "source-0.8-py2.py3-none-any.whl")
    result = script.pip(
        "download",
        "--prefer-binary",
        "--no-index",
        "-f",
        data.packages,
        "-d",
        ".",
        "source",
    )
    result.did_create(Path("scratch") / "source-0.8-py2.py3-none-any.whl")
    result.did_not_create(Path("scratch") / "source-1.0.tar.gz")


def test_prefer_binary_tarball_higher_than_wheel_req_file(
    script: PipTestEnvironment, data: TestData
) -> None:
    fake_wheel(data, "source-0.8-py2.py3-none-any.whl")
    script.scratch_path.joinpath("test-req.txt").write_text(
        textwrap.dedent(
            """
                --prefer-binary
                 source
                """
        )
    )
    result = script.pip(
        "download",
        "-r",
        script.scratch_path / "test-req.txt",
        "--no-index",
        "-f",
        data.packages,
        "-d",
        ".",
    )

    result.did_create(Path("scratch") / "source-0.8-py2.py3-none-any.whl")
    result.did_not_create(Path("scratch") / "source-1.0.tar.gz")


def test_download_prefer_binary_when_wheel_doesnt_satisfy_req(
    script: PipTestEnvironment, data: TestData
) -> None:
    fake_wheel(data, "source-0.8-py2.py3-none-any.whl")
    script.scratch_path.joinpath("test-req.txt").write_text(
        textwrap.dedent(
            """
        source>0.9
        """
        )
    )

    result = script.pip(
        "download",
        "--prefer-binary",
        "--no-index",
        "-f",
        data.packages,
        "-d",
        ".",
        "-r",
        script.scratch_path / "test-req.txt",
    )
    result.did_create(Path("scratch") / "source-1.0.tar.gz")
    result.did_not_create(Path("scratch") / "source-0.8-py2.py3-none-any.whl")


def test_prefer_binary_when_wheel_doesnt_satisfy_req_req_file(
    script: PipTestEnvironment, data: TestData
) -> None:
    fake_wheel(data, "source-0.8-py2.py3-none-any.whl")
    script.scratch_path.joinpath("test-req.txt").write_text(
        textwrap.dedent(
            """
        --prefer-binary
        source>0.9
        """
        )
    )

    result = script.pip(
        "download",
        "--no-index",
        "-f",
        data.packages,
        "-d",
        ".",
        "-r",
        script.scratch_path / "test-req.txt",
    )
    result.did_create(Path("scratch") / "source-1.0.tar.gz")
    result.did_not_create(Path("scratch") / "source-0.8-py2.py3-none-any.whl")


def test_download_prefer_binary_when_only_tarball_exists(
    script: PipTestEnvironment, data: TestData
) -> None:
    result = script.pip(
        "download",
        "--prefer-binary",
        "--no-index",
        "-f",
        data.packages,
        "-d",
        ".",
        "source",
    )
    result.did_create(Path("scratch") / "source-1.0.tar.gz")


def test_prefer_binary_when_only_tarball_exists_req_file(
    script: PipTestEnvironment, data: TestData
) -> None:
    script.scratch_path.joinpath("test-req.txt").write_text(
        textwrap.dedent(
            """
            --prefer-binary
            source
            """
        )
    )
    result = script.pip(
        "download",
        "--no-index",
        "-f",
        data.packages,
        "-d",
        ".",
        "-r",
        script.scratch_path / "test-req.txt",
    )
    result.did_create(Path("scratch") / "source-1.0.tar.gz")


@pytest.fixture(scope="session")
def shared_script(
    tmpdir_factory: pytest.TempPathFactory, script_factory: ScriptFactory
) -> PipTestEnvironment:
    tmpdir = tmpdir_factory.mktemp("download_shared_script")
    script = script_factory(tmpdir.joinpath("workspace"))
    return script


def test_download_file_url(
    shared_script: PipTestEnvironment, shared_data: TestData, tmpdir: Path
) -> None:
    download_dir = tmpdir / "download"
    download_dir.mkdir()
    downloaded_path = download_dir / "simple-1.0.tar.gz"

    simple_pkg = shared_data.packages / "simple-1.0.tar.gz"

    shared_script.pip(
        "download",
        "-d",
        str(download_dir),
        "--no-index",
        simple_pkg.as_uri(),
    )

