# coding: utf-8
# %load nightsresize
import struct
import os
import argparse
import csv

def main(args):
    struct_fmt = '@hhhHh'
    struct_len = struct.calcsize(struct_fmt)
    struct_unpack = struct.Struct(struct_fmt).unpack_from

    in_filename = args.infile

    if not os.path.isfile(in_filename):
        raise ValueError('Path %s not found or is not a file' % in_filename)

    out_filename = args.outfile or '{}{}.{}'.format(os.path.splitext(in_filename)[0], '-THINGS', 'lmp')

    print('Reading %s' % in_filename)

    def read_chunks(f, length):
        while True:
            data = f.read(length)
            if not data: break
            yield data

    header = args.header
    results = []
    with open(in_filename, 'r') as f:
        r = csv.reader(f)
        for row in r:
            if header:
                header = False
                continue
            results.append((int(row[0]), int(row[1]), 0, args.thingnum, int(row[2])*16))
                # csv: x, y, z
                # thing entry: x, y, 0 for angle, thing num, z*16 for z

    out = bytes().join((struct.pack(struct_fmt, *entry) for entry in results))
    with open(out_filename, 'wb') as f:
        f.write(out)

    print('Saved %s things to %s' % (len(results), out_filename))

def get_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("infile", type=str,
                        help="Path to file")
    parser.add_argument('-out', '-o', dest='outfile', type=str, help='Path to output file. Default: append -THINGS to input filename', default=None)
    parser.add_argument('-header', '-d', action='store_true', help='Specify if input CSV has a header row. Default: assume it does not', default=False)
    parser.add_argument('-type', '-t', dest='thingnum', type=int, help='Thing type to write. Default: 300 (Ring)', default=300)
    args = parser.parse_args()
    return args

if __name__ == '__main__':
    main(get_args())