"""
Support for installing and building the "wheel" binary package format.
"""
from __future__ import absolute_import

import collections
import compileall
import csv
import hashlib
import logging
import os.path
import re
import shutil
import stat
import sys
import warnings
from base64 import urlsafe_b64encode
from email.parser import Parser

from pip._vendor import pkg_resources
from pip._vendor.distlib.scripts import ScriptMaker
from pip._vendor.packaging.utils import canonicalize_name
from pip._vendor.six import StringIO

from pip._internal import pep425tags
from pip._internal.download import path_to_url, unpack_url
from pip._internal.exceptions import (
    InstallationError, InvalidWheelFilename, UnsupportedWheel,
)
from pip._internal.locations import (
    PIP_DELETE_MARKER_FILENAME, distutils_scheme,
)
from pip._internal.utils.logging import indent_log
from pip._internal.utils.misc import (
    call_subprocess, captured_stdout, ensure_dir, read_chunks,
)
from pip._internal.utils.setuptools_build import SETUPTOOLS_SHIM
from pip._internal.utils.temp_dir import TempDirectory
from pip._internal.utils.typing import MYPY_CHECK_RUNNING
from pip._internal.utils.ui import open_spinner

if MYPY_CHECK_RUNNING:
    from typing import Dict, List, Optional  # noqa: F401

wheel_ext = '.whl'

VERSION_COMPATIBLE = (1, 0)


logger = logging.getLogger(__name__)


def rehash(path, blocksize=1 << 20):
    """Return (hash, length) for path using hashlib.sha256()"""
    h = hashlib.sha256()
    length = 0
    with open(path, 'rb') as f:
        for block in read_chunks(f, size=blocksize):
            length += len(block)
            h.update(block)
    digest = 'sha256=' + urlsafe_b64encode(
        h.digest()
    ).decode('latin1').rstrip('=')
    return (digest, length)


def open_for_csv(name, mode):
    if sys.version_info[0] < 3:
        nl = {}
        bin = 'b'
    else:
        nl = {'newline': ''}
        bin = ''
    return open(name, mode + bin, **nl)


def fix_script(path):
    """Replace #!python with #!/path/to/python
    Return True if file was changed."""
    # XXX RECORD hashes will need to be updated
    if os.path.isfile(path):
        with open(path, 'rb') as script:
            firstline = script.readline()
            if not firstline.startswith(b'#!python'):
                return False
            exename = sys.executable.encode(sys.getfilesystemencoding())
            firstline = b'#!' + exename + os.linesep.encode("ascii")
            rest = script.read()
        with open(path, 'wb') as script:
            script.write(firstline)
            script.write(rest)
        return True


dist_info_re = re.compile(r"""^(?P<namever>(?P<name>.+?)(-(?P<ver>.+?))?)
                                \.dist-info$""", re.VERBOSE)


def root_is_purelib(name, wheeldir):
    """
    Return True if the extracted wheel in wheeldir should go into purelib.
    """
    name_folded = name.replace("-", "_")
    for item in os.listdir(wheeldir):
        match = dist_info_re.match(item)
        if match and match.group('name') == name_folded:
            with open(os.path.join(wheeldir, item, 'WHEEL')) as wheel:
                for line in wheel:
                    line = line.lower().rstrip()
                    if line == "root-is-purelib: true":
                        return True
    return False


def get_entrypoints(filename):
    if not os.path.exists(filename):
        return {}, {}

    # This is done because you can pass a string to entry_points wrappers which
    # means that they may or may not be valid INI files. The attempt here is to
    # strip leading and trailing whitespace in order to make them valid INI
    # files.
    with open(filename) as fp:
        data = StringIO()
        for line in fp:
            data.write(line.strip())
            data.write("\n")
        data.seek(0)

    # get the entry points and then the script names
    entry_points = pkg_resources.EntryPoint.parse_map(data)
    console = entry_points.get('console_scripts', {})
    gui = entry_points.get('gui_scripts', {})

    def _split_ep(s):
        """get the string representation of EntryPoint, remove space and split
        on '='"""
        return str(s).replace(" ", "").split("=")

    # convert the EntryPoint objects into strings with module:function
    console = dict(_split_ep(v) for v in console.values())
    gui = dict(_split_ep(v) for v in gui.values())
    return console, gui


def message_about_scripts_not_on_PATH(scripts):
    # type: (List[str]) -> Optional[str]
    """Determine if any scripts are not on PATH and format a warning.

    Returns a warning message if one or more scripts are not on PATH,
    otherwise None.
    """
    if not scripts:
        return None

    # Group scripts by the path they were installed in
    grouped_by_dir = collections.defaultdict(set)  # type: Dict[str, set]
    for destfile in scripts:
        parent_dir = os.path.dirname(destfile)
        script_name = os.path.basename(destfile)
        grouped_by_dir[parent_dir].add(script_name)

    # We don't want to warn for directories that are on PATH.
    not_warn_dirs = [
        os.path.normcase(i).rstrip(os.sep) for i in
        os.environ.get("PATH", "").split(os.pathsep)
    ]
    # If an executable sits with sys.executable, we don't warn for it.
    #     This covers the case of venv invocations without activating the venv.
    not_warn_dirs.append(os.path.normcase(os.path.dirname(sys.executable)))
    warn_for = {
        parent_dir: scripts for parent_dir, scripts in grouped_by_dir.items()
        if os.path.normcase(parent_dir) not in not_warn_dirs
    }
    if not warn_for:
        return None

