VILLASnode/include/villas/api/request.hpp

/* API Request.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#include <jansson.h>
#include <regex>
#include <vector>

#include <villas/api/session.hpp>
#include <villas/buffer.hpp>
#include <villas/log.hpp>
#include <villas/plugin.hpp>
#include <villas/super_node.hpp>

#define RE_UUID                                                                \
  "[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{"   \
  "12}"

namespace villas {
namespace node {
namespace api {

// Forward declarations
class Session;
class Response;
class RequestFactory;

class Request {

  friend Session;
  friend RequestFactory;
  friend Response;

protected:
  Session *session;

  Logger logger;
  Buffer buffer;

public:
  std::vector<std::string> matches;
  Session::Method method;
  unsigned long contentLength;
  json_t *body;

  RequestFactory *factory;

  Request(Session *s)
      : session(s), method(Session::Method::UNKNOWN), contentLength(0),
        body(nullptr), factory(nullptr) {}

  virtual ~Request() {
    if (body)
      json_decref(body);
  }

  virtual void prepare() {}

  virtual Response *execute() = 0;

  virtual void decode();

  const std::string &getMatch(int idx) const { return matches[idx]; }

  std::string getQueryArg(const std::string &arg) {
    char buf[1024];
    const char *val;

    val = lws_get_urlarg_by_name(session->wsi, (arg + "=").c_str(), buf,
                                 sizeof(buf));

    return val ? std::string(val) : std::string();
  }

  std::string getHeader(enum lws_token_indexes hdr) {
    char buf[1024];

    lws_hdr_copy(session->wsi, buf, sizeof(buf), hdr);

    return std::string(buf);
  }

  virtual std::string toString();
};

class RequestFactory : public plugin::Plugin {

public:
  using plugin::Plugin::Plugin;

  virtual bool match(const std::string &uri, std::smatch &m) const = 0;

  virtual Request *make(Session *s) = 0;

  static Request *create(Session *s, const std::string &uri,
                         Session::Method meth, unsigned long ct);

  virtual void init(Request *r) { r->logger = getLogger(); }

  virtual std::string getType() const { return "api:request"; }

  virtual bool isHidden() const { return false; }
};

template <typename T, const char *name, const char *re, const char *desc>
class RequestPlugin : public RequestFactory {

protected:
  std::regex regex;

public:
  RequestPlugin() : RequestFactory(), regex(re) {}

  virtual Request *make(Session *s) {
    auto *r = new T(s);

    init(r);

    return r;
  }

  // Get plugin name
  virtual std::string getName() const { return name; }

  // Get plugin description
  virtual std::string getDescription() const { return desc; }

  virtual bool match(const std::string &uri, std::smatch &match) const {
    return std::regex_match(uri, match, regex);
  }
};

} // namespace api
} // namespace node
} // namespace villas