from decimal import Decimal
from datetime import datetime, timedelta, time, timezone
import json

import gpxpy

from pyramid.httpexceptions import HTTPFound, HTTPNotFound
from pyramid.view import view_config
from pyramid.response import Response
from pyramid_simpleform import Form
from pyramid_simpleform.renderers import FormRenderer
from pyramid.i18n import TranslationStringFactory

from ..schemas.workout import (
    UploadedWorkoutSchema,
    ManualWorkoutSchema,
    UpdateWorkoutSchema
)
from ..models.workout import Workout
from ..models.user import User
from ..utilities import slugify, save_map_screenshot, part_of_day
from ..catalog import get_catalog, reindex_object, remove_from_catalog


_ = TranslationStringFactory('OpenWorkouts')


@view_config(
    context=User,
    permission='edit',
    name='add-workout-manually',
    renderer='ow:templates/add_manual_workout.pt')
def add_workout_manually(context, request):
    form = Form(request, schema=ManualWorkoutSchema(),
                defaults={'duration_hours': '0',
                          'duration_minutes': '0',
                          'duration_seconds': '0'})

    if 'submit' in request.POST and form.validate():
        # exclude the three duration_* and start_* fields, so they won't be
        # "bind" to the object, we do calculate both the full duration in
        # seconds and the full datetime "start" and we save that
        #
        # exclude also the distance field, we have to convert to decimal
        # before adding it
        excluded = ['duration_hours', 'duration_minutes', 'duration_seconds',
                    'start_date', 'start_time', 'distance']
        workout = form.bind(Workout(), exclude=excluded)
        duration = timedelta(hours=form.data['duration_hours'],
                             minutes=form.data['duration_minutes'],
                             seconds=form.data['duration_seconds'])
        workout.duration = duration
        # create a time object first using the given hours and minutes
        start_time = time(form.data['start_time'][0],
                          form.data['start_time'][1])
        # combine the given start date with the built time object
        start = datetime.combine(form.data['start_date'], start_time,
                                 tzinfo=timezone.utc)
        workout.start = start
        if not workout.title:
            workout.title = part_of_day(start)
            if workout.sport:
                workout.title += ' ' + workout.sport
            workout.title += ' ' + _('workout')
        workout.distance = Decimal(form.data['distance'])
        context.add_workout(workout)
        return HTTPFound(location=request.resource_url(workout))

    return {
        'form': FormRenderer(form)
    }


@view_config(
    context=User,
    permission='edit',
    name='add-workout',
    renderer='ow:templates/add_workout.pt')
def add_workout(context, request):
    """
    Add a workout uploading a tracking file
    """
    # if not given a file there is an empty byte in POST, which breaks
    # our blob storage validator.
    # dirty fix until formencode fixes its api.is_empty method
    if isinstance(request.POST.get('tracking_file', None), bytes):
        request.POST['tracking_file'] = ''

    form = Form(request, schema=UploadedWorkoutSchema())

    if 'submit' in request.POST and form.validate():
        # Grab some information from the tracking file
        trackfile_ext = request.POST['tracking_file'].filename.split('.')[-1]
        # Create a Workout instance based on the input from the form
        workout = form.bind(Workout())
        # Add the type of tracking file
        workout.tracking_filetype = trackfile_ext
        # Add basic info gathered from the file
        workout.load_from_file()
        # Add the workout
        context.add_workout(workout)
        return HTTPFound(location=request.resource_url(workout))

    return {
        'form': FormRenderer(form)
    }


@view_config(
    context=Workout,
    permission='edit',
    name='edit',
    renderer='ow:templates/edit_manual_workout.pt')
def edit_workout(context, request):
    """
    Edit manually an existing workout. This won't let users attach/update
    tracking files, just manually edit of the values.
    """
    form = Form(request, schema=ManualWorkoutSchema(), obj=context)
    if 'submit' in request.POST and form.validate():
        # exclude the three duration_* and start_* fields, so they won't be
        # "bind" to the object, we do calculate both the full duration in
        # seconds and the full datetime "start" and we save that
        excluded = ['duration_hours', 'duration_minutes', 'duration_seconds',
                    'start_date', 'start_time']

        form.bind(context, exclude=excluded)

        duration = timedelta(hours=form.data['duration_hours'],
                             minutes=form.data['duration_minutes'],
                             seconds=form.data['duration_seconds'])
        context.duration = duration

