import re
import xml.dom.minidom as minidom
from xml.parsers.expat import ExpatError
from enum import IntEnum
from flask import request, redirect, url_for, flash, render_template


class MultiGeo(IntEnum):
    """Formats multiple coordinates, even in multiple lines to [(latitude, longitude, elevation), ...] 
    or [(latitude, longitude, None), ...] tuples."""

    # Valid for input_format
    FORMAT_GUESS = 0  # guesses the input format; default for input_format
    FORMAT_NONE = -1  # indicates missing formats

    # Valid for input_format and output_format
    FORMAT_GEOCACHING = 1  # e.g. "N 47° 13.692 E 011° 25.535"
    FORMAT_WINTERRODELN = 2  # e.g. "47.222134 N 11.467211 E"
    FORMAT_GMAPPLUGIN = 3  # e.g. "47.232922, 11.452239"
    FORMAT_GPX = 4  # e.g. "<trkpt lat="47.181289" lon="11.408827"><ele>1090.57</ele></trkpt>"


def multigeo_from_string(value, input_format):
    assert input_format in [MultiGeo.FORMAT_GUESS, MultiGeo.FORMAT_GEOCACHING, MultiGeo.FORMAT_WINTERRODELN,
                            MultiGeo.FORMAT_GMAPPLUGIN, MultiGeo.FORMAT_GPX], "input_format %d is not recognized"
    lines = [line.strip() for line in value.split("\n") if len(line.strip()) > 0]

    result = []
    for line in lines:
        if input_format == MultiGeo.FORMAT_GUESS or input_format == MultiGeo.FORMAT_GEOCACHING:
            r = re.match('N ?(\d+)° ?(\d+\.\d+) +E ?(\d+)° ?(\d+\.\d+)', line)
            if r is not None:
                g = r.groups()
                result.append((float(g[0]) + float(g[1]) / 60, float(g[2]) + float(g[3]) / 60, None))
                continue

        if input_format == MultiGeo.FORMAT_GUESS or input_format == MultiGeo.FORMAT_WINTERRODELN:
            r = re.match('(\d+\.\d+) N (\d+\.\d+) E', line)
            if not r is None:
                result.append((float(r.groups()[0]), float(r.groups()[1]), None))
                continue

        if input_format == MultiGeo.FORMAT_GUESS or input_format == MultiGeo.FORMAT_GMAPPLUGIN:
            r = re.match('(\d+\.\d+), ?(\d+\.\d+)', line)
            if r is not None:
                result.append((float(r.groups()[0]), float(r.groups()[1]), None))
                continue

        if input_format == MultiGeo.FORMAT_GUESS or input_format == MultiGeo.FORMAT_GPX:
            try:
                xml = minidom.parseString(line)
                coord = xml.documentElement
                lat = float(coord.getAttribute('lat'))
                lon = float(coord.getAttribute('lon'))
                try:
                    ele = float(coord.childNodes[0].childNodes[0].nodeValue)
                except (IndexError, ValueError):
                    ele = None
                result.append((lat, lon, ele))
                continue
            except (ExpatError, IndexError, ValueError):
                pass

        raise ValueError("Coordinates '%s' have no known format" % line, value)
    return result


def multigeo_to_string(value, output_format):
    result = []
    for latitude, longitude, height in value:
        if output_format == MultiGeo.FORMAT_GEOCACHING:
            result.append(
                'N %02d° %02.3f E %03d° %02.3f' % (latitude, latitude % 1 * 60, longitude, longitude % 1 * 60))

        elif output_format == MultiGeo.FORMAT_WINTERRODELN:
            result.append('%.6f N %.6f E' % (latitude, longitude))

        elif output_format == MultiGeo.FORMAT_GMAPPLUGIN:
            result.append('%.6f, %.6f' % (latitude, longitude))

        elif output_format == MultiGeo.FORMAT_GPX:
            if not height is None:
                result.append(
                    '<trkpt lat="%.6f" lon="%.6f"><ele>%.2f</ele></trkpt>' % (latitude, longitude, height))
            else:
                result.append('<trkpt lat="%.6f" lon="%.6f"/>' % (latitude, longitude))

        else:
            raise ValueError("output_format %d is not recognized" % output_format, value)

    return "\n".join(result)


class CoordtoolController:

    def index(self):
        return render_template('coordtool.html', result=None)

    def convert(self):
        assert request.method == 'POST'
        input = request.form['input']
        no_elevation = 'no_elevation' in request.form
        simplify = 'simplify' in request.form
        swap_latlon = 'swap_latlon' in request.form
        no_geoformat = 'no_geoformat' in request.form
        no_gpxformat = 'no_gpxformat' in request.form
        no_gmapsformat = 'no_gmapsformat' in request.form
        no_geocachingformat = 'no_geocachingformat' in request.form
        
        if input is None or len(input.strip()) == 0: 
            return redirect(url_for('coordtool_index'))
        
        try:
            result = multigeo_from_string(input, MultiGeo.FORMAT_GUESS)
        except ValueError as e:
            flash(str(e))
            return redirect(url_for('coordtool_index'))
        
        if swap_latlon:
            result = [(latitude, longitude, elevation) for (longitude, latitude, elevation) in result]
        
        if no_elevation:
            result = [(longitude, latitude, None) for (longitude, latitude, elevation) in result]
        
        geo_winterrodeln = lambda value: multigeo_to_string(value, MultiGeo.FORMAT_WINTERRODELN)
        geo_gmapplugin = lambda value: multigeo_to_string(value, MultiGeo.FORMAT_GMAPPLUGIN)
        geo_gpx = lambda value: multigeo_to_string(value, MultiGeo.FORMAT_GPX)
        geo_geocaching = lambda value: multigeo_to_string(value, MultiGeo.FORMAT_GEOCACHING)
        
        return render_template('coordtool.html', result=result,
                               no_geoformat=no_geoformat, geo_winterrodeln=geo_winterrodeln,
                               no_gmapsformat=no_gmapsformat, geo_gmapplugin=geo_gmapplugin,
                               no_gpxformat=no_gpxformat, geo_gpx=geo_gpx,
                               no_geocachingformat=no_geocachingformat, geo_geocaching=geo_geocaching)