#!/usr/bin/env python3
'''
Version 0.85  By S.N.
DONE:
 + missing data (gap): code ha dasai
 + variable sampling rate (gap)
 + time zone
TODO:
 + misisng data (zero-pad, hold-prev-data)
 + WIN32
'''
import sys
import ctypes as C
import numpy as np
import struct
from obspy import Stream, Trace, UTCDateTime
import time

TZ = '+0900'
#TZ = ''

HEADER_5B = 1048576
MAX_SR = HEADER_5B

__clibwinsystem = C.CDLL("/usr/local/win/lib/libwinsystem.so")

__clibwinsystem.bcd_dec.argtypes = (C.c_int * 6, C.c_char_p)
__clibwinsystem.bcd_dec.restype = None

__clibwinsystem.win2fix.argtypes = (C.c_char_p,
                                    np.ctypeslib.ndpointer(dtype=np.int32, ndim=1, flags='C_CONTIGUOUS'),
                                    C.POINTER(C.c_uint), C.POINTER(C.c_long))
__clibwinsystem.win2fix.restype = C.c_ulong

__clibwinsystem.win_chheader_info.argtypes = (C.c_char_p, C.POINTER(C.c_uint), C.POINTER(C.c_long),
                                              C.POINTER(C.c_int))
__clibwinsystem.win_chheader_info.restype = C.c_ulong

class windata:
    def __init__(self, chid, begintime, endtime, sr, d):
        self.chid = chid
        self.begintime = begintime
        self.endtime = endtime
        self.sr = sr
        self.d = d


def _read_onesec(data, start, output, ch2tr, maxtr):
    tt = (C.c_int * 6)(0,0,0,0,0,0)
    abuf = np.empty(MAX_SR, dtype=np.int32)
    g_size = C.c_ulong()
    sys_ch = C.c_uint()
    s_rate = C.c_long()

    blksizetmp = data[start:start+4]
    blksize = struct.unpack(">I", blksizetmp)[0]
    buff = data[start+4:start+10]
    __clibwinsystem.bcd_dec(tt, buff)

    if tt[0] < 70:
        tt[0] += 2000
    else:
        tt[0] += 1900
    begdate = UTCDateTime(tt[0], tt[1], tt[2], tt[3], tt[4], tt[5])
    prevdate = begdate - 1
    
    blksize -= 10
    buff = data[start+10:start+10+blksize]

    offset = 0
    while offset < blksize:
        g_size = __clibwinsystem.win2fix(buff[offset:], abuf, sys_ch, s_rate)
        chid = sys_ch.value
        if chid in ch2tr and output[ch2tr[chid]].endtime == prevdate and output[ch2tr[chid]].sr == s_rate.value:
            ii = ch2tr[chid]
            output[ii].d = np.append(output[ii].d, abuf[0:s_rate.value])
            output[ii].endtime = begdate.timestamp
        else:
            ii = maxtr
            maxtr = maxtr + 1
            ch2tr[chid] = ii
            output.append(windata(chid, begdate.timestamp, begdate.timestamp, s_rate.value, np.copy(abuf[0:s_rate.value])))

        offset += g_size

    del(abuf)
    return((blksize + 10, maxtr))

def read_winfile(fname):
    output = []
    ch2tr = {}
    maxtr = 0
    
    with open(fname, "rb") as fpin:
        data = fpin.read()
        datasize = len(data)
        offset = 0
        while offset < datasize:
            (blksize, maxtr) = _read_onesec(data, offset, output, ch2tr, maxtr)
            offset += blksize
    fpin.close()
    
    traces = []
    for i in range(maxtr):
        t = Trace(data=np.array(output[i].d).flatten())
        t.stats.channel = format(output[i].chid, '04X')
        t.stats.sampling_rate = float(output[i].sr)
        if not TZ:
            t.stats.starttime = UTCDateTime(output[i].begintime)
        else:
            stime0 = str(UTCDateTime(output[i].begintime))
            stime1 = stime0.replace('Z', TZ)
            t.stats.starttime = UTCDateTime(stime1)
#            print('DEBUG %s %s %s' % (stime0, stime1, t.stats.starttime))
        traces.append(t)

    del(output)
    del(ch2tr)
    return Stream(traces=traces)

if __name__ == '__main__':
    winfname="991109.064607"
    time_sta = time.perf_counter()
    st = read_winfile(winfname)
    time_end = time.perf_counter()
    ela_time = time_end - time_sta
    print('Ellapsed time = %f sec' % ela_time)

    chid = "020*"
    st2 = st.select(channel=chid)
    print(st2)
    st2.plot()

    sys.exit(0)