#!/usr/bin/env python
# encoding: utf-8
"""
fp.py

Created by Brian Whitman on 2010-06-16.
Copyright (c) 2010 The Echo Nest Corporation. All rights reserved.
"""
from __future__ import with_statement
import logging
import solr
import pickle
from collections import defaultdict
import zlib, base64, re, time, random, string, math
import pytyrant
import datetime

now = datetime.datetime.utcnow()
IMPORTDATE = now.strftime("%Y-%m-%dT%H:%M:%SZ")

try:
    import json
except ImportError:
    import simplejson as json

_fp_solr = solr.SolrConnectionPool("http://localhost:8502/solr/fp")
_hexpoch = int(time.time() * 1000)
logger = logging.getLogger(__name__)
_tyrant_address = ['localhost', 1978]
_tyrant = None

class Response(object):
    # Response codes
    NOT_ENOUGH_CODE, CANNOT_DECODE, SINGLE_BAD_MATCH, SINGLE_GOOD_MATCH, NO_RESULTS, MULTIPLE_GOOD_MATCH_HISTOGRAM_INCREASED, \
        MULTIPLE_GOOD_MATCH_HISTOGRAM_DECREASED, MULTIPLE_BAD_HISTOGRAM_MATCH, MULTIPLE_GOOD_MATCH = range(9)

    def __init__(self, code, TRID=None, score=0, qtime=0, tic=0, metadata={}):
        self.code = code
        self.qtime = qtime
        self.TRID = TRID
        self.score = score
        self.total_time = int(time.time()*1000) - tic
        self.metadata = metadata

    def __len__(self):
        if self.TRID is not None:
            return 1
        else:
            return 0
        
    def message(self):
        if self.code == self.NOT_ENOUGH_CODE:
            return "query code length is too small"
        if self.code == self.CANNOT_DECODE:
            return "could not decode query code"
        if self.code == self.SINGLE_BAD_MATCH or self.code == self.NO_RESULTS or self.code == self.MULTIPLE_BAD_HISTOGRAM_MATCH:
            return "no results found (type %d)" % (self.code)
        return "OK (match type %d)" % (self.code)
    
    def match(self):
        return self.TRID is not None
     

def inflate_code_string(s):
    """ Takes an uncompressed code string consisting of 0-padded fixed-width
        sorted hex and converts it to the standard code string."""
    n = int(len(s) / 10.0) # 5 hex bytes for hash, 5 hex bytes for time (40 bits)

    def pairs(l, n=2):
        """Non-overlapping [1,2,3,4] -> [(1,2), (3,4)]"""
        # return zip(*[[v for i,v in enumerate(l) if i % n == j] for j in range(n)])
        end = n
        res = []
        while end <= len(l):
            start = end - n
            res.append(tuple(l[start:end]))
            end += n
        return res

    # Parse out n groups of 5 timestamps in hex; then n groups of 8 hash codes in hex.
    end_timestamps = n*5
    times = [int(''.join(t), 16) for t in chunker(s[:end_timestamps], 5)]
    codes = [int(''.join(t), 16) for t in chunker(s[end_timestamps:], 5)]

    assert(len(times) == len(codes)) # these should match up!
    return ' '.join('%d %d' % (c, t) for c,t in zip(codes, times))

def decode_code_string(compressed_code_string):
    compressed_code_string = compressed_code_string.encode('utf8')
    if compressed_code_string == "":
        return ""
    # do the zlib/base64 stuff
    try:
        # this will decode both URL safe b64 and non-url-safe
        actual_code = zlib.decompress(base64.urlsafe_b64decode(compressed_code_string))
    except (zlib.error, TypeError):
        logger.warn("Could not decode base64 zlib string %s" % (compressed_code_string))
        import traceback; logger.warn(traceback.format_exc())
        return None
    # If it is a deflated code, expand it from hex
    if ' ' not in actual_code:
        actual_code = inflate_code_string(actual_code)
    return actual_code

def metadata_for_track_id(track_id, local=False):
    if not track_id or not len(track_id):
        return {}
    # Assume track_ids have 1 - and it's at the end of the id.
    if "-" not in track_id:
        track_id = "%s-0" % track_id
        
    if local:
        return _fake_solr["metadata"][track_id]
        
    with solr.pooled_connection(_fp_solr) as host:
        response = host.query("track_id:%s" % track_id)

    if len(response.results):
        return response.results[0]
    else:
        return {}

def cut_code_string_length(code_string):
    """ Remove all codes from a codestring that are > 60 seconds in length.
    Because we can only match 60 sec, everything else is unnecessary """
    split = code_string.split()
    if len(split) < 2:
        return code_string

