#!/usr/bin/python
# -*- coding: utf-8 -*-

from __future__ import print_function
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer

import cgi
from storage import Storage
import json
import logging
import pygeoip
import re
import socket
from SocketServer import ThreadingMixIn
import time

import ffstatus

class BatcaveHttpRequestHandler(BaseHTTPRequestHandler):
    DATAKEY_VPN = '__VPN__'
    FIELDKEY_UPDATED = '__UPDATED__'

    def __init__(self, request, client_address, server):
        self.logger = logging.getLogger('API')
        BaseHTTPRequestHandler.__init__(self, request, client_address, server)

    def parse_url_pathquery(self):
        """Extracts the query parameters from the request path."""
        url = re.match(r'^/(?P<path>.*?)(\?(?P<query>.+))?$', self.path.strip())
        if url is None:
            logging.warn('Failed to parse URL \'' + str(self.path) + '\'.')
            return ( None, None )

        path = url.group('path')
        query = {}
        if not url.group('query') is None:
            for m in re.finditer(r'(?P<key>.+?)=(?P<value>.+?)(&|$)', url.group('query')):
                query[m.group('key')] = m.group('value')
        return ( path, query )

    def do_GET(self):
        """Handles all HTTP GET requests."""

        path, query = self.parse_url_pathquery()
        if path is None:
            self.send_error(400, 'Could not parse URL (' + str(self.path) + ')')
            return

        # / - index page, shows generic help
        if path == '':
            self.respond_index(query)
            return

        # /list - list stored nodes
        if path == 'list':
            self.respond_list(query)
            return

        # /vpn - notification endpoint for gateway's VPN connections
        if path == 'vpn':
            self.respond_vpn(query)
            return

        # /providers
        if path == 'providers':
            self.respond_providers(query)
            return

        # /node/<id>.json - node's data
        # /node/<id>/field - return specific field from node's data
        m = re.match(r'node/(?P<id>[a-fA-F0-9]{12})(?P<cmd>\.json|/[a-zA-Z0-9_\-\.]+)$', path)
        if m != None:
            cmd = m.group('cmd')
            nodeid = m.group('id').lower()
            if cmd == '.json':
                self.respond_node(nodeid)
            else:
                self.respond_nodedetail(nodeid, cmd[1:])
            return

        # /status/<id> - node's status
        m = re.match(r'status/([a-f0-9]{12})$', path)
        if m != None:
            self.respond_nodestatus(m.group(1))
            return

        # no match -> 404
        self.send_error(404, 'The URL \'{0}\' was not found here.'.format(path))

    def do_POST(self):
        """Handles all HTTP POST requests."""

        path, query = self.parse_url_pathquery()
        if path is None:
            self.send_error(400, 'Could not parse URL (' + str(self.path) + ')')
            return
        params = self.parse_post_params()

        # node id/mac to name mapping
        if path == 'idmac2name':
            self.respond_nodeidmac2name(params)
            return

        # no match -> 404
        self.send_error(404, 'The URL \'{0}\' was not found here.'.format(path))

    def send_nocache_headers(self):
        """Sets HTTP headers indicating that this response shall not be cached."""

        self.send_header('Cache-Control', 'no-cache, no-store, must-revalidate')
        self.send_header('Pragma', 'no-cache')
        self.send_header('Expires', '0')

    def send_headers(self, content_type='text/html; charset=utf-8', nocache=True):
        """Send HTTP 200 Response header with the given Content-Type.
        Optionally send no-caching headers, too."""

        self.send_response(200)
        self.send_header('Content-Type', content_type)
        if nocache:
            self.send_nocache_headers()
        self.end_headers()

    def parse_post_params(self):
        ctype, pdict = cgi.parse_header(self.headers.getheader('content-type'))
        if ctype == 'multipart/form-data':
            postvars = cgi.parse_multipart(self.rfile, pdict)
        elif ctype == 'application/x-www-form-urlencoded':
            length = int(self.headers.getheader('content-length'))
            postvars = cgi.parse_qs(self.rfile.read(length), keep_blank_values=1)
        else:
            postvars = {}
        return postvars

    def respond_index(self, query):
        """Display the index page."""

