db-lab1/handlers.hpp

267 lines
8.7 KiB
C++

#ifndef _HANDLERS_HPP
#define _HANDLERS_HPP
#include <boost/json.hpp>
#include <string>
#include <memory>
#include <vector>
#include <optional>
#include "bserv/common.hpp"
// register an orm mapping (to convert the db query results into
// json objects).
// the db query results contain several rows, each has a number of
// fields. the order of `make_db_field<Type[i]>(name[i])` in the
// initializer list corresponds to these fields (`Type[0]` and
// `name[0]` correspond to field[0], `Type[1]` and `name[1]`
// correspond to field[1], ...). `Type[i]` is the type you want
// to convert the field value to, and `name[i]` is the identifier
// with which you want to store the field in the json object, so
// if the returned json object is `obj`, `obj[name[i]]` will have
// the type of `Type[i]` and store the value of field[i].
bserv::db_relation_to_object orm_user{
bserv::make_db_field<int>("id"),
bserv::make_db_field<std::string>("username"),
bserv::make_db_field<std::string>("password"),
bserv::make_db_field<bool>("is_superuser"),
bserv::make_db_field<std::string>("first_name"),
bserv::make_db_field<std::string>("last_name"),
bserv::make_db_field<std::string>("email"),
bserv::make_db_field<bool>("is_active")
};
std::optional<boost::json::object> get_user(
bserv::db_transaction& tx,
const std::string& username) {
bserv::db_result r = tx.exec(
"select * from auth_user where username = ?", username);
lginfo << r.query(); // this is how you log info
return orm_user.convert_to_optional(r);
}
std::string get_or_empty(
boost::json::object& obj,
const std::string& key) {
return obj.count(key) ? obj[key].as_string().c_str() : "";
}
// if you want to manually modify the response,
// the return type should be `std::nullopt_t`,
// and the return value should be `std::nullopt`.
std::nullopt_t hello(
bserv::response_type& response,
std::shared_ptr<bserv::session_type> session_ptr) {
bserv::session_type& session = *session_ptr;
boost::json::object obj;
if (session.count("user")) {
// NOTE: modifications to sessions must be performed
// BEFORE referencing objects in them. this is because
// modifications might invalidate referenced objects.
// in this example, "count" might be added to `session`,
// which should be performed first.
// then `user` can be referenced safely.
if (!session.count("count")) {
session["count"] = 0;
}
auto& user = session["user"].as_object();
session["count"] = session["count"].as_int64() + 1;
obj = {
{"welcome", user["username"]},
{"count", session["count"]}
};
} else {
obj = {{"msg", "hello, world!"}};
}
// the response body is a string,
// so the `obj` should be serialized
response.body() = boost::json::serialize(obj);
response.prepare_payload(); // this line is important!
return std::nullopt;
}
// if you return a json object, the serialization
// is performed automatically.
boost::json::object user_register(
bserv::request_type& request,
// the json object is obtained from the request body,
// as well as the url parameters
boost::json::object&& params,
std::shared_ptr<bserv::db_connection> conn) {
if (request.method() != boost::beast::http::verb::post) {
throw bserv::url_not_found_exception{};
}
if (params.count("username") == 0) {
return {
{"success", false},
{"message", "`username` is required"}
};
}
if (params.count("password") == 0) {
return {
{"success", false},
{"message", "`password` is required"}
};
}
auto username = params["username"].as_string();
bserv::db_transaction tx{conn};
auto opt_user = get_user(tx, username.c_str());
if (opt_user.has_value()) {
return {
{"success", false},
{"message", "`username` existed"}
};
}
auto password = params["password"].as_string();
bserv::db_result r = tx.exec(
"insert into ? "
"(?, password, is_superuser, "
"first_name, last_name, email, is_active) values "
"(?, ?, ?, ?, ?, ?, ?)", bserv::db_name("auth_user"),
bserv::db_name("username"),
username.c_str(),
bserv::utils::security::encode_password(
password.c_str()), false,
get_or_empty(params, "first_name"),
get_or_empty(params, "last_name"),
get_or_empty(params, "email"), true);
lginfo << r.query();
tx.commit(); // you must manually commit changes
return {
{"success", true},
{"message", "user registered"}
};
}
boost::json::object user_login(
bserv::request_type& request,
boost::json::object&& params,
std::shared_ptr<bserv::db_connection> conn,
std::shared_ptr<bserv::session_type> session_ptr) {
if (request.method() != boost::beast::http::verb::post) {
throw bserv::url_not_found_exception{};
}
if (params.count("username") == 0) {
return {
{"success", false},
{"message", "`username` is required"}
};
}
if (params.count("password") == 0) {
return {
{"success", false},
{"message", "`password` is required"}
};
}
auto username = params["username"].as_string();
bserv::db_transaction tx{conn};
auto opt_user = get_user(tx, username.c_str());
if (!opt_user.has_value()) {
return {
{"success", false},
{"message", "invalid username/password"}
};
}
auto& user = opt_user.value();
if (!user["is_active"].as_bool()) {
return {
{"success", false},
{"message", "invalid username/password"}
};
}
auto password = params["password"].as_string();
auto encoded_password = user["password"].as_string();
if (!bserv::utils::security::check_password(
password.c_str(), encoded_password.c_str())) {
return {
{"success", false},
{"message", "invalid username/password"}
};
}
bserv::session_type& session = *session_ptr;
session["user"] = user;
return {
{"success", true},
{"message", "login successfully"}
};
}
boost::json::object find_user(
std::shared_ptr<bserv::db_connection> conn,
const std::string& username) {
bserv::db_transaction tx{conn};
auto user = get_user(tx, username);
if (!user.has_value()) {
return {
{"success", false},
{"message", "requested user does not exist"}
};
}
user.value().erase("id");
user.value().erase("password");
return {
{"success", true},
{"user", user.value()}
};
}
boost::json::object user_logout(
std::shared_ptr<bserv::session_type> session_ptr) {
bserv::session_type& session = *session_ptr;
if (session.count("user")) {
session.erase("user");
}
return {
{"success", true},
{"message", "logout successfully"}
};
}
boost::json::object send_request(
std::shared_ptr<bserv::session_type> session,
std::shared_ptr<bserv::http_client> client_ptr,
boost::json::object&& params) {
// post for response:
// auto res = client_ptr->post(
// "localhost", "8080", "/echo", {{"msg", "request"}}
// );
// return {{"response", boost::json::parse(res.body())}};
// -------------------------------------------------------
// - if it takes longer than 30 seconds (by default) to
// - get the response, this will raise a read timeout
// -------------------------------------------------------
// post for json response (json value, rather than json
// object, is returned):
auto obj = client_ptr->post_for_value(
"localhost", "8080", "/echo", {{"request", params}}
);
if (session->count("cnt") == 0) {
(*session)["cnt"] = 0;
}
(*session)["cnt"] = (*session)["cnt"].as_int64() + 1;
return {{"response", obj}, {"cnt", (*session)["cnt"]}};
}
boost::json::object echo(
boost::json::object&& params) {
return {{"echo", params}};
}
// websocket
std::nullopt_t ws_echo(
std::shared_ptr<bserv::session_type> session,
std::shared_ptr<bserv::websocket_server> ws_server) {
ws_server->write_json((*session)["cnt"]);
while (true) {
try {
std::string data = ws_server->read();
ws_server->write(data);
} catch (bserv::websocket_closed&) {
break;
}
}
return std::nullopt;
}
#endif // _HANDLERS_HPP