from flask import Flask, url_for, render_template, abort
import os
from app.config import PANDOC_LINK, PANDOC_PATH, WHITELIST_PATH
from app.hash_manager import hash_file_sha512
from app.page_model import WikiPage
from typing import List

app = Flask(__name__)


@app.context_processor
def override_url_for():
    return dict(url_for=dated_url_for)


def get_all_names():
    whitelist = WHITELIST_PATH
    with open(whitelist, 'r') as f:
        lines = f.read().splitlines()
    return lines


def get_page(name: str) -> WikiPage:
    if name not in get_all_names():
        raise Exception("Page doesn't exist!")
    path = f'{PANDOC_PATH}/{name}'
    with open(f'{path}/config.json', 'r') as f:
        page = WikiPage.parse_raw(f.read())
    return page


def get_all_pages() -> List[WikiPage]:
    return [get_page(name) for name in get_all_names()]


def dated_url_for(endpoint, **values):
    if endpoint == 'static':
        filename = values.get('filename', None)
        if filename:
            file_path = os.path.join(app.root_path, endpoint, filename)
            values['q'] = int(os.stat(file_path).st_mtime)
    return url_for(endpoint, **values)


def render_page(page: WikiPage):
    if page.name not in get_all_names():
        raise Exception("Page doesn't exist!")
    in_filename = page.get_file('main.md')
    out_filename = page.get_file('render.html')
    os.system(f'pandoc {in_filename} --to html --mathjax --output {out_filename}')
    print('Creating lock file')
    os.system(f'echo {hash_file_sha512(in_filename)} > {out_filename}.lock')


@app.route(f'/{PANDOC_LINK}/<name>')
def get_pandoc_page(name: str):
    page = get_page(name)
    if not os.path.exists(page.get_file('render.html')) or not os.path.exists(page.get_file('render.html.lock')):
        print(f'Rendered page or lockfile for {name} does not exist! Rendering {name}')
        render_page(page)
    else:
        with open(page.get_file('render.html.lock'), 'r') as f:
            rendered_hash = f.read().strip()
        current_hash = hash_file_sha512(page.get_file('main.md'))
        if rendered_hash != current_hash:
            print(f'CURRENT: {current_hash}, RENDERED: {rendered_hash}')
            print(f'Integrity test failed, rendering {name}!')
            render_page(page)
    template = page.template
    with open(page.get_file('render.html'), 'r') as f:
        inserted = f.read()
    return render_template(template, markdown=inserted, config=page)


@app.route('/')
def index():
    return render_template('index.html', pages=get_all_pages(), PANDOC_LINK=PANDOC_LINK)