import fnmatch
import subprocess
import shutil
import zipfile
import tarfile
import stat
from ast import Not
from packaging import tags
from packaging.specifiers import SpecifierSet
from packaging.version import Version, parse, InvalidVersion
from packaging.requirements import Requirement
import io

from ci_tools.variables import discover_repo_root, DEV_BUILD_IDENTIFIER, str_to_bool
from ci_tools.parsing import ParsedSetup, get_config_setting, get_pyproject
from pypi_tools.pypi import PyPIClient
from ci_tools.logging import logger

# Re-export venv/pip helpers from their new home so existing imports keep working.
from ci_tools.venv import (  # noqa: F401
    get_venv_call,
    get_pip_command,
    get_venv_python,
    install_into_venv,
    uninstall_from_venv,
    pip_install,
    pip_uninstall,
    pip_install_requirements_file,
    run_pip_freeze,
    get_pip_list_output,
)

import os, sys, platform, glob, re, logging
from typing import List, Any, Optional, Tuple

INACTIVE_CLASSIFIER = "Development Status :: 7 - Inactive"

MANAGEMENT_PACKAGE_IDENTIFIERS = [
    "mgmt",
    "nspkg",
    "azure-cognitiveservices",
    "azure-servicefabric",
    "azure-keyvault",
    "azure-synapse",
    "azure-ai-anomalydetector",
]

NO_TESTS_ALLOWED = []


META_PACKAGES = ["azure", "azure-mgmt", "azure-keyvault"]

REGRESSION_EXCLUDED_PACKAGES = [
    "azure-common",
]

MANAGEMENT_PACKAGES_FILTER_EXCLUSIONS = [
    "azure-mgmt-core",
]

# In very rare situations, we need to actively transition a package from one part of the code base to another
# in a multi-stage process. For example, migrating "azure-ai-textanalytics" from "sdk/textanalytics" to "sdk/ai".
# Both need to simultaneously exist for a short period of time, but we need to prevent discovery of the package
# so that downstream checks aren't broken by this.
# We need to actively prevent ourselves from discovering the package in its old location. To do that we:
#  - Add the path to this list, any entrypoints that use discover_targeted_packages should exclude these paths
#  - This will also affect usage of get_package_properties.py (Save-Package-Properties stage of CI), so please be aware of this!
PATHS_EXCLUDED_FROM_DISCOVERY = []

TEST_COMPATIBILITY_MAP = {"azure-ai-ml": ">=3.7"}
TEST_PYTHON_DISTRO_INCOMPATIBILITY_MAP = {
    "azure-storage-blob": "pypy",
    "azure-storage-queue": "pypy",
    "azure-storage-file-datalake": "pypy",
    "azure-storage-file-share": "pypy",
    "azure-eventhub": "pypy",
    "azure-servicebus": "pypy",
    "azure-ai-projects": "pypy",
    "azure-ai-agents": "pypy",
    "azure-identity-broker": "pypy",
}

omit_regression = (
    lambda x: "nspkg" not in x
    and "mgmt" not in x
    and os.path.basename(x) not in MANAGEMENT_PACKAGE_IDENTIFIERS
    and os.path.basename(x) not in META_PACKAGES
    and str_to_bool(get_config_setting(x, "regression", True))
)

omit_docs = lambda x: "nspkg" not in x and os.path.basename(x) not in META_PACKAGES
omit_build = lambda x: x  # Dummy lambda to match omit type
lambda_filter_azure_pkg = lambda x: x.startswith("azure") and "-nspkg" not in x
omit_mgmt = lambda x: "mgmt" not in x or os.path.basename(x) in MANAGEMENT_PACKAGES_FILTER_EXCLUSIONS


# dict of filter type and filter function
omit_function_dict = {
    "Build": omit_build,
    "Docs": omit_docs,
    "Regression": omit_regression,
    "Omit_management": omit_mgmt,
}


def unzip_file_to_directory(path_to_zip_file: str, extract_location: str) -> str:
    """
    Unzips a zip or tar.gz file to a given location.

