Merge branch 'develop' into main

examples/example06_update_name.cpp

@@ -51,7 +51,7 @@ int main(int argc, char *argv[])
         const auto answer{connection.patch(
                 masto::API::v1::accounts_update_credentials,
                 {
-                    {"display_name", name},
+                    {"display_name", name}
                 })};
         if (answer)
         {

examples/example08_obtain_token.cpp

@@ -0,0 +1,111 @@
+/*  This file is part of mastodonpp.
+ *  Copyright © 2020 tastytea <tastytea@tastytea.de>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ *  SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ *  OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ *  CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+// Obtain an access token and verify that it works.
+
+#include "mastodonpp.hpp"
+
+#include <cstdlib>
+#include <iostream>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace masto = mastodonpp;
+using std::exit;
+using std::cout;
+using std::cerr;
+using std::endl;
+using std::cin;
+using std::string;
+using std::to_string;
+using std::string_view;
+using std::vector;
+
+void handle_error(const masto::answer_type &answer);
+
+int main(int argc, char *argv[])
+{
+    const vector<string_view> args(argv, argv + argc);
+    if (args.size() <= 1)
+    {
+        cerr << "Usage: " << args[0] << " <instance hostname>\n";
+        return 1;
+    }
+
+    try
+    {
+        // Initialize Instance and Instance::ObtainToken.
+        masto::Instance instance{args[1], {}};
+        masto::Instance::ObtainToken token{instance};
+
+        // Create an “Application” (/api/v1/apps),
+        // and get URI for the authorization code (/oauth/authorize).
+        auto answer{token.step_1("Testclient", "read:blocks read:mutes",
+                                 "https://tastytea.de/")};
+        if (!answer)
+        {
+            handle_error(answer);
+        }
+
+        cout << "Please visit " << answer << "\nand paste the code here: ";
+        string code;
+        cin >> code;
+
+        // Obtain the token (/oauth/token).
+        answer = token.step_2(code);
+        if (!answer)
+        {
+            handle_error(answer);
+        }
+
+        cout << "Your access token is: " << answer << endl;
+
+        // Test if the token works.
+        masto::Connection connection{instance};
+        answer = connection.get(masto::API::v1::apps_verify_credentials);
+        if (!answer)
+        {
+            handle_error(answer);
+        }
+
+        cout << answer << endl;
+    }
+    catch (const masto::CURLException &e)
+    {
+        // Only libcurl errors that are not network errors will be thrown.
+        // There went probably something wrong with the initialization.
+        cerr << e.what() << endl;
+    }
+
+    return 0;
+}
+
+void handle_error(const masto::answer_type &answer)
+{
+    if (answer.curl_error_code == 0)
+    {
+        // If it is no libcurl error, it must be an HTTP error.
+        cerr << "HTTP status: " << answer.http_status << endl;
+    }
+    else
+    {
+        // Network errors like “Couldn't resolve host.”.
+        cerr << "libcurl error " << to_string(answer.curl_error_code)
+             << ": " << answer.error_message << endl;
+    }
+
+    exit(1);
+}

include/answer.hpp

@@ -18,6 +18,7 @@
 #define MASTODONPP_ANSWER_HPP
 
 #include <cstdint>
+#include <ostream>
 #include <string>
 #include <string_view>
 
@@ -26,6 +27,7 @@ namespace mastodonpp
 
 using std::uint8_t;
 using std::uint16_t;
+using std::ostream;
 using std::string;
 using std::string_view;
 
@@ -97,8 +99,7 @@ struct answer_type
      *
      *  @since  0.1.0
      */
-    friend std::ostream &operator <<(std::ostream &out,
+    friend ostream &operator <<(ostream &out, const answer_type &answer);
-                                     const answer_type &answer);
 
     /*!
      *  @brief  Returns the value of a header field.

include/connection.hpp

@@ -82,7 +82,12 @@ public:
      *
      *  @since  0.1.0
      */
-    explicit Connection(Instance &instance);
+    explicit Connection(Instance &instance)
+        : _instance{instance}
+        , _baseuri{instance.get_baseuri()}
+    {
+        _instance.copy_connection_properties(*this);
+    }
 
     /*!
      *  @brief  Make a HTTP GET call with parameters.

