"""This has to do with creating elevation data files for use with ferret2sww.
It reads a bathymetry ascii file and creates a NetCDF (nc) file similar to
MOSTs output.

 $Author: Peter Row
 
"""
from __future__ import division

from builtins import range
from past.utils import old_div
import sys
from anuga.file.netcdf import NetCDFFile
from anuga.config import netcdf_mode_r, netcdf_mode_w, netcdf_mode_a
import anuga.utilities.log as log


def most2nc(input_file, output_file, inverted_bathymetry=False, verbose=True):
    """Convert a MOST file to NetCDF format.

    input_file           the input file to convert
    output_file          the name of the oputput NetCDF file to create
    inverted_bathymetry  ??
    verbose              True if the function is to be verbose
    """

    # variable names
    long_name = 'LON'
    lat_name = 'LAT'
    elev_name = 'ELEVATION'

    # set up bathymetry
    if inverted_bathymetry:
        up = -1.
    else:
        up = +1.

    # read data from the MOST file
    in_file = open(input_file, 'r')

    if verbose:
        log.critical('reading header')

    nx_ny_str = in_file.readline()
    nx_str, ny_str = nx_ny_str.split()
    nx = int(nx_str)
    ny = int(ny_str)
    h1_list = []
    for i in range(nx):
        h1_list.append(float(in_file.readline()))

    h2_list = []
    for j in range(ny):
        h2_list.append(float(in_file.readline()))

    h2_list.reverse()

    if verbose:
        log.critical('reading depths')

    in_depth_list = in_file.readlines()
    in_file.close()

    out_depth_list = [[]]

    if verbose:
        log.critical('processing depths')

    k = 1
    for in_line in in_depth_list:
        for string in in_line.split():
            #j = k/nx
            out_depth_list[old_div((k-1), nx)].append(float(string)*up)
            if k == nx*ny:
                break
            if k-(old_div(k, nx))*nx == 0:
                out_depth_list.append([])
            k += 1

    in_file.close()
    out_depth_list.reverse()
    depth_list = out_depth_list

    # write the NetCDF file
    if verbose:
        log.critical('writing results')

    out_file = NetCDFFile(output_file, netcdf_mode_w)

    out_file.createDimension(long_name, nx)

    out_file.createVariable(long_name, 'd', (long_name,))
    out_file.variables[long_name].point_spacing = 'uneven'
    out_file.variables[long_name].units = 'degrees_east'
    out_file.variables[long_name][:] = h1_list

    out_file.createDimension(lat_name, ny)
    out_file.createVariable(lat_name, 'd', (lat_name,))
    out_file.variables[lat_name].point_spacing = 'uneven'
    out_file.variables[lat_name].units = 'degrees_north'
    out_file.variables[lat_name][:] = h2_list

    out_file.createVariable(elev_name, 'd', (lat_name, long_name))
    out_file.variables[elev_name].point_spacing = 'uneven'
    out_file.variables[elev_name].units = 'meters'
    out_file.variables[elev_name][:] = depth_list

    out_file.close()
