import os

import helper
import slides as slides_helper

root = ""
lang = ""

# Compiles a presentation's chapters (the content without the wrapper)
# according to slides.yml and returns them as one string of <section>s.
def compile_chapters(root_directory, language):
    global root
    root = root_directory

    global lang
    lang = language

    structure = helper.read_yaml(root, 'slides.yml')
    chapters = ""
    for chapter in structure:
        chapters += '<section>\n' + compile_chapter(chapter) + '\n</section>'
    return chapters # string

# Compiles a presentation's chapter (given its name) by splitting it into
# slides, compiling those, and returning them as a string of <article>s.
def compile_chapter(chapter):
    global root
    if type(chapter) != str:
        raise Exception('Chapters with attributes are not supported yet.\n' +
                str(chapter))
    chapter_file = open(os.path.join(root, 'slides/' + chapter + '.' + lang + '.md'), 'r')
    delimiter = '\n@slide'
    chapter_input = ('\n' + chapter_file.read()).split(delimiter)
    slides = [delimiter + slide for slide in chapter_input][1:]
    chapter = ''
    for slide in slides:
        chapter += '<article>\n' + slides_helper.compile_slide(slide, root) + '\n</article>\n'
    return chapter