from django.db import models
from django.utils.translation import ugettext_lazy as _
from shapely.geometry import CAP_STYLE, JOIN_STYLE, mapping

from c3nav.mapdata.fields import GeometryField
from c3nav.mapdata.models.geometry.base import GeometryMixin
from c3nav.mapdata.models.locations import SpecificLocation
from c3nav.mapdata.utils.json import format_geojson


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

    class Meta:
        abstract = True

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

    def get_geojson_properties(self, *args, **kwargs) -> dict:
        result = super().get_geojson_properties(*args, **kwargs)
        if hasattr(self, 'get_color'):
            color = self.get_color()
            if color:
                result['color'] = color
        return result


class Column(SpaceGeometryMixin, 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(SpecificLocation, SpaceGeometryMixin, models.Model):
    """
    An area in a space.
    """
    geometry = GeometryField('polygon')

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

    def _serialize(self, **kwargs):
        result = super()._serialize(**kwargs)
        return result


class Stair(SpaceGeometryMixin, models.Model):
    """
    A stair
    """
    geometry = GeometryField('linestring')

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


class Obstacle(SpaceGeometryMixin, models.Model):
    """
    An obstacle
    """
    geometry = GeometryField('polygon')

    class Meta:
        verbose_name = _('Obstacle')
        verbose_name_plural = _('Obstacles')
        default_related_name = 'obstacles'


class LineObstacle(SpaceGeometryMixin, models.Model):
    """
    An obstacle that is a line with a specific width
    """
    geometry = GeometryField('linestring')
    width = models.DecimalField(_('obstacle width'), max_digits=4, decimal_places=2, default=0.15)

    class Meta:
        verbose_name = _('Line Obstacle')
        verbose_name_plural = _('Line Obstacles')
        default_related_name = 'lineobstacles'

    def serialize(self, geometry=True, **kwargs):
        result = super().serialize(geometry=geometry, **kwargs)
        if geometry:
            result.move_to_end('buffered_geometry')
        return result

    def _serialize(self, geometry=True, **kwargs):
        result = super()._serialize(geometry=geometry, **kwargs)
        result['width'] = float(str(self.width))
        if geometry:
            result['buffered_geometry'] = format_geojson(mapping(self.buffered_geometry))
        return result

    @property
    def buffered_geometry(self):
        return self.geometry.buffer(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(SpecificLocation, SpaceGeometryMixin, models.Model):
    """
    An point of interest
    """
    geometry = GeometryField('point')

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


class Hole(SpaceGeometryMixin, models.Model):
    """
    A hole in the ground of a space, e.g. for stairs.
    """
    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')
    altitude = models.DecimalField(_('altitude'), null=False, max_digits=6, decimal_places=2)

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