#!/usr/bin/env python3
from http.server import HTTPServer, BaseHTTPRequestHandler, HTTPStatus
import io
import socket
import urllib.request
import xml.etree.ElementTree as ET

class HTTPServerV6(HTTPServer):
    address_family = socket.AF_INET6


class ExporterRequestHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == "/":
            self.make_response("Waldbrandgefahrenstufen Exporter für Brandenburg")
        elif self.path == "/metrics":
            self.export()
        else:
            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
            return

    def do_HEAD(self):
        if self.path == "/":
            self.make_response("Waldbrandgefahrenstufen Exporter für Brandenburg", head_only=True)
        elif self.path == "/metrics":
            self.export(head_only=True)
        else:
            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
            return

    def export(self, head_only=False):
        r = []
        with urllib.request.urlopen("https://mluk.brandenburg.de/mluk/de/wgs.xml") as f:
            tree = ET.parse(f)
            root = tree.getroot()
            for lk in root[0].findall("landkreis"):
                r.append('waldbrandgefahrenstufe{{landkreis="{landkreis}"}} {value}'.format(landkreis=lk.attrib["name"], value=lk.text))
        self.make_response("\n".join(r), head_only=head_only)

    def make_response(self, content, head_only=False):
        encoded = content.encode("utf-8")
        self.send_response(HTTPStatus.OK)
        self.send_header("Content-Type", "text/plain; charset=utf-8")
        self.send_header("Conten-Length", str(len(encoded)))
        self.end_headers()
        if not head_only:
            self.wfile.write(encoded)


def run():
    with HTTPServerV6(("::1", 9242), ExporterRequestHandler) as httpd:
        print("Starting Waldbrandgefahrenstufen Exporter on http://[{}]:{}".format(*httpd.socket.getsockname()[:2]))
        httpd.serve_forever()

if __name__ == "__main__":
    run()