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# Source code for safe.engine.impact_functions_for_testing.BNPB_earthquake_guidelines

    """Impact function based on Padang 2009 post earthquake survey

    This impact function estimates percentual damage to buildings as a
    function of ground shaking measured in MMI.
    Buildings are currently assumed to be represented in OpenStreetMap with
    attributes collected as during the July 2011 Indonesian mapping competition.

    This impact function maps the OSM buildings into 2 classes:
    Unreinforced masonry (URM) and reinforced masonry (RM) according to
    the guidelines.
    """

    import numpy

    from safe.impact_functions.core import FunctionProvider
    from safe.impact_functions.core import get_hazard_layer, get_exposure_layer
    from safe.storage.vector import Vector
    from safe.common.utilities import ugettext as tr
    from safe.impact_functions.mappings import osm2bnpb
    from safe.impact_functions.mappings import unspecific2bnpb
    from safe.impact_functions.mappings import sigab2bnpb
    from safe.engine.interpolation import assign_hazard_values_to_exposure_data

    # Damage 'curves' for the two vulnerability classes
    damage_parameters = {'URM': [6, 7],
                         'RM': [6, 8]}

    class EarthquakeGuidelinesFunction(FunctionProvider):
        """Risk plugin for BNPB guidelines for earthquake damage to buildings

        :param requires category=='hazard' and \
                        subcategory.startswith('earthquake') and \
                        layertype=='raster' and \
                        unit=='MMI'

        :param requires category=='exposure' and \
                        subcategory=='structure' and \
                        layertype=='vector'
        """

        vclass_tag = 'VCLASS'
        target_field = 'DMGLEVEL'

        def run(self, layers):
            """Risk plugin for earthquake school damage
            """

            # Extract data
            H = get_hazard_layer(layers)    # Ground shaking
            E = get_exposure_layer(layers)  # Building locations

            keywords = E.get_keywords()
            if 'datatype' in keywords:
                datatype = keywords['datatype']
                if datatype.lower() == 'osm':
                    # Map from OSM attributes to the guideline classes (URM and RM)
                    E = osm2bnpb(E, target_attribute=self.vclass_tag)
                elif datatype.lower() == 'sigab':
                    # Map from SIGAB attributes to the guideline classes
                    # (URM and RM)
                    E = sigab2bnpb(E)
                else:
                    E = unspecific2bnpb(E, target_attribute=self.vclass_tag)
            else:
                E = unspecific2bnpb(E, target_attribute=self.vclass_tag)

            # Interpolate hazard level to building locations
            H = assign_hazard_values_to_exposure_data(H, E,
                                                 attribute_name='MMI')

            # Extract relevant numerical data
            coordinates = E.get_geometry()
            shaking = H.get_data()
            N = len(shaking)

            # List attributes to carry forward to result layer
            attributes = E.get_attribute_names()

            # Calculate building damage
            count3 = 0
            count2 = 0
            count1 = 0
            count_unknown = 0
            building_damage = []
            for i in range(N):
                mmi = float(shaking[i]['MMI'])

                building_class = E.get_data(self.vclass_tag, i)
                lo, hi = damage_parameters[building_class]

                if numpy.isnan(mmi):
                    # If we don't know the shake level assign Not-a-Number
                    damage = numpy.nan
                    count_unknown += 1
                elif mmi < lo:
                    damage = 1  # Low
                    count1 += 1
                elif lo <= mmi < hi:
                    damage = 2  # Medium
                    count2 += 1
                elif mmi >= hi:
                    damage = 3  # High
                    count3 += 1
                else:
                    msg = 'Undefined shakelevel %s' % str(mmi)
                    raise Exception(msg)

                # Collect shake level and calculated damage
                result_dict = {self.target_field: damage,
                               'MMI': mmi}

                # Carry all orginal attributes forward
                for key in attributes:
                    result_dict[key] = E.get_data(key, i)

                # Record result for this feature
                building_damage.append(result_dict)

            # Create report
            impact_summary = ('<table border="0" width="320px">'
                       '   <tr><th><b>%s</b></th><th><b>%s</b></th></th>'
                        '   <tr></tr>'
                        '   <tr><td>%s&#58;</td><td>%i</td></tr>'
                        '   <tr><td>%s (10-25%%)&#58;</td><td>%i</td></tr>'
                        '   <tr><td>%s (25-50%%)&#58;</td><td>%i</td></tr>'
                        '   <tr><td>%s (50-100%%)&#58;</td><td>%i</td></tr>'
                        % (tr('Buildings'), tr('Total'),
                           tr('All'), N,
                           tr('Low damage'), count1,
                           tr('Medium damage'), count2,
                           tr('High damage'), count3))
            impact_summary += ('   <tr><td>%s (NaN)&#58;</td><td>%i</td></tr>'
                        % ('Unknown', count_unknown))
            impact_summary += '</table>'

            # Create style
            style_classes = [dict(label=tr('Low damage'), min=0.5, max=1.5,
                                  colour='#fecc5c', transparency=1),
                             dict(label=tr('Medium damage'), min=1.5, max=2.5,
                                  colour='#fd8d3c', transparency=1),
                             dict(label=tr('High damage'), min=2.5, max=3.5,
                                  colour='#f31a1c', transparency=1)]
            style_info = dict(target_field=self.target_field,
                              style_classes=style_classes)

            # Create vector layer and return
            V = Vector(data=building_damage,
                       projection=E.get_projection(),
                       geometry=coordinates,
                       name='Estimated damage level',
                       keywords={'impact_summary': impact_summary},
                       style_info=style_info)

            return V

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