"""Stuff to parse WAVE files.

Usage.

Reading WAVE files:
 f = wave.open(file, 'r')
where file is either the name of a file or an open file pointer.
The open file pointer must have methods read(), seek(), and close().
When the setpos() and rewind() methods are not used, the seek()
method is not necessary.

This returns an instance of a class with the following public methods:
 getnchannels() -- returns number of audio channels (1 for
 mono, 2 for stereo)
 getsampwidth() -- returns sample width in bytes
 getframerate() -- returns sampling frequency
 getnframes() -- returns number of audio frames
 getcomptype() -- returns compression type ('NONE' for linear samples)
 getcompname() -- returns human-readable version of
 compression type ('not compressed' linear samples)
 getparams() -- returns a namedtuple consisting of all of the
 above in the above order
 getmarkers() -- returns None (for compatibility with the
 aifc module)
 getmark(id) -- raises an error since the mark does not
 exist (for compatibility with the aifc module)
 readframes(n) -- returns at most n frames of audio
 rewind() -- rewind to the beginning of the audio stream
 setpos(pos) -- seek to the specified position
 tell() -- return the current position
 close() -- close the instance (make it unusable)
The position returned by tell() and the position given to setpos()
are compatible and have nothing to do with the actual position in the
file.
The close() method is called automatically when the class instance
is destroyed.

Writing WAVE files:
 f = wave.open(file, 'w')
where file is either the name of a file or an open file pointer.
The open file pointer must have methods write(), tell(), seek(), and
close().

This returns an instance of a class with the following public methods:
 setnchannels(n) -- set the number of channels
 setsampwidth(n) -- set the sample width
 setframerate(n) -- set the frame rate
 setnframes(n) -- set the number of frames
 setcomptype(type, name)
 -- set the compression type and the
 human-readable compression type
 setparams(tuple)
 -- set all parameters at once
 tell() -- return current position in output file
 writeframesraw(data)
 -- write audio frames without patching up the
 file header
 writeframes(data)
 -- write audio frames and patch up the file header
 close() -- patch up the file header and close the
 output file
You should set the parameters before the first writeframesraw or
writeframes. The total number of frames does not need to be set,
but when it is set to the correct value, the header does not have to
be patched up.
It is best to first set all parameters, perhaps possibly the
compression type, and then write audio frames using writeframesraw.
When all frames have been written, either call writeframes(b'') or
close() to patch up the sizes in the header.
The close() method is called automatically when the class instance
is destroyed.
"""

import builtins

__all__ = ["open", "openfp", "Error", "Wave_read", "Wave_write"]

class Error(Exception):
 pass

WAVE_FORMAT_PCM = 0x0001

_array_fmts = None, 'b', 'h', None, 'i'

import audioop
import struct
import sys
from chunk import Chunk
from collections import namedtuple
import warnings

_wave_params = namedtuple('_wave_params',
 'nchannels sampwidth framerate nframes comptype compname')

class Wave_read:
 """Variables used in this class:

 These variables are available to the user though appropriate
 methods of this class:
 _file -- the open file with methods read(), close(), and seek()
 set through the __init__() method
 _nchannels -- the number of audio channels
 available through the getnchannels() method
 _nframes -- the number of audio frames
 available through the getnframes() method
 _sampwidth -- the number of bytes per audio sample
 available through the getsampwidth() method
 _framerate -- the sampling frequency
 available through the getframerate() method
 _comptype -- the AIFF-C compression type ('NONE' if AIFF)
 available through the getcomptype() method
 _compname -- the human-readable AIFF-C compression type
 available through the getcomptype() method
 _soundpos -- the position in the audio stream
 available through the tell() method, set through the
 setpos() method

 These variables are used internally only:
 _fmt_chunk_read -- 1 iff the FMT chunk has been read
 _data_seek_needed -- 1 iff positioned correctly in audio
 file for readframes()
 _data_chunk -- instantiation of a chunk class for the DATA chunk
 _framesize -- size of one frame in the file
 """

 def initfp(self, file):
 self._convert = None
 self._soundpos = 0
 self._file = Chunk(file, bigendian = 0)
 if self._file.getname() != b'RIFF':
 raise Error('file does not start with RIFF id')
 if self._file.read(4) != b'WAVE':
 raise Error('not a WAVE file')
 self._fmt_chunk_read = 0
 self._data_chunk = None
 while 1:
 self._data_seek_needed = 1
 try:
 chunk = Chunk(self._file, bigendian = 0)
 except EOFError:
 break
 chunkname = chunk.getname()
 if chunkname == b'fmt ':
 self._read_fmt_chunk(chunk)
 self._fmt_chunk_read = 1
 elif chunkname == b'data':
 if not self._fmt_chunk_read:
 raise Error('data chunk before fmt chunk')
 self._data_chunk = chunk
 self._nframes = chunk.chunksize // self._framesize
 self._data_seek_needed = 0
 break
 chunk.skip()
 if not self._fmt_chunk_read or not self._data_chunk:
 raise Error('fmt chunk and/or data chunk missing')

 def __init__(self, f):
 self._i_opened_the_file = None
 if isinstance(f, str):
 f = builtins.open(f, 'rb')
 self._i_opened_the_file = f
 # else, assume it is an open file object already
 try:
 self.initfp(f)
 except:
 if self._i_opened_the_file:
 f.close()
 raise

 def __del__(self):
 self.close()

 def __enter__(self):
 return self

 def __exit__(self, *args):
 self.close()

