#!/usr/bin/python3 -B

# https://developer.spotify.com/console/

from urllib import request
from json import loads as json_read, dumps as json_write
from random import shuffle
from time import strftime


def unduplicate_list (tracks):
	known = []
	cur = 0
	while cur < len (tracks):
		if tracks [cur] in known:
			del tracks [cur]
			continue
		known.append (tracks [cur])
		cur += 1


def get_or_post (token, url, data = None):
	d = None
	if type (data) == bytes:
		d = data
	elif type (data) == str:
		d = data.encode ('UTF-8')
	t = request.urlopen (request.Request (url, data = d, headers = {'Authorization': 'Bearer ' + token}))
	return (json_read (t.read ()))


def get_user_id (token):
	return (get_or_post (token, 'https://api.spotify.com/v1/me') ['id'])


def list_playlists (token):
	r = {}
	for i in get_or_post (token, 'https://api.spotify.com/v1/me/playlists') ['items']:
		r [i ['id']] = i ['name']
	return (r)


def read_playlist (token, id):
	r = []
	index = 0
	limit = 100
	while True:
		count = 0
		for i in get_or_post (token, 'https://api.spotify.com/v1/playlists/' + id + '/tracks?offset=' + str (index) + '&limit=' + str (limit)) ['items']:
			r.append (i ['track'] ['uri'])
			count += 1
		index += limit
		if count != limit:
			break
	return (r)


def create_playlist (token, name, description, tracks):
	playlist_id = get_or_post (token, 'https://api.spotify.com/v1/users/' + get_user_id (token) + '/playlists', data = json_write ({'name': name, 'description': description, 'public': False})) ['id']
	
	p = 0
	limit = 100
	while True:
		t = tracks [p:p+limit]
		get_or_post (token, 'https://api.spotify.com/v1/playlists/' + playlist_id + '/tracks', data = json_write ({'position': p, 'uris': t}))
		if len (t) == limit:
			p += limit
		else:
			break


def playlist_shuffle (token, playlist):
	tracks = read_playlist (token, playlist)
	unduplicate_list (tracks)
	shuffle (tracks)
	create_playlist (token, list_playlists (token) [playlist] + ' - Shuffled ' + strftime ('%Y-%m-%d %H:%M:%S'), 'Shuffled playlist', tracks)


def playlist_unduplicate (token, playlist):
	tracks = read_playlist (token, playlist)
	unduplicate_list (tracks)
	create_playlist (token, list_playlists (token) [playlist] + ' - Undiplicates', 'Non duplicated playlist', tracks)


if __name__ == '__main__':
	raise (NotImplementedError ('no CLI interface yet'))