import pytest
import os
from os import path
import netCDF4
from tests.TestUtils import TestUtils
from netCDF4 import Dataset

from SDToolBox import main as main
from SDToolBox.extract_data import ExtractData
from SDToolBox.data_acquisition import InputData
import SDToolBox.outputmessages as om


class Test_create:

    @pytest.mark.unittest
    def test_given_no_input_data_then_exception_is_risen(self):
        # 1. Given
        input_data = None
        output_result = None
        expected_error = om.error_no_valid_input_data
        # 2. When
        with pytest.raises(IOError) as e_info:
            output_result = ExtractData(input_data)

        # 3. Then
        error_message = str(e_info.value)
        assert output_result is None
        assert error_message == expected_error, '' + \
            'Expected exception message {},'.format(expected_error) + \
            'retrieved {}'.format(error_message)

    @pytest.mark.unittest
    def test_given_no_input_coords_then_exception_is_risen(self):
        # 1. Given
        input_data = InputData()
        input_data.input_coordinates = []
        input_data.input_years = [2014]
        input_data.input_variables = ['var']
        data_extractor = None
        expected_error = om.error_not_enough_coordinates
        # 2. When
        with pytest.raises(IOError) as e_info:
            data_extractor = ExtractData(input_data)

        # 3. Then
        error_message = str(e_info.value)
        assert data_extractor is None
        assert error_message == expected_error, '' + \
            'Expected exception message {},'.format(expected_error) + \
            'retrieved {}'.format(error_message)

    @pytest.mark.unittest
    def test_given_no_list_of_vars_then_exception_is_risen(self):
        # 1. Given
        input_data = InputData()
        input_data.input_coordinates = [(4.2, 42)]
        input_data.input_years = [2014]
        input_data.input_variables = None
        data_extractor = None
        expected_error = om.error_no_valid_list_of_vars
        # 2. When
        with pytest.raises(IOError) as e_info:
            data_extractor = ExtractData(input_data)

        # 3. Then
        error_message = str(e_info.value)
        assert data_extractor is None
        assert error_message == expected_error, '' + \
            'Expected exception message {},'.format(expected_error) + \
            'retrieved {}'.format(error_message)

    @pytest.mark.unittest
    def test_given_no_list_of_years_then_exception_is_risen(self):
        # 1. Given
        input_data = InputData()
        input_data.input_coordinates = [(4.2, 42)]
        input_data.input_variables = ['var']
        input_data.input_years = None
        data_extractor = None
        expected_error = om.error_no_valid_list_of_years
        # 2. When
        with pytest.raises(IOError) as e_info:
            data_extractor = ExtractData(input_data)

        # 3. Then
        error_message = str(e_info.value)
        assert data_extractor is None
        assert error_message == expected_error, '' + \
            'Expected exception message {},'.format(expected_error) + \
            'retrieved {}'.format(error_message)


    @pytest.mark.unittest
    def test_given_valid_input_args_then_data_is_set(self):
        # 1. Given
        input_data = InputData()
        input_data.input_coordinates = [(42, 4.2)]
        input_data.input_variables = ['swh']
        input_data.input_years = [1942]
        data_extractor = None
        expected_lon_list, expected_lat_list = \
            zip(*input_data.input_coordinates)

        # 2. When
        try:
            data_extractor = ExtractData(input_data)
        except Exception as e_info:
            pytest.fail(
                'Exception risen {}'.format(str(e_info)) +
                ' but not expected.')

        # 3. Then
        assert data_extractor is not None
        assert data_extractor._input_variables == input_data.input_variables
        assert data_extractor._input_years == input_data.input_years
        assert data_extractor._input_lon == expected_lon_list
        assert data_extractor._input_lat == expected_lat_list