#!/usr/bin/env python

# Copyright (C) 2012 Michael Gorven <http://michael.gorven.za.net/>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

from csv import reader
from datetime import datetime, timedelta
from optparse import OptionParser
from sys import stdin, stdout

from dateutil.tz import tzlocal
from dateutil.parser import parse as parsedate
from lxml import etree

parser = OptionParser()

GPX_NAMESPACE = 'http://www.topografix.com/GPX/1/1'
TPX_NAMESPACE = 'http://www.garmin.com/xmlschemas/TrackPointExtension/v1'
GPX='{%s}' % GPX_NAMESPACE
TPX='{%s}' % TPX_NAMESPACE

class HeartTrack(object):

    def __init__(self, name, description, samplingrate, starttime, trackpoints=[]):
        self.name = name
        self.description = description
        self.samplingrate = samplingrate
        self.starttime = starttime
        self.trackpoints = trackpoints or []

    def __repr__(self):
        return '<HeartTrack %s %s points every %ss from %s>' % (self.name, len(self.trackpoints), self.samplingrate.total_seconds(), self.starttime.isoformat())

    @classmethod
    def read_csv(self, filename):
        csv = reader(open(filename))
        headers = True
        for line in csv:
            field = line[0]
            value = line[1] if len(line) > 1 else None
            if headers:
                if field.lower() == 'name':
                    name = value
                elif field.lower() == 'description':
                    description = value
                elif field.lower() == 'samplingrate':
                    samplingrate = timedelta(seconds=int(value))
                elif field.lower() == 'date':
                    date = value
                elif field.lower() == 'time':
                    time = value
                elif field.lower() == 'heartrate':
                    starttime = datetime.strptime('%s %s' % (date, time), '%m/%d/%Y %H:%M:%S').replace(tzinfo=tzlocal())
                    track = HeartTrack(name, description, samplingrate, starttime)
                    currenttime = starttime
                    headers = False
            else:
                currenttime += track.samplingrate
                track.trackpoints.append(HeartTrackpoint(int(value), currenttime))

        return track


class HeartTrackpoint(object):

    def __init__(self, heart, time):
        self.heart = int(heart)
        self.time = time

    def __repr__(self):
        return '<HeartTrackpoint %sbpm at %s>' % (self.heart, self.time.isoformat())


def add_heart(gpx, heart):

    nsmap = gpx.getroot().nsmap
    nsmap['gpxtpx'] = TPX_NAMESPACE
    root = etree.Element(gpx.getroot().tag, nsmap=nsmap, version='1.1', creator='wm100gpx.py')
    root[:] = gpx.getroot()[:]

    for trk in root.iterfind(GPX+'trk'):
        for trkseg in trk.iterfind(GPX+'trkseg'):
            for trkpt in trkseg.iterfind(GPX+'trkpt'):
                time = parsedate(trkpt.find(GPX+'time').text)
                hrpt = None
                for heartpoint in heart.trackpoints:
                    if heartpoint.time > time:
                        break
                    hrpt = heartpoint
                if hrpt and time - hrpt.time <= heart.samplingrate:
                    extensions = etree.SubElement(trkpt, 'extensions')
                    tpe = etree.SubElement(extensions, TPX+'TrackPointExtension')
                    hr = etree.SubElement(tpe, TPX+'hr')
                    hr.text = str(hrpt.heart)

    return etree.ElementTree(root)


if __name__ == '__main__':
    options, args = parser.parse_args()
    parser = etree.XMLParser(remove_blank_text=True)
    heart = HeartTrack.read_csv(args[0])
    gpx = etree.parse(stdin, parser)
    merged = add_heart(gpx, heart)
    merged.write(stdout, encoding='UTF-8', pretty_print=True)