/// \file controller.cpp
/// Contains all code for the controller executable.

#include <iostream>
#include <vector>
#include <sys/stat.h>
#include <mist/config.h>
#include <mist/socket.h>
#include <mist/http_parser.h>
#include <mist/procs.h>
#include <mist/auth.h>
#include <mist/timing.h>
#include "controller_storage.h"
#include "controller_connectors.h"
#include "controller_streams.h"
#include "controller_capabilities.h"
#include "server.html.h"

#define UPLINK_INTERVAL 30
#define COMPILED_USERNAME ""
#define COMPILED_PASSWORD ""

namespace Controller {

  Secure::Auth keychecker; ///< Checks key authorization.

  class ConnectedUser{
    public:
      Socket::Connection C;
      HTTP::Parser H;
      bool Authorized;
      bool clientMode;
      int logins;
      std::string Username;
      ConnectedUser(Socket::Connection c){
        C = c;
        H.Clean();
        logins = 0;
        Authorized = false;
        clientMode = false;
      }
  };

  void Authorize(JSON::Value & Request, JSON::Value & Response, ConnectedUser & conn){
    time_t Time = time(0);
    tm * TimeInfo = localtime( &Time);
    std::stringstream Date;
    std::string retval;
    Date << TimeInfo->tm_mday << "-" << TimeInfo->tm_mon << "-" << TimeInfo->tm_year + 1900;
    std::string Challenge = Secure::md5(Date.str().c_str() + conn.C.getHost());
    if (Request.isMember("authorize")){
      std::string UserID = Request["authorize"]["username"];
      if (Storage["account"].isMember(UserID)){
        if (Secure::md5(Storage["account"][UserID]["password"].asString() + Challenge) == Request["authorize"]["password"].asString()){
          Response["authorize"]["status"] = "OK";
          conn.Username = UserID;
          conn.Authorized = true;
          return;
        }
      }
      if (UserID != ""){
        if (Request["authorize"]["password"].asString() != ""
            && Secure::md5(Storage["account"][UserID]["password"].asString()) != Request["authorize"]["password"].asString()){
          Log("AUTH", "Failed login attempt " + UserID + " @ " + conn.C.getHost());
        }
      }
      conn.logins++;
    }
    conn.Username = "";
    conn.Authorized = false;
    Response["authorize"]["status"] = "CHALL";
    Response["authorize"]["challenge"] = Challenge;
    return;
  }

  void CheckConfig(JSON::Value & in, JSON::Value & out){
    for (JSON::ObjIter jit = in.ObjBegin(); jit != in.ObjEnd(); jit++){
      if (jit->first == "version"){
        continue;
      }
      if (out.isMember(jit->first)){
        if (jit->second != out[jit->first]){
          if (jit->first != "time"){
            Log("CONF", std::string("Updated configuration value ") + jit->first);
          }
        }
      }else{
        Log("CONF", std::string("New configuration value ") + jit->first);
      }
    }
    for (JSON::ObjIter jit = out.ObjBegin(); jit != out.ObjEnd(); jit++){
      if ( !in.isMember(jit->first) || jit->first == "version"){
        Log("CONF", std::string("Deleted configuration value ") + jit->first);
      }
    }
    out = in;
  }

  void CheckStats(JSON::Value & stats){
    long long int currTime = Util::epoch();
    for (JSON::ObjIter jit = stats.ObjBegin(); jit != stats.ObjEnd(); jit++){
      if (currTime - lastBuffer[jit->first] > 120){
        stats.removeMember(jit->first);
        return;
      }else{
        if (jit->second.isMember("curr") && jit->second["curr"].size() > 0){
          for (JSON::ObjIter u_it = jit->second["curr"].ObjBegin(); u_it != jit->second["curr"].ObjEnd(); ++u_it){
            if (u_it->second.isMember("now") && u_it->second["now"].asInt() < currTime - 3){
              jit->second["log"].append(u_it->second);
              jit->second["curr"].removeMember(u_it->first);
              if ( !jit->second["curr"].size()){
                break;
              }
              u_it = jit->second["curr"].ObjBegin();
            }
          }
        }
      }
    }
  }

