import os
import sys
import shutil
from dotenv import load_dotenv
from markdown_parser import parse_md
from datetime import datetime


def md2html(filename, env_vars):
    """
    Create the html webpage from template and markdown content
    filename: file to transform into HTML
    env_vars: dictionnary of env variables
    return: a dictionnary containing title, metadata, local path, content for HTML
    """
    # Getting parsed content of markdown file & page template
    data = parse_md(filename, env_vars)
    template = open(env_vars['templates_folder'] + "/" + env_vars["lang"] + "/page_template.html", 'r').read()

    # Generating the HTML page
    output = open(env_vars['pages_path'] + '/' + env_vars["lang"] + "/" + filename.split('.')[0] + '.html', 'w')
    output.write(template.replace("$CONTENT", data['content']).replace("$TITLE", data['title']).replace("$DATE", data['date']).replace("$DESC", data['description']))
    output.close()

    return data


def generate_page_XML(data, env_vars):
    """
    Generate a RSS / Atom post for the page
    data: dictionnary generated by the markdown parser
    env_vars: dictionnary of env variables
    return: RSS / Atom post
    """
    template = open(env_vars['templates_folder'] + "/" + env_vars["lang"] + "/atom_post_template.xml", 'r').read()
    date = datetime.strptime(data['date'], "%d-%m-%Y").isoformat() + "Z"
    return template.replace("$TITLE", data['title']).replace("$DATE", date).replace("$CONTENT", data['content']).replace("$URL", env_vars['website_url'] + data['filepath'])


def generate_atom_feed(posts, env_vars):
    """
    Generate a RSS / Atom feed
    posts: list of data get from markdown pages
    env_vars: dictionnary of env variables
    """
    # Generate RSS / Atom post
    atom_content = ""
    for post in posts:
        # Checking if there is metadata, if not we don't create a RSS / Atom post
        if post['date'] != '01-01-0001':
            atom_content += generate_page_XML(post, env_vars)

    # Generate RSS / atom feed
    template = open(env_vars['templates_folder'] + "/" + env_vars["lang"] + "/atom_feed_template.xml", 'r').read()
    output = open(env_vars['parent_path'] + "/atom_" + env_vars["lang"] + ".xml", "w")
    output.write(template.replace('$CONTENT', atom_content).replace('$DATE', datetime.today().strftime("%Y-%m-%d")))
    output.close()


def generate_tags_pages(tags_dict, env_vars):
    """
    Generate page for each tag, which link to each content tagged
    tags_dict: A dictionnary with tag name as key, and a list of post (title & url) with that tag
    env_vars: dictionnary of env variables
    """
    if not os.path.exists(env_vars['pages_path'] + "/" + env_vars["lang"] + '/tags'):
        os.mkdir(env_vars['pages_path'] + "/" + env_vars["lang"] + '/tags')

    # Going on every tag and creating it's page
    for tag, pages in tags_dict.items():
        template = open(env_vars['templates_folder'] + "/" + env_vars["lang"] + "/tags_template.html", 'r').read()
        # Generating the HTML page
        output = open(env_vars['pages_path'] + "/" + env_vars["lang"] + '/tags/' + tag.replace(' ', '_') + '.html', 'w')

        # Adding all links for page with this tag
        content = "<ul>\n"
        for page in pages:
            content += '\t\t\t\t<li><a href="' + '../../../' + page[1] + '">' + page[0] + '</a></li>\n'
        content += "\t\t\t</ul>\n"

        output.write(template.replace("$CONTENT", content).replace("$TITLE", tag))
        output.close()
    pass


def generate_index(data, env_vars):
    """
    Generate the main page
    data: list of data get from markdown pages
    env_vars: dictionnary of env variables
    """
    # Create the index content
    tags_dict = {}
    index_content = "<ul>\n"

