import typing
from decimal import Decimal

from django.conf import settings
from django.core.exceptions import ObjectDoesNotExist
from django.core.validators import MinValueValidator, RegexValidator
from django.db import models
from django.urls import reverse
from django.utils.functional import cached_property
from django.utils.text import format_lazy
from django.utils.translation import gettext_lazy as _
from shapely.geometry import CAP_STYLE, JOIN_STYLE, mapping

from c3nav.mapdata.fields import GeometryField, I18nField
from c3nav.mapdata.grid import grid
from c3nav.mapdata.models import Space, Level
from c3nav.mapdata.models.access import AccessRestrictionMixin
from c3nav.mapdata.models.base import SerializableMixin, TitledMixin
from c3nav.mapdata.models.geometry.base import GeometryMixin
from c3nav.mapdata.models.locations import SpecificLocation
from c3nav.mapdata.utils.cache.changes import changed_geometries
from c3nav.mapdata.utils.geometry import unwrap_geom
from c3nav.mapdata.utils.json import format_geojson

if typing.TYPE_CHECKING:
    from c3nav.mapdata.render.theme import ThemeColorManager


class SpaceGeometryMixin(GeometryMixin):
    space = models.ForeignKey('mapdata.Space', on_delete=models.CASCADE, verbose_name=_('space'))

    class Meta:
        abstract = True

    @cached_property
    def level_id(self):
        try:
            return self.space.level_id
        except ObjectDoesNotExist:
            return None

    def get_geojson_properties(self, *args, **kwargs) -> dict:
        result = super().get_geojson_properties(*args, **kwargs)
        if hasattr(self, 'get_color'):
            from c3nav.mapdata.render.theme import ColorManager
            color = self.get_color(ColorManager.for_theme(None))
            if color:
                result['color'] = color
        if hasattr(self, 'opacity'):
            result['opacity'] = self.opacity
        return result

    def _serialize(self, space=True, **kwargs):
        result = super()._serialize(**kwargs)
        if space:
            result['space'] = self.space_id
        return result

    @property
    def subtitle(self):
        base_subtitle = super().subtitle
        space = getattr(self, '_space_cache', None)
        if space is not None:
            level = getattr(space, '_level_cache', None)
            if level is not None:
                return format_lazy(_('{category}, {space}, {level}'),
                                   category=base_subtitle,
                                   space=space.title,
                                   level=level.title)
            return format_lazy(_('{category}, {space}'),
                               category=base_subtitle,
                               level=space.title)
        return base_subtitle

    @classmethod
    def q_for_request(cls, request, prefix='', allow_none=False):
        return (
            super().q_for_request(request, prefix=prefix, allow_none=allow_none) &
            Space.q_for_request(request, prefix=prefix + 'space__', allow_none=allow_none)
        )

    def register_change(self, force=False):
        space = self.space
        force = force or self.all_geometry_changed
        if force or self.geometry_changed:
            changed_geometries.register(space.level_id, space.geometry.intersection(
                unwrap_geom(self.geometry if force else self.get_changed_geometry())
            ))

    def details_display(self, **kwargs):
        result = super().details_display(**kwargs)
        result['display'].insert(3, (
            _('Space'),
            {
                'id': self.space_id,
                'slug': self.space.effective_slug,
                'title': self.space.title,
                'can_search': self.space.can_search,
            },
        ))
        result['level'] = self.level_id
        return result

    def register_delete(self):
        space = self.space
        changed_geometries.register(space.level_id, space.geometry.intersection(unwrap_geom(self.geometry)))

    def save(self, *args, **kwargs):
        self.register_change()
        super().save(*args, **kwargs)


class Column(SpaceGeometryMixin, AccessRestrictionMixin, models.Model):
    """
    An column in a space, also used to be able to create rooms within rooms.
    """
    geometry = GeometryField('polygon')

    class Meta:
        verbose_name = _('Column')
        verbose_name_plural = _('Columns')
        default_related_name = 'columns'


class Area(SpaceGeometryMixin, SpecificLocation, models.Model):
    """
    An area in a space.
    """
    new_serialize = True

    geometry = GeometryField('polygon')
    slow_down_factor = models.DecimalField(_('slow down factor'), max_digits=6, decimal_places=2, default=1,
                                           validators=[MinValueValidator(Decimal('0.01'))],
                                           help_text=_('values of overlapping areas get multiplied!'))
    main_point = GeometryField('point', null=True, blank=True,
                               help_text=_('main routing point (optional)'))

    class Meta:
        verbose_name = _('Area')
        verbose_name_plural = _('Areas')
        default_related_name = 'areas'