    assert downloaded_path.exists()
    assert simple_pkg.read_bytes() == downloaded_path.read_bytes()


def test_download_file_url_existing_ok_download(
    shared_script: PipTestEnvironment, shared_data: TestData, tmpdir: Path
) -> None:
    download_dir = tmpdir / "download"
    download_dir.mkdir()
    downloaded_path = download_dir / "simple-1.0.tar.gz"
    fake_existing_package = shared_data.packages / "simple-2.0.tar.gz"
    shutil.copy(str(fake_existing_package), str(downloaded_path))
    downloaded_path_bytes = downloaded_path.read_bytes()

    simple_pkg = shared_data.packages / "simple-1.0.tar.gz"
    url = f"{simple_pkg.as_uri()}#sha256={sha256(downloaded_path_bytes).hexdigest()}"

    shared_script.pip("download", "-d", str(download_dir), url)

    assert downloaded_path_bytes == downloaded_path.read_bytes()


def test_download_file_url_existing_bad_download(
    shared_script: PipTestEnvironment, shared_data: TestData, tmpdir: Path
) -> None:
    download_dir = tmpdir / "download"
    download_dir.mkdir()
    downloaded_path = download_dir / "simple-1.0.tar.gz"
    fake_existing_package = shared_data.packages / "simple-2.0.tar.gz"
    shutil.copy(str(fake_existing_package), str(downloaded_path))

    simple_pkg = shared_data.packages / "simple-1.0.tar.gz"
    simple_pkg_bytes = simple_pkg.read_bytes()
    url = f"{simple_pkg.as_uri()}#sha256={sha256(simple_pkg_bytes).hexdigest()}"

    result = shared_script.pip(
        "download",
        "-d",
        str(download_dir),
        url,
        allow_stderr_warning=True,  # bad hash
    )

    assert simple_pkg_bytes == downloaded_path.read_bytes()
    assert "WARNING: Previously-downloaded file" in result.stderr
    assert "has bad hash. Re-downloading." in result.stderr


def test_download_http_url_bad_hash(
    shared_script: PipTestEnvironment,
    shared_data: TestData,
    tmpdir: Path,
    mock_server: MockServer,
) -> None:
    """
    If already-downloaded file has bad checksum, re-download.
    """
    download_dir = tmpdir / "download"
    download_dir.mkdir()
    downloaded_path = download_dir / "simple-1.0.tar.gz"
    fake_existing_package = shared_data.packages / "simple-2.0.tar.gz"
    shutil.copy(str(fake_existing_package), str(downloaded_path))

    simple_pkg = shared_data.packages / "simple-1.0.tar.gz"
    simple_pkg_bytes = simple_pkg.read_bytes()
    digest = sha256(simple_pkg_bytes).hexdigest()
    mock_server.set_responses([file_response(simple_pkg)])
    mock_server.start()
    base_address = f"http://{mock_server.host}:{mock_server.port}"
    url = f"{base_address}/simple-1.0.tar.gz#sha256={digest}"

    result = shared_script.pip(
        "download",
        "-d",
        str(download_dir),
        url,
        allow_stderr_warning=True,  # bad hash
    )

    assert simple_pkg_bytes == downloaded_path.read_bytes()
    assert "WARNING: Previously-downloaded file" in result.stderr
    assert "has bad hash. Re-downloading." in result.stderr

    mock_server.stop()
    requests = mock_server.get_requests()
    assert len(requests) == 1
    assert requests[0]["PATH_INFO"] == "/simple-1.0.tar.gz"
    assert requests[0]["HTTP_ACCEPT_ENCODING"] == "identity"


def test_download_editable(
    script: PipTestEnvironment, data: TestData, tmpdir: Path
) -> None:
    """
    Test 'pip download' of editables in requirement file.
    """
    editable_path = str(data.src / "simplewheel-1.0").replace(os.path.sep, "/")
    requirements_path = tmpdir / "requirements.txt"
    requirements_path.write_text("-e " + editable_path + "\n")
    download_dir = tmpdir / "download_dir"
    script.pip(
        "download", "--no-deps", "-r", str(requirements_path), "-d", str(download_dir)
    )
    downloads = os.listdir(download_dir)
    assert len(downloads) == 1
    assert downloads[0].endswith(".zip")


def test_download_use_pep517_propagation(
    script: PipTestEnvironment, tmpdir: Path, common_wheels: Path
) -> None:
    """
    Check that --use-pep517 applies not just to the requirements specified
    on the command line, but to their dependencies too.
    """

    create_basic_sdist_for_package(script, "fake_proj", "1.0", depends=["fake_dep"])