include/curl_wrapper.hpp

@@ -145,18 +145,6 @@ public:
         return _connection;
     }
 
-    /*!
-     *  @brief  Set the proxy to use.
-     *
-     *  See [CURLOPT_PROXY(3)]
-     *  (https://curl.haxx.se/libcurl/c/CURLOPT_PROXY.html).
-     *
-     *  @param  proxy Examples: "socks4a://127.0.0.1:9050", "http://[::1]:3128".
-     *
-     *  @since  0.1.0
-     */
-    void set_proxy(string_view proxy);
-
     /*!
      *  @brief  URL encodes the given string.
      *
@@ -169,6 +157,7 @@ public:
      *
      *  @since  0.3.0
      */
+    [[nodiscard]]
     inline string escape_url(const string_view url) const
     {
         char *cbuf{curl_easy_escape(_connection, url.data(),
@@ -190,6 +179,7 @@ public:
      *
      *  @since  0.3.0
      */
+    [[nodiscard]]
     inline string unescape_url(const string_view url) const
     {
         char *cbuf{curl_easy_unescape(_connection, url.data(),
@@ -199,6 +189,18 @@ public:
         return sbuf;
     }
 
+    /*!
+     *  @brief  Set some properties of the connection.
+     *
+     *  Meant for internal use. See Instance::copy_connection_properties().
+     *
+     *  @since  0.3.0
+     */
+    void setup_connection_properties(string_view proxy,
+                                     string_view access_token,
+                                     string_view cainfo,
+                                     string_view useragent);
+
 protected:
     /*!
      *  @brief  Mutex for #get_buffer a.k.a. _curl_buffer_body.
@@ -248,6 +250,18 @@ protected:
         _stream_cancelled = true;
     }
 
+    /*!
+     *  @brief  Set the proxy to use.
+     *
+     *  See [CURLOPT_PROXY(3)]
+     *  (https://curl.haxx.se/libcurl/c/CURLOPT_PROXY.html).
+     *
+     *  @param  proxy Examples: "socks4a://127.0.0.1:9050", "http://[::1]:3128".
+     *
+     *  @since  0.1.0
+     */
+    void set_proxy(string_view proxy);
+
     /*!
      *  @brief  Set OAuth 2.0 Bearer Access Token.
      *
@@ -259,10 +273,12 @@ protected:
     /*!
      *  @brief  Set path to Certificate Authority (CA) bundle.
      *
-     *  @since  0.2.1
+     *  @since  0.3.0
      */
     void set_cainfo(string_view path);
 
+    void set_useragent(string_view useragent);
+
 private:
     CURL *_connection;
     char _curl_buffer_error[CURL_ERROR_SIZE];
@@ -356,7 +372,7 @@ private:
      *  @param  data Data of the field. If it begins with <tt>`\@file:<tt>, the
      *               rest of the ergument is treated as a filename.
      *
-     *  @since  0.1.1
+     *  @since  0.2.0
      */
     void add_mime_part(curl_mime *mime,
                        string_view name, string_view data) const;

include/instance.hpp

@@ -53,7 +53,29 @@ public:
      *
      *  @since  0.1.0
      */
-    explicit Instance(string_view hostname, string_view access_token);
+    explicit Instance(const string_view hostname,
+                      const string_view access_token)
+        : _hostname{hostname}
+        , _baseuri{"https://" + _hostname}
+        , _access_token{access_token}
+        , _max_chars{0}
+    {}
+
+    /*!
+     *  @brief  Set the properties of the connection of the calling class up.
+     *
+     *  Meant for internal use. This aligns the properties of the connection of
+     *  the calling class with the properties of connection of this class.
+     *
+     *  @param  curlwrapper The CURLWrapper parent of the calling class.
+     *
+     *  @since  0.3.0
+     */
+    inline void copy_connection_properties(CURLWrapper &curlwrapper)
+    {
+        curlwrapper.setup_connection_properties(_proxy, _access_token, _cainfo,
+                                                _useragent);
+    }
 
     /*!
      *  @brief  Returns the hostname.
@@ -61,7 +83,7 @@ public:
      *  @since  0.1.0
      */
     [[nodiscard]]
-    inline string_view get_hostname() const
+    inline string_view get_hostname() const noexcept
     {
         return _hostname;
     }
@@ -74,7 +96,7 @@ public:
      *  @since  0.1.0
      */
     [[nodiscard]]
-    inline string_view get_baseuri() const
+    inline string_view get_baseuri() const noexcept
     {
         return _baseuri;
     }
@@ -85,7 +107,7 @@ public:
      *  @since  0.1.0
      */
     [[nodiscard]]
-    inline string_view get_access_token() const
+    inline string_view get_access_token() const noexcept
     {
         return _access_token;
     }
@@ -115,7 +137,7 @@ public:
      *  @since  0.1.0
      */
     [[nodiscard]]
-    uint64_t get_max_chars();
+    uint64_t get_max_chars() noexcept;
 
