# -*- coding: utf-8; -*-
################################################################################
#
#  Rattail -- Retail Software Framework
#  Copyright © 2010-2020 Lance Edgar
#
#  This file is part of Rattail.
#
#  Rattail is free software: you can redistribute it and/or modify it under the
#  terms of the GNU General Public License as published by the Free Software
#  Foundation, either version 3 of the License, or (at your option) any later
#  version.
#
#  Rattail is distributed in the hope that it will be useful, but WITHOUT ANY
#  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
#  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
#  details.
#
#  You should have received a copy of the GNU General Public License along with
#  Rattail.  If not, see <http://www.gnu.org/licenses/>.
#
################################################################################
"""
Fabric Library for Python
"""

from contextlib import contextmanager

from rattail_fabric2 import apt, exists, make_deploy, mkdir


deploy = make_deploy(__file__)


def bootstrap_python(c, pip_from_apt=True, pip_eager=True,
                     pip_auto=False,
                     pip_package_name=None,
                     virtualenvwrapper_from_apt=False,
                     upgrade_virtualenvwrapper=True,
                     workon_home='/srv/envs', user='rattail',
                     python3=False):
    """
    Bootstrap a "complete" Python install.
    """
    # build dependencies
    apt.install(
        c,
        'python3-dev',
        'libffi-dev',
        'libjpeg-dev',
        'libssl-dev',
    )
    if not python3:
        apt.install(c, 'python-dev')

    # pip
    install_pip(c, auto=pip_auto, python3=python3,
                use_apt=pip_from_apt,
                apt_package_name=pip_package_name,
                eager=pip_eager)

    # virtualenvwrapper
    workon_home = workon_home.rstrip('/')
    install_virtualenvwrapper(c, workon_home=workon_home, user=user,
                              use_apt=virtualenvwrapper_from_apt,
                              upgrade=upgrade_virtualenvwrapper,
                              configure_me=False)
    deploy(c, 'python/premkvirtualenv', '{}/premkvirtualenv'.format(workon_home), owner=user, use_sudo=True)


def install_pythonz(c):
    """
    Install the 'pythonz' utility, for installing arbitrary versions of python.

    https://github.com/saghul/pythonz/blob/master/README.rst#installation
    """
    apt.install(
        c,
        'curl',
        # these are needed when building python:
        'libsqlite3-dev',
        'zlib1g-dev',
    )
    if not exists(c, '/usr/local/pythonz'):
        if not exists(c, '/usr/local/src/pythonz'):
            mkdir(c, '/usr/local/src/pythonz', use_sudo=True)
        if not exists(c, '/usr/local/src/pythonz/pythonz-install'):
            c.sudo('curl -kL -o /usr/local/src/pythonz/pythonz-install https://raw.github.com/saghul/pythonz/master/pythonz-install')
            c.sudo('chmod +x /usr/local/src/pythonz/pythonz-install')
        c.sudo('/usr/local/src/pythonz/pythonz-install')


def install_python(c, version, globally=False, verbose=False):
    """
    Install a specific version of python, via pythonz.

    :param globally: Whether or not this python should be registered globally,
       by placing a symlink to it in ``/usr/local/bin``.  Note that this
       symlink, if installed, will use the "short" version, e.g. if the
       ``version`` specified is ``'3.5.3'`` then the symlink will be named
       ``'python3.5'``.
    """
    if not exists(c, '/usr/local/pythonz/pythons/CPython-{}'.format(version)):
        verbose = '--verbose' if verbose else ''
        c.sudo("bash -lc 'pythonz install {} {}'".format(verbose, version))
    if globally:
        short_version = '.'.join(version.split('.')[:2])
        c.sudo('ln -sf /usr/local/pythonz/pythons/CPython-{0}/bin/python{1} /usr/local/bin/python{1}'.format(
            version, short_version))


def install_pip(c, auto=False, python3=False,
                use_apt=False, apt_package_name=None,
                eager=True):
    """
    Install/upgrade the Pip installer for Python.
    """
    # first check for existing pip; we do nothing if already present
    pip_ = 'pip3' if python3 else 'pip2'
    if not c.sudo('which {}'.format(pip_), warn=True).failed:
        return

    if auto: # try apt first, then fall back to get-pip.py
        package = apt_package_name
        if not package:
            package = 'python3-pip' if python3 else 'python-pip'
        result = apt.install(c, package, warn=True)
        if result.failed:
            c.sudo('wget -O get-pip.py https://bootstrap.pypa.io/get-pip.py')
            python = 'python3' if python3 else 'python2'
            c.sudo('{} get-pip.py'.format(python))
            c.sudo('rm get-pip.py')

    elif use_apt: # use apt only, w/ no fallback
        if not apt_package_name:
            apt_package_name = 'python3-pip' if python3 else 'python-pip'
        apt.install(c, apt_package_name)

