""" Unit Tests for Py-ART's io/mdv_radar.py module. """

import numpy as np
from numpy.testing import assert_almost_equal
from numpy.ma.core import MaskedArray

import pyart

############################################
# read_mdv tests (verify radar attributes) #
############################################

# read in the sample file and create a a Radar object
radar = pyart.io.read_mdv(pyart.testing.MDV_PPI_FILE)


# time attribute
def test_time():
    assert 'comment' in radar.time.keys()
    assert 'long_name' in radar.time.keys()
    assert 'standard_name' in radar.time.keys()
    assert 'units' in radar.time.keys()
    assert 'calendar' in radar.time.keys()
    assert 'data' in radar.time.keys()
    assert radar.time['units'] == 'seconds since 2011-05-20T11:01:00Z'
    assert radar.time['data'].shape == (360, )
    assert_almost_equal(radar.time['data'][200], 187, 0)


# range attribute
def test_range():
    assert 'long_name' in radar.range
    assert 'standard_name' in radar.range
    assert 'meters_to_center_of_first_gate' in radar.range
    assert 'meters_between_gates' in radar.range
    assert 'units' in radar.range
    assert 'data' in radar.range
    assert 'spacing_is_constant' in radar.range
    assert radar.range['data'].shape == (110, )
    assert_almost_equal(radar.range['data'][0], 118, 0)


# fields attribute is tested later


# metadata attribute
def test_metadata():
    assert 'instrument_name' in radar.metadata
    assert 'source' in radar.metadata


# scan_type attribute
def test_scan_type():
    assert radar.scan_type == 'ppi'


# latitude attribute
def test_latitude():
    assert 'data' in radar.latitude
    assert 'standard_name' in radar.latitude
    assert 'units' in radar.latitude
    assert radar.latitude['data'].shape == (1, )
    assert_almost_equal(radar.latitude['data'], 37, 0)


# longitude attribute
def test_longitude():
    assert 'data' in radar.longitude
    assert 'standard_name' in radar.longitude
    assert 'units' in radar.longitude
    assert radar.longitude['data'].shape == (1, )
    assert_almost_equal(radar.longitude['data'], -97, 0)


# altitude attribute
def test_altitude():
    assert 'data' in radar.altitude
    assert 'standard_name' in radar.altitude
    assert 'units' in radar.altitude
    assert 'positive' in radar.altitude
    assert radar.altitude['data'].shape == (1, )
    assert_almost_equal(radar.altitude['data'], 328, 0)


# altitude_agl attribute
def test_altitude_agl():
    assert radar.altitude_agl is None


# sweep_number attribute
def test_sweep_number():
    assert 'standard_name' in radar.sweep_number
    assert np.all(radar.sweep_number['data'] == range(1))


# sweep_mode attribute
def test_sweep_mode():
    assert 'standard_name' in radar.sweep_mode
    assert radar.sweep_mode['data'].shape == (1, )
    assert radar.sweep_mode['data'].dtype.char == 'S'
    assert np.all(radar.sweep_mode['data'] == [b'azimuth_surveillance'])


# fixed_angle attribute
def test_fixed_angle():
    assert 'standard_name' in radar.fixed_angle
    assert 'units' in radar.fixed_angle
    assert radar.fixed_angle['data'].shape == (1, )
    assert_almost_equal(radar.fixed_angle['data'][0], 0.75, 2)


# sweep_start_ray_index attribute
def test_sweep_start_ray_index():
    assert 'long_name' in radar.sweep_start_ray_index
    assert radar.sweep_start_ray_index['data'].shape == (1, )
    assert_almost_equal(radar.sweep_start_ray_index['data'][0], 0, 0)


# sweep_end_ray_index attribute
def test_sweep_end_ray_index():
    assert 'long_name' in radar.sweep_end_ray_index
    assert radar.sweep_end_ray_index['data'].shape == (1, )
    assert_almost_equal(radar.sweep_end_ray_index['data'][0], 359, 0)


# target_scan_rate attribute
def test_target_scan_rate():
    assert radar.target_scan_rate is None


# azimuth attribute
def test_azimuth():
    assert 'standard_name' in radar.azimuth
    assert 'long_name' in radar.azimuth
    assert 'units' in radar.azimuth
    assert 'axis' in radar.azimuth
    assert_almost_equal(radar.azimuth['data'][0], 0, 0)
    assert_almost_equal(radar.azimuth['data'][10], 10.0, 0)


# elevation attribute
def test_elevation():
    assert 'standard_name' in radar.elevation
    assert 'long_name' in radar.azimuth
    assert 'units' in radar.elevation
    assert 'axis' in radar.elevation
    assert radar.elevation['data'].shape == (360, )
    assert_almost_equal(radar.elevation['data'][0], 0.75, 2)


# scan_rate attribute
def test_scan_rate():
    assert radar.scan_rate is None


# antenna_transition attribute
def test_antenna_transition():
    assert radar.antenna_transition is None


# instrument_parameters attribute
def test_instument_parameters():
    # instrument_parameter sub-convention
    keys = ['prt', 'unambiguous_range', 'prt_mode', 'nyquist_velocity']
    for k in keys:
        description = 'instrument_parameters: %s' % k
        check_instrument_parameter.description = description
        yield check_instrument_parameter, k


def check_instrument_parameter(param):
    assert param in radar.instrument_parameters
    param_dic = radar.instrument_parameters[param]
    assert param_dic['meta_group'] == 'instrument_parameters'