     /*! @copydoc CURLWrapper::set_proxy(string_view)
      *
@@ -128,19 +150,6 @@ public:
         CURLWrapper::set_proxy(proxy);
     }
 
-    /*!
-     *  @brief  Returns the proxy string that was previously set.
-     *
-     *  Does not return the proxy if it was set from an environment variable.
-     *
-     *  @since  0.1.0
-     */
-    [[nodiscard]]
-    string_view get_proxy() const
-    {
-        return _proxy;
-    }
-
     /*!
      *  @brief  Returns the NodeInfo of the instance.
      *
@@ -164,7 +173,7 @@ public:
      *
      *  @since  0.3.0
      */
-    vector<string> get_post_formats();
+    vector<string> get_post_formats() noexcept;
 
     /*!
      *  @brief  Set path to Certificate Authority (CA) bundle.
@@ -172,7 +181,7 @@ public:
      *  Sets also the CA info for all Connection%s that are initialized with
      *  this Instance afterwards.
      *
-     *  @since  0.2.1
+     *  @since  0.3.0
      */
     void set_cainfo(string_view path)
     {
@@ -180,18 +189,95 @@ public:
         CURLWrapper::set_cainfo(path);
     }
 
-    /*!
+    void set_useragent(const string_view useragent)
-     *  @brief  Returns the cainfo path that was previously set.
-     *
-     *  This is used when initializing a Connection.
-     *
-     *  @since  0.2.1
-     */
-    string_view get_cainfo()
     {
-        return _cainfo;
+        _useragent = useragent;
+        CURLWrapper::set_useragent(useragent);
     }
 
+    /*!
+     *  @brief  Simplifies obtaining an OAuth 2.0 Bearer Access Token.
+     *
+     *  * Create an Instance() and initialize this class with it.
+     *  * Call step_1() to get the URI your user has to visit.
+     *  * Get the authorization code from your user.
+     *  * Call step_2() with the code.
+     *
+     *  Example:
+     *  @code
+     *  mastodonpp::Instance instance("example.com", {});
+     *  mastodonpp::Instance::ObtainToken token(instance);
+     *  auto answer{token.step1("Good program", "read:blocks read:mutes", "")};
+     *  if (answer)
+     *  {
+     *      std::cout << "Please visit " << answer << "\nand paste the code: ";
+     *      std::string code;
+     *      std::cin >> code;
+     *      answer = access_token{token.step2(code)};
+     *      if (answer)
+     *      {
+     *          std::cout << "Success!\n";
+     *      }
+     *  }
+     *  @endcode
+     *
+     *  @since  0.3.0
+     */
+    class ObtainToken : public CURLWrapper
+    {
+    public:
+        ObtainToken(Instance &instance)
+            : _instance{instance}
+            , _baseuri{instance.get_baseuri()}
+        {
+            _instance.copy_connection_properties(*this);
+        }
+
+        /*!
+         *  @brief  Creates an application via `/api/v1/apps`.
+         *
+         *  The `body` of the returned @link answer_type answer @endlink
+         *  contains only the URI, not the whole JSON response.
+         *
+         *  @param  client_name The name of your application.
+         *  @param  scopes      Space separated list of scopes. Defaults to
+         *                      “read” if empty.
+         *  @param  website     The URI to the homepage of your application. Can
+         *                      be an empty string.
+         *
+         *  @return The URI your user has to visit.
+         *
+         *  @since  0.3.0
+         */
+        [[nodiscard]]
+        answer_type step_1(string_view client_name, string_view scopes,
+                           string_view website);
+
+        /*!
+         *  @brief  Creates a token via `/oauth/token`.
+         *
+         *  The `body` of the returned @link answer_type answer @endlink
+         *  contains only the access token, not the whole JSON response.
+         *
+         *  The access token will be set in the parent Instance.
+         *
+         *  @param  code The authorization code you got from the user.
+         *
+         *  @return The access token.
+         *
+         *  @since  0.3.0
+         */
+        [[nodiscard]]
+        answer_type step_2(string_view code);
+
+    private:
+        Instance &_instance;
+        const string _baseuri;
+        string _scopes;
+        string _client_id;
+        string _client_secret;
+    };
+
 private:
     const string _hostname;
     const string _baseuri;
@@ -200,6 +286,7 @@ private:
     string _proxy;
     vector<string> _post_formats;
     string _cainfo;
+    string _useragent;
 };
 