 #
 # User visible methods.
 #
 def getfp(self):
 return self._file

 def rewind(self):
 self._data_seek_needed = 1
 self._soundpos = 0

 def close(self):
 self._file = None
 file = self._i_opened_the_file
 if file:
 self._i_opened_the_file = None
 file.close()

 def tell(self):
 return self._soundpos

 def getnchannels(self):
 return self._nchannels

 def getnframes(self):
 return self._nframes

 def getsampwidth(self):
 return self._sampwidth

 def getframerate(self):
 return self._framerate

 def getcomptype(self):
 return self._comptype

 def getcompname(self):
 return self._compname

 def getparams(self):
 return _wave_params(self.getnchannels(), self.getsampwidth(),
 self.getframerate(), self.getnframes(),
 self.getcomptype(), self.getcompname())

 def getmarkers(self):
 return None

 def getmark(self, id):
 raise Error('no marks')

 def setpos(self, pos):
 if pos < 0 or pos > self._nframes:
 raise Error('position not in range')
 self._soundpos = pos
 self._data_seek_needed = 1

 def readframes(self, nframes):
 if self._data_seek_needed:
 self._data_chunk.seek(0, 0)
 pos = self._soundpos * self._framesize
 if pos:
 self._data_chunk.seek(pos, 0)
 self._data_seek_needed = 0
 if nframes == 0:
 return b''
 data = self._data_chunk.read(nframes * self._framesize)
 if self._sampwidth != 1 and sys.byteorder == 'big':
 data = audioop.byteswap(data, self._sampwidth)
 if self._convert and data:
 data = self._convert(data)
 self._soundpos = self._soundpos + len(data) // (self._nchannels * self._sampwidth)
 return data

 #
 # Internal methods.
 #

 def _read_fmt_chunk(self, chunk):
 try:
 wFormatTag, self._nchannels, self._framerate, dwAvgBytesPerSec, wBlockAlign = struct.unpack_from('<HHLLH', chunk.read(14))
 except struct.error:
 raise EOFError from None
 if wFormatTag == WAVE_FORMAT_PCM:
 try:
 sampwidth = struct.unpack_from('<H', chunk.read(2))[0]
 except struct.error:
 raise EOFError from None
 self._sampwidth = (sampwidth + 7) // 8
 if not self._sampwidth:
 raise Error('bad sample width')
 else:
 raise Error('unknown format: %r' % (wFormatTag,))
 if not self._nchannels:
 raise Error('bad # of channels')
 self._framesize = self._nchannels * self._sampwidth
 self._comptype = 'NONE'
 self._compname = 'not compressed'

class Wave_write:
 """Variables used in this class:

 These variables are user settable through appropriate methods
 of this class:
 _file -- the open file with methods write(), close(), tell(), seek()
 set through the __init__() method
 _comptype -- the AIFF-C compression type ('NONE' in AIFF)
 set through the setcomptype() or setparams() method
 _compname -- the human-readable AIFF-C compression type
 set through the setcomptype() or setparams() method
 _nchannels -- the number of audio channels
 set through the setnchannels() or setparams() method
 _sampwidth -- the number of bytes per audio sample
 set through the setsampwidth() or setparams() method
 _framerate -- the sampling frequency
 set through the setframerate() or setparams() method
 _nframes -- the number of audio frames written to the header
 set through the setnframes() or setparams() method

 These variables are used internally only:
 _datalength -- the size of the audio samples written to the header
 _nframeswritten -- the number of frames actually written
 _datawritten -- the size of the audio samples actually written
 """

 def __init__(self, f):
 self._i_opened_the_file = None
 if isinstance(f, str):
 f = builtins.open(f, 'wb')
 self._i_opened_the_file = f
 try:
 self.initfp(f)
 except:
 if self._i_opened_the_file:
 f.close()
 raise

 def initfp(self, file):
 self._file = file
 self._convert = None
 self._nchannels = 0
 self._sampwidth = 0
 self._framerate = 0
 self._nframes = 0
 self._nframeswritten = 0
 self._datawritten = 0
 self._datalength = 0
 self._headerwritten = False

 def __del__(self):
 self.close()

 def __enter__(self):
 return self

 def __exit__(self, *args):
 self.close()