    # If --use-pep517 is in effect, then setup.py should be running in an isolated
    # environment that doesn't have pip in it.
    create_basic_sdist_for_package(
        script,
        "fake_dep",
        "1.0",
        setup_py_prelude=textwrap.dedent(
            """\
            try:
                import pip
            except ImportError:
                pass
            else:
                raise Exception(f"not running in isolation")
            """
        ),
    )

    download_dir = tmpdir / "download_dir"
    script.pip(
        "download",
        f"--dest={download_dir}",
        "--no-index",
        f"--find-links={common_wheels}",
        f"--find-links={script.scratch_path}",
        "--use-pep517",
        "fake_proj",
    )

    downloads = os.listdir(download_dir)
    assert len(downloads) == 2


class MetadataKind(Enum):
    """All the types of values we might be provided for the data-dist-info-metadata
    attribute from PEP 658."""

    # Valid: will read metadata from the dist instead.
    No = "none"
    # Valid: will read the .metadata file, but won't check its hash.
    Unhashed = "unhashed"
    # Valid: will read the .metadata file and check its hash matches.
    Sha256 = "sha256"
    # Invalid: will error out after checking the hash.
    WrongHash = "wrong-hash"
    # Invalid: will error out after failing to fetch the .metadata file.
    NoFile = "no-file"


@dataclass(frozen=True)
class Package:
    """Mock package structure used to generate a PyPI repository.

    Package name and version should correspond to sdists (.tar.gz files) in our test
    data."""

    name: str
    version: str
    filename: str
    metadata: MetadataKind
    # This will override any dependencies specified in the actual dist's METADATA.
    requires_dist: Tuple[str, ...] = ()

    def metadata_filename(self) -> str:
        """This is specified by PEP 658."""
        return f"{self.filename}.metadata"

    def generate_additional_tag(self) -> str:
        """This gets injected into the <a> tag in the generated PyPI index page for this
        package."""
        if self.metadata == MetadataKind.No:
            return ""
        if self.metadata in [MetadataKind.Unhashed, MetadataKind.NoFile]:
            return 'data-dist-info-metadata="true"'
        if self.metadata == MetadataKind.WrongHash:
            return 'data-dist-info-metadata="sha256=WRONG-HASH"'
        assert self.metadata == MetadataKind.Sha256
        checksum = sha256(self.generate_metadata()).hexdigest()
        return f'data-dist-info-metadata="sha256={checksum}"'

    def requires_str(self) -> str:
        if not self.requires_dist:
            return ""
        joined = " and ".join(self.requires_dist)
        return f"Requires-Dist: {joined}"

    def generate_metadata(self) -> bytes:
        """This is written to `self.metadata_filename()` and will override the actual
        dist's METADATA, unless `self.metadata == MetadataKind.NoFile`."""
        return dedent(
            f"""\
        Metadata-Version: 2.1
        Name: {self.name}
        Version: {self.version}
        {self.requires_str()}
        """
        ).encode("utf-8")


@pytest.fixture(scope="function")
def write_index_html_content(tmpdir: Path) -> Callable[[str], Path]:
    """Generate a PyPI package index.html within a temporary local directory."""
    html_dir = tmpdir / "index_html_content"
    html_dir.mkdir()

    def generate_index_html_subdir(index_html: str) -> Path:
        """Create a new subdirectory after a UUID and write an index.html."""
        new_subdir = html_dir / uuid.uuid4().hex
        new_subdir.mkdir()

        with open(new_subdir / "index.html", "w") as f:
            f.write(index_html)

        return new_subdir

    return generate_index_html_subdir


@pytest.fixture(scope="function")
def html_index_for_packages(
    shared_data: TestData,
    write_index_html_content: Callable[[str], Path],
) -> Callable[..., Path]:
    """Generate a PyPI HTML package index within a local directory pointing to
    blank data."""