    :param path_to_zip_file: The path to the zip or tar.gz file.
    :param extract_location: The directory where the contents will be extracted.
    :return: The path to the directory where the archive was extracted.
    """
    if path_to_zip_file.endswith(".zip"):
        with zipfile.ZipFile(path_to_zip_file, "r") as zip_ref:
            zip_ref.extractall(extract_location)
            extracted_dir = os.path.basename(os.path.splitext(path_to_zip_file)[0])
            return os.path.join(extract_location, extracted_dir)
    else:
        with tarfile.open(path_to_zip_file) as tar_ref:
            tar_ref.extractall(extract_location)
            extracted_dir = os.path.basename(path_to_zip_file).replace(".tar.gz", "")
            return os.path.join(extract_location, extracted_dir)


def apply_compatibility_filter(package_set: List[ParsedSetup]) -> List[ParsedSetup]:
    """
    This function takes in a set of paths to python packages. It returns the set filtered by compatibility with the currently running python executable.
    If a package is unsupported by the executable, it will be omitted from the returned list.

    A manual override list of these compatibilities is also supported, but requires code change to enable. Check TEST_COMPATIBILITY_MAP in this same file.

    :param List[str] package_set: a list of paths to python packages. Each item can either be a package folder or a direct path to setup.py.
    """
    collected_packages = []
    v = sys.version_info
    running_major_version = Version(".".join([str(v[0]), str(v[1]), str(v[2])]))

    for pkg in package_set:
        spec_set = SpecifierSet(pkg.python_requires)

        pkg_specs_override = TEST_COMPATIBILITY_MAP.get(pkg.name, None)

        if pkg_specs_override:
            spec_set = SpecifierSet(pkg_specs_override)

        distro_compat = True
        distro_incompat = TEST_PYTHON_DISTRO_INCOMPATIBILITY_MAP.get(pkg.name, None)
        if distro_incompat and distro_incompat in platform.python_implementation().lower():
            distro_compat = False

        if running_major_version in spec_set and distro_compat:
            collected_packages.append(pkg)

    logging.debug(
        "Package(s) omitted by compatibility filter: {}".format(
            generate_difference([origpkg.name for origpkg in package_set], [pkg.name for pkg in collected_packages])
        )
    )

    return collected_packages


def compare_python_version(version_spec: str) -> bool:
    """
    Compares the current running platform version of python against a version spec. Sanitizes
    the running platform version to just the major version.
    """
    platform_version = platform.python_version()
    parsed_version = re.match(r"[0-9\.]+", platform_version, re.IGNORECASE)

    # we want to be loud if we can't parse out a major version from the version string, not silently
    # fail and skip running samples on a platform we really should be
    if parsed_version is None:
        raise InvalidVersion(f'Unable to parse the platform version. Unparsed value was "{platform_version}".')
    else:
        current_sys_version = parse(parsed_version[0])
        spec_set = SpecifierSet(version_spec)

    return current_sys_version in spec_set


def generate_difference(original_packages: List[str], filtered_packages: List[str]):
    return list(set(original_packages) - set(filtered_packages))


def glob_packages(glob_string: str, target_root_dir: str) -> List[str]:
    if glob_string:
        individual_globs = [glob_string.strip() for glob_string in glob_string.split(",")]
    else:
        individual_globs = "azure-*"
    collected_top_level_directories = []

    for glob_string in individual_globs:
        globbed = glob.glob(os.path.join(target_root_dir, glob_string, "setup.py"), recursive=True) + glob.glob(
            os.path.join(target_root_dir, "sdk/*/", glob_string, "setup.py")
        )
        collected_top_level_directories.extend([os.path.dirname(p) for p in globbed])

    # handle pyproject.toml separately, as we need to filter them by the presence of a `[project]` section
    for glob_string in individual_globs:
        globbed = glob.glob(os.path.join(target_root_dir, glob_string, "pyproject.toml"), recursive=True) + glob.glob(
            os.path.join(target_root_dir, "sdk/*/", glob_string, "pyproject.toml")
        )
        for p in globbed:
            if get_pyproject(os.path.dirname(p)):
                collected_top_level_directories.append(os.path.dirname(p))

    # drop any packages that exist within a tests or test directory
    collected_top_level_directories = [
        p for p in collected_top_level_directories if not any(part in ("test", "tests") for part in p.split(os.sep))
    ]

    # remove any packages that might exist in the PATHS_EXCLUDED_FROM_DISCOVERY path list (relative from repo root)
    excluded = set(PATHS_EXCLUDED_FROM_DISCOVERY)
    filtered = []
    for pkg_path in collected_top_level_directories:
        rel = os.path.relpath(pkg_path, target_root_dir).replace(os.sep, "/")
        if not any(rel == excl or rel.startswith(excl + "/") for excl in excluded):
            filtered.append(pkg_path)
    collected_top_level_directories = filtered

