import unittest

import Census
import Configuration.Defaults
import GPS
import SummaryFile1
import Tests.Fixtures


class DatabaseTest(unittest.TestCase):

    def setUp(self):
        self.cdb = Census.Database(Configuration.Defaults.DATABASE_HOST,
                                   Configuration.Defaults.DATABASE_NAME,
                                   Configuration.Defaults.DATABASE_USERNAME,
                                   Configuration.Defaults.SRID)
        
        
    def testEachBlockContainsItsOwnPopulation(self):
        # These calculations are slightly off due to a discrepancy
        # between the WKB/WKT format calculations. It would appear
        # that converting from WKB to WKT and then back loses some
        # information.
        #
        # The error is 1/100th of a person. Should be pretty safe.
        error_threshold = 0.01
        
        grp = SummaryFile1.GeoRecordParser()
        fixtures_path = Tests.Fixtures.Path() + '/SummaryFile1/one_hundred_records.txt'
        fixtures = grp.parse_blocks(fixtures_path)
        
        for b in fixtures:
            block_boundary = self.cdb.get_block_geometry_as_wkt(b.tiger_blkidfp00())
            contained_population = self.cdb.find_contained_population(block_boundary)
            error = abs(b.pop100 - contained_population)
            self.assertTrue(error <= error_threshold)
            
    
def suite():
    suite = unittest.TestSuite()
    suite.addTest(unittest.makeSuite(DatabaseTest))
    return suite