    # If we use the codegen on a file with start/stop times, the first timestamp
    # is ~= the start time given. There might be a (slightly) earlier timestamp
    # in another band, but this is good enough
    first_timestamp = int(split[1])
    sixty_seconds = int(60.0 * 1000.0 / 23.2 + first_timestamp)
    parts = []
    for (code, t) in zip(split[::2], split[1::2]):
        tstamp = int(t)
        if tstamp <= sixty_seconds:
            parts.append(code)
            parts.append(t)
    return " ".join(parts)

def best_match_for_query(code_string, elbow=10, local=False):
    # DEC strings come in as unicode so we have to force them to ASCII
    code_string = code_string.encode("utf8")
    tic = int(time.time()*1000)

    # First see if this is a compressed code
    if re.match('[A-Za-z\/\+\_\-]', code_string) is not None:
        code_string = decode_code_string(code_string)
        if code_string is None:
            return Response(Response.CANNOT_DECODE, tic=tic)
    
    code_len = len(code_string.split(" ")) / 2

    if code_len < elbow:
        logger.warn("Query code length (%d) is less than elbow (%d)" % (code_len, elbow))
        return Response(Response.NOT_ENOUGH_CODE, tic=tic)

    # code_string = cut_code_string_length(code_string)
    code_len = len(code_string.split(" ")) / 2

    # Query the FP flat directly.
    response = query_fp(code_string, rows=30, local=local, get_data=True)
    logger.debug("solr qtime is %d" % (response.header["QTime"]))
    
    if len(response.results) == 0:
        return Response(Response.NO_RESULTS, qtime=response.header["QTime"], tic=tic)

    # If we just had one result, make sure that it is close enough. We rarely if ever have a single match so this is not helpful (and probably doesn't work well.)
    top_match_score = int(response.results[0]["score"])
    if len(response.results) == 1:
        trackid = response.results[0]["track_id"]
        trackid = trackid.split("-")[0] # will work even if no `-` in trid
        meta = metadata_for_track_id(trackid, local=local)
        if code_len - top_match_score < elbow:
            return Response(Response.SINGLE_GOOD_MATCH, TRID=trackid, score=top_match_score, qtime=response.header["QTime"], tic=tic, metadata=meta)
        else:
            return Response(Response.SINGLE_BAD_MATCH, qtime=response.header["QTime"], tic=tic)

    # If the scores are really low (less than 5% of the query length) then say no results
    if top_match_score < code_len * 0.05:
        return Response(Response.MULTIPLE_BAD_HISTOGRAM_MATCH, qtime = response.header["QTime"], tic=tic)

    # Not a strong match, so we look up the codes in the keystore and compute actual matches...

    # Get the actual score for all responses
    original_scores = {}
    actual_scores = {}
    
    trackids = [r["track_id"].encode("utf8") for r in response.results]
    if local:
        tcodes = [_fake_solr["store"][t] for t in trackids]
    else:
        tcodes = get_tyrant().multi_get(trackids)
    
    # For each result compute the "actual score" (based on the histogram matching)
    for (i, r) in enumerate(response.results):
        track_id = r["track_id"]
        original_scores[track_id] = int(r["score"])
        track_code = tcodes[i]
        if track_code is None:
            # Solr gave us back a track id but that track
            # is not in our keystore
            continue
        actual_scores[track_id] = actual_matches(code_string, track_code, elbow = elbow)
    