    # deduplicate, in case we have double coverage from the glob strings. Example: "azure-mgmt-keyvault,azure-mgmt-*"
    return list(set(collected_top_level_directories))


def apply_business_filter(collected_packages: List[ParsedSetup], filter_type: str) -> List[ParsedSetup]:
    pkg_set_ci_filtered = []

    for pkg in collected_packages:
        if omit_function_dict.get(filter_type, omit_build)(pkg.folder):
            pkg_set_ci_filtered.append(pkg)

    logging.debug(
        "Package(s) omitted by business filter: {}".format(
            generate_difference([pkg.name for pkg in collected_packages], [pkg.name for pkg in pkg_set_ci_filtered])
        )
    )

    return pkg_set_ci_filtered


def discover_targeted_packages(
    glob_string: str,
    target_root_dir: str,
    additional_contains_filter: str = "",
    filter_type: str = "Build",
    compatibility_filter: bool = True,
    include_inactive: bool = False,
) -> List[str]:
    """
    During build and test, the set of targeted packages may expand or contract depending on the needs of the invocation.
    This function centralizes business and material requirements and outputs the set of packages that should be targeted.

    :param str glob_string: The basic glob used to query packages within the repo. Defaults to "azure-*"
    :param str target_root_dir: The root directory in which globbing will begin.
    :param str additional_contains_filter: Additional filter option.
        Used when needing to provide one-off filtration that doesn't merit an additional filter_type. Defaults to empty string.
    :param str filter_type: One a string representing a filter function as a set of options.
        Options [ "Build", "Docs", "Regression", "Omit_management" ] Defaults to "Build".
    :param bool compatibility_filter: Enables or disables compatibility filtering of found packages.
        If the invoking python executable does not match a found package's specifiers, the package will be omitted.
        Defaults to True.
    """

    # glob the starting package set
    collected_packages = glob_packages(glob_string, target_root_dir)
    logger.debug(
        f'Results for glob_string "{glob_string}" and root directory "{target_root_dir}" are: {collected_packages}'
    )

    # apply the additional contains filter (purely string based)
    collected_packages = [pkg for pkg in collected_packages if additional_contains_filter in pkg]
    logger.debug(f'Results after additional contains filter: "{additional_contains_filter}" {collected_packages}')

    # now the have the initial package set, we need to walk the set and attempt to parse_setup each package
    # this will have the impact of cleaning out any packages that have been set to not buildable anymore (EG namespace packages)
    parsed_packages = []
    for pkg in collected_packages:
        try:
            parsed_packages.append(ParsedSetup.from_path(pkg))
        except RuntimeError as e:
            logging.error(f"Unable to parse metadata for package {pkg}, omitting from build.")
            continue

    # filter for compatibility, this means excluding a package that doesn't support py36 when we are running a py36 executable
    if compatibility_filter:
        parsed_packages = apply_compatibility_filter(parsed_packages)
        logger.debug(f"Results after compatibility filter: {','.join([p.name for p in parsed_packages])}")

    if not include_inactive:
        parsed_packages = apply_inactive_filter(parsed_packages)

    # Apply filter based on filter type. for e.g. Docs, Regression, Management
    parsed_packages = apply_business_filter(parsed_packages, filter_type)
    logger.debug(f"Results after business filter: {[pkg.name for pkg in parsed_packages]}")

    return sorted([pkg.folder for pkg in parsed_packages])


def is_package_active(pkg: ParsedSetup) -> bool:
    disabled = INACTIVE_CLASSIFIER in pkg.classifiers

    override_value = os.getenv(f"ENABLE_{pkg.name.upper().replace('-', '_')}", None)

    if override_value:
        return str_to_bool(override_value)
    else:
        return not disabled


def apply_inactive_filter(collected_packages: List[ParsedSetup]) -> List[ParsedSetup]:
    packages = [pkg for pkg in collected_packages if is_package_active(pkg)]

    logging.debug(
        "Package(s) omitted by inactive filter: {}".format(
            generate_difference([collected.name for collected in collected_packages], [pkg.name for pkg in packages])
        )
    )

    return packages


def update_requires(setup_path, requires_dict):
    # This method changes package requirement by overriding the specifier
    contents = []
    with open(setup_path, "r") as setup_file:
        contents = setup_file.readlines()

