# flake8: noqa
import json
from collections import OrderedDict
from datetime import timedelta
from typing import Mapping, Optional

import qrcode
from django.conf import settings
from django.core.cache import cache
from django.http import Http404, HttpResponse, JsonResponse
from django.shortcuts import redirect, render
from django.urls import reverse
from django.utils import timezone

from c3nav.mapdata.models import Location, Source
from c3nav.mapdata.models.access import AccessPermission
from c3nav.mapdata.models.level import Level
from c3nav.mapdata.models.locations import LocationRedirect, SpecificLocation
from c3nav.mapdata.utils.locations import get_location_by_slug_for_request
from c3nav.mapdata.views import set_tile_access_cookie

ctype_mapping = {
    'yes': ('up', 'down'),
    'up': ('up', ),
    'down': ('down', ),
    'no': ()
}


def get_ctypes(prefix, value):
    return tuple((prefix+'_'+direction) for direction in ctype_mapping.get(value, ('up', 'down')))


def reverse_ctypes(ctypes, name):
    if name+'_up' in ctypes:
        return 'yes' if name + '_down' in ctypes else 'up'
    else:
        return 'down' if name + '_down' in ctypes else 'no'


def get_location_or_404(request, location):
    if location is None:
        return None

    get_location = None
    location = get_location(request, location)
    if location is None:
        raise Http404

    return location


def qr_code(request, location):
    location = get_location_or_404(request, location)

    qr = qrcode.QRCode(
        version=1,
        error_correction=qrcode.constants.ERROR_CORRECT_L,
        box_size=10,
        border=4,
    )
    qr.add_data(request.build_absolute_uri(reverse('site.location', kwargs={'location': location.location_id})))
    qr.make(fit=True)

    response = HttpResponse(content_type='image/png')
    qr.make_image().save(response, 'PNG')
    return response


def check_location(location: Optional[str], request) -> Optional[SpecificLocation]:
    if location is None:
        return None

    location = get_location_by_slug_for_request(location, request)
    if location is None:
        return None

    if isinstance(location, LocationRedirect):
        location: Location = location.target
    if location is None:
        return None

    if not location.can_search:
        location = None

    return location


@set_tile_access_cookie
def map_index(request, mode=None, slug=None, slug2=None, details=None, level=None, x=None, y=None, zoom=None):
    origin = None
    destination = None
    routing = False
    if slug2 is not None:
        routing = True
        origin = check_location(slug, request)
        destination = check_location(slug2, request)
    else:
        routing = (mode and mode != 'l')
        if mode == 'o':
            origin = check_location(slug, request)
        else:
            destination = check_location(slug, request)

    state = {
        'routing': routing,
        'origin': (origin.serialize(detailed=False, simple_geometry=True, geometry=False)
                   if origin else None),
        'destination': (destination.serialize(detailed=False, simple_geometry=True, geometry=False)
                        if destination else None),
        'sidebar': routing or destination is not None,
        'details': True if details else False,
    }

    levels_cache_key = 'mapdata:levels:%s' % AccessPermission.cache_key_for_request(request)
    levels = cache.get(levels_cache_key, None)
    if levels is None:
        levels = OrderedDict(
            (level.slug, (level.pk, level.slug, level.short_label))
            for level in Level.qs_for_request(request).filter(on_top_of_id__isnull=True).order_by('base_altitude')
        )
        cache.set(levels_cache_key, levels, 300)

    level = levels.get(level, None) if level else None
    if level is not None:
        state.update({
            'level': level[0],
            'center': (float(x), float(y)),
            'zoom': float(zoom),
        })

    ctx = {
        'bounds': json.dumps(Source.max_bounds(), separators=(',', ':')),
        'levels': json.dumps(tuple(levels.values()), separators=(',', ':')),
        'state': json.dumps(state, separators=(',', ':')),
        'tile_cache_server': settings.TILE_CACHE_SERVER,
    }
    return render(request, 'site/map.html', ctx)


def main(request, location=None, origin=None, destination=None):
    location = get_location_or_404(request, location)
    origin = get_location_or_404(request, origin)
    destination = get_location_or_404(request, destination)

    mode = 'location' if not origin and not destination else 'route'

    active_field = None
    if not origin and not destination:
        active_field = 'location'
    elif origin and not destination:
        active_field = 'destination'
    elif destination and not origin:
        active_field = 'origin'

    ctx = {
        'location': location,
        'origin': origin,
        'destination': destination,
        'mode': mode,
        'active_field': active_field,

