#!/bin/python2

# only using python2 because mutagen
from __future__ import print_function

import os
import os.path
import sys
import shutil
import mutagen

import mutaext
import convert

updatabletags = [\
    'albumartist', 'composer', 'comment' \
    'tracknumber', 'discnumber', \
    'genre', 'date', \
]
updatabletags.extend(mutaext.replaygain_tags)
updatabletags.extend(mutaext.extra_tags)

alltags = list(updatabletags)
alltags.extend(['artist', 'album', 'title'])

def G(d, k):
    try:
        return d[k]
    except KeyError:
        return None

def walkfiles(walker):
    for root, _, files in walker:
        for f in files:
            yield os.path.join(root, f)

def filterext(paths, exts):
    for p in paths:
        ext = os.path.splitext(p)[1].lower()
        if ext in exts:
            yield p

def shouldsync(md):
    rating = G(md, 'rating')
    sync = G(md, 'sync')
    try:
        rating = int(rating[0])
    except:
        pass
    if sync:
        sync = sync[0].lower()
    else:
        sync = u''

    if sync == u'no' or sync == u'space':
        return False
    if sync == u'yes' or sync == u'share':
        return True
    if type(rating) == int and rating >= 3:
        return True
    return False

def fixmetadata(md):
    if 'artist' not in md:
        md['artist'] = "Unknown Artist"
    if 'album' not in md:
        md['album'] = "Unknown Album"
    if 'title' not in md:
        fn = os.path.basename(md.path)
        fn = os.path.splitext(fn)[0]
        # TODO: attempt to infer trackNum/discNum from fn
        md['title'] = fn

def findmatching(haystack, needle):
    # TODO: don't match mismatched lengths (Xing?)
    artist = G(needle, 'artist')
    album = G(needle, 'album')
    title = G(needle, 'title')
    match = None
    for hay in haystack:
        if artist == G(hay, 'artist') \
          and album == G(hay, 'album') \
          and title == G(hay, 'title'):
            match = hay
            if match.seen:
                # TODO: check other tags and filename and such?
                print("Warning: duplicate match found:", file=sys.stderr)
                print("{0} by {1} from {2}".format(artist,album,title), file=sys.stderr)
            else:
                match.seen = True
                break
    return match

def updatemetadata(mdold, mdnew):
    modified = False
    # TODO: ensure genre and date work properly (special cases in EasyID3)
    for tag in updatabletags:
        if tag in mdnew:
            if not tag in mdold:
                #print("not in old:",tag)
                mdold[tag] = mdnew[tag]
            elif mdnew[tag][0] != mdold[tag][0]:
                #print("in old:",tag)
                mdold[tag] = mdnew[tag]
                modified = True
        elif tag in mdold:
            del mdold[tag]
            modified = True
    return modified

def makefilename(md):
    fn = ""
    title = md['title'][0]
    artist = md['artist'][0]
    album = md['album'][0]
    fn = u"{1} - {2} - {0}".format(title,artist,album)
    fn += ".ogg"
    return fn

def run(args):
    if not len(args) in (2, 3):
        print("I need a path or two!", file=sys.stderr)
        return 1

    inonly = len(args) == 2

    # BUG: doesn't work with my .m4a files?
    goodexts = ('.mp3', '.m4a', '.flac', '.ogg')
    tosync = []
    indir = args[1]
    paths = lambda dir: filterext(walkfiles(os.walk(dir)), goodexts)

    for p in paths(indir):
        md = mutagen.File(p, easy=True)
        if shouldsync(md):
            if inonly:
                print(p)
            else:
                # TODO: don't use custom members on external metadata class
                md.path = p
                md.seen = False
                fixmetadata(md)
                tosync.append(md)

    if inonly:
        return 0

    print("Matching...", file=sys.stderr)

    outdir = args[2]
    for p in paths(outdir):
        md = mutagen.File(p, easy=True)
        match = findmatching(tosync, md)
        if match:
            if updatemetadata(md, match):
                print("UPD", p)
                md.save()
        else:
            print("DEL", p)
            os.remove(p)

    for md in tosync:
        if md.seen == False:
            print("ADD", md.path)
            outf = os.path.join(outdir, makefilename(md))
            #print("TO", outf)
            temppath = convert.ogg(md.path)
            mdnew = mutagen.File(temppath, easy=True)
            for tag in alltags:
                if tag in md:
                    mdnew[tag] = md[tag]
            mdnew.save()
            shutil.move(temppath, outf)

    return 0

ret = 0
try:
    ret = run(sys.argv)
except KeyboardInterrupt:
    sys.exit(1)
sys.exit(ret)