    @property
    def grid_square(self):
        if "geometry" in self.get_deferred_fields():
            return None
        return grid.get_squares_for_bounds(self.geometry.bounds) or ''

    def details_display(self, editor_url=True, **kwargs):
        result = super().details_display(**kwargs)
        if editor_url:
            result['editor_url'] = reverse('editor.areas.edit', kwargs={'space': self.space_id, 'pk': self.pk})
        return result


class Stair(SpaceGeometryMixin, models.Model):
    """
    A stair
    """
    new_serialize = True

    geometry = GeometryField('linestring')

    class Meta:
        verbose_name = _('Stair')
        verbose_name_plural = _('Stairs')
        default_related_name = 'stairs'


class Ramp(SpaceGeometryMixin, models.Model):
    """
    A ramp
    """
    new_serialize = True

    geometry = GeometryField('polygon')

    class Meta:
        verbose_name = _('Ramp')
        verbose_name_plural = _('Ramps')
        default_related_name = 'ramps'


class ObstacleGroup(TitledMixin, models.Model):
    color = models.CharField(max_length=32, null=True, blank=True)
    in_legend = models.BooleanField(default=False, verbose_name=_('show in legend (if color set)'))

    class Meta:
        verbose_name = _('Obstacle Group')
        verbose_name_plural = _('Obstacle Groups')
        default_related_name = 'groups'

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.orig_color = self.color

    def save(self, *args, **kwargs):
        if self.pk and (self.orig_color != self.color):
            self.register_changed_geometries()
        super().save(*args, **kwargs)

    def delete(self, *args, **kwargs):
        self.register_changed_geometries()
        super().delete(*args, **kwargs)

    def register_changed_geometries(self):
        for obj in self.obstacles.select_related('space'):
            obj.register_change(force=True)
        for obj in self.lineobstacles.select_related('space'):
            obj.register_change(force=True)


class Obstacle(SpaceGeometryMixin, models.Model):
    """
    An obstacle
    """
    new_serialize = True

    group = models.ForeignKey(ObstacleGroup, null=True, blank=True, on_delete=models.SET_NULL)
    geometry = GeometryField('polygon')
    height = models.DecimalField(_('height'), max_digits=6, decimal_places=2, default=0.8,
                                 validators=[MinValueValidator(Decimal('0'))])
    altitude = models.DecimalField(_('altitude above ground'), max_digits=6, decimal_places=2, default=0,
                                   validators=[MinValueValidator(Decimal('0'))])

    class Meta:
        verbose_name = _('Obstacle')
        verbose_name_plural = _('Obstacles')
        default_related_name = 'obstacles'
        ordering = ('altitude', 'height')

    def get_geojson_properties(self, *args, **kwargs) -> dict:
        result = super().get_geojson_properties(*args, **kwargs)
        from c3nav.mapdata.render.theme import ColorManager
        color = self.get_color(ColorManager.for_theme(None))
        if color:
            result['color'] = color
        return result

    @property
    def color(self):
        from c3nav.mapdata.render.theme import ColorManager
        return self.get_color(ColorManager.for_theme(None))

    def get_color(self, color_manager: 'ThemeColorManager'):
        return (
            color_manager.obstaclegroup_fill_color(self.group)
            if self.group is not None
            else color_manager.obstacles_default_fill
        )


class LineObstacle(SpaceGeometryMixin, models.Model):
    """
    An obstacle that is a line with a specific width
    """
    new_serialize = True

    group = models.ForeignKey(ObstacleGroup, null=True, blank=True, on_delete=models.SET_NULL)
    geometry = GeometryField('linestring')
    width = models.DecimalField(_('width'), max_digits=4, decimal_places=2, default=0.15)
    height = models.DecimalField(_('height'), max_digits=6, decimal_places=2, default=0.8,
                                 validators=[MinValueValidator(Decimal('0'))])
    altitude = models.DecimalField(_('altitude above ground'), max_digits=6, decimal_places=2, default=0,
                                   validators=[MinValueValidator(Decimal('0'))])

    class Meta:
        verbose_name = _('Line Obstacle')
        verbose_name_plural = _('Line Obstacles')
        default_related_name = 'lineobstacles'
        ordering = ('altitude', 'height')

    def get_geojson_properties(self, *args, **kwargs) -> dict:
        result = super().get_geojson_properties(*args, **kwargs)
        from c3nav.mapdata.render.theme import ColorManager
        color = self.get_color(ColorManager.for_theme(None))
        if color:
            result['color'] = color
        return result

    def _serialize(self, geometry=True, **kwargs):
        result = super()._serialize(geometry=geometry, **kwargs)
        result['width'] = float(str(self.width))
        result['height'] = float(str(self.height))
        result['altitude'] = float(str(self.altitude))
        from c3nav.mapdata.render.theme import ColorManager
        result['color'] = self.get_color(ColorManager.for_theme(None))
        if geometry:
            result['buffered_geometry'] = format_geojson(mapping(self.buffered_geometry))
        return result