} //Controller namespace

int main(int argc, char ** argv){
  Controller::Storage = JSON::fromFile("config.json");
  JSON::Value stored_port = JSON::fromString("{\"long\":\"port\", \"short\":\"p\", \"arg\":\"integer\", \"help\":\"TCP port to listen on.\"}");
  stored_port["default"] = Controller::Storage["config"]["controller"]["port"];
  if ( !stored_port["default"]){
    stored_port["default"] = 4242;
  }
  JSON::Value stored_interface =
      JSON::fromString(
          "{\"long\":\"interface\", \"short\":\"i\", \"arg\":\"string\", \"help\":\"Interface address to listen on, or 0.0.0.0 for all available interfaces.\"}");
  stored_interface["default"] = Controller::Storage["config"]["controller"]["interface"];
  if ( !stored_interface["default"]){
    stored_interface["default"] = "0.0.0.0";
  }
  JSON::Value stored_user = JSON::fromString(
      "{\"long\":\"username\", \"short\":\"u\", \"arg\":\"string\", \"help\":\"Username to drop privileges to, or root to not drop provileges.\"}");
  stored_user["default"] = Controller::Storage["config"]["controller"]["username"];
  if ( !stored_user["default"]){
    stored_user["default"] = "root";
  }
  Util::Config conf = Util::Config(argv[0], PACKAGE_VERSION " / " RELEASE);
  conf.addOption("listen_port", stored_port);
  conf.addOption("listen_interface", stored_interface);
  conf.addOption("username", stored_user);
  conf.addOption("daemonize",
      JSON::fromString(
          "{\"long\":\"daemon\", \"short\":\"d\", \"default\":1, \"long_off\":\"nodaemon\", \"short_off\":\"n\", \"help\":\"Whether or not to daemonize the process after starting.\"}"));
  conf.addOption("account",
      JSON::fromString(
          "{\"long\":\"account\", \"short\":\"a\", \"arg\":\"string\" \"default\":\"\", \"help\":\"A username:password string to create a new account with.\"}"));
  conf.addOption("uplink", JSON::fromString("{\"default\":0, \"help\":\"Enable MistSteward uplink.\", \"short\":\"U\", \"long\":\"uplink\"}"));
  conf.parseArgs(argc, argv);

  std::string account = conf.getString("account");
  if (account.size() > 0){
    size_t colon = account.find(':');
    if (colon != std::string::npos && colon != 0 && colon != account.size()){
      std::string uname = account.substr(0, colon);
      std::string pword = account.substr(colon + 1, std::string::npos);
      Controller::Log("CONF", "Created account " + uname + " through commandline option");
      Controller::Storage["account"][uname]["password"] = Secure::md5(pword);
    }
  }
  time_t lastuplink = 0;
  time_t processchecker = 0;
  Socket::Server API_Socket = Socket::Server(conf.getInteger("listen_port"), conf.getString("listen_interface"), true);
  mkdir("/tmp/mist", S_IRWXU | S_IRWXG | S_IRWXO); //attempt to create /tmp/mist/ - ignore failures
  Socket::Server Stats_Socket = Socket::Server("/tmp/mist/statistics", true);
  conf.activate();
  Socket::Connection Incoming;
  std::vector<Controller::ConnectedUser> users;
  std::vector<Socket::Connection> buffers;
  JSON::Value Request;
  JSON::Value Response;
  std::string jsonp;
  Controller::ConnectedUser * uplink = 0;
  Controller::Log("CONF", "Controller started");
  conf.activate();
  while (API_Socket.connected() && conf.is_active){
    usleep(10000); //sleep for 10 ms - prevents 100% CPU time

