import urllib
import socket
import os
import urllib.parse
import urllib.request
import subprocess
import logging
from .common import KEY_ALBUM, KEY_ARTIST, KEY_GENRE, KEY_TITLE, KEY_TRACK, KEY_YEAR

try:
    from config import APP_NAME as ROOT_LOGGER_NAME
except ImportError:
    ROOT_LOGGER_NAME = 'root'
logger = logging.getLogger(ROOT_LOGGER_NAME).getChild(__name__)


version = 2.0
if 'EMAIL' in os.environ:
    (default_user, hostname) = os.environ['EMAIL'].split('@')
else:
    default_user = os.environ['USER'] or os.geteuid() or 'user'
    hostname = socket.gethostname() or 'host'

proto = 6
default_server = 'http://gnudb.gnudb.org/~cddb/cddb.cgi'


def my_disc_metadata(**kwargs):
    """Generate my disc metadata

    kwargs needs to include the following data:
        * KEY_ARTIST (str)
        * KEY_ALBUM (str)
        * KEY_YEAR (int) - will be converted here
        * KEY_GENRE (str)
        * "track_xx" (str) - where xx is the track number which will be converted to int here
    """
    main_dict = {}
    for key in [KEY_ARTIST, KEY_ALBUM, KEY_YEAR, KEY_GENRE]:
        try:
            value = kwargs.pop(key)
        except KeyError:
            logger.error("Information is missing in kwargs - key=%s", key)
            return None
        if key in [KEY_YEAR]:
            try:
                main_dict[key] = int(value)
            except ValueError:
                logger.error("Can't convert %s (key=%s) to integer value", value, key)
                return None
        else:
            main_dict[key] = value
    rv = dict(main_dict)
    rv["tracks"] = []
    for key in list(kwargs):
        value = kwargs.pop(key)
        if key.startswith("track_"):
            track = dict(main_dict)
            try:
                track[KEY_TRACK] = int(key[6:])
            except ValueError:
                logger.warning("Useless information kwargs - kwargs[%s] = %s", key, repr(value))
            track[KEY_TITLE] = value
            rv["tracks"].append(track)
        else:
            logger.warning("Useless information kwargs - key=%s", key)
    return rv


def query(data_str, server_url=default_server, user=default_user, host=hostname, client_name=ROOT_LOGGER_NAME, client_version=version):
    url = f"{server_url}?cmd=cddb+query+{data_str}&hello={user}+{host}+{client_name}+{client_version}&proto={proto}"
    response = urllib.request.urlopen(url)
    header = response.readline().decode("utf-8").rstrip().split(" ", 3)
    header[0] = int(header[0])

    if header[0] not in (210, ):
        logger.error("Error while querying cddb entry: \"%d - %s\"", header[0], header[3])
        return None

    rv = {}
    for line in response.readlines():
        line = line.decode("utf-8").rstrip()
        if line == '.':                # end of matches
            break
        dummy, did, txt = line.split(" ", 2)
        rv[did] = txt
    return rv


def cddb(disc_id, server_url=default_server, user=default_user, host=hostname, client_name=ROOT_LOGGER_NAME, client_version=version):
    KEY_TRANSLATOR = {
        "DGENRE": KEY_GENRE,
        "DYEAR": KEY_YEAR
    }
    #
    url = f"{server_url}?cmd=cddb+read+data+{disc_id}&hello={default_server}+{hostname}+{client_name}+{client_version}&proto={proto}"
    response = urllib.request.urlopen(url)

    header = response.readline().decode("utf-8").rstrip().split(" ", 3)
    header[0] = int(header[0])

    if header[0] not in (210, ):
        logger.error("Error while reading cddb entry: \"%d - %s\"", header[1], header[3])
        return None
    data = {}
    for line in response.readlines():
        line = line.decode("utf-8").rstrip()
        if line == '.':                # end of matches
            break
        if not line.startswith("#"):
            match = line.split('=', 2)
            key = KEY_TRANSLATOR.get(match[0])
            value = match[1].strip()
            if key:
                if key == KEY_YEAR:
                    value = int(value)
                data[key] = value
            elif match[0] == "DTITLE":
                art_tit = value.split("/", 2)
                data[KEY_ARTIST] = art_tit[0].strip()
                data[KEY_ALBUM] = art_tit[1].strip()
            elif match[0].startswith("TTITLE"):
                data["track_%02d" % (int(match[0][6:]) + 1)] = value
            else:
                logger.debug("cddb line ignored: \"%s\"", line)
    return my_disc_metadata(**data)


def discid():
    discid_cmd = subprocess.getoutput("which cd-discid")
    if not discid_cmd:
        logger.error("cd-discid is required for encoding. You need to install it to your system.")
        return None
    else:
        try:
            return subprocess.check_output(discid_cmd).decode("utf-8").strip().replace(" ", "+")
        except subprocess.CalledProcessError as e:
            return None