#!/usr/bin/env python3

""" Script to convert a Nikola blog to Hugo

Requirements:
    - toml

Usage:
   ./nikola-to-hugo.py /path/to/nikola/blog

"""

import os
from os.path import abspath, dirname, exists, join, sep
from shutil import copytree, rmtree
import subprocess
import sys

import toml
from nikola import Nikola


def nikola_site(path):
    sys.path.insert(0, path)
    import conf
    site = Nikola(**conf.__dict__)
    site.init_plugins()
    site.scan_posts()
    return site


def create_hugo_site(path):
    hugo_path = '{}-hugo'.format(path.rstrip(sep))
    subprocess.call(['hugo', 'new', 'site', hugo_path])
    return hugo_path


def convert_blog(path):
    site = nikola_site(path)
    hugo_path = create_hugo_site(path)
    update_conf(site.config, hugo_path)
    for post in site.timeline:
        convert_post(site, post, path, hugo_path)
    copy_static_files(path, hugo_path)


def copy_static_files(path, hugo_path):
    files = join(path, 'files')
    static = join(hugo_path, 'static')
    rmtree(static, ignore_errors=True)
    copytree(files, static)


def update_conf(nikola_conf, hugo_path):
    conf = join(hugo_path, 'config.toml')
    with open(conf) as f:
        hugo_config = toml.load(f)
    hugo_config['baseurl'] = nikola_conf['BASE_URL']
    hugo_config['title'] = nikola_conf['BLOG_TITLE']()
    if nikola_conf['COMMENT_SYSTEM'] == 'disqus':
        hugo_config['disqusShortname'] = nikola_conf['COMMENT_SYSTEM_ID']
    with open(conf, 'w') as g:
        toml.dump(hugo_config, g)


def get_post_content(site, src):
    compiler = site.get_compiler(src)
    with open(src) as f:
        return compiler.split_metadata(f.read())[1]


def toml_metadata(post):
    meta = post.meta['en']
    if 'tags' in meta:
        meta['tags'] = post.tags
    if 'date' in meta:
        meta['date'] = post.date
    if 'updated' in meta:
        meta['updated'] = post.updated
    if post.is_draft or post.is_private:
        meta['draft'] = True
    meta['type'] = 'post' if post.is_post else 'page'
    return toml.dumps(meta)


def convert_post(site, post, path, hugo_path):
    src = join(path, post.source_path)
    dst = join(hugo_path, 'content', post.source_path)
    if not exists(dirname(dst)):
        os.mkdir(dirname(dst))
    meta = "+++\n{}\n+++\n\n".format(toml_metadata(post))
    content = get_post_content(site, src)
    with open(dst, 'w') as f:
        f.write(meta)
        f.write(content)


def main():
    if len(sys.argv) != 2:
        print(__doc__)
        sys.exit(1)
    path = abspath(sys.argv[1])
    convert_blog(path)


if __name__ == '__main__':
    main()