    #logger.debug("Actual score for %s is %d (code_len %d), original was %d" % (r["track_id"], actual_scores[r["track_id"]], code_len, top_match_score))
    # Sort the actual scores
    sorted_actual_scores = sorted(actual_scores.iteritems(), key=lambda (k,v): (v,k), reverse=True)

    # Because we split songs up into multiple parts, sometimes the results will have the same track in the
    # first few results. Remove these duplicates so that the falloff is (potentially) higher.
    # new_sorted_actual_scores = []
    # existing_trids = []
    # for trid, result in sorted_actual_scores:
    #     trid_split = trid.split("-")[0]
    #     if trid_split not in existing_trids:
    #         new_sorted_actual_scores.append((trid, result))
    #         existing_trids.append(trid_split)
    # sorted_actual_scores = new_sorted_actual_scores

    # We might have reduced the length of the list to 1
    if len(sorted_actual_scores) == 1:
        logger.info("only have 1 score result...")
        (top_track_id, top_score) = sorted_actual_scores[0]
        if top_score < code_len * 0.1:
            logger.info("only result less than 10%% of the query string (%d < %d *0.1 (%d)) SINGLE_BAD_MATCH", top_score, code_len, code_len*0.1)
            return Response(Response.SINGLE_BAD_MATCH, qtime = response.header["QTime"], tic=tic)
        else:
            if top_score > (original_scores[top_track_id] / 2): 
                logger.info("top_score > original_scores[%s]/2 (%d > %d) GOOD_MATCH_DECREASED",
                    top_track_id, top_score, original_scores[top_track_id]/2)
                trid = top_track_id.split("-")[0]
                meta = metadata_for_track_id(trid, local=local)
                return Response(Response.MULTIPLE_GOOD_MATCH_HISTOGRAM_DECREASED, TRID=trid, score=top_score, qtime=response.header["QTime"], tic=tic, metadata=meta)
            else:
                logger.info("top_score NOT > original_scores[%s]/2 (%d <= %d) BAD_HISTOGRAM_MATCH",
                    top_track_id, top_score, original_scores[top_track_id]/2)
                return Response(Response.MULTIPLE_BAD_HISTOGRAM_MATCH, qtime=response.header["QTime"], tic=tic)
        
    # Get the top one
    (actual_score_top_track_id, actual_score_top_score) = sorted_actual_scores[0]
    # Get the 2nd top one (we know there is always at least 2 matches)
    (actual_score_2nd_track_id, actual_score_2nd_score) = sorted_actual_scores[1]

    trackid = actual_score_top_track_id.split("-")[0]
    meta = metadata_for_track_id(trackid, local=local)

    if actual_score_top_score < code_len * 0.05:
        return Response(Response.MULTIPLE_BAD_HISTOGRAM_MATCH, qtime = response.header["QTime"], tic=tic)
    else:
        # If the actual score went down it still could be close enough, so check for that
        if actual_score_top_score > (original_scores[actual_score_top_track_id] / 4): 
            if (actual_score_top_score - actual_score_2nd_score) >= (actual_score_top_score / 3):  # for examples [10,4], 10-4 = 6, which >= 5, so OK
                return Response(Response.MULTIPLE_GOOD_MATCH_HISTOGRAM_DECREASED, TRID=trackid, score=actual_score_top_score, qtime=response.header["QTime"], tic=tic, metadata=meta)
            else:
                return Response(Response.MULTIPLE_BAD_HISTOGRAM_MATCH, qtime = response.header["QTime"], tic=tic)
        else:
            # If the actual score was not close enough, then no match.
            return Response(Response.MULTIPLE_BAD_HISTOGRAM_MATCH, qtime=response.header["QTime"], tic=tic)

def actual_matches(code_string_query, code_string_match, slop = 2, elbow = 10):
    code_query = code_string_query.split(" ")
    code_match = code_string_match.split(" ")
    if (len(code_match) < (elbow*2)):
        return 0

    time_diffs = {}

    # Normalise the query timecodes to start with offset 0
    code_query_int = [int(x) for x in code_query]
    min_time = min(code_query_int[1::2])
    code_query[1::2] = [str(x - min_time) for x in code_query_int[1::2]]
    
