# -*- coding: utf-8 -*-
"""
Classe for reading data from WinEdr, a software tool written by
John Dempster.

WinEdr is free:
http://spider.science.strath.ac.uk/sipbs/software.htm

Depend on:

Supported : Read

Author: sgarcia

"""

import os
import struct
import sys

import numpy as np
import quantities as pq

from neo.io.baseio import BaseIO
from neo.core import Segment, AnalogSignal

PY3K = (sys.version_info[0] == 3)


class WinEdrIO(BaseIO):
    """
    Class for reading data from WinEDR.

    Usage:
        >>> from neo import io
        >>> r = io.WinEdrIO(filename='File_WinEDR_1.EDR')
        >>> seg = r.read_segment(lazy=False, cascade=True,)
        >>> print seg.analogsignals
        [<AnalogSignal(array([ 89.21203613,  88.83666992,  87.21008301, ...,  64.56298828,
                67.94128418,  68.44177246], dtype=float32) * pA, [0.0 s, 101.5808 s], sampling rate: 10000.0 Hz)>]

    """

    is_readable        = True
    is_writable        = False

    supported_objects  = [ Segment , AnalogSignal ]
    readable_objects   = [Segment]
    writeable_objects  = []

    has_header         = False
    is_streameable     = False

    read_params        = { Segment : [ ], }

    write_params       = None

    name               = 'WinEDR'
    extensions          = [ 'EDR' ]

    mode = 'file'

    def __init__(self , filename = None) :
        """
        This class read a WinEDR file.

        Arguments:
            filename : the filename

        """
        BaseIO.__init__(self)
        self.filename = filename


    def read_segment(self , lazy = False, cascade = True):
        seg  = Segment(
                                    file_origin = os.path.basename(self.filename),
                                    )

        if not cascade:
            return seg

        fid = open(self.filename , 'rb')

        headertext = fid.read(2048)
        if PY3K:
            headertext = headertext.decode('ascii')
        header = {}
        for line in headertext.split('\r\n'):
            if '=' not in line : continue
            #print '#' , line , '#'
            key,val = line.split('=')
            if key in ['NC', 'NR','NBH','NBA','NBD','ADCMAX','NP','NZ','ADCMAX' ] :
                val = int(val)
            elif key in ['AD', 'DT', ] :
                val = val.replace(',','.')
                val = float(val)
            header[key] = val

        if not lazy:
            data = np.memmap(self.filename , np.dtype('i2')  , 'r',
                  #shape = (header['NC'], header['NP']) ,
                  shape = (header['NP']//header['NC'],header['NC'], ) ,
                  offset = header['NBH'])

        for c in range(header['NC']):

            YCF = float(header['YCF%d'%c].replace(',','.'))
            YAG = float(header['YAG%d'%c].replace(',','.'))
            YZ = float(header['YZ%d'%c].replace(',','.'))

            ADCMAX = header['ADCMAX']
            AD = header['AD']
            DT = header['DT']

            if 'TU' in header:
                if header['TU'] == 'ms':
                    DT *= .001

            unit = header['YU%d'%c]
            try :
                unit = pq.Quantity(1., unit)
            except:
                unit = pq.Quantity(1., '')

            if lazy:
                signal = [ ] * unit
            else:
                chan = int(header['YO%d'%c])
                signal = (data[:,chan].astype('float32')-YZ) *AD/( YCF*YAG*(ADCMAX+1)) * unit

            ana = AnalogSignal(signal,
                               sampling_rate=pq.Hz / DT,
                               t_start=0. * pq.s,
                               name=header['YN%d' % c],
                               channel_index=c)
            if lazy:
                ana.lazy_shape = header['NP']/header['NC']

            seg.analogsignals.append(ana)

        seg.create_many_to_one_relationship()
        fid.close()
        return seg






AnalysisDescription = [
    ('RecordStatus','8s'),
    ('RecordType','4s'),
    ('GroupNumber','f'),
    ('TimeRecorded','f'),
    ('SamplingInterval','f'),
    ('VMax','8f'),
    ]


class HeaderReader():
    def __init__(self,fid ,description ):
        self.fid = fid
        self.description = description
    def read_f(self, offset =0):
        self.fid.seek(offset)
        d = { }
        for key, fmt in self.description :
            val = struct.unpack(fmt , self.fid.read(struct.calcsize(fmt)))
            if len(val) == 1:
                val = val[0]
            else :
                val = list(val)
            d[key] = val
        return d