#!/usr/bin/env python
"""
Small flask server to serve map tiles.
"""
from argparse import ArgumentParser
import importlib.util
from http import HTTPStatus
import errno
import os.path
import sys
from flask import Flask, send_file, Response, render_template

# Parse Arguments
parser = ArgumentParser(description="Map Tile Server")
parser.add_argument(
    "--tile-path",
    type=str,
    help="Location of map tiles on the filesystem",
    default=f"{os.path.expanduser('~')}/.local/share/marble/maps/earth/openstreetmap"
)
parser.add_argument("--port", type=int, help="Port to bind to.", default=9001)
args = vars(parser.parse_args())


# Try to locate mapserver folder
root_path = "mapserver"
if not os.path.isdir(root_path):
    spec_location = importlib.util.find_spec('mapserver')
    if spec_location is None or spec_location.origin is None:
        print("mapserver folder is not in current directory or installed.")
        sys.exit(1)
    root_path = os.path.dirname(spec_location.origin)


app = Flask(__name__, root_path=root_path)

@app.route('/tiles/<zoom>/<y>/<x>')
def tiles(zoom, y, x):
    """Serve tiles directly from filesystem if found."""
    filename = args['tile_path'] + f"/{zoom}/{x}/{y}.jpg"
    if os.path.isfile(filename):
        return send_file(filename)
    return Response(status=HTTPStatus.NOT_FOUND)

@app.route('/')
def index():
    """Return a sample fullscreen map application."""
    return render_template("index.html")

if __name__ == '__main__':
    try:
        app.run(port=args['port'])
    except OSError as e:
        if e.errno == errno.EADDRINUSE:
            print("Address-Port Combination in use. Is another servemaps running?")
            os._exit(errno.EADDRINUSE)
        raise e