        # create a time object first using the given hours and minutes
        start_time = time(form.data['start_time'][0],
                          form.data['start_time'][1])
        # combine the given start date with the built time object
        start = datetime.combine(form.data['start_date'], start_time,
                                 tzinfo=timezone.utc)
        context.start = start
        # ensure distance is a decimal
        context.distance = Decimal(context.distance)
        catalog = get_catalog(context)
        reindex_object(catalog, context)
        return HTTPFound(location=request.resource_url(context))

    # round some values before rendering
    if form.data['distance']:
        form.data['distance'] = round(form.data['distance'], 2)

    return {
        'form': FormRenderer(form)
    }


@view_config(
    context=Workout,
    permission='edit',
    name='update-from-file',
    renderer='ow:templates/update_workout_from_file.pt')
def update_workout_from_file(context, request):
    # if not given a file there is an empty byte in POST, which breaks
    # our blob storage validator.
    # dirty fix until formencode fixes its api.is_empty method
    if isinstance(request.POST.get('tracking_file', None), bytes):
        request.POST['tracking_file'] = ''

    form = Form(request, schema=UpdateWorkoutSchema())
    if 'submit' in request.POST and form.validate():
        # Grab some information from the tracking file
        trackfile_ext = request.POST['tracking_file'].filename.split('.')[-1]
        # Update the type of tracking file
        context.tracking_filetype = trackfile_ext
        form.bind(context)
        # Override basic info gathered from the file
        context.load_from_file()
        catalog = get_catalog(context)
        reindex_object(catalog, context)
        return HTTPFound(location=request.resource_url(context))
    return {
        'form': FormRenderer(form)
    }


@view_config(
    context=Workout,
    permission='delete',
    name='delete',
    renderer='ow:templates/delete_workout.pt')
def delete_workout(context, request):
    """
    Delete a workout
    """
    if 'submit' in request.POST:
        if request.POST.get('delete', None) == 'yes':
            catalog = get_catalog(context)
            remove_from_catalog(catalog, context)
            del request.root[request.authenticated_userid][context.workout_id]
            return HTTPFound(location=request.resource_url(request.root))
    return {}


@view_config(
    context=Workout,
    permission='view',
    renderer='ow:templates/workout.pt')
def workout(context, request):
    """
    Details page for a workout
    """
    start_point = {}
    if context.has_gpx:
        with context.tracking_file.open() as gpx_file:
            gpx_contents = gpx_file.read()
            gpx_contents = gpx_contents.decode('utf-8')
            gpx = gpxpy.parse(gpx_contents)
            if gpx.tracks:
                track = gpx.tracks[0]
                center_point = track.get_center()
                start_point = {'latitude': center_point.latitude,
                               'longitude': center_point.longitude,
                               'elevation': center_point.elevation}
    return {'start_point': start_point}


@view_config(
    context=Workout,
    name='gpx')
def workout_gpx(context, request):
    """
    Return a gpx file with the workout tracking information, if any.
    For now, simply return the gpx file if it has been attached to the
    workout.

    This view requires no permission, as we access it from an non-authenticated
    request in a separate job, to generate the static map screenshot.
    """
    if not context.has_gpx:
        return HTTPNotFound()
    # Generate a proper file name to suggest on the download
    gpx_slug = slugify(context.title) + '.gpx'
    return Response(
        content_type='application/xml',
        content_disposition='attachment; filename="%s"' % gpx_slug,
        body_file=context.tracking_file.open())


@view_config(
    context=Workout,
    name='map',
    renderer='ow:templates/workout-map.pt')
def workout_map(context, request):
    """
    Render a page that has only a map with tracking info.
    This view requires no permission, as we access it from an non-authenticated
    request in a separate job, to generate the static map screenshot.
    """
    start_point = {}
    if context.has_gpx:
        with context.tracking_file.open() as gpx_file:
            gpx_contents = gpx_file.read()
            gpx_contents = gpx_contents.decode('utf-8')
            gpx = gpxpy.parse(gpx_contents)
            if gpx.tracks:
                track = gpx.tracks[0]
                center_point = track.get_center()
                start_point = {'latitude': center_point.latitude,
                               'longitude': center_point.longitude,
                               'elevation': center_point.elevation}
    return {'start_point': start_point}


@view_config(
    context=Workout,
    permission='edit',
    name='map-shot')
def workout_map_shot(context, request):
    """
    Ask for the screenshot of a map, creating one if it does not exist.
    A json object is returned, containing the info for the needed screenshot
    """
    if context.map_screenshot is None:
        save_map_screenshot(context, request)

    info = {'url': request.static_url(context.map_screenshot)}
    return Response(content_type='application/json',
                    charset='utf-8',
                    body=json.dumps(info))