#!/usr/bin/python3
import argparse
import json
from typing import Optional
from xml.etree.ElementTree import ElementTree

from wrpylib.argparse_tools import bool_type
from wrpylib.json_tools import format_json
from wrpylib.wrgeojson import join_wrgeojson_ways, simplify_ways
from wrpylib.wrosm import find_sledrun_relations, tags, convert_osm_to_geojson, DeRefError


def process_osm_file(filename: str, single: Optional[int], join_ways: bool, simplify: bool):
    """converts an .osm file to <wrmap>(s).

    :param filename: name of the .osm file
    :param single: if not None, an int argument that specifies the number of the <wrmap> to display (1 based)
    :param join_ways: joins subsequent ways of same type
    :param simplify_max_dist: If not None, omit points to make the map file size smaller.
        The float value gives the number of meters of way error that is maximally accepted.
    """
    osm_tree = ElementTree()
    osm_tree.parse(filename)

    # Search all sled run relations
    sledrun_list = list(find_sledrun_relations(osm_tree))
    if single is not None:
        sledrun_list = [sledrun_list[single - 1]]

    for sledrun_relation in sledrun_list:  # sledrun is an Element 'relation'
        # Make a nice title
        sledrun_tags = tags(sledrun_relation)
        title = f"{sledrun_tags.get('name')} ({sledrun_tags.get('website')}) [{sledrun_relation.get('id')}]"
        print(title)
        print("-" * len(title))

        # Convert to geojson
        try:
            sledrun_geojson = convert_osm_to_geojson(osm_tree, sledrun_relation)
        except DeRefError:
            print('Error: Incomplete XML - please load larger region.')
            continue

        # Merge sledrun ways of the same type
        if join_ways:
            join_wrgeojson_ways(sledrun_geojson)

        # Simplify the sledrunMap
        if simplify:
            simplify_ways(sledrun_geojson)

        # Print result
        print(format_json(sledrun_geojson))
        print()


def main():
    epilog = "Writing result to a file without encoding errors:\n" + \
             "$ PYTHONIOENCODING='ISO8859-15' python osm_to_wrgeojson.py mymap.osm > mymap.json"
    parser = argparse.ArgumentParser(description='Converts an OpenStreetMap .osm file to wrgeojson.',
                                     epilog=epilog, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument('--single', type=int, help='just display the ith (1 based) <wrmap> instead of all')
    parser.add_argument('--join-ways', type=bool_type, default=True,
                        help='joins subsequent ways of same type (default: True)')
    parser.add_argument('--simplify', type=bool_type, default=False,
                        help='simplify the map (reduce number of points in paths) (default: False)')
    parser.add_argument('osmfile', type=str, help='input file name (.osm file)')
    args = parser.parse_args()

    process_osm_file(args.osmfile, single=args.single, join_ways=args.join_ways, simplify=args.simplify)


if __name__ == '__main__':
    main()