 } // namespace mastodonpp

include/mastodonpp.hpp

@@ -105,6 +105,7 @@
  *  @example example05_update_notification_settings.cpp
  *  @example example06_update_name.cpp
  *  @example example07_delete_status.cpp
+ *  @example example08_obtain_token.cpp
  */
 
 /*!

src/api.cpp

@@ -28,7 +28,7 @@ API::API(const endpoint_type &endpoint)
 const map<API::endpoint_type,string_view> API::_endpoint_map
 {
     {v1::apps, "/api/v1/apps"},
-    {v1::apps_verify_credentials, "/api/v1/apps/verify/credentials"},
+    {v1::apps_verify_credentials, "/api/v1/apps/verify_credentials"},
 
     {v1::accounts, "/api/v1/accounts"},
     {v1::accounts_verify_credentials, "/api/v1/accounts/verify_credentials"},

src/connection.cpp

@@ -21,26 +21,6 @@ namespace mastodonpp
 
 using std::holds_alternative;
 
-Connection::Connection(Instance &instance)
-    : _instance{instance}
-    , _baseuri{instance.get_baseuri()}
-{
-    auto proxy{_instance.get_proxy()};
-    if (!proxy.empty())
-    {
-        CURLWrapper::set_proxy(proxy);
-    }
-
-    if (!_instance.get_access_token().empty())
-    {
-        CURLWrapper::set_access_token(_instance.get_access_token());
-    }
-    if (!_instance.get_cainfo().empty())
-    {
-        CURLWrapper::set_cainfo(_instance.get_cainfo());
-    }
-}
-
 string Connection::endpoint_to_uri(const endpoint_variant &endpoint) const
 {
     if (holds_alternative<API::endpoint_type>(endpoint))

src/curl_wrapper.cpp

@@ -64,16 +64,6 @@ CURLWrapper::~CURLWrapper() noexcept
     }
 }
 
-void CURLWrapper::set_proxy(const string_view proxy)
-{
-    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
-    CURLcode code{curl_easy_setopt(_connection, CURLOPT_PROXY, proxy.data())};
-    if (code != CURLE_OK)
-    {
-        throw CURLException{code, "Failed to set proxy", _curl_buffer_error};
-    }
-}
-
 answer_type CURLWrapper::make_request(const http_method &method, string uri,
                                       const parametermap &parameters)
 {
@@ -197,6 +187,42 @@ answer_type CURLWrapper::make_request(const http_method &method, string uri,
     return answer;
 }
 
+void CURLWrapper::setup_connection_properties(const string_view proxy,
+                                              const string_view access_token,
+                                              const string_view cainfo,
+                                              const string_view useragent)
+{
+    if (!proxy.empty())
+    {
+        set_proxy(proxy);
+    }
+
+    if (!access_token.empty())
+    {
+        set_access_token(access_token);
+    }
+
+    if (!cainfo.empty())
+    {
+        set_cainfo(cainfo);
+    }
+
+    if (!useragent.empty())
+    {
+        set_useragent(useragent);
+    }
+}
+
+void CURLWrapper::set_proxy(const string_view proxy)
+{
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    CURLcode code{curl_easy_setopt(_connection, CURLOPT_PROXY, proxy.data())};
+    if (code != CURLE_OK)
+    {
+        throw CURLException{code, "Failed to set proxy", _curl_buffer_error};
+    }
+}
+
 void CURLWrapper::set_access_token(const string_view access_token)
 {
     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg, hicpp-signed-bitwise)
@@ -223,7 +249,7 @@ void CURLWrapper::set_access_token(const string_view access_token)
     debuglog << "Set authorization token.\n";
 }
 
-void CURLWrapper::set_cainfo(string_view path)
+void CURLWrapper::set_cainfo(const string_view path)
 {
     CURLcode code{curl_easy_setopt(_connection, CURLOPT_CAINFO, path.data())};
     if (code != CURLE_OK)
@@ -232,6 +258,19 @@ void CURLWrapper::set_cainfo(string_view path)
     }
 }
 
