#! /usr/bin/python
# vim: ts=4 sw=4 et set fileencoding=utf-8

from datetime import date, timedelta, datetime
import os.path, errno, sys

# CONFIG
HTDOCS_DIR="/var/www/comics.spline.de/htdocs"
IMAGE_DIR=HTDOCS_DIR + "/imgs/"
TARGET_DIR=HTDOCS_DIR + "/sites/"
TEMPLATE_DIR="/var/www/comics.spline.de/templates"

from jinja2 import Environment, FileSystemLoader
env = Environment(loader=FileSystemLoader(TEMPLATE_DIR), autoescape=True)
template = env.get_template('base.html')

first_date = date(1997,01,01)

comics = {
        "dilbert": {
            "name": "Dilbert",
            "url": "http://www.dilbert.com/",
            "imageformat": "gif"
            },
        "xkcd": {
            "name": "xkcd",
            "url": "http://www.xkcd.com",
            "imageformat": "png"
            },
        "calvin": {
            "name": "Calvin",
            "url": "http://www.ucomics.com/calvinandhobbes/viewch.htm",
            "imageformat": "gif"
            },
        "garfield": {
            "name": "garfield",
            "url": "http://garfield.ucomics.com/garfield/gaview.htm",
            "imageformat": "gif"
            },
        "touche": {
            "name": u"Touché",
            "url": "http://www.taz.de/",
            "imageformat": "gif"
            },
        "userfriendly": {
            "name": "Userfriendly",
            "url": "http://www.userfriendly.org/static/",
            "imageformat": "gif"
            },
        "zits": {
            "name": "Zits",
            "url": "http://www.kingfeatures.com/features/comics/zits/about.htm",
            "imageformat": "gif"
            },
        "nichtlustig": {
            "name": "Nicht lustig!",
            "url": "http://www.nichtlustig.de",
            "imageformat": "jpg"
            },
        "claybennett": {
            "name": "Clay Bennett",
            "url": "http://www.csmonitor.com/commentary/index.html",
            "imageformat": "jpg"
            },
        "geekandpoke": {
            "name": "Geek and Poke",
            "url": "http://geekandpoke.typepad.com/",
            "imageformat": "jpg"
            },
        "snoopy": {
            "name": "Snoopy",
            "imageformat": "gif",
            "url": "http://www.gocomics.com/peanuts"
            },
        "cyanide": {
            "name": "Cyanide and Happiness",
            "imageformat": "png",
            "url": "http://www.explosm.net/comics/"
            },
        "phdcomics": {
            "name": "PHD comics",
            "imageformat": "gif",
            "url": "http://www.phdcomics.com/comics/archive.php"
            },
        "smbc": {
            "name": "SMBC",
            "imageformat": "png",
            "url": "http://www.smbc-comics.com/index.php"
            },
        "nerdragecomic": {
            "name": "Nerd Rage",
            "imageformat": "jpg",
            "url": "http://nerdragecomic.com/index.php"
            },
        "jeremykaye": {
            "name": "Up and Out",
            "imageformat": "png",
            "url": "http://jeremykaye.tumblr.com/"
            },
        }


# source: http://www.ianlewis.org/en/python-date-range-iterator
def datetimeIterator(from_date=None, to_date=None, delta=timedelta(minutes=1)):
    from_date = from_date or datetime.now()
    while to_date is None or from_date <= to_date:
        yield from_date
        from_date = from_date + delta
    return


def render_page(date, entries, prev=None, next=None):
    out_file = date.strftime("%%s/%Y/%m/%d.html") % TARGET_DIR

    try:
        os.makedirs(os.path.dirname(out_file))
    except OSError as exc:
        if exc.errno == errno.EEXIST:
            pass
        else: raise

    text = template.render(entries=entries, date=date, next=next, prev=prev)
    with open(out_file,'w') as f:
        f.write(text.encode('utf8'))


def render_all():
    date_range = datetimeIterator(first_date, date.today(), timedelta(days=1)) 
    relevant_dates = [d for d in date_range if exists_any_comic(d)]
    relevant_dates.append(None)

    prev_date, cur_date = None, None
    for next_date in relevant_dates:
        if cur_date:
            render_page(cur_date, gather_all_entries(cur_date), prev_date, next_date)
        prev_date, cur_date = cur_date, next_date


def find_surrounding_date(cur, delta):
    new_date = cur + delta

    while new_date >= first_date and new_date <= date.today():
        if exists_any_comic(new_date):
            return new_date
        new_date += delta
    return None


def render_date(cur_date, recurse=True):
    if not exists_any_comic(cur_date):
        return
    
    prev_date = find_surrounding_date(cur_date, timedelta(days=-1))
    next_date = find_surrounding_date(cur_date, timedelta(days=1))

    render_page(cur_date, gather_all_entries(cur_date), prev_date, next_date)
    print "Rendered page for: %s" % cur_date

    if recurse and prev_date:
        render_date(prev_date, False)
    if recurse and next_date:
        render_date(next_date, False)


def generate_basename(comic_id, date):
    return date.strftime("%%s/%%s/%Y-%m/%d") % (IMAGE_DIR, comic_id)


def add_support_content(entry, basename, type):
    if os.path.isfile(basename + "." + type):
        with open(basename + "." + type) as f:
            entry[type] = f.read().strip().decode('utf8')


def gather_all_entries(my_date):
    entries = []
    for (comic_id, comic) in comics.iteritems():
        basename = generate_basename(comic_id, my_date)
        expected_path = basename + "." + comic["imageformat"]

        if os.path.isfile(expected_path):
            if expected_path.startswith(HTDOCS_DIR):
                expected_path = expected_path[len(HTDOCS_DIR):]

            entry = {
               "path":  expected_path,
               "comic": comic,
            }

            add_support_content(entry, basename, "title");
            add_support_content(entry, basename, "alt");
            entries.append(entry)

    return entries


def exists_any_comic(my_date):
    for (comic_id, comic) in comics.iteritems():
        basename = generate_basename(comic_id, my_date)
        expected_path = basename + "." + comic["imageformat"]

        if os.path.isfile(expected_path):
            return True

    return False


if __name__ == "__main__":
    if len(sys.argv) > 1 and sys.argv[1] == "-a": 
        render_all()
    else:
        ago = date.today()
        try:
            if len(sys.argv) > 1:
                ago -= timedelta(days=int(sys.argv[1]))
        except ValueError:
            pass

        render_date(ago)