# Landsat Util
# License: CC0 1.0 Universal

import json
import time
import requests

import settings
from utils import three_digit, create_paired_list


class Search(object):
    """ The search class """

    def __init__(self):
        self.api_url = settings.API_URL

    def search(self, paths_rows=None, lat=None, lon=None, start_date=None, end_date=None, cloud_min=None,
               cloud_max=None, limit=1):
        """
        The main method of Search class. It searches Development Seed's Landsat API.

        :param paths_rows:
            A string in this format: "003,003,004,004". Must be in pairs and separated by comma.
        :type paths_rows:
            String
        :param lat:
            The latitude
        :type lat:
            String, float, integer
        :param lon:
            The The longitude
        :type lon:
            String, float, integer
        :param start_date:
            Date string. format: YYYY-MM-DD
        :type start_date:
            String
        :param end_date:
            date string. format: YYYY-MM-DD
        :type end_date:
            String
        :param cloud_min:
            float specifying the minimum percentage. e.g. 4.3
        :type cloud_min:
            float
        :param cloud_max:
            float specifying the maximum percentage. e.g. 78.9
        :type cloud_max:
            float
        :param limit:
            integer specigying the maximum results return.
        :type limit:
            integer

        :returns:
            dict

        :example:
            >>> search = Search()
            >>> search('003,003', '2014-01-01', '2014-06-01')
            >>> {
                    'status': u'SUCCESS',
                    'total_returned': 1,
                    'total': 1,
                    'limit': 1
                    'results': [
                        {
                            'sat_type': u'L8',
                            'sceneID': u'LC80030032014142LGN00',
                            'date': u'2014-05-22',
                            'path': u'003',
                            'thumbnail': u'http://....../landsat_8/2014/003/003/LC80030032014142LGN00.jpg',
                            'cloud': 33.36,
                            'row': u'003
                        }
                    ]
                }
        """

        search_string = self.query_builder(paths_rows, lat, lon, start_date, end_date, cloud_min, cloud_max)

        # Have to manually build the URI to bypass requests URI encoding
        # The api server doesn't accept encoded URIs

        r = requests.get('%s?search=%s&limit=%s' % (self.api_url, search_string, limit))

        r_dict = json.loads(r.text)
        result = {}

        if 'error' in r_dict:
            result['status'] = u'error'
            result['code'] = r_dict['error']['code']
            result['message'] = r_dict['error']['message']

        elif 'meta' in r_dict:
            result['status'] = u'SUCCESS'
            result['total'] = r_dict['meta']['results']['total']
            result['limit'] = r_dict['meta']['results']['limit']
            result['total_returned'] = len(r_dict['results'])
            result['results'] = [{'sceneID': i['sceneID'],
                                  'sat_type': u'L8',
                                  'path': three_digit(i['path']),
                                  'row': three_digit(i['row']),
                                  'thumbnail': i['browseURL'],
                                  'date': i['acquisitionDate'],
                                  'cloud': i['cloudCoverFull']}
                                 for i in r_dict['results']]

        return result

    def query_builder(self, paths_rows=None, lat=None, lon=None, start_date=None, end_date=None,
                      cloud_min=None, cloud_max=None):
        """ Builds the proper search syntax (query) for Landsat API.

        :param paths_rows:
            A string in this format: "003,003,004,004". Must be in pairs and separated by comma.
        :type paths_rows:
            String
        :param lat:
            The latitude
        :type lat:
            String, float, integer
        :param lon:
            The The longitude
        :type lon:
            String, float, integer
        :param start_date:
            Date string. format: YYYY-MM-DD
        :type start_date:
            String
        :param end_date:
            date string. format: YYYY-MM-DD
        :type end_date:
            String
        :param cloud_min:
            float specifying the minimum percentage. e.g. 4.3
        :type cloud_min:
            float
        :param cloud_max:
            float specifying the maximum percentage. e.g. 78.9
        :type cloud_max:
            float

        :returns:
            String
        """

        query = []
        or_string = ''
        and_string = ''
        search_string = ''

        if paths_rows:
            # Coverting rows and paths to paired list
            new_array = create_paired_list(paths_rows)
            paths_rows = ['(%s)' % self.row_path_builder(i[0], i[1]) for i in new_array]
            or_string = '+OR+'.join(map(str, paths_rows))

        if start_date and end_date:
            query.append(self.date_range_builder(start_date, end_date))
        elif start_date:
            query.append(self.date_range_builder(start_date, '2100-01-01'))
        elif end_date:
            query.append(self.date_range_builder('2009-01-01', end_date))

        if cloud_min and cloud_max:
            query.append(self.cloud_cover_prct_range_builder(cloud_min, cloud_max))
        elif cloud_min:
            query.append(self.cloud_cover_prct_range_builder(cloud_min, '100'))
        elif cloud_max:
            query.append(self.cloud_cover_prct_range_builder('-1', cloud_max))

        if lat and lon:
            query.append(self.lat_lon_builder(lat, lon))

        if query:
            and_string = '+AND+'.join(map(str, query))

        if and_string and or_string:
            search_string = and_string + '+AND+(' + or_string + ')'
        else:
            search_string = or_string + and_string

        return search_string

    def row_path_builder(self, path='', row=''):
        """
        Builds row and path query.

        :param path:
            Landsat path. Must be three digits
        :type path:
            String
        :param row:
            Landsat row. Must be three digits
        :type row:
            String

        :returns:
            String
        """
        return 'path:%s+AND+row:%s' % (path, row)

    def date_range_builder(self, start='2013-02-11', end=None):
        """
        Builds date range query.

        :param start:
            Date string. format: YYYY-MM-DD
        :type start:
            String
        :param end:
            date string. format: YYYY-MM-DD
        :type end:
            String

        :returns:
            String
        """
        if not end:
            end = time.strftime('%Y-%m-%d')

        return 'acquisitionDate:[%s+TO+%s]' % (start, end)

    def cloud_cover_prct_range_builder(self, min=0, max=100):
        """
        Builds cloud cover percentage range query.

        :param min:
            float specifying the minimum percentage. Default is 0
        :type min:
            float
        :param max:
            float specifying the maximum percentage. Default is 100
        :type max:
            float

        :returns:
            String
        """
        return 'cloudCoverFull:[%s+TO+%s]' % (min, max)

    def lat_lon_builder(self, lat=0, lon=0):
        """ Builds lat and lon query.

        :param lat:
            The latitude. Default is 0
        :type lat:
            float
        :param lon:
            The The longitude. Default is 0
        :type lon:
            float

        :returns:
            String
        """
        return ('upperLeftCornerLatitude:[%s+TO+1000]+AND+lowerRightCornerLatitude:[-1000+TO+%s]'
                '+AND+lowerLeftCornerLongitude:[-1000+TO+%s]+AND+upperRightCornerLongitude:[%s+TO+1000]'
                % (lat, lat, lon, lon))