    def generate_html_index_for_packages(packages: Dict[str, List[Package]]) -> Path:
        """
        Produce a PyPI directory structure pointing to the specified packages.
        """
        # (1) Generate the content for a PyPI index.html.
        pkg_links = "\n".join(
            f'    <a href="{pkg}/index.html">{pkg}</a>' for pkg in packages.keys()
        )
        index_html = f"""\
<!DOCTYPE html>
<html>
  <head>
    <meta name="pypi:repository-version" content="1.0">
    <title>Simple index</title>
  </head>
  <body>
{pkg_links}
  </body>
</html>"""
        # (2) Generate the index.html in a new subdirectory of the temp directory.
        index_html_subdir = write_index_html_content(index_html)

        # (3) Generate subdirectories for individual packages, each with their own
        # index.html.
        for pkg, links in packages.items():
            pkg_subdir = index_html_subdir / pkg
            pkg_subdir.mkdir()

            download_links: List[str] = []
            for package_link in links:
                # (3.1) Generate the <a> tag which pip can crawl pointing to this
                # specific package version.
                download_links.append(
                    f'    <a href="{package_link.filename}" {package_link.generate_additional_tag()}>{package_link.filename}</a><br/>'  # noqa: E501
                )
                # (3.2) Copy over the corresponding file in `shared_data.packages`.
                shutil.copy(
                    shared_data.packages / package_link.filename,
                    pkg_subdir / package_link.filename,
                )
                # (3.3) Write a metadata file, if applicable.
                if package_link.metadata != MetadataKind.NoFile:
                    with open(pkg_subdir / package_link.metadata_filename(), "wb") as f:
                        f.write(package_link.generate_metadata())

            # (3.4) After collating all the download links and copying over the files,
            # write an index.html with the generated download links for each
            # copied file for this specific package name.
            download_links_str = "\n".join(download_links)
            pkg_index_content = f"""\
<!DOCTYPE html>
<html>
  <head>
    <meta name="pypi:repository-version" content="1.0">
    <title>Links for {pkg}</title>
  </head>
  <body>
    <h1>Links for {pkg}</h1>
{download_links_str}
  </body>
</html>"""
            with open(pkg_subdir / "index.html", "w") as f:
                f.write(pkg_index_content)

        return index_html_subdir

    return generate_html_index_for_packages


@pytest.fixture(scope="function")
def download_generated_html_index(
    script: PipTestEnvironment,
    html_index_for_packages: Callable[[Dict[str, List[Package]]], Path],
    tmpdir: Path,
) -> Callable[..., Tuple[TestPipResult, Path]]:
    """Execute `pip download` against a generated PyPI index."""
    download_dir = tmpdir / "download_dir"

    def run_for_generated_index(
        packages: Dict[str, List[Package]],
        args: List[str],
        allow_error: bool = False,
    ) -> Tuple[TestPipResult, Path]:
        """
        Produce a PyPI directory structure pointing to the specified packages, then
        execute `pip download -i ...` pointing to our generated index.
        """
        index_dir = html_index_for_packages(packages)
        pip_args = [
            "download",
            "-d",
            str(download_dir),
            "-i",
            path_to_url(str(index_dir)),
            *args,
        ]
        result = script.pip(*pip_args, allow_error=allow_error)
        return (result, download_dir)