    # find and replace all existing package requirement with new requirement
    for i in range(0, len(contents) - 1):
        keys = [k for k in requires_dict.keys() if k in contents[i]]
        for key in keys:
            contents[i] = contents[i].replace(key, requires_dict[key])

    with open(setup_path, "w") as setup_file:
        setup_file.writelines(contents)


def is_required_version_on_pypi(package_name, spec):
    client = PyPIClient()
    try:
        pypi_results = client.get_ordered_versions(package_name)
    except:
        pypi_results = []

    versions = [str(v) for v in pypi_results if str(v) in spec]
    return versions


def get_package_from_repo(pkg_name: str, repo_root: Optional[str] = None) -> Optional[ParsedSetup]:
    root_dir = discover_repo_root(repo_root)

    paths = discover_targeted_packages(pkg_name, root_dir, filter_type="Build", include_inactive=True)

    if len(paths) >= 2:
        raise RuntimeError(
            f"Multiple packages found for {pkg_name} within {root_dir}, please specify a more specific glob."
        )

    if paths and len(paths) == 1:
        return ParsedSetup.from_path(paths[0])

    raise RuntimeError(f"Package {pkg_name} not found in repo {root_dir}.")


def get_package_from_repo_or_folder(req: str, prebuilt_wheel_dir: Optional[str] = None) -> Optional[str]:
    """Takes a package name and a possible prebuilt wheel directory. Attempts to resolve a wheel that matches the package name, and if it can't,
    attempts to find the package within the repo to install directly from path on disk.

    During a CI build, it is preferred that the package is installed from a prebuilt wheel directory, as multiple CI environments attempting to install the relative
    req can cause inconsistent installation issues during parallel tox environment execution.
    """

    local_package = get_package_from_repo(req)

    if prebuilt_wheel_dir and os.path.exists(prebuilt_wheel_dir) and local_package:
        prebuilt_package = discover_prebuilt_package(prebuilt_wheel_dir, local_package.setup_filename, "wheel")
        if prebuilt_package:
            # return the first package found, there should only be a single one matching given that our prebuilt wheel directory
            # is populated by the replacement of dev_reqs.txt with the prebuilt wheels
            # ref tox_harness replace_dev_reqs() calls
            return os.path.join(prebuilt_wheel_dir, prebuilt_package[0])

    if local_package:
        return local_package.folder
    else:
        return None


def get_version_from_repo(pkg_name: str, repo_root: Optional[str] = None) -> str:
    pkg_info = get_package_from_repo(pkg_name, repo_root)
    if pkg_info:
        # Remove dev build part if version for this package is already updated to dev build
        # When building package with dev build version, version for packages in same service is updated to dev build
        # and other packages will not have dev build number
        # strip dev build number so we can check if package exists in PyPI and replace
        version_obj = Version(pkg_info.version)
        if version_obj.pre:
            if version_obj.pre[0] == DEV_BUILD_IDENTIFIER:
                return version_obj.base_version
        return str(version_obj)
    else:
        raise RuntimeError(f"setup.py is not found for package {pkg_name} to identify current version")


def get_base_version(pkg_name: str) -> str:
    root_dir = discover_repo_root()

    parsed_setup = get_package_from_repo(pkg_name, root_dir)

    if parsed_setup:
        version_obj = Version(parsed_setup.version)
        return version_obj.base_version
    else:
        raise RuntimeError("setup.py is not found for package {} to identify current version".format(pkg_name))


def process_requires(setup_py_path: str, is_dev_build: bool = False):
    """
    This method processes a setup.py's package requirements to verify if all required packages are available on PyPI.
    If any azure sdk package is not available on PyPI then requirement will be updated to refer to the sdk "dev_identifier".

    Examples:
    azure-storage-blob >= 1.0.1b1
    <there is no azure-storage-blob with any 1.0.1 patch version>
    update to require 1.0.1a1 to allow previously published dev versions to be allowed.
    """

    pkg_details = ParsedSetup.from_path(setup_py_path)
    azure_requirements = [Requirement(r) for r in pkg_details.requires if r.startswith("azure")]