    else: # *deprecated* method using easy_install
        apt.install(c, 'build-essential', 'python-dev', 'libssl-dev', 'libffi-dev')
        if c.run('which pip', warn=True).failed:
            apt.install(c, 'python-pkg-resources', 'python-setuptools')
            c.sudo('easy_install pip')
            c.sudo('apt-get --assume-yes purge python-setuptools')
            pip(c, 'setuptools')
        pip(c, 'pip', upgrade=True)
        kwargs = {}
        if eager:
            kwargs['upgrade_strategy'] = 'eager'
        pip(c, 'setuptools', 'wheel', 'ndg-httpsclient', upgrade=True, **kwargs)


def pip(c, *packages, **kwargs):
    """
    Install one or more packages via ``pip install``.
    """
    upgrade = kwargs.pop('upgrade', False)
    upgrade = '--upgrade' if upgrade else ''
    upgrade_strategy = kwargs.pop('upgrade_strategy', None)
    if upgrade and upgrade_strategy:
        upgrade_strategy = '--upgrade-strategy {}'.format(upgrade_strategy)
    else:
        upgrade_strategy = ''
    use_sudo = kwargs.pop('use_sudo', True)
    runas_user = kwargs.pop('runas_user', None)
    if kwargs:
        raise RuntimeError("Unknown kwargs for pip(): {}".format(kwargs))
    packages = ["'{}'".format(p) for p in packages]
    cmd = 'pip install {} {} {}'.format(upgrade, upgrade_strategy, ' '.join(packages))
    if use_sudo:
        kw = {}
        if runas_user:
            kw['user'] = runas_user
        c.sudo(cmd, **kw)
    else:
        c.run(cmd)


def install_virtualenvwrapper(c, workon_home='/srv/envs', user='root',
                              use_apt=False, upgrade=True, configure_me=True):
    """
    Install the `virtualenvwrapper`_ system, with the given ``workon`` home,
    owned by the given user.
    """
    mkdir(c, workon_home, owner=user, use_sudo=True)
    if use_apt:
        apt.install(c, 'virtualenvwrapper')
        configure_virtualenvwrapper(c, user, workon_home,
                                    wrapper='/usr/share/virtualenvwrapper/virtualenvwrapper.sh')
    else:
        pip(c, 'virtualenvwrapper', upgrade=upgrade)
        configure_virtualenvwrapper(c, user, workon_home)
        if configure_me:
            # TODO
            # configure_virtualenvwrapper(c, env.user, workon_home)
            raise NotImplementedError


def configure_virtualenvwrapper(c, user, workon_home='/srv/envs',
                                wrapper='/usr/local/bin/virtualenvwrapper.sh'):
    """
    Configure virtualenvwrapper for the given user account.
    """
    home = c.run('getent passwd {} | cut -d: -f6'.format(user)).stdout.strip()
    home = home.rstrip('/')

    def update(script):
        script = '{}/{}'.format(home, script)
        if not exists(c, script, use_sudo=True):
            c.sudo('touch {}'.format(script))
            c.sudo('chown {}: {}'.format(user, script))

        if c.sudo("grep '^export WORKON_HOME.*' {}".format(script), warn=True).failed:
            c.sudo("""bash -c 'echo "export WORKON_HOME={}" >> {}'""".format(workon_home, script))
            c.sudo("""bash -c 'echo "source {}" >> {}'""".format(wrapper, script))
        else:
            c.sudo("sed -i.bak -e 's/^export WORKON_HOME=.*/export WORKON_HOME={}/' {}".format(
                workon_home.replace('/', '\\/'), script))

    update('.profile')
    update('.bashrc')
    c.sudo("bash -l -c 'whoami'", user=user)


def mkvirtualenv(c, name, workon_home='/srv/envs', python=None,
                 use_sudo=True, runas_user=None):
    """
    Make a new Python virtual environment.
    """
    cmd = 'mkvirtualenv {} {}'.format('--python={}'.format(python) if python else '', name)
    if use_sudo:
        kw = {}
        if runas_user:
            kw = {'user': runas_user}
        c.sudo("bash -l -c '{}'".format(cmd), **kw)
    else:
        # TODO: need to use `bash -l` for this too?
        c.run(cmd)


@contextmanager
def workon(c, name):
    """
    Context manager to prefix your command(s) with the ``workon`` command.
    """
    with c.prefix('workon {}'.format(name)):
        yield


@contextmanager
def cdvirtualenv(c, name, subdirs=[], workon_home='/srv/envs'):
    """
    Context manager to prefix your command(s) with the ``cdvirtualenv`` command.
    """
    if isinstance(subdirs, str):
        subdirs = [subdirs]
    path = '{}/{}'.format(workon_home, name)
    if subdirs:
        path = '{}/{}'.format(path, '/'.join(subdirs))
    with workon(c, name):
        with c.cd(path):
            yield