#!/usr/bin/env python
from __future__ import print_function
from contextlib import contextmanager
from glob import glob
from path import path
import os
from os.path import abspath, basename, dirname, exists, isfile
from shutil import move, rmtree
from subprocess import check_call

HERE = dirname(abspath(__file__))
ZIPLINE_ROOT = dirname(HERE)
TEMP_LOCATION = '/tmp/zipline-doc'
TEMP_LOCATION_GLOB = TEMP_LOCATION + '/*'


@contextmanager
def removing(path):
    try:
        yield
    finally:
        rmtree(path)


def ensure_not_exists(path):
    if not exists(path):
        return
    if isfile(path):
        os.unlink(path)
    else:
        rmtree(path)


def main():
    print("Moving to %s." % HERE)
    with path(HERE):
        print("Building docs with 'make html'")
        check_call(['make', 'html'])

        print("Clearing temp location '%s'" % TEMP_LOCATION)
        rmtree(TEMP_LOCATION, ignore_errors=True)

        with removing(TEMP_LOCATION):
            print("Copying built files to temp location.")
            move('build/html', TEMP_LOCATION)

            print("Moving to '%s'" % ZIPLINE_ROOT)
            os.chdir(ZIPLINE_ROOT)

            print("Checking out gh-pages branch.")
            check_call(
                [
                    'git', 'branch', '-f',
                    '--track', 'gh-pages', 'origin/gh-pages'
                ]
            )
            check_call(['git', 'checkout', 'gh-pages'])
            check_call(['git', 'reset', '--hard', 'origin/gh-pages'])

            print("Copying built files:")
            for file_ in glob(TEMP_LOCATION_GLOB):
                base = basename(file_)

                print("%s -> %s" % (file_, base))
                ensure_not_exists(base)
                move(file_, '.')

    print()
    print("Updated documentation branch in directory %s" % ZIPLINE_ROOT)
    print("If you are happy with these changes, commit and push to gh-pages.")

if __name__ == '__main__':
    main()