    # Find package requirements that are not available on PyPI
    requirement_to_update = {}
    for req in azure_requirements:
        pkg_name = req.name
        spec = SpecifierSet(str(req).replace(pkg_name, ""))

        if not is_required_version_on_pypi(pkg_name, spec) or is_dev_build:
            old_req = str(req)
            version = get_version_from_repo(pkg_name)
            base_version = get_base_version(pkg_name)
            logging.info("Updating version {0} in requirement {1} to dev build version".format(version, old_req))
            #       {} =             <must have a base version>
            #       (                <optionally, we have a prerelease version>
            #        (               <we must have 0 or 1 prerelease versions>
            #            (a|b|rc)    <we must have a prelease identifier>
            #            \d+         <followed by a number of digits N>
            #        )?
            #        (               <optionally, we have a postrelease version>
            #            \.post      <which is ".post">
            #            \d+         <followed by number of digits N>
            #        )?
            #       )?
            rx = r"{}(((a|b|rc)\d+)?(\.post\d+)?)?".format(base_version)
            new_req_format = f"{base_version}{DEV_BUILD_IDENTIFIER}1,<{base_version}b0"
            new_req = re.sub(rx, new_req_format, str(req), flags=re.IGNORECASE)
            logging.info("New requirement for package {0}: {1}".format(pkg_name, new_req))
            requirement_to_update[old_req] = new_req

    if not requirement_to_update:
        logging.info("All required packages are available on PyPI")
    else:
        logging.info("Packages not available on PyPI:{}".format(requirement_to_update))
        update_requires(setup_py_path, requirement_to_update)
        logging.info(
            f"Package requirement is updated in {'pyproject.toml' if pkg_details.is_pyproject else 'setup.py'}."
        )


def find_sdist(dist_dir: str, pkg_name: str, pkg_version: str) -> Optional[str]:
    """This function attempts to look within a directory (and all subdirs therein) and find a source distribution for the targeted package and version."""
    # This function will find a sdist for given package name
    if not os.path.exists(dist_dir):
        logging.error("dist_dir is incorrect")
        return

    if pkg_name is None:
        logging.error("Package name cannot be empty to find sdist")
        return
    else:
        # ensure package name matches cananonicalized package name
        pkg_name = pkg_name.replace("-", "[-_]")

    pkg_format = f"{pkg_name}-{pkg_version}.tar.gz"

    packages = []
    for root, dirnames, filenames in os.walk(dist_dir):
        for filename in fnmatch.filter(filenames, pkg_format):
            packages.append(os.path.join(root, filename))

    packages = [os.path.relpath(w, dist_dir) for w in packages]

    if not packages:
        logging.error(f"No sdist is found in directory {dist_dir} with package name format {pkg_format}.")
        return
    return packages[0]


def pytest(args: list, cwd: Optional[str] = None, python_executable: Optional[str] = None) -> bool:
    """
    Invokes a set of tests, returns true if successful, false otherwise.
    """

    exe = python_executable or sys.executable

    commands = [
        exe,
        "-m",
        "pytest",
    ]

    commands.extend(args)

    logging.info(commands)
    if cwd:
        result = subprocess.run(commands, cwd=cwd)
    else:
        result = subprocess.run(commands)

    return result.returncode == 0


def get_interpreter_compatible_tags() -> List[str]:
    """
    This function invokes pip from the invoking interpreter and discovers which tags the interpreter is compatible with.
    """

    return [str(t) for t in tags.sys_tags()]


def check_whl_against_tags(whl_name: str, tags: List[str]) -> bool:
    for tag in tags:
        if tag in whl_name:
            return True
    return False


def find_whl(whl_dir: str, pkg_name: str, pkg_version: str) -> Optional[str]:
    """This function attempts to look within a directory (and all subdirs therein) and find a wheel that matches our targeted name and version AND
    whose compilation is compatible with the invoking interpreter."""
    if not os.path.exists(whl_dir):
        logging.error("whl_dir is incorrect")
        return

    if pkg_name is None:
        logging.error("Package name cannot be empty to find whl")
        return

    pkg_name_format = f"{pkg_name.replace('-', '_')}-{pkg_version}*.whl"
    whls = []

    # todo: replace with glob, we aren't using py2 anymore!
    for root, dirnames, filenames in os.walk(whl_dir):
        for filename in fnmatch.filter(filenames, pkg_name_format):
            whls.append(os.path.join(root, filename))

    whls = [os.path.relpath(w, whl_dir) for w in whls]

    if not whls:
        logging.info(f"No whl is found in directory {whl_dir} with package name format {pkg_name_format}")
        logging.info(f"List of whls in directory: {glob.glob(os.path.join(whl_dir, '*.whl'))}")
        return

    compatible_tags = get_interpreter_compatible_tags()

    logging.debug("Dumping visible tags and whls")
    logging.debug(compatible_tags)
    logging.debug(whls)

    if whls:
        # grab the first whl that matches a tag from our compatible_tags list
        for whl in whls:
            if check_whl_against_tags(whl, compatible_tags):
                logging.info(f"Found whl {whl}")
                return whl

