import re
import os
import hashlib
from threading import Thread
import pickle
import urllib
import datetime


### TSV files

def parseTSV(filename,*args,escape=True):
	f = open(filename)
	
	result = []
	for l in [l for l in f if (not l.startswith("#")) and (not l.strip()=="")]:
		
		l = l.replace("\n","")
		if escape:
			l = l.split("#")[0]
		l = l.replace(r"\num","#") # translate escape sequences even if we don't support comments in the file and they are not actually necessary (they might still be used for some reason)
		data = list(filter(None,l.split("\t"))) # Multiple tabs are okay, we don't accept empty fields unless trailing
		entry = [] * len(args)
		for i in range(len(args)):
			if args[i]=="list":
				try:
					entry.append(data[i].split("␟"))
				except:
					entry.append([])
			elif args[i]=="string":
				try:
					entry.append(data[i])
				except:
					entry.append("")
			elif args[i]=="int":
				try:
					entry.append(int(data[i]))
				except:
					entry.append(0)
			elif args[i]=="bool":
				try:
					entry.append((data[i].lower() in ["true","yes","1","y"]))
				except:
					entry.append(False)
				
		result.append(entry)
		
	f.close()
	return result
	
def checksumTSV(folder):
	
	sums = ""
	
	for f in os.listdir(folder + "/"):
		if (f.endswith(".tsv")):
			f = open(folder + "/" + f,"rb")
			sums += hashlib.md5(f.read()).hexdigest() + "\n"
			f.close()
			
	return sums
	
# returns whether checksums match and sets the checksum to invalid if they don't (or sets the new one if no previous one exists)
def combineChecksums(filename,checksums):
	import os
	
	if os.path.exists(filename + ".rulestate"):
		f = open(filename + ".rulestate","r")
		oldchecksums = f.read()
		f.close()
		if oldchecksums == checksums:
		# the new checksum given by the calling db server represents the rule state that all current unsaved scrobbles were created under
		# if this is the same as the existing one, we're all good
			return True
		elif (oldchecksums != "INVALID"):
			#if not, the file is not consistent to any single rule state (some scrobbles were created with an old ruleset, some not)
			f = open(filename + ".rulestate","w")
			f.write("INVALID") # this will never match any sha256sum
			f.close()
			return False
		else:
			#if the file already says invalid, no need to open it and rewrite
			return False
	else:
		f = open(filename + ".rulestate","w")
		f.write(checksums)
		f.close()
		return True
	
# checks ALL files for their rule state. if they are all the same as the current loaded one, the entire database can be assumed to be consistent with the current ruleset
# in any other case, get out
def consistentRulestate(folder,checksums):
	
	result = []
	for scrobblefile in os.listdir(folder + "/"):
		
		if (scrobblefile.endswith(".tsv")):
		
			try:
				f = open(folder + "/" + scrobblefile + ".rulestate","r")
				if f.read() != checksums:
					return False
			
			except:
				return False
			finally:
				f.close()
	
	return True
	
	
def parseAllTSV(path,*args,escape=True):

	
	result = []
	for f in os.listdir(path + "/"):
		
		if (f.endswith(".tsv")):
			
			result += parseTSV(path + "/" + f,*args,escape=escape)
			
	return result
	
def createTSV(filename):

	if not os.path.exists(filename):
		open(filename,"w").close()

def addEntry(filename,a,escape=True):

	createTSV(filename)
	
	line = "\t".join(a)
	if escape: line = line.replace("#",r"\num")
	with open(filename,"a") as f:
		f.write(line + "\n")

def addEntries(filename,al,escape=True):
	
	with open(filename,"a") as f:
		for a in al:
			line = "\t".join(a)
			if escape: line = line.replace("#",r"\num")
			f.write(line + "\n")



### Useful functions

def int_or_none(input_):
	try:
		return int(input_)
	except:
		return None
		
def cleandict(d):
	newdict = {k:d[k] for k in d if d[k] is not None}
	d.clear()
	d.update(newdict)



