#!/usr/local/bin/python2.6
# dst2tank.py

from tracebuf2 import tracebuf2
from struct import pack

def getEndtime(time, samprate, nsamp):
    return getTime(time, samprate, nsamp-1)

def getTime(time, samprate, nsamp):
    return time + float(nsamp)/float(samprate)

def writeTracebuf(tb2, infile, outfile, maxsamp):
    samples = []
    nextSecs = None
    for n in range (0, maxsamp):
        line = infile.readline()
        if len(line) == 0:
           break
        (date, str_value) = line.split()
        secs = int(date)
        if (nextSecs == None):
            tb2.setStarttime(secs)
        elif (secs != nextSecs):
           break
        nextSecs = getTime(secs, tb2.getSamprate(), 1)
        float_value = float(str_value)
        int_value = int(round(float_value * 1000.))
        samples.append(int_value)
    nsamp = len(samples)
    if (nsamp > 0):
       tb2.setNsamp(nsamp)
       tb2.setEndtime("auto")
       tb2.setTheader()
       outfile.write(tb2.getTheader())
       for sample in samples:
          outfile.write(pack("<i", sample))
    return nsamp

def createTracebuf(sta=None, chan=None, net=None, loc=None, samprate=1/60.):
    tb2 = tracebuf2()
    tb2.setDatatype("i4")
    if sta != None:
        tb2.setSta(sta)
    if chan != None:
        tb2.setChan(chan)
    if net != None:
        tb2.setNet(net)
    if loc != None:
        tb2.setLoc(loc)
    tb2.setSamprate(samprate)
    return tb2

def processDstFile(tb2,
                   infn="opDst.txt", outfn="opDst.tnk",
                   maxsamp=5):
    infile = open(infn, "r")
    outfile = open(outfn, "wb")
    while True:
        if writeTracebuf(tb2, infile, outfile, maxsamp) == 0:
            break
    infile.close()
    outfile.close()

S = "USGS"
C = "DST"
N = "NT"
L = "R0"
processDstFile(createTracebuf(S, C, N, L))