    @property
    def color(self):
        from c3nav.mapdata.render.theme import ColorManager
        return self.get_color(ColorManager.for_theme(None))

    def get_color(self, color_manager: 'ThemeColorManager'):
        # TODO: should line obstacles use border color?
        return (
            color_manager.obstaclegroup_fill_color(self.group)
            if self.group is not None
            else color_manager.obstacles_default_fill
        )

    @property
    def buffered_geometry(self):
        return self.geometry.buffer(float(self.width / 2), join_style=JOIN_STYLE.mitre, cap_style=CAP_STYLE.flat)

    def to_geojson(self, *args, **kwargs):
        result = super().to_geojson(*args, **kwargs)
        result['original_geometry'] = result['geometry']
        result['geometry'] = format_geojson(mapping(self.buffered_geometry))
        return result


class POI(SpaceGeometryMixin, SpecificLocation, models.Model):
    """
    A point of interest
    """
    new_serialize = True

    geometry = GeometryField('point')

    class Meta:
        verbose_name = _('Point of Interest')
        verbose_name_plural = _('Points of Interest')
        default_related_name = 'pois'

    def details_display(self, editor_url=True, **kwargs):
        result = super().details_display(**kwargs)
        if editor_url:
            result['editor_url'] = reverse('editor.pois.edit', kwargs={'space': self.space_id, 'pk': self.pk})
        return result

    @property
    def grid_square(self):
        if "geometry" in self.get_deferred_fields():
            return None
        return grid.get_square_for_point(self.x, self.y) or ''

    @property
    def x(self):
        return self.geometry.x

    @property
    def y(self):
        return self.geometry.y


class Hole(SpaceGeometryMixin, models.Model):
    """
    A hole in the ground of a space, e.g. for stairs.
    """
    new_serialize = True

    geometry = GeometryField('polygon')

    class Meta:
        verbose_name = _('Hole')
        verbose_name_plural = _('Holes')
        default_related_name = 'holes'


class AltitudeMarker(SpaceGeometryMixin, models.Model):
    """
    An altitude marker
    """
    geometry = GeometryField('point')
    groundaltitude = models.ForeignKey('mapdata.GroundAltitude', on_delete=models.CASCADE,
                                       verbose_name=_('altitude'))

    class Meta:
        verbose_name = _('Altitude Marker')
        verbose_name_plural = _('Altitude Markers')
        default_related_name = 'altitudemarkers'

    @property
    def altitude(self) -> Decimal:
        return self.groundaltitude.altitude

    @property
    def title(self):
        return f'#{self.pk}: {self.groundaltitude.title}'


class LeaveDescription(SerializableMixin):
    """
    A description for leaving a space to another space
    """
    space = models.ForeignKey('mapdata.Space', on_delete=models.CASCADE, verbose_name=_('space'))
    target_space = models.ForeignKey('mapdata.Space', on_delete=models.CASCADE, verbose_name=_('target space'),
                                     related_name='enter_descriptions')
    description = I18nField(_('description'))

    class Meta:
        verbose_name = _('Leave description')
        verbose_name_plural = _('Leave descriptions')
        default_related_name = 'leave_descriptions'
        unique_together = (
            ('space', 'target_space')
        )

    def _serialize(self, **kwargs):
        result = super()._serialize(**kwargs)
        result['space'] = self.space_id
        result['target_space'] = self.target_space_id
        result['descriptions'] = self.description_i18n
        result['description'] = self.description
        return result

    @cached_property
    def title(self):
        return self.target_space.title

    @classmethod
    def q_for_request(cls, request, prefix='', allow_none=False):
        return (
            Space.q_for_request(request, prefix='space__', allow_none=allow_none) &
            Space.q_for_request(request, prefix='target_space__', allow_none=allow_none)
        )


class CrossDescription(SerializableMixin):
    """
    A description for crossing a space from one space to another space
    """
    space = models.ForeignKey('mapdata.Space', on_delete=models.CASCADE, verbose_name=_('space'))
    origin_space = models.ForeignKey('mapdata.Space', on_delete=models.CASCADE, verbose_name=_('origin space'),
                                     related_name='leave_cross_descriptions')
    target_space = models.ForeignKey('mapdata.Space', on_delete=models.CASCADE, verbose_name=_('target space'),
                                     related_name='cross_enter_descriptions')
    description = I18nField(_('description'))