		
		
### Logging
		
def log(msg,module=None):
	now = datetime.datetime.utcnow().strftime("%Y/%m/%d %H:%M:%S")
	if module is None:
		import inspect
		module = inspect.getmodule(inspect.stack()[1][0]).__name__
		if module == "__main__": module = "mainserver"
	print("[" + module + "] " + msg)
	with open("logs/" + module + ".log","a") as logfile:
		logfile.write(now + "  " + msg + "\n")
	
	
### not meant to be precise, just for a rough idea
measurement = 0
def clock(*args):
	import time
	global measurement
	now = time.time()
	if len(args) > 0:
		print(args[0] + ": " + str(now - measurement))
	measurement = now




### Media info

def apirequest(artists=None,artist=None,title=None):
	
	import urllib.parse, urllib.request
	import json
	
	try:
		with open("apikey","r") as keyfile:
			apikey = keyfile.read().replace("\n","")
			
		if apikey == "NONE": return None
	except:
		return None
	
	
	sites = [
		{
			"name":"lastfm",
			"artisturl":"https://ws.audioscrobbler.com/2.0/?method=artist.getinfo&artist={artist}&api_key=" + apikey + "&format=json",
			"trackurl":"https://ws.audioscrobbler.com/2.0/?method=track.getinfo&track={title}&artist={artist}&api_key=" + apikey + "&format=json",
			"result_artist_imgurl":lambda data:data["artist"]["image"][3]["#text"],
			"result_track_imgurl":lambda data:data["track"]["album"]["image"][3]["#text"]
			#"result_artist_desc":lambda data:data["artist"]["bio"]["summary"],
			#"result_track_desc":lambda data:None
		}
	]
	
	
	# TRACKS
	if title is not None:
		for s in sites:
			try:
				artiststr = urllib.parse.quote(", ".join(artists))
				titlestr = urllib.parse.quote(title)
				response = urllib.request.urlopen(s["trackurl"].format(artist=artiststr,title=titlestr))
				log("API: " + s["name"] + "; Image request: " + "/".join(artists) + " - " + title,module="external")
				data = json.loads(response.read())
				if s["result_track_imgurl"](data) != "":
					return s["result_track_imgurl"](data)
			except:
				pass
		
		if len(artists) == 1:
			#return {"image":apirequest(artist=artists[0])["image"]}
			return None
				
		# try the same track with every single artist
		for a in artists:
			rec = apirequest(artists=[a],title=title)
			if rec is not None:
				return rec
				
		return None
		
	# ARTISTS		
	else:
		for s in sites:
			try:
				response = urllib.request.urlopen(s["artisturl"].format(artist=urllib.parse.quote(artist)))
				log("API: " + s["name"] + "; Image request: " + artist,module="external")
				data = json.loads(response.read())
				if s["result_artist_imgurl"](data) != "":
					return s["result_artist_imgurl"](data)
			except:
				pass
		
		return None

# I think I've only just understood modules
cachedTracks = {}
cachedArtists = {}

def saveCache():
	fl = open("images/cache","wb")
	stream = pickle.dumps((cachedTracks,cachedArtists))
	fl.write(stream)
	fl.close()
	
def loadCache():
	try:
		fl = open("images/cache","rb")
	except:
		return
		
	try:
		ob = pickle.loads(fl.read())
		global cachedTracks, cachedArtists
		(cachedTracks, cachedArtists) = ob
	finally:
		fl.close()
		
	# remove corrupt caching from previous versions
	toremove = []
	for k in cachedTracks:
		if cachedTracks[k] == "":
			toremove.append(k)
	for k in toremove:
		del cachedTracks[k]
		log("Removed invalid cache key: " + str(k))
	
	toremove = []
	for k in cachedArtists:
		if cachedArtists[k] == "":
			toremove.append(k)
	for k in toremove:
		del cachedArtists[k]
		log("Removed invalid cache key: " + str(k))

def getTrackImage(artists,title,fast=False):

	obj = (frozenset(artists),title)
	filename = "-".join([re.sub("[^a-zA-Z0-9]","",artist) for artist in artists]) + "_" + re.sub("[^a-zA-Z0-9]","",title)
	if filename == "": filename = str(hash(obj))
	filepath = "images/tracks/" + filename
	
