import jinja2
import os
import subprocess
from operator import itemgetter
from collections import namedtuple
from os.path import getmtime
import json


def extract_metadata(ipynb_file):
    Metadata = namedtuple('Metadata', ['tags', 'completion_date'])
    with open(ipynb_file, 'r') as f:
        j = json.load(f)
    try:
        tags = j['metadata']['tags']
        completion_date = j['metadata']['completion_date']
    except KeyError:
        raise Exception('Failed extracting meta from {}.'.format(ipynb_file))
    return Metadata(tags, completion_date)


def file_name_to_solution(name):
    Solution = namedtuple('Solution', ["number", "ipynb", "html", "name", "metadata"])
    number = int(name.replace("EulerProblem", "").replace(".ipynb", ""))
    ipynb = name
    metadata =  extract_metadata(ipynb)
    html = name.replace(".ipynb", ".html")
    name = name.replace("EulerProblem", "Problem ").replace(".ipynb", "")
    return Solution(number, ipynb, html, name, metadata)


def get_solution_list(directory="./"):
    l = [file_name_to_solution(f) for f in os.listdir(directory)
        if f.endswith(".ipynb") and f.startswith("EulerProblem")]
    l.sort(key=itemgetter(0))
    return l


def convert_solutions_to_html(solutions):
    for s in solutions:
        if getmtime(s.html) < getmtime(s.ipynb):
            args = ["ipython", "nbconvert", s.ipynb]
            subprocess.call(args)


def render_solutions(solutions):
    loader = jinja2.FileSystemLoader(searchpath="./")
    env = jinja2.Environment(loader=loader)
    template = env.get_template("template.html")
    d = {"solutions": solutions}
    with open("index.html", 'w') as f:
        f.write(template.render(**d))


def convert_solutions_to_html(solutions):
    for s in solutions:
        if not os.path.isfile(s.html) or getmtime(s.html) < getmtime(s.ipynb):
            args = ["ipython", "nbconvert", s.ipynb]
            subprocess.call(args)


def ship_to_failx():
    for f in os.listdir():
        if f.endswith(".html"):
            args = ["scp", f, "failx@felixm.de:~/html/euler/"]
            subprocess.call(args)


if __name__ == "__main__":
    solutions = get_solution_list()
    convert_solutions_to_html(solutions)
    render_solutions(solutions)
    #ship_to_failx()