import os
import sys
import tempfile
import shutil
from pip.req import InstallRequirement, RequirementSet, parse_requirements
from pip.log import logger
from pip.locations import (src_prefix, virtualenv_no_global, distutils_scheme,
                           build_prefix)
from pip.basecommand import Command
from pip.index import PackageFinder
from pip.exceptions import InstallationError, CommandError, PreviousBuildDirError
from pip import cmdoptions
from pip.util import BuildDirectory


class InstallCommand(Command):
    """
    Install packages from:

    - PyPI (and other indexes) using requirement specifiers.
    - VCS project urls.
    - Local project directories.
    - Local or remote source archives.

    pip also supports installing from "requirements files", which provide
    an easy way to specify a whole environment to be installed.
    """
    name = 'install'

    usage = """
      %prog [options] <requirement specifier> ...
      %prog [options] -r <requirements file> ...
      %prog [options] [-e] <vcs project url> ...
      %prog [options] [-e] <local project path> ...
      %prog [options] <archive url/path> ..."""

    summary = 'Install packages.'
    bundle = False

    def __init__(self, *args, **kw):
        super(InstallCommand, self).__init__(*args, **kw)

        cmd_opts = self.cmd_opts

        cmd_opts.add_option(
            '-e', '--editable',
            dest='editables',
            action='append',
            default=[],
            metavar='path/url',
            help='Install a project in editable mode (i.e. setuptools "develop mode") from a local project path or a VCS url.')

        cmd_opts.add_option(cmdoptions.requirements.make())
        cmd_opts.add_option(cmdoptions.build_dir.make())

        cmd_opts.add_option(
            '-t', '--target',
            dest='target_dir',
            metavar='dir',
            default=None,
            help='Install packages into <dir>.')

        cmd_opts.add_option(
            '-d', '--download', '--download-dir', '--download-directory',
            dest='download_dir',
            metavar='dir',
            default=None,
            help="Download packages into <dir> instead of installing them, regardless of what's already installed.")

        cmd_opts.add_option(cmdoptions.download_cache.make())

        cmd_opts.add_option(
            '--src', '--source', '--source-dir', '--source-directory',
            dest='src_dir',
            metavar='dir',
            default=src_prefix,
            help='Directory to check out editable projects into. '
            'The default in a virtualenv is "<venv path>/src". '
            'The default for global installs is "<current dir>/src".')

        cmd_opts.add_option(
            '-U', '--upgrade',
            dest='upgrade',
            action='store_true',
            help='Upgrade all packages to the newest available version. '
            'This process is recursive regardless of whether a dependency is already satisfied.')

        cmd_opts.add_option(
            '--force-reinstall',
            dest='force_reinstall',
            action='store_true',
            help='When upgrading, reinstall all packages even if they are '
                 'already up-to-date.')

        cmd_opts.add_option(
            '-I', '--ignore-installed',
            dest='ignore_installed',
            action='store_true',
            help='Ignore the installed packages (reinstalling instead).')

        cmd_opts.add_option(cmdoptions.no_deps.make())

        cmd_opts.add_option(
            '--no-install',
            dest='no_install',
            action='store_true',
            help="DEPRECATED. Download and unpack all packages, but don't actually install them.")

        cmd_opts.add_option(
            '--no-download',
            dest='no_download',
            action="store_true",
            help="DEPRECATED. Don't download any packages, just install the ones already downloaded "
            "(completes an install run with --no-install).")

        cmd_opts.add_option(cmdoptions.install_options.make())
        cmd_opts.add_option(cmdoptions.global_options.make())

        cmd_opts.add_option(
            '--user',
            dest='use_user_site',
            action='store_true',
            help='Install using the user scheme.')

        cmd_opts.add_option(
            '--egg',
            dest='as_egg',
            action='store_true',
            help="Install packages as eggs, not 'flat', like pip normally does. This option is not about installing *from* eggs. (WARNING: Because this option overrides pip's normal install logic, requirements files may not behave as expected.)")

        cmd_opts.add_option(
            '--root',
            dest='root_path',
            metavar='dir',
            default=None,
            help="Install everything relative to this alternate root directory.")

        cmd_opts.add_option(
            '--strip-file-prefix',
            dest='strip_file_prefix',
            metavar='prefix',
            default=None,
            help="Strip given prefix from script paths in wheel RECORD."
        )

        cmd_opts.add_option(
            "--compile",
            action="store_true",
            dest="compile",
            default=True,
            help="Compile py files to pyc",
        )

        cmd_opts.add_option(
            "--no-compile",
            action="store_false",
            dest="compile",
            help="Do not compile py files to pyc",
        )

        cmd_opts.add_option(cmdoptions.use_wheel.make())
        cmd_opts.add_option(cmdoptions.no_use_wheel.make())

        cmd_opts.add_option(
            '--pre',
            action='store_true',
            default=False,
            help="Include pre-release and development versions. By default, pip only finds stable versions.")

