#!/bin/python3

import osmapi
import itertools
import math
# import pickle
# import os

OSM_KOGGENLAND_ID = 161930
PICKLE_FILE = 'koggenland.pickle'


def chunks(lst, n):
    """Yield successive n-sized chunks from lst."""
    for i in range(0, len(lst), n):
        yield lst[i:i + n]


def flatten(lst):
    return list(itertools.chain(*lst))


def main():
    osm_api = osmapi.OsmApi()
    koggenland = osm_api.RelationFullRecur(OSM_KOGGENLAND_ID)
    node_ids = list(map(lambda a: a['data']['id'], filter(
        lambda a: a['type'] == 'node', koggenland)))

    coords = []
    for chunk in chunks(node_ids, 100):
        coords += map(lambda a: (a['lat'], a['lon']),
                      osm_api.NodesGet(chunk).values())

    cx, cy = 0., 0.
    for (x, y) in coords:
        cx += x
        cy += y
    cx /= len(coords)
    cy /= len(coords)

    print('centre', (cx, cy))

    # 7KM radius (eye-balled)

    # max_coord = None
    # max_dist = 0

    # for (x, y) in coords:
    #     dist = math.sqrt((cx - x)**2 + (cy - y)**2)
    #     if dist > max_dist:
    #         max_dist = dist
    #         max_coord = (x, y)

    # print('max', max_coord)


if __name__ == '__main__':
    main()