    if (Util::epoch() - processchecker > 10){
      processchecker = Util::epoch();
      Controller::CheckProtocols(Controller::Storage["config"]["protocols"]);
      Controller::CheckAllStreams(Controller::Storage["streams"]);
      Controller::CheckStats(Controller::Storage["statistics"]);
    }
    if (conf.getBool("uplink") && Util::epoch() - lastuplink > UPLINK_INTERVAL){
      lastuplink = Util::epoch();
      bool gotUplink = false;
      if (users.size() > 0){
        for (std::vector<Controller::ConnectedUser>::iterator it = users.end() - 1; it >= users.begin(); it--){
          if ( !it->C.connected()){
            it->C.close();
            users.erase(it);
            break;
          }
          if (it->clientMode){
            uplink = & *it;
            gotUplink = true;
          }
        }
      }
      if ( !gotUplink){
        Incoming = Socket::Connection("gearbox.ddvtech.com", 4242, true);
        if (Incoming.connected()){
          users.push_back((Controller::ConnectedUser)Incoming);
          users.back().clientMode = true;
          uplink = &users.back();
          gotUplink = true;
        }
      }
      if (gotUplink){
        Response.null(); //make sure no data leaks from previous requests
        Response["config"] = Controller::Storage["config"];
        Response["streams"] = Controller::Storage["streams"];
        Response["log"] = Controller::Storage["log"];
        Response["statistics"] = Controller::Storage["statistics"];
        Response["now"] = (unsigned int)lastuplink;
        uplink->H.Clean();
        uplink->H.SetBody("command=" + HTTP::Parser::urlencode(Response.toString()));
        uplink->H.BuildRequest();
        uplink->C.Send(uplink->H.BuildResponse("200", "OK"));
        uplink->H.Clean();
        //Controller::Log("UPLK", "Sending server data to uplink.");
      }else{
        Controller::Log("UPLK", "Could not connect to uplink.");
      }
    }