 #
 # User visible methods.
 #
 def setnchannels(self, nchannels):
 if self._datawritten:
 raise Error('cannot change parameters after starting to write')
 if nchannels < 1:
 raise Error('bad # of channels')
 self._nchannels = nchannels

 def getnchannels(self):
 if not self._nchannels:
 raise Error('number of channels not set')
 return self._nchannels

 def setsampwidth(self, sampwidth):
 if self._datawritten:
 raise Error('cannot change parameters after starting to write')
 if sampwidth < 1 or sampwidth > 4:
 raise Error('bad sample width')
 self._sampwidth = sampwidth

 def getsampwidth(self):
 if not self._sampwidth:
 raise Error('sample width not set')
 return self._sampwidth

 def setframerate(self, framerate):
 if self._datawritten:
 raise Error('cannot change parameters after starting to write')
 if framerate <= 0:
 raise Error('bad frame rate')
 self._framerate = int(round(framerate))

 def getframerate(self):
 if not self._framerate:
 raise Error('frame rate not set')
 return self._framerate

 def setnframes(self, nframes):
 if self._datawritten:
 raise Error('cannot change parameters after starting to write')
 self._nframes = nframes

 def getnframes(self):
 return self._nframeswritten

 def setcomptype(self, comptype, compname):
 if self._datawritten:
 raise Error('cannot change parameters after starting to write')
 if comptype not in ('NONE',):
 raise Error('unsupported compression type')
 self._comptype = comptype
 self._compname = compname

 def getcomptype(self):
 return self._comptype

 def getcompname(self):
 return self._compname

 def setparams(self, params):
 nchannels, sampwidth, framerate, nframes, comptype, compname = params
 if self._datawritten:
 raise Error('cannot change parameters after starting to write')
 self.setnchannels(nchannels)
 self.setsampwidth(sampwidth)
 self.setframerate(framerate)
 self.setnframes(nframes)
 self.setcomptype(comptype, compname)

 def getparams(self):
 if not self._nchannels or not self._sampwidth or not self._framerate:
 raise Error('not all parameters set')
 return _wave_params(self._nchannels, self._sampwidth, self._framerate,
 self._nframes, self._comptype, self._compname)

 def setmark(self, id, pos, name):
 raise Error('setmark() not supported')

 def getmark(self, id):
 raise Error('no marks')

 def getmarkers(self):
 return None

 def tell(self):
 return self._nframeswritten

 def writeframesraw(self, data):
 if not isinstance(data, (bytes, bytearray)):
 data = memoryview(data).cast('B')
 self._ensure_header_written(len(data))
 nframes = len(data) // (self._sampwidth * self._nchannels)
 if self._convert:
 data = self._convert(data)
 if self._sampwidth != 1 and sys.byteorder == 'big':
 data = audioop.byteswap(data, self._sampwidth)
 self._file.write(data)
 self._datawritten += len(data)
 self._nframeswritten = self._nframeswritten + nframes

 def writeframes(self, data):
 self.writeframesraw(data)
 if self._datalength != self._datawritten:
 self._patchheader()

 def close(self):
 try:
 if self._file:
 self._ensure_header_written(0)
 if self._datalength != self._datawritten:
 self._patchheader()
 self._file.flush()
 finally:
 self._file = None
 file = self._i_opened_the_file
 if file:
 self._i_opened_the_file = None
 file.close()

 #
 # Internal methods.
 #

 def _ensure_header_written(self, datasize):
 if not self._headerwritten:
 if not self._nchannels:
 raise Error('# channels not specified')
 if not self._sampwidth:
 raise Error('sample width not specified')
 if not self._framerate:
 raise Error('sampling rate not specified')
 self._write_header(datasize)

 def _write_header(self, initlength):
 assert not self._headerwritten
 self._file.write(b'RIFF')
 if not self._nframes:
 self._nframes = initlength // (self._nchannels * self._sampwidth)
 self._datalength = self._nframes * self._nchannels * self._sampwidth
 try:
 self._form_length_pos = self._file.tell()
 except (AttributeError, OSError):
 self._form_length_pos = None
 self._file.write(struct.pack('<L4s4sLHHLLHH4s',
 36 + self._datalength, b'WAVE', b'fmt ', 16,
 WAVE_FORMAT_PCM, self._nchannels, self._framerate,
 self._nchannels * self._framerate * self._sampwidth,
 self._nchannels * self._sampwidth,
 self._sampwidth * 8, b'data'))
 if self._form_length_pos is not None:
 self._data_length_pos = self._file.tell()
 self._file.write(struct.pack('<L', self._datalength))
 self._headerwritten = True

 def _patchheader(self):
 assert self._headerwritten
 if self._datawritten == self._datalength:
 return
 curpos = self._file.tell()
 self._file.seek(self._form_length_pos, 0)
 self._file.write(struct.pack('<L', 36 + self._datawritten))
 self._file.seek(self._data_length_pos, 0)
 self._file.write(struct.pack('<L', self._datawritten))
 self._file.seek(curpos, 0)
 self._datalength = self._datawritten

def open(f, mode=None):
 if mode is None:
 if hasattr(f, 'mode'):
 mode = f.mode
 else:
 mode = 'rb'
 if mode in ('r', 'rb'):
 return Wave_read(f)
 elif mode in ('w', 'wb'):
 return Wave_write(f)
 else:
 raise Error("mode must be 'r', 'rb', 'w', or 'wb'")

def openfp(f, mode=None):
 warnings.warn("wave.openfp is deprecated since Python 3.7. "
 "Use wave.open instead.", DeprecationWarning, stacklevel=2)
 return open(f, mode=mode)