        'full_access': request.c3nav_full_access,
        'access_list': request.c3nav_access_list,
        'visible_areas': get_visible_areas(request),
    }

    width, height = get_dimensions()
    sections = tuple(section for id_, section in get_sections_cached().items())

    ctx.update({
        'width': width,
        'height': height,
        'svg_width': int(width * 6),
        'svg_height': int(height * 6),
        'sections': sections,
    })

    map_level = request.GET.get('map-level')
    if map_level in sections:
        ctx.update({
            'map_level': map_level
        })

        if 'x' in request.POST and 'y' in request.POST:
            x = request.POST.get('x')
            y = request.POST.get('y')
            if x.isnumeric() and y.isnumeric():
                coords = 'c:%s:%d:%d' % (map_level, int(int(x)/6*100), height-int(int(y)/6*100))
                if active_field == 'origin':
                    return redirect('site.route', origin=coords, destination=destination.location_id)
                elif active_field == 'destination':
                    return redirect('site.route', origin=origin.location_id, destination=coords)
                elif active_field == 'location':
                    return redirect('site.location', location=coords)

    if active_field is not None:
        search_query = request.POST.get(active_field+'_search', '').strip() or None
        if search_query:
            results = search_location(request, search_query)

            url = 'site.location' if active_field == 'location' else 'site.route'
            kwargs = {}
            if origin:
                kwargs['origin'] = origin.location_id
            if destination:
                kwargs['destination'] = destination.location_id
            for result in results:
                kwargs[active_field] = result.location_id
                result.url = reverse(url, kwargs=kwargs)

            ctx.update({
                'search': active_field,
                'search_query': search_query,
                'search_results': results,
            })

    # everything about settings
    include = ()
    avoid = ()
    stairs = 'yes'
    escalators = 'yes'
    elevators = 'yes'

    save_settings = False
    if 'c3nav_settings' in request.COOKIES:
        cookie_value = request.COOKIES['c3nav_settings']

        if isinstance(cookie_value, dict):
            stairs = cookie_value.get('stairs', stairs)
            escalators = cookie_value.get('escalators', escalators)
            elevators = cookie_value.get('elevators', elevators)

            if isinstance(cookie_value.get('include'), list):
                include = cookie_value.get('include')

            if isinstance(cookie_value.get('avoid'), list):
                avoid = cookie_value.get('avoid')

        save_settings = True

    if request.method == 'POST':
        stairs = request.POST.get('stairs', stairs)
        escalators = request.POST.get('escalators', escalators)
        elevators = request.POST.get('elevators', elevators)

        include = request.POST.getlist('include')
        avoid = request.POST.getlist('avoid')

    allowed_ctypes = ('', )
    allowed_ctypes += get_ctypes('stairs', request.POST.get('stairs', stairs))
    allowed_ctypes += get_ctypes('escalator', request.POST.get('escalators', escalators))
    allowed_ctypes += get_ctypes('elevator', request.POST.get('elevators', elevators))

    stairs = reverse_ctypes(allowed_ctypes, 'stairs')
    escalators = reverse_ctypes(allowed_ctypes, 'escalator')
    elevators = reverse_ctypes(allowed_ctypes, 'elevator')

    includables, avoidables = get_includables_avoidables(request)
    allow_nonpublic, include, avoid = parse_include_avoid(request, include, avoid)

    if request.method == 'POST':
        save_settings = request.POST.get('save_settings', '') == '1'

    ctx.update({
        'stairs': stairs,
        'escalators': escalators,
        'elevators': elevators,
        'excludables': avoidables.items(),
        'includables': includables.items(),
        'include': include,
        'avoid': avoid,
        'save_settings': save_settings,
    })

    # routing
    if request.method == 'POST' and origin and destination:
        graph = Graph.load()

        try:
            route = graph.get_route(origin, destination, allowed_ctypes, allow_nonpublic=allow_nonpublic,
                                    avoid=avoid-set(':public'), include=include-set(':nonpublic'))
        except NoRouteFound:
            ctx.update({'error': 'noroutefound'})
        except AlreadyThere:
            ctx.update({'error': 'alreadythere'})
        except NotYetRoutable:
            ctx.update({'error': 'notyetroutable'})
        else:
            route.describe(allowed_ctypes)
            ctx.update({'route': route})

    if request.GET.get('format') == 'json':
        if 'error' in ctx:
            return JsonResponse({'error': ctx['error']})
        if 'route' in ctx:
            return JsonResponse({'route': ctx['route'].serialize()})

    response = render(request, 'site/main.html', ctx)

    if request.method == 'POST' and save_settings:
        cookie_value = {
            'stairs': stairs,
            'escalators': escalators,
            'elevators': elevators,
            'include': tuple(include),
            'avoid': tuple(avoid),
        }
        response.set_cookie('c3nav_settings', cookie_value, expires=timezone.now() + timedelta(days=30))

    return response