    Incoming = API_Socket.accept(true);
    if (Incoming.connected()){
      users.push_back((Controller::ConnectedUser)Incoming);
    }
    Incoming = Stats_Socket.accept(true);
    if (Incoming.connected()){
      buffers.push_back(Incoming);
    }
    if (buffers.size() > 0){
      for (std::vector<Socket::Connection>::iterator it = buffers.begin(); it != buffers.end(); it++){
        if ( !it->connected()){
          it->close();
          buffers.erase(it);
          break;
        }
        if (it->spool()){
          while (it->Received().size()){
            it->Received().get().resize(it->Received().get().size() - 1);
            Request = JSON::fromString(it->Received().get());
            it->Received().get().clear();
            if (Request.isMember("buffer")){
              std::string thisbuffer = Request["buffer"];
              Controller::lastBuffer[thisbuffer] = Util::epoch();
              //if metadata is available, store it
              if (Request.isMember("meta")){
                Controller::Storage["streams"][thisbuffer]["meta"] = Request["meta"];
              }
              if (Request.isMember("totals")){
                Controller::Storage["statistics"][thisbuffer]["curr"] = Request["curr"];
                std::string nowstr = Request["totals"]["now"].asString();
                Controller::Storage["statistics"][thisbuffer]["totals"][nowstr] = Request["totals"];
                Controller::Storage["statistics"][thisbuffer]["totals"][nowstr].removeMember("now");
                Controller::Storage["statistics"][thisbuffer]["totals"].shrink(600); //limit to 10 minutes of data
                for (JSON::ObjIter jit = Request["log"].ObjBegin(); jit != Request["log"].ObjEnd(); jit++){
                  Controller::Storage["statistics"][thisbuffer]["log"].append(jit->second);
                  Controller::Storage["statistics"][thisbuffer]["log"].shrink(1000); //limit to 1000 users per buffer
                }
              }
            }
            if (Request.isMember("vod")){
              std::string thisfile = Request["vod"]["filename"];
              for (JSON::ObjIter oit = Controller::Storage["streams"].ObjBegin(); oit != Controller::Storage["streams"].ObjEnd(); ++oit){
                if (oit->second["channel"]["URL"].asString() == thisfile){
                  Controller::lastBuffer[oit->first] = Util::epoch();
                  if (Request["vod"].isMember("meta")){
                    Controller::Storage["streams"][oit->first]["meta"] = Request["vod"]["meta"];
                  }
                  JSON::Value sockit = (long long int)it->getSocket();
                  std::string nowstr = Request["vod"]["now"].asString();
                  Controller::Storage["statistics"][oit->first]["curr"][sockit.asString()] = Request["vod"];
                  Controller::Storage["statistics"][oit->first]["curr"][sockit.asString()].removeMember("meta");
                  JSON::Value nowtotal;
                  for (JSON::ObjIter u_it = Controller::Storage["statistics"][oit->first]["curr"].ObjBegin();
                      u_it != Controller::Storage["statistics"][oit->first]["curr"].ObjEnd(); ++u_it){
                    nowtotal["up"] = nowtotal["up"].asInt() + u_it->second["up"].asInt();
                    nowtotal["down"] = nowtotal["down"].asInt() + u_it->second["down"].asInt();
                    nowtotal["count"] = nowtotal["count"].asInt() + 1;
                  }
                  Controller::Storage["statistics"][oit->first]["totals"][nowstr] = nowtotal;
                  Controller::Storage["statistics"][oit->first]["totals"].shrink(600);
                }
              }
            }
          }
        }
      }
    }
    if (users.size() > 0){
      for (std::vector<Controller::ConnectedUser>::iterator it = users.begin(); it != users.end(); it++){
        if ( !it->C.connected() || it->logins > 3){
          it->C.close();
          users.erase(it);
          break;
        }
        if (it->C.spool() || it->C.Received().size()){
          if ( *(it->C.Received().get().rbegin()) != '\n'){
            std::string tmp = it->C.Received().get();
            it->C.Received().get().clear();
            if (it->C.Received().size()){
              it->C.Received().get().insert(0, tmp);
            }else{
              it->C.Received().append(tmp);
            }
            continue;
          }
          if (it->H.Read(it->C.Received().get())){
            Response.null(); //make sure no data leaks from previous requests
            if (it->clientMode){
              // In clientMode, requests are reversed. These are connections we initiated to GearBox.
              // They are assumed to be authorized, but authorization to gearbox is still done.
              // This authorization uses the compiled-in username and password (account).
              Request = JSON::fromString(it->H.body);
              if (Request["authorize"]["status"] != "OK"){
                if (Request["authorize"].isMember("challenge")){
                  it->logins++;
                  if (it->logins > 2){
                    Controller::Log("UPLK", "Max login attempts passed - dropping connection to uplink.");
                    it->C.close();
                  }else{
                    Response["config"] = Controller::Storage["config"];
                    Response["streams"] = Controller::Storage["streams"];
                    Response["log"] = Controller::Storage["log"];