	# check if custom image exists
	if os.path.exists(filepath + ".png"):
		imgurl = "/" + filepath + ".png"
		return imgurl
	elif os.path.exists(filepath + ".jpg"):
		imgurl = "/" + filepath + ".jpg"
		return imgurl
	elif os.path.exists(filepath + ".jpeg"):
		imgurl = "/" + filepath + ".jpeg"
		return imgurl
		
	try:
		# check our cache
		# if we have cached the nonexistence of that image, we immediately return the redirect to the artist and let the resolver handle it
		# (even if we're not in a fast lookup right now)
		result = cachedTracks[(frozenset(artists),title)]
		if result is not None: return result
		else:
			for a in artists:
				res = getArtistImage(artist=a,fast=True)
				if res != "": return res
			return ""
	except:
		pass
	
	
	# fast request only retuns cached and local results, generates redirect link for rest
	if fast: return "/image?title=" + urllib.parse.quote(title) + "&" + "&".join(["artist=" + urllib.parse.quote(a) for a in artists])
	
	# non-fast lookup (esentially only the resolver lookup)
	result = apirequest(artists=artists,title=title)
	
	# cache results (even negative ones)
	cachedTracks[(frozenset(artists),title)] = result
	
	# return either result or redirect to artist
	if result is not None: return result
	else:
		for a in artists:
			res = getArtistImage(artist=a,fast=False)
			if res != "": return res
		return ""

	
	
def getArtistImage(artist,fast=False):	
		
	obj = artist
	filename = re.sub("[^a-zA-Z0-9]","",artist)
	if filename == "": filename = str(hash(obj))
	filepath = "images/artists/" + filename
	#filepath_cache = "info/artists_cache/" + filename
	
	# check if custom image exists
	if os.path.exists(filepath + ".png"):
		imgurl = "/" + filepath + ".png"
		return imgurl
	elif os.path.exists(filepath + ".jpg"):
		imgurl = "/" + filepath + ".jpg"
		return imgurl
	elif os.path.exists(filepath + ".jpeg"):
		imgurl = "/" + filepath + ".jpeg"
		return imgurl
	

	try:
		result = cachedArtists[artist]
		if result is not None: return result
		else: return ""
	except:
		pass
		
	
		
	# fast request only retuns cached and local results, generates redirect link for rest
	if fast: return "/image?artist=" + urllib.parse.quote(artist)
	
	# non-fast lookup (esentially only the resolver lookup)	
	result = apirequest(artist=artist)
	
	# cache results (even negative ones)
	cachedArtists[artist] = result
	
	if result is not None: return result
	else: return ""

def getTrackImages(trackobjectlist,fast=False):

	threads = []
	
	for track in trackobjectlist:
		t = Thread(target=getTrackImage,args=(track["artists"],track["title"],),kwargs={"fast":fast})
		t.start()
		threads.append(t)
	
	for t in threads:
		t.join()
		
		
	return [getTrackImage(t["artists"],t["title"]) for t in trackobjectlist]
	
def getArtistImages(artistlist,fast=False):
	
	threads = []
	
	for artist in artistlist:
		t = Thread(target=getArtistImage,args=(artist,),kwargs={"fast":fast})
		t.start()
		threads.append(t)
	
	for t in threads:
		t.join()
	
	# async calls only cached results, now we need to get them	
	return [getArtistImage(a) for a in artistlist]



# new way of serving images
# instead always generate a link locally, but redirect that on the fly
# this way the page can load faster and images will trickle in without having to resort to XHTTP requests

def resolveImage(artist=None,track=None):
	if track is not None:
		return getTrackImage(track["artists"],track["title"])
	elif artist is not None:
		return getArtistImage(artist)