    #
    # Invert the query codes
    query_codes = {}
    for (qcode, qtime) in zip(code_query[::2], code_query[1::2]):
        qtime = int(qtime) / slop
        if qcode in query_codes:
            query_codes[qcode].append(qtime)
        else:
            query_codes[qcode] = [qtime]

    #
    # Walk the document codes, handling those that occur in the query
    match_counter = 1
    for match_code in code_match[::2]:
        if match_code in query_codes:
            match_code_time = int(code_match[match_counter])/slop
            min_dist = 32767
            for qtime in query_codes[match_code]:
                # match_code_time > qtime for all corresponding
                # hashcodes since normalising query timecodes, so no
                # need for abs() anymore
                dist = match_code_time - qtime
                if dist < min_dist:
                    min_dist = dist
            if min_dist < 32767:
                if time_diffs.has_key(min_dist):
                    time_diffs[min_dist] += 1
                else:
                    time_diffs[min_dist] = 1
        match_counter += 2

    # sort the histogram, pick the top 2 and return that as your actual score
    actual_match_list = sorted(time_diffs.iteritems(), key=lambda (k,v): (v,k), reverse=True)

    if(len(actual_match_list)>1):
        return actual_match_list[0][1] + actual_match_list[1][1]
    if(len(actual_match_list)>0):
        return actual_match_list[0][1]
    return 0        

def get_tyrant():
    global _tyrant
    if _tyrant is None:
        _tyrant = pytyrant.PyTyrant.open(*_tyrant_address)
    return _tyrant

"""
    fp can query the live production flat or the alt flat, or it can query and ingest in memory.
    the following few functions are to support local query and ingest that ape the response of the live server
    This is useful for small collections and testing, deduplicating, etc, without having to boot a server.
    The results should be equivalent but i need to run tests. 
    
    NB: delete is not supported locally yet
    
"""
_fake_solr = {"index": {}, "store": {}, "metadata": {}}

class FakeSolrResponse(object):
    def __init__(self, results):
        self.header = {'QTime': 0}
        self.results = []
        for r in results:
            # If the result list has more than 2 elements we've asked for data as well
            if len(r) > 2:
                data = {"score":r[1], "track_id":r[0], "fp":r[2]}
                metadata = r[3]
                data["length"] = metadata["length"]
                for m in ["artist", "release", "track"]:
                    if m in metadata:
                        data[m] = metadata[m]
                self.results.append(data)
            else:
                self.results.append({"score":r[1], "track_id":r[0]})
    
def local_load(filename):
    global _fake_solr
    print "Loading from " + filename
    disk = open(filename,"rb")
    _fake_solr = pickle.load(disk)
    disk.close()
    print "Done"
    
def local_save(filename):
    print "Saving to " + filename
    disk = open(filename,"wb")
    pickle.dump(_fake_solr,disk)
    disk.close()
    print "Done"
    
def local_ingest(docs, codes):
    store = dict(codes)
    _fake_solr["store"].update(store)
    for fprint in docs:
        trackid = fprint["track_id"]
        keys = set(fprint["fp"].split(" ")[0::2]) # just one code indexed
        for k in keys:
            tracks = _fake_solr["index"].setdefault(k,[])
            if trackid not in tracks:
                tracks.append(trackid)
        _fake_solr["metadata"][trackid] = {"length": fprint["length"], "codever": fprint["codever"]}
        if "artist" in fprint:
            _fake_solr["metadata"][trackid]["artist"] = fprint["artist"]
        if "release" in fprint:
            _fake_solr["metadata"][trackid]["release"] = fprint["release"]
        if "track" in fprint:
            _fake_solr["metadata"][trackid]["track"] = fprint["track"]

def local_delete(tracks):
    for track in tracks:
        codes = set(_fake_solr["store"][track].split(" ")[0::2])
        del _fake_solr["store"][track]
        for code in codes:
            # Make copy so destructive editing doesn't break for loop
            codetracks = list(_fake_solr["index"][code])
            for trid in codetracks:
                if trid.startswith(track):
                    _fake_solr["index"][code].remove(trid)
                    try:
                        del _fake_solr["metadata"][trid]
                    except KeyError:
                        pass
            if len(_fake_solr["index"][code]) == 0:
                del _fake_solr["index"][code]
        

