from django.contrib.gis.db import models

from ..utils import gisfield_may_be_null

class NamedModel(models.Model):

    name = models.CharField(max_length=30)

    class Meta:

        abstract = True

    def __str__(self):

        return self.name

class SouthTexasCity(NamedModel):

    "City model on projected coordinate system for South Texas."

    point = models.PointField(srid=32140)

    radius = models.IntegerField(default=10000)

class SouthTexasCityFt(NamedModel):

    "Same City model as above, but U.S. survey feet are the units."

    point = models.PointField(srid=2278)

class AustraliaCity(NamedModel):

    "City model for Australia, using WGS84."

    point = models.PointField()

    radius = models.IntegerField(default=10000)

    allowed_distance = models.FloatField(default=0.5)

    ref_point = models.PointField(null=True)

class CensusZipcode(NamedModel):

    "Model for a few South Texas ZIP codes (in original Census NAD83)."

    poly = models.PolygonField(srid=4269)

class SouthTexasZipcode(NamedModel):

    "Model for a few South Texas ZIP codes."

    poly = models.PolygonField(srid=32140, null=gisfield_may_be_null)

class Interstate(NamedModel):

    "Geodetic model for U.S. Interstates."

    path = models.LineStringField()

class SouthTexasInterstate(NamedModel):

    "Projected model for South Texas Interstates."

    path = models.LineStringField(srid=32140)