#!/usr/bin/env python
from __future__ import print_function
from contextlib import contextmanager
from glob import glob
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():
    old_dir = os.getcwd()
    print("Moving to %s." % HERE)
    os.chdir(HERE)

    try:
        print("Cleaning docs with 'make clean'")
        check_call(['make', 'clean'])
        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_, '.')
    finally:
        os.chdir(old_dir)

    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()