"""
A file conversion.

Duncan Gray, GA - 2007 

"""


#----------------------------------------------------------------------------
# Import necessary modules
#----------------------------------------------------------------------------

from Scientific.IO.NetCDF import NetCDFFile
from Numeric import zeros, Float
  
from anuga.utilities.numerical_tools import ensure_numeric
from anuga.utilities.interp import interp


def csv2tms(filename, offshore_bed_elevation):
    """
    Convert Hinwood boundary file to NetCDF tms file.
    the filename is the name of the output tms file, eg 'hi.tsm'.
    There must be an equivalent .csv file, eg 'hi.csv'.
   
    """
    print 'Creating', filename

    # Read the ascii (.csv) version of this file
    fid = open(filename[:-4] + '.csv')

    #Skip first line
    line = fid.readline()
    
    # Read remaining lines
    lines = fid.readlines()
    fid.close()

    N = len(lines)
    T = zeros(N, Float)  #Time
    Q = zeros(N, Float)  #Stage
    X = zeros(N, Float)  #XMomentum
    Y = zeros(N, Float)  #YMomentum

    for i, line in enumerate(lines):
        fields = line.split(',')

        T[i] = float(fields[0])
        Q[i] = float(fields[1])
        depth = Q[i] - offshore_bed_elevation
        X[i] = float(fields[2]) * depth
        Y[i] = float(fields[3]) * depth
    
    # Create tms NetCDF file
    fid = NetCDFFile(filename, 'w')
    fid.institution = 'Geoscience Australia'
    fid.description = 'Input wave for Benchmark 2'
    fid.starttime = 0.0
    fid.createDimension('number_of_timesteps', len(T))
    fid.createVariable('time', Float, ('number_of_timesteps',))
    fid.variables['time'][:] = T

    fid.createVariable('stage', Float, ('number_of_timesteps',))
    fid.variables['stage'][:] = Q[:]

    fid.createVariable('xmomentum', Float, ('number_of_timesteps',))
    fid.variables['xmomentum'][:] =  X[:]

    fid.createVariable('ymomentum', Float, ('number_of_timesteps',))
    fid.variables['ymomentum'][:] =  Y[:]

    fid.close()