    return run_for_generated_index


# The package database we generate for testing PEP 658 support.
_simple_packages: Dict[str, List[Package]] = {
    "simple": [
        Package("simple", "1.0", "simple-1.0.tar.gz", MetadataKind.Sha256),
        Package("simple", "2.0", "simple-2.0.tar.gz", MetadataKind.No),
        # This will raise a hashing error.
        Package("simple", "3.0", "simple-3.0.tar.gz", MetadataKind.WrongHash),
    ],
    "simple2": [
        # Override the dependencies here in order to force pip to download
        # simple-1.0.tar.gz as well.
        Package(
            "simple2",
            "1.0",
            "simple2-1.0.tar.gz",
            MetadataKind.Unhashed,
            ("simple==1.0",),
        ),
        # This will raise an error when pip attempts to fetch the metadata file.
        Package("simple2", "2.0", "simple2-2.0.tar.gz", MetadataKind.NoFile),
    ],
    "colander": [
        # Ensure we can read the dependencies from a metadata file within a wheel
        # *without* PEP 658 metadata.
        Package(
            "colander", "0.9.9", "colander-0.9.9-py2.py3-none-any.whl", MetadataKind.No
        ),
    ],
    "compilewheel": [
        # Ensure we can override the dependencies of a wheel file by injecting PEP
        # 658 metadata.
        Package(
            "compilewheel",
            "1.0",
            "compilewheel-1.0-py2.py3-none-any.whl",
            MetadataKind.Unhashed,
            ("simple==1.0",),
        ),
    ],
    "has-script": [
        # Ensure we check PEP 658 metadata hashing errors for wheel files.
        Package(
            "has-script",
            "1.0",
            "has.script-1.0-py2.py3-none-any.whl",
            MetadataKind.WrongHash,
        ),
    ],
    "translationstring": [
        Package(
            "translationstring", "1.1", "translationstring-1.1.tar.gz", MetadataKind.No
        ),
    ],
    "priority": [
        # Ensure we check for a missing metadata file for wheels.
        Package(
            "priority", "1.0", "priority-1.0-py2.py3-none-any.whl", MetadataKind.NoFile
        ),
    ],
}


@pytest.mark.parametrize(
    "requirement_to_download, expected_outputs",
    [
        ("simple2==1.0", ["simple-1.0.tar.gz", "simple2-1.0.tar.gz"]),
        ("simple==2.0", ["simple-2.0.tar.gz"]),
        (
            "colander",
            ["colander-0.9.9-py2.py3-none-any.whl", "translationstring-1.1.tar.gz"],
        ),
        (
            "compilewheel",
            ["compilewheel-1.0-py2.py3-none-any.whl", "simple-1.0.tar.gz"],
        ),
    ],
)
def test_download_metadata(
    download_generated_html_index: Callable[..., Tuple[TestPipResult, Path]],
    requirement_to_download: str,
    expected_outputs: List[str],
) -> None:
    """Verify that if a data-dist-info-metadata attribute is present, then it is used
    instead of the actual dist's METADATA."""
    _, download_dir = download_generated_html_index(
        _simple_packages,
        [requirement_to_download],
    )
    assert sorted(os.listdir(download_dir)) == expected_outputs


@pytest.mark.parametrize(
    "requirement_to_download, real_hash",
    [
        (
            "simple==3.0",
            "95e0f200b6302989bcf2cead9465cf229168295ea330ca30d1ffeab5c0fed996",
        ),
        (
            "has-script",
            "16ba92d7f6f992f6de5ecb7d58c914675cf21f57f8e674fb29dcb4f4c9507e5b",
        ),
    ],
)
def test_incorrect_metadata_hash(
    download_generated_html_index: Callable[..., Tuple[TestPipResult, Path]],
    requirement_to_download: str,
    real_hash: str,
) -> None:
    """Verify that if a hash for data-dist-info-metadata is provided, it must match the
    actual hash of the metadata file."""
    result, _ = download_generated_html_index(
        _simple_packages,
        [requirement_to_download],
        allow_error=True,
    )
    assert result.returncode != 0
    expected_msg = f"""\
        Expected sha256 WRONG-HASH
             Got        {real_hash}"""
    assert expected_msg in result.stderr


@pytest.mark.parametrize(
    "requirement_to_download, expected_url",
    [
        ("simple2==2.0", "simple2-2.0.tar.gz.metadata"),
        ("priority", "priority-1.0-py2.py3-none-any.whl.metadata"),
    ],
)
def test_metadata_not_found(
    download_generated_html_index: Callable[..., Tuple[TestPipResult, Path]],
    requirement_to_download: str,
    expected_url: str,
) -> None:
    """Verify that if a data-dist-info-metadata attribute is provided, that pip will
    fetch the .metadata file at the location specified by PEP 658, and error
    if unavailable."""
    result, _ = download_generated_html_index(
        _simple_packages,
        [requirement_to_download],
        allow_error=True,
    )
    assert result.returncode != 0
    expected_re = re.escape(expected_url)
    pattern = re.compile(
        f"ERROR: 404 Client Error: FileNotFoundError for url:.*{expected_re}"
    )
    assert pattern.search(result.stderr), (pattern, result.stderr)