                    Response["statistics"] = Controller::Storage["statistics"];
                    Response["authorize"]["username"] = COMPILED_USERNAME;
                    Controller::checkCapable(Response["capabilities"]);
                    Controller::Log("UPLK", "Responding to login challenge: " + Request["authorize"]["challenge"].asString());
                    Response["authorize"]["password"] = Secure::md5(COMPILED_PASSWORD + Request["authorize"]["challenge"].asString());
                    it->H.Clean();
                    it->H.SetBody("command=" + HTTP::Parser::urlencode(Response.toString()));
                    it->H.BuildRequest();
                    it->C.Send(it->H.BuildResponse("200", "OK"));
                    it->H.Clean();
                    Controller::Log("UPLK", "Attempting login to uplink.");
                  }
                }
              }else{
                if (Request.isMember("config")){
                  Controller::CheckConfig(Request["config"], Controller::Storage["config"]);
                  Controller::CheckProtocols(Controller::Storage["config"]["protocols"]);
                }
                if (Request.isMember("streams")){
                  Controller::CheckStreams(Request["streams"], Controller::Storage["streams"]);
                  Controller::CheckAllStreams(Controller::Storage["streams"]);
                }
                if (Request.isMember("clearstatlogs")){
                  Controller::Storage["log"].null();
                  Controller::Storage["statistics"].null();
                }
              }
            }else{
              Request = JSON::fromString(it->H.GetVar("command"));
              if ( !Request.isObject() && it->H.url != "/api"){
                it->H.Clean();
                it->H.SetHeader("Content-Type", "text/html");
                it->H.SetHeader("X-Info", "To force an API response, request the file /api");
                it->H.SetHeader("Server", "mistserver/" PACKAGE_VERSION "/" + Util::Config::libver + "/" RELEASE);
                it->H.SetBody(std::string((char*)server_html, (size_t)server_html_len));
                it->C.Send(it->H.BuildResponse("200", "OK"));
                it->H.Clean();
              }else{
                Authorize(Request, Response, ( *it));
                if (it->Authorized){
                  //Parse config and streams from the request.
                  if (Request.isMember("config")){
                    Controller::CheckConfig(Request["config"], Controller::Storage["config"]);
                    Controller::CheckProtocols(Controller::Storage["config"]["protocols"]);
                  }
                  if (Request.isMember("streams")){
                    Controller::CheckStreams(Request["streams"], Controller::Storage["streams"]);
                    Controller::CheckAllStreams(Controller::Storage["streams"]);
                  }
                  if (Request.isMember("capabilities")){
                    Controller::checkCapable(Response["capabilities"]);
                  }
                  if (Request.isMember("save")){
                    Controller::WriteFile("config.json", Controller::Storage.toString());
                    Controller::Log("CONF", "Config written to file on request through API");
                  }
                  //sent current configuration, no matter if it was changed or not
                  //Response["streams"] = Storage["streams"];
                  Response["config"] = Controller::Storage["config"];
                  Response["config"]["version"] = PACKAGE_VERSION "/" + Util::Config::libver + "/" RELEASE;
                  Response["streams"] = Controller::Storage["streams"];
                  //add required data to the current unix time to the config, for syncing reasons
                  Response["config"]["time"] = Util::epoch();
                  if ( !Response["config"].isMember("serverid")){
                    Response["config"]["serverid"] = "";
                  }
                  //sent any available logs and statistics
                  Response["log"] = Controller::Storage["log"];
                  Response["statistics"] = Controller::Storage["statistics"];
                  //clear log and statistics if requested
                  if (Request.isMember("clearstatlogs")){
                    Controller::Storage["log"].null();
                    Controller::Storage["statistics"].null();
                  }
                }
                jsonp = "";
                if (it->H.GetVar("callback") != ""){
                  jsonp = it->H.GetVar("callback");
                }
                if (it->H.GetVar("jsonp") != ""){
                  jsonp = it->H.GetVar("jsonp");
                }
                it->H.Clean();
                it->H.SetHeader("Content-Type", "text/javascript");
                if (jsonp == ""){
                  it->H.SetBody(Response.toString() + "\n\n");
                }else{
                  it->H.SetBody(jsonp + "(" + Response.toString() + ");\n\n");
                }
                it->C.Send(it->H.BuildResponse("200", "OK"));
                it->H.Clean();
              }
            }
          }
        }
      }
    }
  }
  API_Socket.close();
  Controller::Log("CONF", "Controller shutting down");
  Util::Procs::StopAll();
  Controller::WriteFile("config.json", Controller::Storage.toString());
  std::cout << "Killed all processes, wrote config to disk. Exiting." << std::endl;
  return 0;
}