        cmd_opts.add_option(cmdoptions.no_clean.make())

        index_opts = cmdoptions.make_option_group(cmdoptions.index_group, self.parser)

        self.parser.insert_option_group(0, index_opts)
        self.parser.insert_option_group(0, cmd_opts)

    def _build_package_finder(self, options, index_urls, session):
        """
        Create a package finder appropriate to this install command.
        This method is meant to be overridden by subclasses, not
        called directly.
        """
        return PackageFinder(find_links=options.find_links,
                             index_urls=index_urls,
                             use_wheel=options.use_wheel,
                             allow_external=options.allow_external,
                             allow_unverified=options.allow_unverified,
                             allow_all_external=options.allow_all_external,
                             allow_all_prereleases=options.pre,
                             process_dependency_links=
                                options.process_dependency_links,
                             session=session,
                            )

    def run(self, options, args):

        if (
            options.no_install or
            options.no_download or
            options.build_dir or
            options.no_clean
        ):
            logger.deprecated('1.7', 'DEPRECATION: --no-install, --no-download, --build, '
                              'and --no-clean are deprecated.  See https://github.com/pypa/pip/issues/906.')

        if options.download_dir:
            options.no_install = True
            options.ignore_installed = True

        # If we have --no-install or --no-download and no --build we use the
        # legacy static build dir
        if (options.build_dir is None
                and (options.no_install or options.no_download)):
            options.build_dir = build_prefix

        if options.build_dir:
            options.build_dir = os.path.abspath(options.build_dir)

        options.src_dir = os.path.abspath(options.src_dir)
        install_options = options.install_options or []
        if options.use_user_site:
            if virtualenv_no_global():
                raise InstallationError("Can not perform a '--user' install. User site-packages are not visible in this virtualenv.")
            install_options.append('--user')

        temp_target_dir = None
        if options.target_dir:
            options.ignore_installed = True
            temp_target_dir = tempfile.mkdtemp()
            options.target_dir = os.path.abspath(options.target_dir)
            if os.path.exists(options.target_dir) and not os.path.isdir(options.target_dir):
                raise CommandError("Target path exists but is not a directory, will not continue.")
            install_options.append('--home=' + temp_target_dir)

        global_options = options.global_options or []
        index_urls = [options.index_url] + options.extra_index_urls
        if options.no_index:
            logger.notify('Ignoring indexes: %s' % ','.join(index_urls))
            index_urls = []

        if options.use_mirrors:
            logger.deprecated("1.7",
                        "--use-mirrors has been deprecated and will be removed"
                        " in the future. Explicit uses of --index-url and/or "
                        "--extra-index-url is suggested.")

        if options.mirrors:
            logger.deprecated("1.7",
                        "--mirrors has been deprecated and will be removed in "
                        " the future. Explicit uses of --index-url and/or "
                        "--extra-index-url is suggested.")
            index_urls += options.mirrors

        session = self._build_session(options)

        finder = self._build_package_finder(options, index_urls, session)

        build_delete = (not (options.no_clean or options.build_dir))
        with BuildDirectory(options.build_dir, delete=build_delete) as build_dir:
            requirement_set = RequirementSet(
                build_dir=build_dir,
                src_dir=options.src_dir,
                download_dir=options.download_dir,
                download_cache=options.download_cache,
                upgrade=options.upgrade,
                as_egg=options.as_egg,
                ignore_installed=options.ignore_installed,
                ignore_dependencies=options.ignore_dependencies,
                force_reinstall=options.force_reinstall,
                use_user_site=options.use_user_site,
                target_dir=temp_target_dir,
                session=session,
                pycompile=options.compile,
            )
            for name in args:
                requirement_set.add_requirement(
                    InstallRequirement.from_line(name, None))
            for name in options.editables:
                requirement_set.add_requirement(
                    InstallRequirement.from_editable(name, default_vcs=options.default_vcs))
            for filename in options.requirements:
                for req in parse_requirements(filename, finder=finder, options=options, session=session):
                    requirement_set.add_requirement(req)
            if not requirement_set.has_requirements:
                opts = {'name': self.name}
                if options.find_links:
                    msg = ('You must give at least one requirement to %(name)s '
                           '(maybe you meant "pip %(name)s %(links)s"?)' %
                           dict(opts, links=' '.join(options.find_links)))
                else:
                    msg = ('You must give at least one requirement '
                           'to %(name)s (see "pip help %(name)s")' % opts)
                logger.warn(msg)
                return

            try:
                if not options.no_download:
                    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
                else:
                    requirement_set.locate_files()

                if not options.no_install and not self.bundle:
                    requirement_set.install(
                        install_options,
                        global_options,
                        root=options.root_path,
                        strip_file_prefix=options.strip_file_prefix)
                    installed = ' '.join([req.name for req in
                                          requirement_set.successfully_installed])
                    if installed:
                        logger.notify('Successfully installed %s' % installed)
                elif not self.bundle:
                    downloaded = ' '.join([req.name for req in
                                           requirement_set.successfully_downloaded])
                    if downloaded:
                        logger.notify('Successfully downloaded %s' % downloaded)
                elif self.bundle:
                    requirement_set.create_bundle(self.bundle_filename)
                    logger.notify('Created bundle in %s' % self.bundle_filename)
            except PreviousBuildDirError:
                options.no_clean = True
                raise
            finally:
                # Clean up
                if (not options.no_clean) and ((not options.no_install) or options.download_dir):
                    requirement_set.cleanup_files(bundle=self.bundle)

        if options.target_dir:
            if not os.path.exists(options.target_dir):
                os.makedirs(options.target_dir)
            lib_dir = distutils_scheme('', home=temp_target_dir)['purelib']
            for item in os.listdir(lib_dir):
                shutil.move(
                    os.path.join(lib_dir, item),
                    os.path.join(options.target_dir, item)
                    )
            shutil.rmtree(temp_target_dir)
        return requirement_set
