import os.path
import json

from jinja2 import Environment, FileSystemLoader

from utils.reST import reST_to_html


def build_entry(jenv, entry, older=None, newer=None):
    entry_template = jenv.get_template('entry.html')

    source_file = 'entries/{}.rst'.format(entry['file'])
    with open(source_file, 'r') as f:
        source = f.read()

    rendered_source = reST_to_html(source)

    rendered = entry_template.render(entry=entry,
                                     older=older,
                                     newer=newer,
                                     content=rendered_source)
    with open('out/{}.html'.format(entry['file']), 'w+') as f:
        f.write(rendered)


def build_index(jenv, entry, older=None):
    index_template = jenv.get_template('index.html')

    source_file = 'entries/{}.rst'.format(entry['file'])
    with open(source_file, 'r') as f:
        source = f.read()

    rendered_source = reST_to_html(source)

    rendered = index_template.render(entry=entry,
                                     older=older,
                                     content=rendered_source)
    with open('out/index.html', 'w+') as f:
        f.write(rendered)


def build_archive(jenv, entries):
    archive_template = jenv.get_template('archive.html')
    rendered = archive_template.render(entries=entries)
    with open('out/archive.html', 'w+') as f:
        f.write(rendered)


def entry_exists(entry):
    path = 'entries/{}.rst'.format(entry['file'])
    if not os.path.isfile(path):
        print('''Source file '{}' for entry '{}' does not exist. Skipping.'''
              .format(path, entry['title']))
        return False
    return True


if __name__ == '__main__':
    jenv = Environment(loader=FileSystemLoader('templates'),
                       trim_blocks=True,
                       lstrip_blocks=True)

    with open('entries.json') as f:
        entries = json.load(f)

    entries = list(filter(entry_exists, entries))

    for index, entry in enumerate(entries):
        older = None
        newer = None
        if index > 0:
            older = entries[index-1]
        if index < len(entries) - 1:
            newer = entries[index+1]

        build_entry(jenv, entry, older, newer)

    if len(entries) > 1:
        build_index(jenv, entries[-1], entries[-2])
    else:
        build_index(jenv, entries[-1], None)

    build_archive(jenv, entries)