from bitarray import bitarray
from itertools import islice
import os
import glob

class readAMBE:
    
    def __init__(self, lang,path):
        self.lang = lang
        self.path = path
        self.prefix = path+lang
    
    def _make_bursts(self,data):
        it = iter(data)
        for i in range(0, len(data), 108):
            yield bitarray([k for k in islice(it, 108)] )
    
    #Read indexed files
    def readfiles(self):
        _AMBE_LENGTH = 9
        indexDict = {}
        
        if os.path.isdir(self.prefix):
            ambeBytearray = {}
            _wordBitarray = bitarray(endian='big')
            _wordBADict = {}
            _glob = self.prefix + "/*.ambe"
            for ambe in glob.glob(_glob):
                basename = os.path.basename(ambe)
                _voice,ext = basename.split('.')
                inambe = open(ambe,'rb')
                _wordBitarray.frombytes(inambe.read())
                inambe.close()
                _wordBADict[_voice] = []
                pairs = 1
                _lastburst = ''
                for _burst in self._make_bursts(_wordBitarray):
#Not sure if we need to pad or not? Seems to make little difference. 
                    if len(_burst) < 108:
                        pad = (108 - len(_burst))
                        for i in range(0,pad,1):
                            _burst.append(False)
                    if pairs == 2:
                        _wordBADict[_voice].append([_lastburst,_burst])  
                        _lastburst = ''
                        pairs = 1
                        next
                    else:
                        pairs = pairs + 1
                        _lastburst = _burst
                    
                _wordBitarray.clear()
            _wordBADict['silence'] = ([
                    [bitarray('101011000000101010100000010000000000001000000000000000000000010001000000010000000000100000000000100000000000'),
                    bitarray('001010110000001010101000000100000000000010000000000000000000000100010000000100000000001000000000001000000000')]
            ])
            return _wordBADict
        else:
            try:
                with open(self.prefix+'.indx') as index:
                    for line in index:
                        (voice,start,length) = line.split()
                        indexDict[voice] = [int(start) * _AMBE_LENGTH ,int(length) * _AMBE_LENGTH]
                index.close()
            except IOError:
                return False
            
            ambeBytearray = {}
            _wordBitarray = bitarray(endian='big')
            _wordBADict = {}
            try:
                with open(self.prefix+'.ambe','rb') as ambe:            
                    for _voice in indexDict:
                        ambe.seek(indexDict[_voice][0])
                        _wordBitarray.frombytes(ambe.read(indexDict[_voice][1]))
                        #108
                        _wordBADict[_voice] = []
                        pairs = 1
                        _lastburst = ''
                        for _burst in self._make_bursts(_wordBitarray):
    #Not sure if we need to pad or not? Seems to make little difference. 
                            if len(_burst) < 108:
                                pad = (108 - len(_burst))
                                for i in range(0,pad,1):
                                    _burst.append(False)
                            if pairs == 2:
                                _wordBADict[_voice].append([_lastburst,_burst])  
                                _lastburst = ''
                                pairs = 1
                                next
                            else:
                                pairs = pairs + 1
                                _lastburst = _burst
                            
                        _wordBitarray.clear()
                    ambe.close()
            except IOError:
                return False
            _wordBADict['silence'] = ([
                    [bitarray('101011000000101010100000010000000000001000000000000000000000010001000000010000000000100000000000100000000000'),
                    bitarray('001010110000001010101000000100000000000010000000000000000000000100010000000100000000001000000000001000000000')]
            ])
            return _wordBADict

    #Read a single ambe file from the audio directory
    def readSingleFile(self,filename):
        ambeBytearray = {}
        _wordBitarray = bitarray(endian='big')
        _wordBA= []
        try:
            with open(self.path+filename,'rb') as ambe:            
                _wordBitarray.frombytes(ambe.read())
                #108
                _wordBA = []
                pairs = 1
                _lastburst = ''
                for _burst in self._make_bursts(_wordBitarray):
#Not sure if we need to pad or not? Seems to make little difference. 
                    if len(_burst) < 108:
                        pad = (108 - len(_burst))
                        for i in range(0,pad,1):
                            _burst.append(False)
                    if pairs == 2:
                        _wordBA.append([_lastburst,_burst])  
                        _lastburst = ''
                        pairs = 1
                        next
                    else:
                        pairs = pairs + 1
                        _lastburst = _burst
                    
                _wordBitarray.clear()
                ambe.close()
        except IOError:
            return(False)
        
        return(_wordBA)
        
  
if __name__ == '__main__':
    
    #test = readAMBE('en_GB','./Audio/')
    
    #print(test.readfiles())
    test = readAMBE('en_GB_2','./Audio/')
    print(test.readfiles())
    print(test.readSingleFile('44xx.ambe'))