import email
import time
from pathlib import Path
from xml.etree import ElementTree


POST_ACTUALITIES = 'actualites'
POST_JOBS = 'emplois'
POSTS = {POST_ACTUALITIES: "Actualités", POST_JOBS: "Offres d’emploi"}

STATE_WAITING = 'waiting'
STATE_PUBLISHED = 'published'
STATES = {STATE_WAITING: "En attente", STATE_PUBLISHED: "Publié"}

ACTION_PUBLISH = 'publish'
ACTION_UNPUBLISH = 'unpublish'
ACTIONS = {ACTION_PUBLISH: "Publier", ACTION_UNPUBLISH: "Dépublier"}

TIMESTAMP = '_timestamp'
STATE = '_state'
PATH = '_path'
DIR = '_dir'

BASE_DIR = 'posts'
BASE_FILE = 'post.xml'


class DataException(Exception):
    def __init__(self, *args, http_code=None, **kwargs):
        self.http_code = http_code
        super().__init__(*args, **kwargs)


root = Path(__file__).parent / BASE_DIR
for category in POSTS:
    for state in STATES:
        (root / category / state).mkdir(parents=True, exist_ok=True)


def get_path(category, state, timestamp, *args, create_dir=False):
    path = root / category / state / timestamp
    if create_dir:
        path.mkdir(exist_ok=True)
    for arg in args:
        path /= arg
    return path


def count_posts(category, state=STATE_PUBLISHED):
    return len(tuple((root / category / state).iterdir()))


def get_posts(category, state=STATE_PUBLISHED, start=0, end=None):
    path = root / category / state
    timestamps = sorted(path.iterdir(), reverse=True)
    timestamps = timestamps[start:end] if end else timestamps[start:]
    for timestamp in timestamps:
        yield get_post(category, timestamp.name, state)


def get_post(category, timestamp, states=None):
    states = (
        states
        if isinstance(states, (tuple, list))
        else [states]
        if isinstance(states, str)
        else STATES
    )
    for state in states:
        dir = root / category / state / timestamp
        path = dir / BASE_FILE
        if path.is_file():
            break
    else:
        return None
    tree = ElementTree.parse(path)
    post = {item.tag: (item.text or '').strip() for item in tree.iter()}
    post[TIMESTAMP] = int(timestamp)
    post[STATE] = state
    post[DIR] = dir
    post[PATH] = path
    return post


def save_post(category, timestamp, admin, form):
    if timestamp is None:
        status = STATE_WAITING
        timestamp = str(int(time.time()))
    elif get_path(category, STATE_WAITING, timestamp, BASE_FILE).is_file():
        status = STATE_WAITING
    elif get_path(category, STATE_PUBLISHED, timestamp, BASE_FILE).is_file():
        status = STATE_PUBLISHED
    else:
        raise DataException(http_code=404)
    if status == STATE_PUBLISHED and not admin:
        raise DataException(http_code=401)

    post = get_path(category, status, timestamp, BASE_FILE, create_dir=True)
    tree = ElementTree.Element('entry')
    for key, value in form.items():
        if key.startswith('_'):
            continue
        element = ElementTree.SubElement(tree, key)
        element.text = value
    element = ElementTree.SubElement(tree, STATE_PUBLISHED)
    element.text = email.utils.formatdate(
        int(timestamp) if timestamp else time.time()
    )
    ElementTree.ElementTree(tree).write(post)

    if admin:
        if ACTION_PUBLISH in form and status == STATE_WAITING:
            (root / category / STATE_WAITING / timestamp).rename(
                root / category / STATE_PUBLISHED / timestamp
            )
        elif ACTION_UNPUBLISH in form and status == STATE_PUBLISHED:
            (root / category / STATE_PUBLISHED / timestamp).rename(
                root / category / STATE_WAITING / timestamp
            )

    return get_post(category, timestamp)