def local_dump():
    print "Stored tracks:"
    print _fake_solr["store"].keys()
    print "Metadata:"
    for t in _fake_solr["metadata"].keys():
        print t, _fake_solr["metadata"][t]
    print "Keys:"
    for k in _fake_solr["index"].keys():
        print "%s -> %s" % (k, ", ".join(_fake_solr["index"][k]))

def local_query_fp(code_string,rows=10,get_data=False):
    keys = code_string.split(" ")[0::2]
    track_hist = []
    unique_keys = []
    for k in keys:
        if k not in unique_keys:
            track_hist += _fake_solr["index"].get(k, [])
            unique_keys += [k]
    top_matches = defaultdict(int)
    for track in track_hist:
        top_matches[track] += 1
    if not get_data:
        # Make a list of lists that have track_id, score
        return FakeSolrResponse(sorted(top_matches.iteritems(), key=lambda (k,v): (v,k), reverse=True)[0:rows])
    else:
        # Make a list of lists that have track_id, score, then fp
        lol = sorted(top_matches.iteritems(), key=lambda (k,v): (v,k), reverse=True)[0:rows]
        lol = map(list, lol)
        
        for x in lol:
            trackid = x[0].split("-")[0]
            x.append(_fake_solr["store"][x[0]])
            x.append(_fake_solr["metadata"][x[0]])
        return FakeSolrResponse(lol)

def local_fp_code_for_track_id(track_id):
    return _fake_solr["store"][track_id]
    
"""
    and these are the server-hosted versions of query, ingest and delete 
"""

def delete(track_ids, do_commit=True, local=False):
    # delete one or more track_ids from the fp flat. 
    if not isinstance(track_ids, list):
        track_ids = [track_ids]

    # delete a code from FP flat
    if local:
        return local_delete(track_ids)

    with solr.pooled_connection(_fp_solr) as host:
        for t in track_ids:
            host.delete_query("track_id:%s*" % t)
    
    try:
        get_tyrant().multi_del(track_ids)
    except KeyError:
        pass
    
    if do_commit:
        commit()

def local_erase_database():
    global _fake_solr
    _fake_solr = {"index": {}, "store": {}, "metadata": {}}

def erase_database(really_delete=False, local=False):
    """ This method will delete your ENTIRE database. Only use it if you
        know what you're doing.
    """ 
    if not really_delete:
        raise Exception("Won't delete unless you pass in really_delete=True")

    if local:
        return local_erase_database()

    with solr.pooled_connection(_fp_solr) as host:
        host.delete_query("*:*")
        host.commit()

    tyrant = get_tyrant()
    tyrant.multi_del(tyrant.keys())

def chunker(seq, size):
    return [tuple(seq[pos:pos + size]) for pos in xrange(0, len(seq), size)]

def split_codes(fp):
    """ Split a codestring into a list of codestrings. Each string contains
        at most 60 seconds of codes, and codes overlap every 30 seconds. Given a
        track id, return track ids of the form trid-0, trid-1, trid-2, etc. """

    # Convert seconds into time units
    segmentlength = 60 * 1000.0 / 23.2
    halfsegment = segmentlength / 2.0
    
    trid = fp["track_id"]
    codestring = fp["fp"]

    codes = codestring.split()
    pairs = chunker(codes, 2)
    pairs = [(int(x[1]), " ".join(x)) for x in pairs]

    pairs.sort()
    size = len(pairs)

    if len(pairs):
        lasttime = pairs[-1][0]
        numsegs = int(lasttime / halfsegment) + 1
    else:
        numsegs = 0

    ret = []
    sindex = 0
    for i in range(numsegs):
        s = i * halfsegment
        e = i * halfsegment + segmentlength
        #print i, s, e
        
        while sindex < size and pairs[sindex][0] < s:
            #print "s", sindex, l[sindex]
            sindex+=1
        eindex = sindex
        while eindex < size and pairs[eindex][0] < e:
            #print "e",eindex,l[eindex]
            eindex+=1
        key = "%s-%d" % (trid, i)
        
