#!/usr/bin/env python
# -*- coding: utf-8 -*-
# A utility to compute the distance travelled by axes out of log messages that
# look like:
# Updated position to {'s': 0.0029690275, 'l': 0.0505179063}
# To test:
# ./util/axes-odometer summary-booo.log
#
################################################################################
# Created on 6 Aug 2018
#
# @author: Éric Piel
#
# Copyright © 2018 Éric Piel, Delmic
#
# axes-odometer is free software: you can redistribute it and/or modify it under the terms
# of the GNU General Public License version 2 as published by the Free Software
# Foundation.
#
# axes-odometer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
# PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# axes-odometer. If not, see http://www.gnu.org/licenses/.
################################################################################

from __future__ import division, absolute_import, print_function

import argparse
from collections import OrderedDict
import logging
import re
import sys
import gzip
import ast
import numbers

# logging.getLogger().setLevel(logging.DEBUG)


def open_file(fn, mode="rb"):
    """
    Open a file, which can be compressed
    fn (string): filename. If it ends with .gz, it will be decompressed on the fly
    mode (string): cf open()
    return (File): a file stream
    """
    if fn.endswith(".gz"):
        return gzip.open(fn, mode)
    elif fn == "-":
        return sys.stdin
    else:
        return open(fn, mode)


RE_UPD_POS = re.compile(r"Updated position to (\{[^}]*\})")
def read_pos(line):
    """
    Read a position update in a line
    return (dict str-> float): axes -> position.
      If nothing found, return {}
    """
    # Look for line of the style:
    # .*Updated position to {'s': 0.0029690275, 'l': 0.0505179063}
    m = RE_UPD_POS.search(line)
    if m:
        # Convert to a dict
        return ast.literal_eval(m.group(1))
    else:
        logging.debug("Failed to find position in: %s", line)
        return {}


def add_distances(f):
    prev_pos = {}
    tot_dist = {}
    for l in f.readlines():
        try:
            pos = read_pos(l)
            # Compute the delta with the previous position and add it to the total
            for ax, p in pos.items():
                if not isinstance(p, numbers.Real):
                    logging.debug("Skipping axis %s which doesn't have a numerical value: %s", ax, p)
                    continue
                if ax in tot_dist:
                    tot_dist[ax] += abs(prev_pos[ax] - p)
                else:
                    # First time
                    tot_dist[ax] = 0

            prev_pos.update(pos)
        except Exception:
            logging.exception("Failed to parse %s", l)

    return tot_dist


def main(args):
    """
    Handles the command line arguments
    args is the list of arguments passed
    return (int): value to return to the OS as program exit code
    """

    # arguments handling
    parser = argparse.ArgumentParser(description="Computes the distances travelled by each axis from a log file")

    parser.add_argument('input', default="-",
                        help='Input file name (default: -, which means stdin)')

    options = parser.parse_args(args[1:])

    try:
        inf = open_file(options.input)
        try:
            odo = add_distances(inf)
        finally:
            inf.close()

        # sorted_odo = OrderedDict(sorted(odo.items()))
        print("Distance: %s" % (odo,))

    except ValueError as exp:
        logging.error("%s", exp)
        return 127
    except IOError as exp:
        logging.error("%s", exp)
        return 129
    except Exception:
        logging.exception("Unexpected error while performing action.")
        return 130
    except KeyboardInterrupt:
        return 1

    return 0


if __name__ == '__main__':
    ret = main(sys.argv)
    exit(ret)