        # if whl is platform independent then there should only be one whl in filtered list
        if len(whls) > 1:
            # if we have reached here, that means we have whl specific to platform as well.
            # for now we are failing the test if platform specific wheels are found. Todo: enhance to find platform specific whl
            logging.error(f"We were unable to locate a compatible wheel for {pkg_name}")
            sys.exit(1)

    return None


def error_handler_git_access(func, path, exc):
    """
    This function exists because the git idx file is written with strange permissions that prevent it from being
    deleted. Due to this, we need to register an error handler that attempts to fix the file permissions before
    re-attempting the delete operations.
    """

    if not os.access(path, os.W_OK):
        os.chmod(path, stat.S_IWUSR)
        func(path)
    else:
        raise


def cleanup_directory(target_directory: str) -> None:
    """Invokes a directory delete. Specifically handles the case where bad permissions on a git .idx file
    prevent cleanup of the directory with a generic error.
    """
    if os.path.exists(target_directory):
        shutil.rmtree(target_directory, ignore_errors=False, onerror=error_handler_git_access)


def discover_prebuilt_package(dist_directory: str, setup_path: str, package_type: str) -> List[str]:
    """Discovers a prebuild wheel or sdist for a given setup path."""
    packages = []
    pkg = ParsedSetup.from_path(setup_path)
    if package_type == "wheel":
        prebuilt_package = find_whl(dist_directory, pkg.name, pkg.version)
    else:
        prebuilt_package = find_sdist(dist_directory, pkg.name, pkg.version)

    if prebuilt_package is not None:
        packages.append(prebuilt_package)
    return packages


def is_package_compatible(
    package_name: str,
    package_requirements: List[Requirement],
    immutable_requirements: List[Requirement],
    should_log: bool = True,
) -> bool:
    """
    This function accepts a set of requirements for a package, and ensures that the package is compatible with the
    immutable_requirements.

    It is factored this way because we retrieve requirements differently according to the source of the package.
        If published, we can get requires() from PyPI
        If locally built wheel, we can get requires() from the metadata of the package
        If local relative requirement, we can get requires() from a ParsedSetup of the setup.py for the package

    :param List[Requirement] package_requirements: The dependencies of a dev_requirement file. This is the set of
        requirements that we are checking compatibility for.
    :param List[Requirement] immutable_requirements: A list of requirements that the other packages must be compatible
        with.
    """

    for immutable_requirement in immutable_requirements:
        for package_requirement in package_requirements:
            if package_requirement.name == immutable_requirement.name:
                # if the dev_req line has a requirement that conflicts with the immutable requirement,
                # we need to resolve it. We KNOW that the immutable requirement will be of form package==version,
                # so we can reliably pull out the version and check it against the specifier of the dev_req line.
                try:
                    immutable_version = next(iter(immutable_requirement.specifier)).version
                # we have no specifier set, so we don't even need to check this
                except StopIteration:
                    continue

                if not package_requirement.specifier.contains(immutable_version):
                    if should_log:
                        logging.info(
                            f"Dev req dependency {package_name}'s requirement specifier of {package_requirement}"
                            f"is not compatible with immutable requirement {immutable_requirement}."
                        )
                    return False

    return True


def get_total_coverage(
    coverage_file: str, coverage_config_file: str, package_name: str, repo_root: Optional[str] = None
) -> Optional[float]:
    try:
        import coverage
        from coverage.exceptions import NoDataError
    except ImportError:
        logging.error("Coverage is not installed.")
        return None

    cov = coverage.Coverage(data_file=coverage_file, config_file=coverage_config_file)
    cov.load()
    original = os.getcwd()
    output = io.StringIO()

    old_stdout = sys.stdout
    sys.stdout = output

    report = 0.0
    try:
        if repo_root:
            os.chdir(repo_root)
        logging.info(
            f'Running coverage report against "{coverage_file}" with "{coverage_config_file}" from "{os.getcwd()}".'
        )
        report = cov.report()
    except NoDataError as e:
        logging.info(f"Package {package_name} did not generate any coverage output: {e}")
    except Exception as e:
        logging.error(f"An error occurred while generating the coverage report for {package_name}: {e}")
    finally:
        if repo_root:
            os.chdir(original)
        sys.stdout = old_stdout
        logging.info(f"Total coverage {report} for package {package_name}")
        return report


def resolve_compatible_package(package_name: str, immutable_requirements: List[Requirement]) -> Optional[str]:
    """
    This function attempts to resolve a compatible package version for whatever set of immutable_requirements that
    the package must be compatible with.

