log_collector.h

/*******************************************************************************
The MIT License (MIT)

Copyright (c) 2015 Dmitry "Dima" Korolev <dmitry.korolev@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
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The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

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*******************************************************************************/

#ifndef LOG_COLLECTOR_H
#define LOG_COLLECTOR_H

#include <string>
#include <map>
#include <ostream>

#include "../../Current/Bricks/net/api/api.h"
#include "../../Current/Bricks/time/chrono.h"
#include "../../Current/Bricks/cerealize/cerealize.h"

// An entry to log. Keeps everything that is easy to dig out. :-)
struct LogEntry {
  uint64_t t;                            // Unix epoch time in milliseconds.
  std::string m;                         // HTTP method.
  std::string u;                         // URL without fragments and query parameters.
  std::map<std::string, std::string> q;  // URL query parameters.
  std::string b;                         // HTTP body.
  std::string f;                         // URL fragment.

  // TODO(dkorolev): Add HTTP headers support to Bricks `net/api/types.h` HTTP client.
  // std::map<std::string, std::string> h;  // Extra HTTP headers.

  // TODO(dkorolev): Inbound IP address.
  // TODO(dkorolev): Everything else we can/should think of.
  // TODO(dkorolev): Resolve geolocation from IP?

  template <typename A>
  void serialize(A& ar) {
    ar(CEREAL_NVP(t), CEREAL_NVP(m), CEREAL_NVP(u), CEREAL_NVP(q), CEREAL_NVP(b), CEREAL_NVP(f));
  }
};

class LogCollectorHTTPServer {
 public:
  LogCollectorHTTPServer(int http_port,
                         std::ostream& ostream,
                         const std::string& route = "/log",
                         const std::string& response_text = "OK\n")
      : http_port_(http_port), ostream_(ostream), route_(route), response_text_(response_text) {
    HTTP(http_port_).Register(route_, [this](Request r) {
      LogEntry entry;
      entry.t = static_cast<uint64_t>(bricks::time::Now());
      entry.m = r.method;
      entry.u = r.url.url_without_parameters;
      entry.q = r.url.AllQueryParameters();
      entry.b = r.body;
      entry.f = r.url.fragment;
      // TODO(dkorolev): HTTP headers come here.
      // entry.h = { ... }
      ostream_ << JSON(entry, "log_entry") << std::endl;
      r(response_text_);
    });
  }

  ~LogCollectorHTTPServer() { HTTP(http_port_).UnRegister(route_); }

  void Join() { HTTP(http_port_).Join(); }

 private:
  const int http_port_;
  std::ostream& ostream_;
  const std::string route_;
  const std::string response_text_;
};

#endif  // LOG_COLLECTOR_H