        segment = {"track_id": key,
                   "fp": " ".join((p[1]) for p in pairs[sindex:eindex]),
                   "length": fp["length"],
                   "codever": fp["codever"]}
        if "artist" in fp: segment["artist"] = fp["artist"]
        if "release" in fp: segment["release"] = fp["release"]
        if "track" in fp: segment["track"] = fp["track"]
        if "source" in fp: segment["source"] = fp["source"]
        if "import_date" in fp: segment["import_date"] = fp["import_date"]
        ret.append(segment)
    return ret

def ingest(fingerprint_list, do_commit=True, local=False, split=True):
    """ Ingest some fingerprints into the fingerprint database.
        The fingerprints should be of the form
          {"track_id": id,
          "fp": fp string,
          "artist": artist,
          "release": release,
          "track": track,
          "length": length,
          "codever": "codever",
          "source": source,
          "import_date":import date}
        or a list of the same. All parameters except length must be strings. Length is an integer.
        artist, release and track are not required but highly recommended.
        The import date should be formatted as an ISO 8601 date (yyyy-mm-ddThh:mm:ssZ) and should
        be the UTC time that the the import was performed. If the date is missing, the time the
        script was started will be used.
        length is the length of the track being ingested in seconds.
        if track_id is empty, one will be generated.
    """
    if not isinstance(fingerprint_list, list):
        fingerprint_list = [fingerprint_list]
        
    docs = []
    codes = []
    if split:
        for fprint in fingerprint_list:
            if not ("track_id" in fprint and "fp" in fprint and "length" in fprint and "codever" in fprint):
                raise Exception("Missing required fingerprint parameters (track_id, fp, length, codever")
            if "import_date" not in fprint:
                fprint["import_date"] = IMPORTDATE
            if "source" not in fprint:
                fprint["source"] = "local"
            split_prints = split_codes(fprint)
            docs.extend(split_prints)
            codes.extend(((c["track_id"].encode("utf-8"), c["fp"].encode("utf-8")) for c in split_prints))
    else:
        for fprint in fingerprint_list:
            if not ("track_id" in fprint and "fp" in fprint and "length" in fprint and "codever" in fprint):
                raise Exception("Missing required fingerprint parameters (track_id, fp, length, codever")
            if "import_date" not in fprint:
                fprint["import_date"] = IMPORTDATE
            if "source" not in fprint:
                fprint["source"] = "local"
        docs.extend(fingerprint_list)
        codes.extend(((c["track_id"].encode("utf-8"), c["fp"].encode("utf-8")) for c in fingerprint_list))

    if local:
        return local_ingest(docs, codes)

    with solr.pooled_connection(_fp_solr) as host:
        host.add_many(docs)

    get_tyrant().multi_set(codes)

    if do_commit:
        commit()

def commit(local=False):
    with solr.pooled_connection(_fp_solr) as host:
        host.commit()

def query_fp(code_string, rows=15, local=False, get_data=False):
    if local:
        return local_query_fp(code_string, rows, get_data=get_data)
    
    try:
        # query the fp flat
        if get_data:
            fields = "track_id,artist,release,track,length"
        else:
            fields = "track_id"
        with solr.pooled_connection(_fp_solr) as host:
            resp = host.query(code_string, qt="/hashq", rows=rows, fields=fields)
        return resp
    except solr.SolrException:
        return None

def fp_code_for_track_id(track_id, local=False):
    if local:
        return local_fp_code_for_track_id(track_id)
    
    return get_tyrant().get(track_id.encode("utf-8"))

def new_track_id():
    rand5 = ''.join(random.choice(string.letters) for x in xrange(5)).upper()
    global _hexpoch
    _hexpoch += 1
    hexpoch = str(hex(_hexpoch))[2:].upper()
    ## On 32-bit machines, the number of milliseconds since 1970 is 
    ## a longint. On 64-bit it is not.
    hexpoch = hexpoch.rstrip('L')
    return "TR" + rand5 + hexpoch