    It should only be utilized when a package is found to be incompatible with the immutable_requirements.
    It will attempt to resolve the incompatibility by walking backwards through different versions of <package_name>
    until a compatible version is found that works with the immutable_requirements.
    """

    pypi = PyPIClient()
    immovable_pkgs = {req.name: req for req in immutable_requirements}

    # Let's use a real use-case to walk through this function. We're going to use the azure-ai-language-conversations
    # package as an example.

    # immovable_pkgs = the selected mindependency for azure-ai-language-conversations
    #   -> "azure-core==1.28.0",
    #   -> "isodate==0.6.1",
    #   -> "typing-extensions==4.0.1",
    # we have the following dev_reqs for azure-ai-language-conversations
    #   -> ../azure-sdk-tools
    #   ->  ../azure-identity
    #   -> ../azure-core

    # as we walk each of the dev reqs, we check for compatibility with the immovable_packages.
    # (this happens in is_package_compatible) if the dev req is incompatible, we need to resolve it.
    # THIS function is what resolves it!

    # since we already know that package_name is incompatible with the immovable_pkgs, we need to walk backwards
    # through the versions of package_name checking to ensure that each version is compatible with the immovable_pkgs.
    # if we find one that is, we will return a new requirement string for that package which will replace this dev_req line.
    for pkg in immovable_pkgs:
        required_package = immovable_pkgs[pkg].name
        try:
            required_pkg_version = next(iter(immovable_pkgs[pkg].specifier)).version
        except StopIteration:
            required_pkg_version = None

        versions = pypi.get_ordered_versions(package_name, True)
        versions.reverse()

        # only allow prerelease versions if the dev_req we're targeting is also prerelease
        if required_pkg_version:
            if not Version(required_pkg_version).is_prerelease:
                versions = [v for v in versions if not v.is_prerelease]

        for version in versions:
            version_release = pypi.project_release(package_name, version).get("info", {}).get("requires_dist", [])

            if version_release:
                requirements_for_dev_req = [Requirement(r) for r in version_release]

                compatible = is_package_compatible(
                    required_package, requirements_for_dev_req, immutable_requirements, should_log=False
                )
                if compatible:
                    # we have found a compatible version. We can return this as the new requirement line for the dev_req file.
                    return f"{package_name}=={version}"

    # no changes necessary
    return None


def handle_incompatible_minimum_dev_reqs(
    setup_path: str, filtered_requirement_list: List[str], packages_for_install: List[Requirement]
) -> List[str]:
    """
    This function is used to handle the case where a dev requirement is incompatible with the current set of packages
    being installed. This is used to update or remove dev_requirements that are incompatible with a targeted set of
        packages.

    :param str setup_path: The path to the setup.py file whose dev_requirements are being filtered.

    :param List[str] filtered_requirement_list: A filtered copy of the dev_requirements.txt for the targeted package.
        This list will be
    modified in place to remove any requirements incompatible with the packages_for_install.

    :param List[Requirement] packages_for_install: A list of packages that dev_requirements MUST be compatible with.
    """

    cleansed_reqs = []

    for dev_requirement_line in filtered_requirement_list:
        cleansed_dev_requirement_line = dev_requirement_line.strip().replace("-e ", "").split("#")[0].split(";")[0]

        if cleansed_dev_requirement_line:
            dev_req_package = None
            dev_req_version = None
            requirements_for_dev_req = []

            # this is a locally built wheel file, ise pkginfo to get the metadata
            if os.path.exists(cleansed_dev_requirement_line) and os.path.isfile(cleansed_dev_requirement_line):
                logging.info(
                    f"We are processing a replaced relative requirement built into a wheel: {cleansed_dev_requirement_line}"
                )
                import pkginfo

                try:
                    local_package_metadata = pkginfo.get_metadata(cleansed_dev_requirement_line)
                    if local_package_metadata:
                        dev_req_package = local_package_metadata.name
                        dev_req_version = local_package_metadata.version
                        requirements_for_dev_req = [Requirement(r) for r in local_package_metadata.requires_dist]
                    else:
                        logging.error(
                            f"Error while processing locally built requirement {cleansed_dev_requirement_line}. Unable to resolve metadata."
                        )
                        cleansed_reqs.append(cleansed_dev_requirement_line)
                except Exception as e:
                    logging.error(
                        f"Unable to determine metadata for locally built requirement {cleansed_dev_requirement_line}: {e}"
                    )
                    cleansed_reqs.append(cleansed_dev_requirement_line)
                    continue

