# =================================================================
#
# Authors: Matthew Perry <perrygeo@gmail.com>
#
# Copyright (c) 2018 Matthew Perry
# Copyright (c) 2022 Tom Kralidis
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
# =================================================================

import json
import logging
import os
import uuid

from shapely.geometry import box, shape

from pygeoapi.crs import crs_transform
from pygeoapi.provider.base import BaseProvider, ProviderItemNotFoundError

LOGGER = logging.getLogger(__name__)


class GeoJSONProvider(BaseProvider):
    """Provider class backed by local GeoJSON files

    This is meant to be simple
    (no external services, no dependencies, no schema)

    at the expense of performance
    (no indexing, full serialization roundtrip on each request)

    Not thread safe, a single server process is assumed

    This implementation uses the feature 'id' heavily
    and will override any 'id' provided in the original data.
    The feature 'properties' will be preserved.

    TODO:
    * query method should take bbox
    * instead of methods returning FeatureCollections,
    we should be yielding Features and aggregating in the view
    * there are strict id semantics; all features in the input GeoJSON file
    must be present and be unique strings. Otherwise it will break.
    * How to raise errors in the provider implementation such that
    * appropriate HTTP responses will be raised
    """

    def __init__(self, provider_def):
        """initializer"""

        super().__init__(provider_def)
        self.get_fields()

    def get_fields(self):
        """
         Get provider field information (names, types)

        :returns: dict of fields
        """

        if not self._fields:
            LOGGER.debug('Treating all columns as string types')
            if os.path.exists(self.data):
                with open(self.data) as src:
                    data = json.loads(src.read())
                for key, value in data['features'][0]['properties'].items():
                    if isinstance(value, float):
                        type_ = 'number'
                    elif isinstance(value, int):
                        type_ = 'integer'
                    else:
                        type_ = 'string'

                    self._fields[key] = {'type': type_}
            else:
                LOGGER.warning(f'File {self.data} does not exist.')

        return self._fields

    def _load(self, bbox=[], skip_geometry=None, properties=[],
              select_properties=[]):
        """Load and validate the source GeoJSON file
        at self.data

        Yes loading from disk, deserializing and validation
        happens on every request. This is not efficient.
        """

        if os.path.exists(self.data):
            with open(self.data) as src:
                data = json.loads(src.read())
        else:
            LOGGER.warning(f'File {self.data} does not exist.')
            data = {
                'type': 'FeatureCollection',
                'features': []}

        # Must be a FeatureCollection
        assert data['type'] == 'FeatureCollection'

        # filter by properties if set
        if properties:
            data['features'] = [f for f in data['features'] if \
                all([str(f['properties'][p[0]]) == str(p[1]) for p in properties])]  # noqa

        # filter by bbox if set
        if bbox:
            LOGGER.debug('processing bbox parameter')
            if len(bbox) > 4:
                LOGGER.debug("bbox reduced to 4 elements")
                bbox = bbox[:4]
            data['features'] = [f for f in data['features'] if \
                self._intersects(f['geometry'], bbox)]  # noqa

        # All features must have ids, TODO must be unique strings
        for i in data['features']:
            if 'id' not in i and self.id_field in i['properties']:
                i['id'] = i['properties'][self.id_field]
            if skip_geometry:
                i['geometry'] = None
            if self.properties or select_properties:
                i['properties'] = {k: v for k, v in i['properties'].items()
                                   if k in set(self.properties) | set(select_properties)}  # noqa
        return data

    def _intersects(self, geometry, bbox):
        """
        Helper function to evaluate feature geometry intersection with a bbox

        :param geometry: `dict` of GeoJSON geometry
        :param bbox: `list` of bbox

        :returns: `bool` of whether geometry intersects with bbox
        """

        if geometry is None:
            return True

        bbox2 = box(*bbox)
        geometry2 = shape(geometry)

        return geometry2.intersects(bbox2)

    @crs_transform
    def query(self, offset=0, limit=10, resulttype='results',
              bbox=[], datetime_=None, properties=[], sortby=[],
              select_properties=[], skip_geometry=False, q=None, **kwargs):
        """
        query the provider

        :param offset: starting record to return (default 0)
        :param limit: number of records to return (default 10)
        :param resulttype: return results or hit limit (default results)
        :param bbox: bounding box [minx,miny,maxx,maxy]
        :param datetime_: temporal (datestamp or extent)
        :param properties: list of tuples (name, value)
        :param sortby: list of dicts (property, order)
        :param select_properties: list of property names
        :param skip_geometry: bool of whether to skip geometry (default False)
        :param q: full-text search term(s)

        :returns: FeatureCollection dict of 0..n GeoJSON features
        """

        # TODO filter by bbox without resorting to third-party libs
        data = self._load(bbox=bbox, skip_geometry=skip_geometry,
                          properties=properties,
                          select_properties=select_properties)

        data['numberMatched'] = len(data['features'])

        if resulttype == 'hits':
            data['features'] = []
        else:
            data['features'] = data['features'][offset:offset+limit]
            data['numberReturned'] = len(data['features'])

        return data

    @crs_transform
    def get(self, identifier, **kwargs):
        """
        query the provider by id

        :param identifier: feature id
        :returns: dict of single GeoJSON feature
        """

        all_data = self._load()
        # if matches
        for feature in all_data['features']:
            if str(feature.get('id')) == identifier:
                return feature
        # default, no match
        err = f'item {identifier} not found'
        LOGGER.error(err)
        raise ProviderItemNotFoundError(err)

    def create(self, new_feature):
        """Create a new feature

        :param new_feature: new GeoJSON feature dictionary
        """

        all_data = self._load()

        if self.id_field not in new_feature and\
           self.id_field not in new_feature['properties']:
            new_feature['properties'][self.id_field] = str(uuid.uuid4())

        all_data['features'].append(new_feature)

        with open(self.data, 'w') as dst:
            dst.write(json.dumps(all_data))

    def update(self, identifier, new_feature):
        """Updates an existing feature id with new_feature

        :param identifier: feature id
        :param new_feature: new GeoJSON feature dictionary
        """

        all_data = self._load()
        for i, feature in enumerate(all_data['features']):
            if self.id_field in feature:
                if feature[self.id_field] == identifier:
                    new_feature['properties'][self.id_field] = identifier
                    all_data['features'][i] = new_feature
            elif self.id_field in feature['properties']:
                if feature['properties'][self.id_field] == identifier:
                    new_feature['properties'][self.id_field] = identifier
                    all_data['features'][i] = new_feature
        with open(self.data, 'w') as dst:
            dst.write(json.dumps(all_data))

    def delete(self, identifier):
        """Deletes an existing feature

        :param identifier: feature id
        """

        all_data = self._load()
        for i, feature in enumerate(all_data['features']):
            if self.id_field in feature:
                if feature[self.id_field] == identifier:
                    all_data['features'].pop(i)
            elif self.id_field in feature['properties']:
                if feature['properties'][self.id_field] == identifier:
                    all_data['features'].pop(i)
        with open(self.data, 'w') as dst:
            dst.write(json.dumps(all_data))

    def __repr__(self):
        return f'<GeoJSONProvider> {self.data}'