    # Getting data of each page
    for page in data:
        # Checking if there is metadata, if not we don't add the page in the index
        if page['date'] != '01-01-0001':
            index_content += ('\t\t\t\t<li><a href="' + page['filepath'] + '">' + page['title'] + '</a><p>'
                              + page['date'] + '</p></li>\n')

        # Adding page into tags categorie
        for tag in page['tags']:
            if tag not in tags_dict:
                tags_dict[tag] = []
            tags_dict[tag].append([page['title'], page['filepath']])

    index_content += '\t\t\t</ul>\n\t\t\t<h2>Tags:</h2>\n\t\t\t<div class="tags">\n\t\t\t\t<ul>\n'

    # Adding tags browsing into the page
    for tag in list(tags_dict.keys()):
        index_content += ('\t\t\t\t\t<li><a href="' + env_vars['pages_path'].replace(
            env_vars['parent_path'] + '/', '') + "/" + env_vars["lang"] + '/tags/' + tag.replace(' ', '_') + '.html' + '">' + tag + '</a></li>\n')
        generate_tags_pages(tags_dict, env_vars)
    index_content += '\t\t\t\t</ul>\n\t\t\t</div>'

    # Generate main page
    template = open(env_vars['templates_folder'] + "/" + env_vars["lang"] + "/index_template.html", 'r').read()
    output = open(env_vars['parent_path'] + "/index_" + env_vars["lang"] + ".html", 'w')
    output.write(template.replace('$CONTENT', index_content))
    output.close()

def check_env():
    """Check environment variables are set and not empty"""
    env = ['PARENT_PATH', 'PAGES_PATH', 'MARKDOWN_PATH', 'TEMPLATES_FOLDER', 'WEBSITE_URL', 'LANGS']
    for variable in env:
        if variable not in os.environ:
            print(
                f"{color['red']}{variable} isn't present in the .env file, please fix this {color['end']}")
            sys.exit()

        if (os.environ.get(variable) or '') == '':
            print(
                f"{color['red']}{variable} isn't setup in the .env file, please fix this {color['end']}")
            sys.exit()



if __name__ == "__main__":
    # Load .env file into python environment
    load_dotenv()

    # Color for print
    color = {'red': '\033[1;31m', 'green': '\033[1;32m', 'end': '\033[0m'}

    # Checking if all environment variable are present & setup
    check_env()

    # Getting env variable
    env_vars = {'parent_path': os.environ.get('PARENT_PATH'), 'pages_path': os.environ.get('PAGES_PATH'), 'markdown_path': os.environ.get('MARKDOWN_PATH'), 'templates_folder': os.environ.get('TEMPLATES_FOLDER'), 'website_url': os.environ.get('WEBSITE_URL')}
    langs = os.environ.get('LANGS').lower().split(',')

    # Checking if generate folder exist to remove previouly generated content, if not create it
    if os.path.exists(env_vars['pages_path']):
        shutil.rmtree(env_vars['pages_path'])
        for lang in langs:
            os.remove(env_vars['parent_path'] + "/atom_" + lang + ".xml")
            os.remove(env_vars['parent_path'] + "/index_" + lang + ".html")
    else:
        os.mkdir(env_vars['pages_path'])
        for lang in langs:
            os.mkdir(env_vars['pages_path'] + "/" + lang)

    data = []  # A list for data generated by md2html

    # Generate for each lang
    for lang in langs:
        env_vars['lang'] = lang

        # Generate all markdown file
        for file in os.listdir(env_vars['markdown_path'] + "/" + lang):

            # Generating HTML page
            print(f"{color['green']}Generating file: {file} in {lang} {color['end']}")
            data.append(md2html(file, env_vars))

        sorted_data = sorted(data, key=lambda x: datetime.strptime(x['date'], '%d-%m-%Y'))

        # Generating atom feed
        print(f"{color['green']}Generating RSS / Atom feed in {lang} {color['end']}")
        generate_atom_feed(data, env_vars)

        # Generating index
        print(f"{color['green']}Generating main page in {lang} :{color['end']}")
        generate_index(data, env_vars)