            # this is a relative requirement to a package path in the repo, use our ParsedSetup class to get data from setup.py or pyproject.toml
            elif cleansed_dev_requirement_line.startswith("."):
                logging.info(f"We are processing a relative requirement: {cleansed_dev_requirement_line}")
                try:
                    local_package = ParsedSetup.from_path(os.path.join(setup_path, cleansed_dev_requirement_line))

                    if local_package:
                        dev_req_package = local_package.name
                        dev_req_version = local_package.version
                        requirements_for_dev_req = [Requirement(r) for r in local_package.requires]
                    else:
                        logging.error(
                            f"Error while processing relative requirement {cleansed_dev_requirement_line}. Unable to resolve metadata."
                        )
                        cleansed_reqs.append(cleansed_dev_requirement_line)

                except Exception as e:
                    logging.error(
                        f'Unable to determine metadata for relative requirement "{cleansed_dev_requirement_line}", not modifying: {e}'
                    )
                    cleansed_reqs.append(cleansed_dev_requirement_line)
                    continue
            # If we got here, this has to be a standard requirement, attempt to parse it as a specifier and if unable to do so,
            # simply add it to the list as a last fallback. we will log so that we can implement a fix for the edge case later.
            else:
                logging.info(f"We are processing a standard requirement: {cleansed_dev_requirement_line}")
                cleansed_reqs.append(dev_requirement_line)

            # we understand how to parse it, so we should handle it
            if dev_req_package:
                if not is_package_compatible(dev_req_package, requirements_for_dev_req, packages_for_install):
                    new_req = resolve_compatible_package(dev_req_package, packages_for_install)

                    if new_req:
                        cleansed_reqs.append(new_req)
                    else:
                        logging.error(
                            f'Found incompatible dev requirement {dev_req_package}, but unable to locate a compatible version. Not modifying the line: "{dev_requirement_line}".'
                        )
                        cleansed_reqs.append(cleansed_dev_requirement_line)
                else:
                    cleansed_reqs.append(cleansed_dev_requirement_line)

    return cleansed_reqs


def verify_package_classifiers(
    package_name: str, package_version: str, package_classifiers: List[str]
) -> Tuple[bool, Optional[str]]:
    """
    Verify that the package classifiers match the expected classifiers.
    :param str package_name: The name of the package being verified. Used for detail in the error response.
    :param str package_version: The version of the package being verified.
    :param List[str] package_classifiers: The classifiers of the package being verified.
    :returns: A tuple, (x, y), where x is whether the package version matches its classifiers, and y is an error message or None.
    """

    dev_status = parse(package_version)

    # gather all development‐status classifiers
    dev_classifiers = [c for c in package_classifiers if c.startswith("Development Status ::")]

    # beta releases: enforce that only development status 4 is present
    if dev_status.is_prerelease:
        for c in dev_classifiers:
            if "4 - Beta" not in c:
                return (
                    False,
                    f"{package_name} has version {package_version} and is a beta release, but has development status '{c}'. Expected 'Development Status :: 4 - Beta' ONLY.",
                )
        return True, None

    # ga releases: all development statuses must be >= 5
    for c in dev_classifiers:
        try:
            # "Development Status :: 5 - Production/Stable"
            # or Development Status :: 6 - Mature
            # or Development Status :: 7 - Inactive
            num = int(c.split("::")[1].split("-")[0].strip())
        except (IndexError, ValueError):
            return (
                False,
                f"{package_name} has version {package_version} and is a GA release, but failed to pull a status number from status '{c}'. Expecting format identical to 'Development Status :: 5 - Production/Stable'.",
            )
        if num < 5:
            return (
                False,
                f"{package_name} has version {package_version} and is a GA release, but had development status '{c}'. Expecting a development classifier that is equal or greater than 'Development Status :: 5 - Production/Stable'.",
            )
    return True, None


def is_error_code_5_allowed(target_pkg: str, pkg_name: str):
    """
    Determine if error code 5 (no pytests run) is allowed for the given package.
    """
    if (
        all(
            map(
                lambda x: any([pkg_id in x for pkg_id in MANAGEMENT_PACKAGE_IDENTIFIERS]),
                [target_pkg],
            )
        )
        or pkg_name in MANAGEMENT_PACKAGE_IDENTIFIERS
        or pkg_name in NO_TESTS_ALLOWED
    ):
        return True
    else:
        return False
