#!/usr/bin/env python3
# File: fifconfig.py
# Location: https://gitlab.com/bgstack15/fifconfig
# Author: bgstack15
# SPDX-License-Identifier: GPL-3.0
# Startdate: 2022-03-15 20:35
# Title: Flask-ifconfig
# Purpose: Act similar to http://ifconfig.me but with flask, for my network testing usage
# History:
# Usage:
# Reference:
#    https://tedboy.github.io/flask/generated/generated/flask.Request.html
#    https://bgstack15.ddns.net/cgit/stackbin/tree/stackbin.py
#    https://pypi.org/project/dicttoxml/
# Improve:
# Dependencies:
#    pip-devuan: json2html
#    pip-centos7: json2html
#    dep-devuan: python3-dicttoxml | python3-xmltodict
#    dep-centos7: python36-xmltodict
#    reverse-proxy configs that include X-Forwarded-Prefix headers.
# Documentation: see README.md

from flask import Flask, request, jsonify, url_for
import os

app = Flask(__name__)
try:
   app.config.from_pyfile(os.environ['FIFCONFIG_CONF'])
except:
   app.config.from_pyfile('fifconfig.conf')

def _make_dict_safe_for_text(response):
   """ Mostly for converting the silly x-forwarded-for ImmutableList so that it does not show that class name. """
   # This works except for the silly "ImmutableList([" text output for that one 'via' item.
   #response = { i:str(response[i]) for i in response }
   # So instead of that beautiful oneliner, you get this stupid 9-line block.
   gen = (i for i in response)
   new_response = {}
   for i in gen:
      if "<class 'werkzeug.datastructures.ImmutableList'>" == str(type(response[i])):
         #print(f"i {i} is a immutablelist")
         new_response[i] = ','.join(response[i])
      else:
         new_response[i] = str(response[i])
   return new_response

def get_attribs(
   request,
   lia = False,
   ia = False,
   ua = False,
   l = False,
   re = False,
   m = False,
   e = False,
   mt = False,
   c = False,
   xff = False
):
   """
   Main function that builds the desired response dict
   that will later be turned into json or html by the
   various small @app.route functions.
   """
   response = {}
   r = request
   rh = r.headers
   if lia:
      response['lastipaddress'] = r.remote_addr
   if ia:
      response['ipaddress'] = r.remote_addr
      if r.access_route and len(r.access_route) > 0:
         response['ipaddress'] = r.access_route[0]
   if ua:
      response['useragent'] = str(r.user_agent)
   if l:
      response['language'] = r.accept_languages
   if re:
      response['referer'] = r.referrer
   if m:
      response['method'] = r.method
   if e:
      response['encoding'] = r.accept_encodings
   if mt:
      response['mimetype'] = r.accept_mimetypes
   if c:
      response['charset'] = r.accept_charsets
   if xff:
      #response['x-forwarded-for'] = rh.get('X-Forwarded-For') or ''
      response['x-forwarded-for'] = r.access_route
   #'charset': rh.get('Accept-Charset') or '',
   #'endpoint': request.endpoint
   # via is the same as x-forwarded-for
   #'via': r.access_route
   print(f"DEBUG: dict is {response}")
   return response

def prepare_output(request, response):
   """
   Used to customize the output to json, html, or text depending on what the client asked for. In order of most important to least important:
      1. request argument, i.e., '?json'
      2. Accept-Mimetypes header
   """
   possible_formats = ['json','html','text','xml']
   _format = "text"
   # priority two
   for i in request.accept_mimetypes:
      for j in i:
         if 'application/xml' == j and _format != "html":
            _format = "xml"
         if 'application/json' == j:
            _format = "json"
         if 'application/xhtml+xml' == j or 'text/html' == j:
            _format = "html"
         if 'text/plain' == j:
            _format = "text"
   # priority one
   if request.args:
      if 'xml' in request.args:
         _format = "xml"
      if 'json' in request.args:
         _format = "json"
      if 'html' in request.args:
         _format = "html"
      if 'text' in request.args:
         _format = "text"
   if _format not in possible_formats:
      print(f"DEBUG (prepare_output): how did format {_format} get defined?! Using text.")
      _format = "text"
   # main process
   if "html" == _format:
      print("Sending html")
      if True:
         from json2html import json2html
         response = _make_dict_safe_for_text(response)
         response = json2html.convert(json = response)
         if not 'nolinks' in request.args:
            prefix = ''
            if 'HTTP_X_FORWARDED_PREFIX' in request.environ:
               prefixes = request.environ['HTTP_X_FORWARDED_PREFIX']
               prefix = ''.join(prefixes.split(',')).replace(' ','')
            response += f"<div style='font-size: 80%;'>"
            response += f"<a href='{prefix}{url_for('ip')}'>ip</a> "
            response += f"<a href='{prefix}{url_for('ua')}'>ua</a> "
            response += f"<a href='{prefix}{url_for('lang')}'>lang</a> "
            response += f"<a href='{prefix}{url_for('encoding')}'>encoding</a> "
            response += f"<a href='{prefix}{url_for('mime')}'>mime</a> "
            response += f"<a href='{prefix}{url_for('charset')}'>charset</a> "
            response += f"<a href='{prefix}{url_for('forwarded')}'>forwarded</a> "
            #response += f"<p>{request.environ}<p>"
            response += f"<a href='{app.config['SOURCE_URL']}'>SOURCE</a>"
            response += f"</div>"
         return response
      else:
         print("Unable to load json2html, sending plain text.")
         return str(response)
   elif "xml" == _format:
      print("Sending xml")
      pretty = False
      if request.args and 'pretty' in request.args:
         pretty = True
      try:
         import xmltodict
         response = xmltodict.unparse({'info':response})
      except:
         try:
            # This lib is objectively better but not available natively on CentOS 7
            print("Trying dicttoxml")
            from dicttoxml import dicttoxml
            response = dicttoxml(response,custom_root="info")
         except:
            print("Unable to load xmltodict, sending plain text.")
            return str(response)
      if pretty:
         try:
            from xml.dom.minidom import parseString
            response = parseString(response).toprettyxml()
         except:
            pass
      return response
   elif "json" == _format:
      print("Sending json")
      return jsonify(response)
   else:
      # the only other option is text
      print("Sending text")
      response = _make_dict_safe_for_text(response)
      new_response = ""
      if 1 == len(response):
         for i in response:
            return response[i]
      else:
         for i in response:
            new_response = new_response + '\n' + str(i) + ': ' + str(response[i])
      return new_response

@app.route('/')
def root():
   response = get_attribs(request, lia = False, ia = True, ua = True, l = True, re = True, m = True, e = True, mt = True, c = True, xff = True)
   response = prepare_output(request, response)
   return response

@app.route('/ip')
def ip():
   return prepare_output(request, get_attribs(request, ia = True))

@app.route('/ua')
def ua():
   return prepare_output(request, get_attribs(request, ua = True))

@app.route('/lang')
def lang():
   return prepare_output(request, get_attribs(request, l = True))

@app.route('/encoding')
def encoding():
   return prepare_output(request, get_attribs(request, e = True))

@app.route('/mime')
def mime():
   return prepare_output(request, get_attribs(request, mt = True))

@app.route('/charset')
def charset():
   return prepare_output(request, get_attribs(request, c = True))

@app.route('/forwarded')
def forwarded():
   return prepare_output(request, get_attribs(request, xff = True))

if __name__ == "__main__":
   app.run()