        storage = self.server.storage
        self.send_headers()

        self.wfile.write('<!DOCTYPE html><html><head><title>BATCAVE</title></head>\n')
        self.wfile.write('<body>\n')
        self.wfile.write('<H1 title="Batman/Alfred Transmission Collection, Aggregation & Value Engine">BATCAVE</H1>\n')

        self.wfile.write('<p>Dies ist ein interner Hintergrund-Dienst. Er wird nur von anderen Diensten\n')
        self.wfile.write('angesprochen und sollte aus einer Mehrzahl von Gr&uuml;nden nicht &ouml;ffentlich\n')
        self.wfile.write('zug&auml;nglich sein.</p>\n')

        self.wfile.write('<H2>Status</H2>\n')
        self.wfile.write('Daten: <span id="datacount" class="value">')
        self.wfile.write(len(storage.data))
        self.wfile.write('</span>\n')

        self.wfile.write('<H2>API</H2>\n')
        self.wfile.write('<p>Grundsätzlich ist das Antwort-Format JSON und alle Daten sind Live-Daten (kein Cache) die ggf. etwas Bearbeitungs-Zeit erfordern.</p>')
        self.wfile.write('<dl>\n')
        self.wfile.write('<dt><a href="/nodes.json">nodes.json</a></dt><dd>zur Verwendung mit ffmap (MACs anonymisiert)</dd>\n')
        self.wfile.write('<dt><a href="/node/ff00ff00ff00.json">/node/&lt;id&gt;.json</a></dt><dd><u>alle</u> vorhandenen Information zu der gewünschten Node</dd>\n')
        self.wfile.write('</dl>\n')
        self.wfile.write('</body></html>')

    def respond_list(self, query):
        """List stored data."""

        storage = self.server.storage
        self.send_headers()

        self.wfile.write('<!DOCTYPE html><html>\n')
        self.wfile.write('<head><title>BATCAVE</title></head>\n')
        self.wfile.write('<body>\n')
        self.wfile.write('<H1>BATCAVE - LIST</H1>\n')

        self.wfile.write('<table>\n')
        self.wfile.write('<thead><tr><th>ID</th><th>Name</th></tr></thead>\n')
        self.wfile.write('<tbody>\n')

        data = storage.data
        if 'sort' in query:
            if query['sort'] == 'name':
                sorteddata = sorted(data, key=lambda x: data[x]['hostname'].lower())
                data = sorteddata
            elif query['sort'] == 'id':
                sorteddata = sorted(data)
                data = sorteddata

        for nodeid in data:
            if nodeid.startswith('__'):
                continue
            nodename = storage.data[nodeid]['hostname'] if 'hostname' in storage.data[nodeid] else '&lt;?&gt;'
            self.wfile.write('<tr><td><a href="/node/' + nodeid + '.json">' + nodeid + '</a></td><td>' + nodename + '</td></tr>')

        self.wfile.write('</tbody>\n')
        self.wfile.write('</table>\n')

    def find_node(self, rawid):
        """Fetch node data from storage by given id, if necessary looking thorugh node aliases."""

        storage = self.server.storage

        # if we have a direct hit, return it immediately
        if rawid in storage.data:
            return storage.data[rawid]

        # no direct hit -> search via aliases
        nodeid = rawid
        for nid in storage.data:
            if 'aliases' in storage.data[nid] and rawid in storage.data[nid]['aliases']:
                nodeid = nid

        # return found node
        return storage.data[nodeid] if nodeid in storage.data else None

    def find_node_by_mac(self, mac):
        """Fetch node data from storage by given MAC address."""

        storage = self.server.storage
        needle = mac.lower()

        # iterate over all nodes
        for nodeid in storage.data:
            if nodeid.startswith('__'):
                continue
            node = storage.data[nodeid]

            # check node's primary MAC
            if 'mac' in node and needle == node['mac'].lower():
                return node

            # check alias MACs
            if 'macs' in node:
                haystack = [x.lower() for x in node['macs']]
                if mac in haystack:
                    return node

        # MAC address not found
        return None

    def respond_node(self, rawid):
        """Display node data."""

        # handle API example linked on index page
        if rawid == 'ff00ff00ff00':
            self.send_headers('text/json')
            self.wfile.write(json.dumps({
                'name': 'API-Example',
                'nodeid': rawid,
                'META': 'Dies ist ein minimaler Beispiel-Datensatz. Herzlichen Glückwunsch, du hast das Prinzip der API kapiert.',
            }))
            return

        # search node by the given id
        node = self.find_node(rawid)

        # handle unknown nodes
        if node is None:
            self.send_error(404, 'No node with id \'' + rawid + '\' present.')
            return

        # remove fields from output: __RAW__
        export = ffstatus.dict_merge({}, node)
        if '__RAW__' in export:
            del export['__RAW__']

        # dump node data as JSON
        self.send_headers('text/json')
        self.wfile.write(json.dumps(export))

    def get_nodestatus(self, rawid):
        """Determine node's status."""

