install_deps

#!/usr/bin/env python

import os
import subprocess
import shutil
import stat
import platform

from StringIO import StringIO
from zipfile import ZipFile
from urllib import urlopen

REQUIREMENTS = ["pip", "git"]

FILES_IGNORED_FOR_DELETION = ["google_appengine"]

PROJECT_DIR = os.path.abspath(os.path.dirname(__file__))
REQUIREMENTS_DIR = os.path.join(PROJECT_DIR, "requirements")
REQUIREMENTS_FILE = os.path.join(REQUIREMENTS_DIR, "prod.txt")
DEV_REQUIREMENTS_FILE = os.path.join(REQUIREMENTS_DIR, "dev.txt")
TARGET_DIR = os.path.join(PROJECT_DIR, "sitepackages")
DEV_TARGET_DIR = os.path.join(TARGET_DIR, "dev")
PROD_TARGET_DIR = os.path.join(TARGET_DIR, "prod")

# we don't need to upload the SDK so it lives in the dev sitepackages directory
APPENGINE_TARGET_DIR = os.path.join(DEV_TARGET_DIR, "google_appengine")

APPENGINE_SDK_VERSION = "1.9.40"
APPENGINE_SDK_FILENAME = "google_appengine_{}.zip".format(APPENGINE_SDK_VERSION)

# Google move versions from 'featured' to 'deprecated' when they bring
# out new releases
FEATURED_SDK_REPO = "https://storage.googleapis.com/appengine-sdks/featured/"
DEPRECATED_SDK_REPO = "https://storage.googleapis.com/appengine-sdks/deprecated/{}/".format(
    APPENGINE_SDK_VERSION.replace('.', '')
)


def check_commands_installed():
    """Check pip and git are installed."""
    where = 'which'
    if platform.system() == 'Windows':
        where = 'where'

    for command in REQUIREMENTS:
        try:
            subprocess.check_output([where, command])
        except subprocess.CalledProcessError:
            raise RuntimeError("You must install the '{}' command".format(command))


def install_app_engine_sdk():
    """Download and install the Google App Engine SDK."""
    if not os.path.exists(APPENGINE_TARGET_DIR):
        print('Downloading the AppEngine SDK...')

        # First try and get it from the 'featured' folder
        sdk_file = urlopen(FEATURED_SDK_REPO + APPENGINE_SDK_FILENAME)
        if sdk_file.getcode() == 404:
            # Failing that, 'deprecated'
            sdk_file = urlopen(DEPRECATED_SDK_REPO + APPENGINE_SDK_FILENAME)

        # Handle other errors
        if sdk_file.getcode() >= 299:
            raise Exception(
                'App Engine SDK could not be found. {} returned code {}.'.format(
                    sdk_file.geturl(), sdk_file.getcode())
            )

        zipfile = ZipFile(StringIO(sdk_file.read()))
        zipfile.extractall(DEV_TARGET_DIR)

        # Make sure the dev_appserver and appcfg are executable
        for module in ("dev_appserver.py", "appcfg.py"):
            app = os.path.join(APPENGINE_TARGET_DIR, module)
            st = os.stat(app)
            os.chmod(app, st.st_mode | stat.S_IEXEC)

    else:
        print(
            'Not updating SDK as it exists. Remove {} and re-run to get the '
            'latest SDK'.format(APPENGINE_TARGET_DIR)
        )


def install_requirements():
    """Install all the prod and dev requirements into their respective directories."""
    pip_msg = "Running pip to install {filename} dependencies into {target}..."

    pip_targets = [
        (REQUIREMENTS_FILE, PROD_TARGET_DIR),
        (DEV_REQUIREMENTS_FILE, DEV_TARGET_DIR)
    ]
    for requirements, target in pip_targets:

        if os.path.exists(target):
            # remove all folders and files, leaving symlinks which point to submodules
            filenames = (
                filename for filename in os.listdir(target) if
                filename not in FILES_IGNORED_FOR_DELETION
            )
            for filename in filenames:
                path = os.path.join(target, filename)
                if os.path.isdir(path) and not os.path.islink(path):
                    shutil.rmtree(path)
                elif os.path.isfile(path):
                    os.remove(path)

        # install all the required third party libs into the target directory
        print(pip_msg.format(filename=os.path.basename(requirements), target=target))
        args = ["pip", "install", "-r", requirements, "-t", target, "-I"]
        p = subprocess.Popen(args)
        p.wait()


if __name__ == "__main__":

    # make sure pip and git are installed as the script relies on them
    check_commands_installed()

    # install the app engine SDK if needed
    install_app_engine_sdk()

    # install all the python requirements into sitepackages
    install_requirements()