# radar_parameters attribute
def test_radar_parameters():
    # radar_parameter sub-convention
    keys = ['radar_beam_width_h', 'radar_beam_width_v']
    for k in keys:
        description = 'radar_parameters: %s' % k
        check_radar_parameter.description = description
        yield check_radar_parameter, k


def check_radar_parameter(param):
    assert param in radar.instrument_parameters
    param_dic = radar.instrument_parameters[param]
    assert param_dic['meta_group'] == 'radar_parameters'


# radar_calibration attribute
def test_radar_calibration():
    assert radar.radar_calibration is None


# ngates attribute
def test_ngates():
    assert radar.ngates == 110


# nrays attribute
def test_nrays():
    assert radar.nrays == 360


# nsweeps attribute
def test_nsweeps():
    assert radar.nsweeps == 1


####################
# fields attribute #
####################


def test_field_dics():
    fields = ['reflectivity', ]
    for field in fields:
        description = "field : %s, dictionary" % field
        check_field_dic.description = description
        yield check_field_dic, field


def check_field_dic(field):
    """ Check that the required keys are present in a field dictionary. """
    assert 'standard_name' in radar.fields[field]
    assert 'units' in radar.fields[field]
    assert '_FillValue' in radar.fields[field]
    assert 'coordinates' in radar.fields[field]


def test_field_shapes():
    fields = ['reflectivity', ]
    for field in fields:
        description = "field : %s, shape" % field
        check_field_shape.description = description
        yield check_field_shape, field


def check_field_shape(field):
    assert radar.fields[field]['data'].shape == (360, 110)


def test_field_types():
    fields = {'reflectivity': MaskedArray, }
    for field, field_type in fields.items():
        description = "field : %s, type" % field
        check_field_type.description = description
        yield check_field_type, field, field_type


def check_field_type(field, field_type):
    assert type(radar.fields[field]['data']) is field_type


def test_field_first_points():
    # these values can be found using:
    # [round(radar.fields[f]['data'][0,0]) for f in radar.fields]
    fields = {'reflectivity': 24.0}
    for field, field_value in fields.items():
        description = "field : %s, first point" % field
        check_field_first_point.description = description
        yield check_field_first_point, field, field_value


def check_field_first_point(field, value):
    assert_almost_equal(radar.fields[field]['data'][0, 0], value, 0)


#############
# RHI tests #
#############

RADAR_RHI = pyart.io.read_mdv(pyart.testing.MDV_RHI_FILE,
                              delay_field_loading=True)


# nsweeps attribute
def test_rhi_nsweeps():
    assert RADAR_RHI.nsweeps == 1


# sweep_number attribute
def test_rhi_sweep_number():
    assert 'standard_name' in RADAR_RHI.sweep_number
    assert np.all(RADAR_RHI.sweep_number['data'] == range(1))


# sweep_mode attribute
def test_rhi_sweep_mode():
    assert 'standard_name' in RADAR_RHI.sweep_mode
    assert RADAR_RHI.sweep_mode['data'].shape == (1, )
    assert np.all(RADAR_RHI.sweep_mode['data'] == [b'rhi'])


# fixed_angle attribute
def test_rhi_fixed_angle():
    assert 'standard_name' in RADAR_RHI.fixed_angle
    assert 'units' in RADAR_RHI.fixed_angle
    assert RADAR_RHI.fixed_angle['data'].shape == (1, )
    assert_almost_equal(RADAR_RHI.fixed_angle['data'][0], 189.00, 2)


# sweep_start_ray_index attribute
def test_rhi_sweep_start_ray_index():
    assert 'long_name' in RADAR_RHI.sweep_start_ray_index
    assert RADAR_RHI.sweep_start_ray_index['data'].shape == (1, )
    assert_almost_equal(RADAR_RHI.sweep_start_ray_index['data'][0], 0, 0)


# sweep_end_ray_index attribute
def test_rhi_sweep_end_ray_index():
    assert 'long_name' in RADAR_RHI.sweep_end_ray_index
    assert RADAR_RHI.sweep_end_ray_index['data'].shape == (1, )
    assert_almost_equal(RADAR_RHI.sweep_end_ray_index['data'][0], 282, 0)


# azimuth attribute
def test_rhi_azimuth():
    assert 'standard_name' in RADAR_RHI.azimuth
    assert 'long_name' in RADAR_RHI.azimuth
    assert 'units' in RADAR_RHI.azimuth
    assert 'axis' in RADAR_RHI.azimuth
    assert_almost_equal(RADAR_RHI.azimuth['data'][0], 189, 0)
    assert_almost_equal(RADAR_RHI.azimuth['data'][10], 189, 0)


# elevation attribute
def test_rhi_elevation():
    assert 'standard_name' in RADAR_RHI.elevation
    assert 'long_name' in RADAR_RHI.azimuth
    assert 'units' in RADAR_RHI.elevation
    assert 'axis' in RADAR_RHI.elevation
    assert RADAR_RHI.elevation['data'].shape == (283, )
    assert_almost_equal(RADAR_RHI.elevation['data'][0], 19.6, 2)


# field data
def test_rhi_field_data():
    assert_almost_equal(RADAR_RHI.fields['reflectivity']['data'][0, 0],
                        23.93, 2)


def test_open_from_file_obj():
    fh = open(pyart.testing.MDV_PPI_FILE, 'rb')
    radar = pyart.io.read_mdv(pyart.testing.MDV_PPI_FILE)
    fh.close()


def test_radar_exclude_fields():
    # skip fields
    radar = pyart.io.read_mdv(
        pyart.testing.MDV_PPI_FILE, exclude_fields=['reflectivity'])
    assert 'reflectivity' not in radar.fields
