Source code for snowexsql.data

"""
Module contains all the data models for the database. Classes here actually
represent tables where columns are mapped as attributed. Any class inheriting
from Base is a real table in the database. This is called Object Relational
Mapping in the sqlalchemy or ORM.
"""
import datetime

from geoalchemy2 import Geometry, Raster
from sqlalchemy import Column, Date, DateTime, Float, Integer, String, Time
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.sql import func

Base = declarative_base()


class SnowData(object):
    """
    Base class for which all data will have these attributes
    """
    site_name = Column(String(250))
    date = Column(Date)
    time_created = Column(DateTime(timezone=True), server_default=func.now())
    time_updated = Column(DateTime(timezone=True), onupdate=func.now())
    id = Column(Integer, primary_key=True)
    doi = Column(String(50))
    date_accessed = Column(Date)


class Measurement(object):
    """
    Base Class providing attributes required for a measurement of any kind
    """
    instrument = Column(String(50))
    type = Column(String(50))
    units = Column(String(50))
    observers = Column(String(100))


class SingleLocationData(SnowData):
    """
    Base class for points and profiles
    """
    latitude = Column(Float)
    longitude = Column(Float)
    northing = Column(Float)
    easting = Column(Float)
    elevation = Column(Float)
    utm_zone = Column(Integer)
    geom = Column(Geometry("POINT"))
    time = Column(Time(timezone=True))
    site_id = Column(String(50))


class SiteData(SingleLocationData, Base):
    """
    Table for storing pit site meta data, This table doesn't represent any
    main data record but only support data for each site
    """
    __tablename__ = 'sites'
    __table_args__ = {"schema": "public"}

    pit_id = Column(String(50))
    slope_angle = Column(Float)
    aspect = Column(Float)
    air_temp = Column(Float)
    total_depth = Column(Float)
    weather_description = Column(String(500))
    precip = Column(String(100))
    sky_cover = Column(String(100))
    wind = Column(String(100))
    ground_condition = Column(String(100))
    ground_roughness = Column(String(100))
    ground_vegetation = Column(String(100))
    vegetation_height = Column(String(100))
    tree_canopy = Column(String(100))
    site_notes = Column(String(1000))


class ImageData(SnowData, Measurement, Base):
    """
    Class representing the images table. This table holds all images/rasters
    """
    __tablename__ = 'images'
    __table_args__ = {"schema": "public"}
    raster = Column(Raster)
    description = Column(String(1000))


class PointData(SingleLocationData, Measurement, Base):
    """
    Class representing the points table. This table holds all point data.
    Here a single data entry is a single coordinate pair with a single value
    e.g. snow depths
    """
    __tablename__ = 'points'
    __table_args__ = {"schema": "public"}

    version_number = Column(Integer)
    equipment = Column(String(50))
    value = Column(Float)

    __mapper_args__ = {
        'polymorphic_identity': 'Points',
    }


class LayerData(SingleLocationData, Measurement, Base):
    """
    Class representing the layers table. This table holds all layers or
    profile data. Here a single data entry is a single value at depth in the
    snowpack and a single coordinate pair.  e.g. SMP profiles, Hand hardness,
    temperature etc...
    """
    __tablename__ = 'layers'
    __table_args__ = {"schema": "public"}

    depth = Column(Float)
    site_id = Column(String(50))
    pit_id = Column(String(50))
    bottom_depth = Column(Float)
    comments = Column(String(1000))
    sample_a = Column(String(20))
    sample_b = Column(String(20))
    sample_c = Column(String(20))
    value = Column(String(50))
    flags = Column(String(20))