#!/bin/python

import os, os.path
import sys
from shutil import copy2
from tempfile import mkstemp
from zlib import crc32

import mutaext
import convert
from mutaext import SyncFile

goodexts = ('.mp3', '.flac', '.ogg')

matchtags = ['artist', 'album', 'title']
alltags = [
    'albumartist', 'composer', 'comment',
    'tracknumber', 'discnumber',
    'genre', 'date',
]
alltags.extend(mutaext.replaygain_tags)
alltags.extend(mutaext.extra_tags)
alltags.extend(matchtags)

lament = lambda *args, **kwargs: print(*args, file=sys.stderr, **kwargs)
walkfiles = lambda w: (os.path.join(r, f) for r, _, fs in w for f in fs)
extof = lambda p: os.path.splitext(p)[1].lower()
filterext = lambda ps, es: (p for p in ps if extof(p) in es)

def shouldsync(md):
    rating = md.get('rating', '')
    sync = md.get('sync', '')
    if rating.isnumeric():
        rating = int(rating)
    if sync:
        sync = sync.lower()

    return sync == 'yes' or type(rating) == int and rating >= 3 and sync != 'no' and sync != 'space'

def fixmetadata(md):
    md['artist'] = md.get('artist', "Unknown Artist")
    md['album'] = md.get('album', "Unknown Album")
    if 'title' not in md:
        fn = os.path.basename(md.path)
        fn = os.path.splitext(fn)[0]
        md['title'] = str(fn)

def findmatching(haystack, needle):
    matchme = [needle[t].lower() for t in matchtags]
    ismatch = lambda hay: [hay[t].lower() for t in matchtags] == matchme
    for match in (hay for hay in haystack if ismatch(hay)):
        if match.seen:
            # TODO: check other tags too?
            lament("Duplicate")
            return None
        match.seen = needle.path
        return match

def updatemetadata(mdold, mdnew):
    modified = False
    for tag in alltags:
        if tag in mdnew:
            if tag not in mdold or mdnew[tag] != mdold[tag]:
                mdold[tag] = mdnew[tag]
                modified = True
        elif tag in mdold:
            del mdold[tag]
            modified = True
    return modified

def makefilename(md):
    title = md['title']
    artist = md['artist']
    album = md['album']

    fn = "%(artist)s - %(album)s - %(title)s" % locals()
    # FAT is a pain to deal with so just use nondescript filenames
    crc = crc32(fn.encode('utf-8')) & 0xFFFFFFFF
    fn = '{:08X}.ogg'.format(crc)

    return fn

def run(args):
    if not len(args) in (2, 3):
        lament("I need a path or two!")
        return 1
    inonly = len(args) == 2

    tosync = []
    indir = args[1]
    paths = lambda dir: filterext(walkfiles(os.walk(dir)), goodexts)

    for p in paths(indir):
        md = SyncFile(p)
        if shouldsync(md):
            if inonly:
                print(p)
            else:
                fixmetadata(md)
                tosync.append(md)

    if inonly:
        return 0

    lament("Matching tags...")

    outdir = args[2]
    for p in paths(outdir):
        md = SyncFile(p)
        match = findmatching(tosync, md)
        if match == None:
            print("DEL", p)
            os.remove(p)
        elif updatemetadata(md, match):
            print("UPD", p)
            md.save()

    lament("Syncing files...")

    for md in tosync:
        fn = makefilename(md)
        fout = os.path.join(outdir, fn)

        if md.seen:
            _from = md.seen
            _to = fout
            if _from != _to:
                print("MOV", _from)
                os.rename(_from, _to)
            continue

        print("ADD", md.path)

        _, ftemp = mkstemp()
        try:
            convert.ogg(md.path, ftemp)
            mdnew = SyncFile(ftemp)
            for tag in alltags:
                if tag in md:
                    mdnew[tag] = md[tag]
            mdnew.save()
            copy2(ftemp, fout)
        finally:
            os.remove(ftemp)

    return 0

if __name__ == '__main__':
    ret = 0
    try:
        ret = run(sys.argv)
    except KeyboardInterrupt:
        sys.exit(1)
    sys.exit(ret)