        # search node by the given id
        node = self.find_node(rawid)

        # handle unknown nodes
        if node is None:
            return None

        # check that the last batadv update is noted in the data
        updated = node[self.FIELDKEY_UPDATED] if self.FIELDKEY_UPDATED in node else None
        if updated is None or not 'batadv' in updated:
            return 'unknown'

        # make decision based on time of last batadv update
        diff = time.time() - updated['batadv']
        if diff < 150:
            return 'active'
        elif diff < 300:
            return 'stale'
        else:
            return 'offline'

    def respond_nodestatus(self, rawid):
        """Display node status."""

        status = self.get_nodestatus(rawid)

        if status is None:
            self.send_error(404, 'No node with id \'' + rawid + '\' present.')

        self.send_headers('text/plain')
        self.wfile.write(status)

    def respond_nodeidmac2name(self, ids):
        """Return a mapping of the given IDs (or MACs) into their hostname."""

        self.send_headers('text/plain')
        for nodeid in ids:
            node = self.find_node(nodeid) if not ':' in nodeid else self.find_node_by_mac(nodeid)
            nodename = node['hostname'] if (not node is None) and 'hostname' in node else nodeid
            self.wfile.write('{0}={1}\n'.format(nodeid, nodename))

    def respond_nodedetail(self, nodeid, field):
        """Return a field from the given node - a string is returned as text, all other as JSON."""

        node = self.find_node(nodeid)
        if node is None:
            self.send_error(404, 'No node with id \'' + nodeid + '\' present.')
            return

        return_count = False
        if field.endswith('.count'):
            return_count = True
            field = field[0:-6]

        if not field in node:
            self.send_error(404, 'The node \'' + nodeid + '\' does not have a field named \'' + str(field) + '\'.')
            return

        value = node[field]
        if return_count:
            value = len(value)

        self.send_headers('text/plain' if isinstance(value, basestring) or isinstance(value, int) else 'text/json')
        self.wfile.write(value if isinstance(value, basestring) else json.dumps(value))

    def respond_vpn(self, query):
        storage = self.server.storage
        peername = query['peer'] if 'peer' in query else None
        key = query['key'] if 'key' in query else None
        action = query['action'] if 'action' in query else None
        remote = query['remote'] if 'remote' in query else None
        gw = query['gw'] if 'gw' in query else None
        ts = query['ts'] if 'ts' in query else time.time()

        if action == 'list':
            self.respond_vpnlist()
            return

        if action != 'establish' and action != 'disestablish':
            self.logger.error('VPN: unknown action \'{0}\''.format(action))
            self.send_error(400, 'Invalid action.')
            return

        check = {'peername': peername, 'key': key, 'remote': remote, 'gw': gw}
        for k, val in check.items():
            if val is None or len(val.strip()) == 0:
                self.logger.error('VPN {0}: no or empty {1}'.format(action, k))
                self.send_error(400, 'Missing value for ' + str(k))
                return

        if key is None or re.match(r'^[a-fA-F0-9]+$', key) is None:
            self.logger.error('VPN peer \'{0}\' {1}: bad key \'{2}\''.format(peername, action, key))
            self.send_error(400, 'Bad key.')
            return

        if not self.DATAKEY_VPN in storage.data:
            storage.data[self.DATAKEY_VPN] = {}
        if not key in storage.data[self.DATAKEY_VPN]:
            storage.data[self.DATAKEY_VPN][key] = {'active': {}, 'last': {}}
        item = storage.data[self.DATAKEY_VPN][key]

        # resolve remote addr to its netblock
        remote_raw = remote
        remote_resolved = None
        if not remote is None:
            remote_resolved = ffstatus.resolve_ipblock(remote)
            if not remote_resolved is None:
                self.logger.debug('Resolved IP \'{0}\' to block \'{1}\'.'.format(remote, remote_resolved['name']))
                remote = remote_resolved

        if action == 'establish':
            item['active'][gw] = {
                'establish': ts,
                'peer': peername,
                'remote': remote,
                'remote_raw': remote_raw,
            }

        elif action == 'disestablish':
            active = {}
            if gw in item['active']:
                active = item['active'][gw]
                del item['active'][gw]
            active['disestablish'] = ts
            item['last'][gw] = active

        else:
            self.send_error(500, 'Unknown action not filtered: ' + str(action))
            return

        self.send_headers('text/plain')
        self.wfile.write('OK')

        storage.save()

    def respond_vpnlist(self):
        storage = self.server.storage

        gateways = ['gw01', 'gw02', 'gw03', 'gw04', 'gw05', 'gw06']

