from typing import Dict
from os import walk, makedirs
from os.path import isdir, join, exists
from shutil import copytree
from article import read_article_file, site_from_json
from json import loads

def compile(work_directory: str, template_directory: str=None, target_directory: str=None, force: bool=False):
    if not isdir(work_directory):
        raise FileNotFoundError("One or more of the directories you specified do not exist")

    if template_directory is None:
        template_directory = join(work_directory, 'template')

    if not isdir(template_directory):
        raise FileNotFoundError("Template doesn't exist. Add one to your project or specify one with -t")
    
    if target_directory is None:
        target_directory = join(work_directory, 'generated_out')
        if exists(target_directory) and not force:
            raise FileExistsError(target_directory + " already exists. Delete it, specify a different one with -o, or pass the -f flag to merge")

    copytree(join(template_directory, 'static'), join(target_directory, 'static'), dirs_exist_ok=True)
    copytree(join(work_directory, 'posts'), join(target_directory, 'post'), dirs_exist_ok=True)

    file = open(join(template_directory, 'post.html'))
    post_template = file.read()
    file.close()

    file = open(join(work_directory, 'config.json'))
    site = file.read()
    site = site_from_json(loads(site))
    file.close()

    for root, dirs, files in walk(join(target_directory, 'post')):
        for fn in files:
            if fn.endswith('.html'):
                file = open(join(root, fn), 'r+')
                article = read_article_file(file)

                content = process_html(post_template, {
                    'site_name': site.name,
                    'site_url': site.url,
                    'title': article.title,
                    'summary': article.summary,
                    'content': article.content
                })

                file.seek(0)
                file.write(content)
                file.close()

def process_html(content: str, variables: Dict[str, str]) -> str:
    for k, v in variables.items():
        content = replace_variable(content, k, v)

    return content

def replace_variable(content: str, var: str, val: str) -> str:
    return content.replace('{{ ' + var + ' }}', val)