    class Meta:
        verbose_name = _('Cross description')
        verbose_name_plural = _('Cross descriptions')
        default_related_name = 'cross_descriptions'
        unique_together = (
            ('space', 'origin_space', 'target_space')
        )

    def _serialize(self, **kwargs):
        result = super()._serialize(**kwargs)
        result['space'] = self.space_id
        result['origin_space'] = self.origin_space_id
        result['target_space'] = self.target_space_id
        result['descriptions'] = self.description_i18n
        result['description'] = self.description
        return result

    @cached_property
    def title(self):
        return '%s → %s' % (self.origin_space.title, self.target_space.title)

    @classmethod
    def q_for_request(cls, request, prefix='', allow_none=False):
        return (
            Space.q_for_request(request, prefix='space__', allow_none=allow_none) &
            Space.q_for_request(request, prefix='origin_space__', allow_none=allow_none) &
            Space.q_for_request(request, prefix='target_space__', allow_none=allow_none)
        )


class BeaconMeasurement(SpaceGeometryMixin, models.Model):
    """
    A Beacon (WiFI / iBeacon) measurement
    """
    geometry = GeometryField('point')
    author = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.SET_NULL, null=True, blank=True,
                               verbose_name=_('author'))
    comment = models.TextField(null=True, blank=True, verbose_name=_('comment'))
    data = models.JSONField(_('Measurement list'), default=dict)  # todo: would be nice if this used pydantic

    class Meta:
        verbose_name = _('Beacon Measurement')
        verbose_name_plural = _('Beacon Measurements')
        default_related_name = 'beacon_measurements'

    @property
    def all_geometry_changed(self):
        return False

    @property
    def geometry_changed(self):
        return False


class RangingBeacon(SpaceGeometryMixin, models.Model):
    """
    A ranging beacon
    """
    geometry = GeometryField('point')

    node_number = models.PositiveSmallIntegerField(_('Node Number'), unique=True, null=True, blank=True)

    wifi_bssid = models.CharField(_('WiFi BSSID'), unique=True, null=True, blank=True,
                                  max_length=17,
                                  validators=[RegexValidator(
                                      regex='^([a-f0-9]{2}:){5}[a-f0-9]{2}$',
                                      message='Must be a lower-case bssid',
                                      code='invalid_bssid'
                                  )],
                                  help_text=_("uses node's value if not set"))
    bluetooth_address = models.CharField(_('Bluetooth Address'), unique=True, null=True, blank=True,
                                         max_length=17,
                                         validators=[RegexValidator(
                                             regex='^([a-f0-9]{2}:){5}[a-f0-9]{2}$',
                                             message='Must be a lower-case mac address',
                                             code='invalid_bluetooth_address'
                                         )],
                                         help_text=_("uses node's value if not set"))
    ibeacon_uuid = models.UUIDField(_('iBeacon UUID'), null=True, blank=True,
                                    help_text=_("uses node's value if not set"))
    ibeacon_major = models.PositiveIntegerField(_('iBeacon major value'), null=True, blank=True,
                                    help_text=_("uses node's value if not set"))
    ibeacon_minor = models.PositiveIntegerField(_('iBeacon minor value'), null=True, blank=True,
                                                help_text=_("uses node's value if not set"))
    uwb_address = models.CharField(_('UWB Address'), unique=True, null=True, blank=True,
                                   max_length=23,
                                   validators=[RegexValidator(
                                       regex='^([a-f0-9]{2}:){7}[a-f0-9]{2}$',
                                       message='Must be a lower-case 8-byte UWB address',
                                       code='invalid_uwb_address'
                                   )],
                                   help_text=_("uses node's value if not set"))

    altitude = models.DecimalField(_('altitude above ground'), max_digits=6, decimal_places=2, default=0,
                                   validators=[MinValueValidator(Decimal('0'))])
    comment = models.TextField(null=True, blank=True, verbose_name=_('comment'))

    class Meta:
        verbose_name = _('Ranging beacon')
        verbose_name_plural = _('Ranging beacons')
        default_related_name = 'ranging_beacons'

    @property
    def all_geometry_changed(self):
        return False

    @property
    def geometry_changed(self):
        return False

    @property
    def title(self):
        if self.comment:
            return f'{self.node_number} {self.wifi_bssid} ({self.comment})'.strip()
        return f'{self.node_number} {self.wifi_bssid}'.strip()