import datetime
import glob
import os
import gpxpy
import gpxpy.gpx
from geopy import distance
from geopy import Point

class Segment(object):
    start_time = None
    end_time = None
    distance = 0.0     # [m]

class Track(object):
    start_time = None
    end_time = None
    distance = 0.0     # [m]
    avg_speed = 0.0    # [km/h]
    duration = None

    def __init__(self, raw_track):
        self.__raw = raw_track
        for segment in self.__raw.segments:
            seg = Segment()
            for i in range(1, len(segment.points)):
                if self.start_time is None:
                    self.start_time = segment.points[i - 1].time
                if seg.start_time is None:
                    seg.start_time = segment.points[i - 1].time
                seg.end_time = segment.points[i - 1].time
                point1 = Point(str(segment.points[i - 1].latitude) + \
                    ' ' + str(segment.points[i - 1].longitude))
                point2 = Point(str(segment.points[i].latitude) + \
                    ' ' + str(segment.points[i].longitude))
                seg.distance += distance.distance(point1, point2).meters

            try:
                if self.duration is None:
                    self.duration = seg.end_time - seg.start_time
                else:
                    self.duration += seg.end_time - seg.start_time
            except Exception:
                # TODO: Add logging mechanism.
                pass
            self.end_time = seg.end_time
            self.distance += seg.distance
        self.avg_speed = self.distance / self.duration.total_seconds() * 3.6


class Tracks(object):
    track_list = None

    def __init__(self, folder):
        self.track_list = list()
        gpx_list = glob.glob(os.path.join(folder, '*.gpx'))
        for entry in gpx_list:
            with open(entry, 'r') as gpx_handle:
                gpx = gpxpy.parse(gpx_handle)
                for raw_track in gpx.tracks:
                    self.track_list.append(Track(raw_track))

    def get(self, year='all', month='all', day='all'):
        ret = list()
        if year == 'all':
            ret = self.track_list
        elif month == 'all':
            pick_date = datetime.datetime(year=year, month=1, day=1)
            for entry in self.track_list:
                if pick_date.year == entry.start_time.year:
                    ret.append(entry)
        elif day == 'all':
            pick_date = datetime.datetime(year=year, month=month, day=1)
            ret = list()
            for entry in self.track_list:
                if pick_date.year == entry.start_time.year and \
                    pick_date.month == entry.start_time.month:
                    ret.append(entry)
        else:
            pick_date = datetime.datetime(year=year, month=month, day=day)
            ret = list()
            for entry in self.track_list:
                if pick_date.year == entry.start_time.year and \
                    pick_date.month == entry.start_time.month and \
                    pick_date.day == entry.start_time.day:
                    ret.append(entry)
        return ret