        self.send_headers()
        self.wfile.write('<!DOCTYPE html>\n')
        self.wfile.write('<html><head><title>BATCAVE - VPN LIST</title></head>\n')
        self.wfile.write('<body>\n')
        self.wfile.write('<style type="text/css">\n')
        self.wfile.write('table { border: 2px solid #999; border-collapse: collapse; }\n')
        self.wfile.write('th, td { border: 1px solid #CCC; }\n')
        self.wfile.write('table tbody tr.online { background-color: #CFC; }\n')
        self.wfile.write('table tbody tr.offline { background-color: #FCC; }\n')
        self.wfile.write('</style>\n')
        self.wfile.write('<table>\n<thead>\n')
        self.wfile.write('<tr><th rowspan="2">names (key)</th><th colspan="' + str(len(gateways)) + '">active</th><th colspan="' + str(len(gateways)) + '">last</th></tr>\n')
        self.wfile.write('<tr><th>' + '</th><th>'.join(gateways) + '</th><th>' + '</th><th>'.join(gateways) + '</th></tr>\n')
        self.wfile.write('</thead>\n')

        if self.DATAKEY_VPN in storage.data:
            for key in storage.data[self.DATAKEY_VPN]:
                item = storage.data[self.DATAKEY_VPN][key]
                if not isinstance(item, dict):
                    continue

                names = set()
                count = {}
                for t in [ 'active', 'last' ]:
                    count[t] = 0
                    if t in item:
                        for gw in item[t]:
                            if 'remote' in item[t][gw] and len(item[t][gw]['remote']) > 0:
                                count[t] += 1
                            if 'peer' in item[t][gw]:
                                names.add(item[t][gw]['peer'])

                self.wfile.write('<tr class="online">' if count['active'] > 0 else '<tr class="offline">')
                self.wfile.write('<td title="' + str(key) + '">' + (' / '.join(names) if len(names) > 0 else '?') + '</td>')
                for t in [ 'active', 'last' ]:
                    for gw in gateways:
                        ip = ''
                        if t in item and gw in item[t]:
                            ip = item[t][gw]['remote'] if 'remote' in item[t][gw] else ''
                            if isinstance(ip, dict):
                                ip = ip['name']
                        self.wfile.write('<td title="' + ip + '">' + ('&check;' if len(ip) > 0 else '&times;') + '</td>')

                self.wfile.write('</tr>\n')

        self.wfile.write('</table>\n')
        self.wfile.write('</body>')
        self.wfile.write('</html>')

    def respond_providers(self, query):
        """Return a summary of providers."""

        vpn = self.server.storage.data[self.DATAKEY_VPN]
        outputformat = query['format'].lower() if 'format' in query else 'html'

        isps = {}
        ispblocks = {}
        vpnstorage_updated = False
        vpnstorage_update_allowed = 'update' in query and query['update'] == 'allowed'
        for key in vpn:
            if key is None:
                continue
            item = vpn[key]
            if not isinstance(item, dict):
                continue
            if not 'active' in item:
                continue

            ips = []
            for gw in item['active']:
                if 'remote' in item['active'][gw]:
                    ip = item['active'][gw]['remote']
                    if vpnstorage_update_allowed and not isinstance(ip, dict):
                        # try to resolve ip now
                        resolved = ffstatus.resolve_ipblock(ip)
                        if not resolved is None:
                            self.logger.debug('Resolved IP \'{0}\' to block \'{1}\'.'.format(ip, resolved))
                            item['active'][gw]['remote'] = resolved
                            vpnstorage_updated = True
                            ip = resolved
                        else:
                            self.logger.debug('Failed to resolve IP \'{0}\'.'.format(ip))
                    ips.append(ip)

            if len(ips) == 0:
                # no active dialins -> no need to process this key any further
                continue

            item_isps = set()
            for ip in ips:
                isp = "UNKNOWN"
                ispblock = ip
                if isinstance(ip, dict):
                    ispblock = ip['name']
                    desc_lines = ip['description'].split('\n')
                    isp = desc_lines[0].strip()

                    # normalize name: strip company indication
                    isp = re.sub(r'(AG|UG|G?mbH( ?& ?Co\.? ?(OH|K)G)?)$', '', isp, flags=re.IGNORECASE).strip()

                    # normalize name: strip "pool" suffixes
                    isp = re.sub(r'(dynamic )?(customer |subscriber )?(ip )?(pool|(address )?range|addresses)$', '', isp, flags=re.IGNORECASE).strip()

                    # normalize name: strip "B2B" and aggregation suffixes
                    isp = re.sub(r'(aggregate|aggregation)?$', '', isp, flags=re.IGNORECASE).strip()
                    isp = re.sub(r'(B2B)?$', '', isp, flags=re.IGNORECASE).strip()

