"""
The main file. The AmpacheClient class allows us to make requests to the
API.
"""
from datetime import datetime
from ampache import models, exceptions
import requests


def get_utc_offset(time):
    """
    All the datetimes the API yields are in the form yyyy-mm-ddthh:mm:ss-00:00,
    where the last 5 characters are the UTC offset. Python datetime objects can
    parse this data, but in the form 0000 (sans the :) so we have to remove it.
    """
    prefix = time[:len(time) - 5]
    suffix = time[len(time) - 5:].replace(':', '')

    return prefix + suffix


class AmpacheClient:
    """
    The ampache client class. Responsible for making API calls to your ampache
    instance.
    """
    def __init__(self, host, api_key, version):
        """
        Host: url of your apache instance.
        api_key: your api key (you can get it under settings->account). It's
        preferable that you provide an admin's api key.
        """
        self._endpoint = '/server/json.server.php?'
        self._version = version
        self._host = host
        self._api_key = api_key
        self.authenticate()

    def raise_by_status(self, error):
        """
        The ampache API has a bunch of error codes that can help us diagnose
        the problem. Depending of the error code, we'll raise an appropiate exception.
        """
        if error.code == exceptions.ACCESS_ERROR_CODE:
            raise exceptions.AccessException(error.message)
        elif error.code == exceptions.AUTHENTICATION_ERROR_CODE:
            raise exceptions.AuthenticationException(error.message)
        elif error.code == exceptions.ACCESS_DENIED_ERROR_CODE:
            raise exceptions.AccessDeniedException(error.message)
        elif error.code == exceptions.NOT_FOUND_ERROR_CODE:
            raise exceptions.NotFoundException(error.message)
        elif error.code == exceptions.MISSING_ERROR_CODE:
            raise exceptions.MissingMethodException(error.message)
        elif error.code == exceptions.DEPRECIATED_ERROR_CODE:
            raise exceptions.DepreciatedMethodException(error.message)
        elif error.code == exceptions.BAD_REQUEST_ERROR_CODE:
            raise exceptions.BadRequestException(error.message)
        elif error.code == exceptions.FAILED_ACCESS_ERROR_CODE:
            raise exceptions.FailedAccessException(error.message)

    def request(self, params, headers):
        """
        All in one function to pass requests to the API.
        """
        response = requests.get(self._host + self._endpoint, params=params,
                                headers=headers)
        if not response.ok:
            response.raise_for_status()

        if headers['Content-type'] == 'application/json':
            response = response.json()

            if 'error' in response:
                self.raise_by_status(models.Error(int(response['error']['errorCode']),
                                                  response['error']['errorMessage']))

        return response

    def authenticate(self):
        """
        Authenticate with the API, setting the token.
        """
        params = {
            'action': 'handshake',
            'auth': self._api_key,
            'version': self._version
        }
        headers = {
            'Content-type': 'application/json'
        }

        data = self.request(params, headers)
        self._auth = models.AuthToken(datetime.strptime(get_utc_offset(data['session_expire']), '%Y-%m-%dT%H:%M:%S%z'),
                                      data['auth'])

    def get_song(self, song_id):
        """
        Get the detail of a song given its primary key.
        """
        self.renew_token()

        params = {
            'action': 'song',
            'auth': self._auth.auth,
            'filter': song_id,
            'version': self._version
        }
        headers = {
            'Content-type': 'application/json'
        }
        data = self.request(params, headers)
        song = models.Song(data['id'], data['title'], data['album']['name'],
                           data['albumartist']['name'])

        return song

    def get_album(self, album_id):
        params = {
            'action': 'album_songs',
            'auth': self._auth.auth,
            'filter': album_id,
            'version': self._version
        }
        headers = {
            'Content-type': 'application/json'
        }
        data = self.request(params, headers)
        album = self.process_album(data)

        return album

    def process_album(self, album_data):
        album_id = album_data['song'][0]['album']['id']
        album_title = album_data['song'][0]['album']['name']
        album_artist = album_data['song'][0]['artist']['name']
        songs = []

        for song in album_data['song']:
            new_song = models.Song(song['id'], song['title'], album_title,
                                   album_artist)
            songs.append(new_song)

        return models.Album(album_id, album_title, album_artist, songs)

    def download(self, song_id, destination):
        """
        Download a song to destination.
        """
        params = {
            'action': 'download',
            'auth': self._auth.auth,
            'type': 'song',
            'id': song_id,
            'version': self._version,
            'format': 'mp3'
        }
        headers = {
            'Content-type': 'audio/mpeg'
        }
        data = self.request(params, headers)

        with open(destination, 'wb') as song:
            song.write(data.content)

    def renew_token(self):
        if datetime.now(self._auth.expires.tzinfo) > self._auth.expires:
            self.authenticate()

    def get_token(self):
        return self._auth