    # Format a message
    msg_lines = []
    for parent_dir, scripts in warn_for.items():
        scripts = sorted(scripts)
        if len(scripts) == 1:
            start_text = "script {} is".format(scripts[0])
        else:
            start_text = "scripts {} are".format(
                ", ".join(scripts[:-1]) + " and " + scripts[-1]
            )

        msg_lines.append(
            "The {} installed in '{}' which is not on PATH."
            .format(start_text, parent_dir)
        )

    last_line_fmt = (
        "Consider adding {} to PATH or, if you prefer "
        "to suppress this warning, use --no-warn-script-location."
    )
    if len(msg_lines) == 1:
        msg_lines.append(last_line_fmt.format("this directory"))
    else:
        msg_lines.append(last_line_fmt.format("these directories"))

    # Returns the formatted multiline message
    return "\n".join(msg_lines)


def move_wheel_files(name, req, wheeldir, user=False, home=None, root=None,
                     pycompile=True, scheme=None, isolated=False, prefix=None,
                     warn_script_location=True):
    """Install a wheel"""

    if not scheme:
        scheme = distutils_scheme(
            name, user=user, home=home, root=root, isolated=isolated,
            prefix=prefix,
        )

    if root_is_purelib(name, wheeldir):
        lib_dir = scheme['purelib']
    else:
        lib_dir = scheme['platlib']

    info_dir = []
    data_dirs = []
    source = wheeldir.rstrip(os.path.sep) + os.path.sep

    # Record details of the files moved
    #   installed = files copied from the wheel to the destination
    #   changed = files changed while installing (scripts #! line typically)
    #   generated = files newly generated during the install (script wrappers)
    installed = {}
    changed = set()
    generated = []

    # Compile all of the pyc files that we're going to be installing
    if pycompile:
        with captured_stdout() as stdout:
            with warnings.catch_warnings():
                warnings.filterwarnings('ignore')
                compileall.compile_dir(source, force=True, quiet=True)
        logger.debug(stdout.getvalue())

    def normpath(src, p):
        return os.path.relpath(src, p).replace(os.path.sep, '/')

    def record_installed(srcfile, destfile, modified=False):
        """Map archive RECORD paths to installation RECORD paths."""
        oldpath = normpath(srcfile, wheeldir)
        newpath = normpath(destfile, lib_dir)
        installed[oldpath] = newpath
        if modified:
            changed.add(destfile)

    def clobber(source, dest, is_base, fixer=None, filter=None):
        ensure_dir(dest)  # common for the 'include' path

        for dir, subdirs, files in os.walk(source):
            basedir = dir[len(source):].lstrip(os.path.sep)
            destdir = os.path.join(dest, basedir)
            if is_base and basedir.split(os.path.sep, 1)[0].endswith('.data'):
                continue
            for s in subdirs:
                destsubdir = os.path.join(dest, basedir, s)
                if is_base and basedir == '' and destsubdir.endswith('.data'):
                    data_dirs.append(s)
                    continue
                elif (is_base and
                        s.endswith('.dist-info') and
                        canonicalize_name(s).startswith(
                            canonicalize_name(req.name))):
                    assert not info_dir, ('Multiple .dist-info directories: ' +
                                          destsubdir + ', ' +
                                          ', '.join(info_dir))
                    info_dir.append(destsubdir)
            for f in files:
                # Skip unwanted files
                if filter and filter(f):
                    continue
                srcfile = os.path.join(dir, f)
                destfile = os.path.join(dest, basedir, f)
                # directory creation is lazy and after the file filtering above
                # to ensure we don't install empty dirs; empty dirs can't be
                # uninstalled.
                ensure_dir(destdir)

                # copyfile (called below) truncates the destination if it
                # exists and then writes the new contents. This is fine in most
                # cases, but can cause a segfault if pip has loaded a shared
                # object (e.g. from pyopenssl through its vendored urllib3)
                # Since the shared object is mmap'd an attempt to call a
                # symbol in it will then cause a segfault. Unlinking the file
                # allows writing of new contents while allowing the process to
                # continue to use the old copy.
                if os.path.exists(destfile):
                    os.unlink(destfile)

                # We use copyfile (not move, copy, or copy2) to be extra sure
                # that we are not moving directories over (copyfile fails for
                # directories) as well as to ensure that we are not copying
                # over any metadata because we want more control over what
                # metadata we actually copy over.
                shutil.copyfile(srcfile, destfile)

                # Copy over the metadata for the file, currently this only
                # includes the atime and mtime.
                st = os.stat(srcfile)
                if hasattr(os, "utime"):
                    os.utime(destfile, (st.st_atime, st.st_mtime))

                # If our file is executable, then make our destination file
                # executable.
                if os.access(srcfile, os.X_OK):
                    st = os.stat(srcfile)
                    permissions = (
                        st.st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH
                    )
                    os.chmod(destfile, permissions)

                changed = False
                if fixer:
                    changed = fixer(destfile)
                record_installed(srcfile, destfile, changed)

    clobber(source, lib_dir, True)

    assert info_dir, "%s .dist-info directory not found" % req

    # Get the defined entry points
    ep_file = os.path.join(info_dir[0], 'entry_points.txt')
    console, gui = get_entrypoints(ep_file)

    def is_entrypoint_wrapper(name):
        # EP, EP.exe and EP-script.py are scripts generated for
        # entry point EP by setuptools
        if name.lower().endswith('.exe'):
            matchname = name[:-4]
        elif name.lower().endswith('-script.py'):
            matchname = name[:-10]
        elif name.lower().endswith(".pya"):
            matchname = name[:-4]
        else:
            matchname = name
        # Ignore setuptools-generated scripts
        return (matchname in console or matchname in gui)