                    # normalize name: strip country suffixes (in Germany)
                    isp = re.sub(r'(DE|Deutschland|Germany|Nordrhein[- ]Westfalen|NRW|Baden[- ]Wuerttemburg|BW|Hessen|Niedersachsen|Rheinland[- ]Pfalz|RLP)$', '', isp, flags=re.IGNORECASE).strip()

                isp = str(isp)
                if not isp in ispblocks:
                    ispblocks[isp] = set()
                ispblocks[isp].add(ispblock)

                item_isps.add(isp)

            if len(item_isps) == 0:
                item_isps.add('unknown')

            elif len(item_isps) > 1:
                self.logger.warn('VPN key \'{0}\' has {1} active IPs which resolved to {2} ISPs: \'{3}\''.format(key, len(ips), len(item_isps), '\', \''.join(item_isps)))

            for isp in item_isps:
                if not isp in isps:
                    isps[isp] = 0
                isps[isp] += 1.0 / len(item_isps)

        isps_sum = sum([isps[x] for x in isps])

        if vpnstorage_updated:
            self.server.storage.save()
 
        if outputformat == 'csv':
            self.send_headers('text/csv')

            self.wfile.write('Count;Name\n')
            for isp in isps:
                self.wfile.write('{0};"{1}"\n'.format(isps[isp], isp))

        elif outputformat == 'json':
            self.send_headers('text/json')

            data = [
                {
                    'name': isp,
                    'count': isps[isp],
                    'percentage': isps[isp]*100.0/isps_sum,
                    'blocks': [block for block in ispblocks[isp]],
                } for isp in isps
            ]
            self.wfile.write(json.dumps(data))

        elif outputformat == 'html':
            self.send_headers()

            self.wfile.write('<!DOCTYPE html><html>\n')
            self.wfile.write('<head><title>BATCAVE - PROVIDERS</title></head>\n')
            self.wfile.write('<body>\n')
            self.wfile.write('<table border="2">\n')
            self.wfile.write('<thead><tr><th>Count</th><th>Percentage</th><th>Name</th><th>Blocks</th></tr></thead>\n')
            self.wfile.write('<tbody>\n')

            for isp in sorted(isps, key=lambda x: isps[x], reverse=True):
                self.wfile.write('<tr><td>{0}</td><td>{1:.1f}%</td><td>{2}</td><td>{3}</td></tr>\n'.format(
                    isps[isp],
                    isps[isp]*100.0/isps_sum,
                    isp,
                    ', '.join(sorted(ispblocks[isp])) if isp in ispblocks else '?',
                ))

            self.wfile.write('</tbody></table>\n')
            self.wfile.write('<p>Totals: {0} ISPs, {1} connections</p>\n'.format(len(isps), isps_sum))
            self.wfile.write('</body></html>')

        else:
            self.send_error(400, 'Unknown output format.')

class ApiServer(ThreadingMixIn, HTTPServer):
    def __init__(self, endpoint, storage):
        if ':' in endpoint[0]:
            self.address_family = socket.AF_INET6
        HTTPServer.__init__(self, endpoint, BatcaveHttpRequestHandler)
        self.storage = storage

        # check all entries for a proper 'remote' entry
        vpn = storage.data[BatcaveHttpRequestHandler.DATAKEY_VPN] if BatcaveHttpRequestHandler.DATAKEY_VPN in storage.data else {}
        init_vpn_cache = {}
        for key in vpn:
            if not isinstance(vpn[key], dict):
                continue
            for mode in vpn[key]:
                if not isinstance(vpn[key][mode], dict):
                    continue
                for gw in vpn[key][mode]:
                    if not isinstance(vpn[key][mode][gw], dict):
                        continue
                    item = vpn[key][mode][gw]
                    if 'remote' in item and not 'remote_raw' in item:
                        item['remote_raw'] = item['remote']
                        resolved = None
                        if item['remote'] in init_vpn_cache:
                            resolved = init_vpn_cache[item['remote']]
                        else:
                            resolved = ffstatus.resolve_ipblock(item['remote'])
                            init_vpn_cache[item['remote']] = resolved
                            if not resolved is None:
                                logging.info('Startup: resolved VPN entry \'{0}\' to net \'{1}\'.'.format(item['remote'], resolved['name']))
                        if not resolved is None:
                            item['remote'] = resolved
        storage.save()


    def __str__(self):
        return 'ApiServer on {0}'.format(self.server_address)

if __name__ == '__main__':
    dummystorage = Storage()
    server = ApiServer(('0.0.0.0', 8888), dummystorage)

    print("Server:", str(server))
    server.serve_forever()