+void CURLWrapper::set_useragent(const string_view useragent)
+{
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    CURLcode code{curl_easy_setopt(_connection, CURLOPT_USERAGENT,
+                                   useragent.data())};
+    if (code != CURLE_OK)
+    {
+        throw CURLException{code, "Failed to set User-Agent",
+                _curl_buffer_error};
+    }
+    debuglog << "Set User-Agent to: " << useragent << '\n';
+}
+
 size_t CURLWrapper::writer_body(char *data, size_t size, size_t nmemb)
 {
     if(data == nullptr)
@@ -296,18 +335,11 @@ void CURLWrapper::setup_curl()
     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     curl_easy_setopt(_connection, CURLOPT_NOPROGRESS, 0L);
 
-    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    set_useragent((string("mastodonpp/") += version));
-    CURLcode code{curl_easy_setopt(_connection, CURLOPT_USERAGENT,
-                                   (string("mastodonpp/") += version).c_str())};
-    if (code != CURLE_OK)
-    {
-        throw CURLException{code, "Failed to set User-Agent",
-                _curl_buffer_error};
-    }
 
     // The next 2 only fail if HTTP is not supported.
     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
-    code = curl_easy_setopt(_connection, CURLOPT_FOLLOWLOCATION, 1L);
+    CURLcode code{curl_easy_setopt(_connection, CURLOPT_FOLLOWLOCATION, 1L)};
     if (code != CURLE_OK)
     {
         throw CURLException{code, "HTTP is not supported.", _curl_buffer_error};

src/instance.cpp

@@ -20,6 +20,7 @@
 
 #include <algorithm>
 #include <exception>
+#include <regex>
 
 namespace mastodonpp
 {
@@ -27,54 +28,52 @@ namespace mastodonpp
 using std::sort;
 using std::stoull;
 using std::exception;
+using std::regex;
+using std::regex_search;
+using std::smatch;
 
-Instance::Instance(const string_view hostname, const string_view access_token)
+uint64_t Instance::get_max_chars() noexcept
-    : _hostname{hostname}
-    , _baseuri{"https://" + _hostname}
-    , _access_token{access_token}
-    , _max_chars{0}
-{}
-
-uint64_t Instance::get_max_chars()
 {
     constexpr uint64_t default_max_chars{500};
 
-    if (_max_chars == 0)
+    if (_max_chars != 0)
     {
-        try
+        return _max_chars;
-        {
+    }
-            debuglog << "Querying " << _hostname << " for max_toot_chars…\n";
-            const auto answer{make_request(http_method::GET,
-                                           _baseuri + "/api/v1/instance", {})};
-            if (!answer)
-            {
-                debuglog << "Could not get instance info.\n";
-                return default_max_chars;
-            }
 
-            _max_chars = [&answer]
+    try
-            {
+    {
-                auto &body{answer.body};
+        debuglog << "Querying " << _hostname << " for max_toot_chars…\n";
-                size_t pos_start{body.find("max_toot_chars")};
+        const auto answer{make_request(http_method::GET,
-                if (pos_start == string::npos)
+                                       _baseuri + "/api/v1/instance", {})};
-                {
+        if (!answer)
-                    debuglog << "max_toot_chars not found.\n";
-                    return default_max_chars;
-                }
-                pos_start = body.find(':', pos_start) + 1;
-                const size_t pos_end{body.find(',', pos_start)};
-
-                const auto max_toot_chars{body.substr(pos_start,
-                                                      pos_end - pos_start)};
-                return static_cast<uint64_t>(stoull(max_toot_chars));
-            }();
-            debuglog << "Set _max_chars to: " << _max_chars << '\n';
-        }
-        catch (const exception &e)
         {
-            debuglog << "Unexpected exception: " << e.what() << '\n';
+            debuglog << "Could not get instance info.\n";
             return default_max_chars;
         }
+
+        _max_chars = [&answer]
+        {
+            auto &body{answer.body};
+            size_t pos_start{body.find("max_toot_chars")};
+            if (pos_start == string::npos)
+            {
+                debuglog << "max_toot_chars not found.\n";
+                return default_max_chars;
+            }
+            pos_start = body.find(':', pos_start) + 1;
+            const size_t pos_end{body.find(',', pos_start)};
+
+            const auto max_toot_chars{body.substr(pos_start,
+                                                  pos_end - pos_start)};
+            return static_cast<uint64_t>(stoull(max_toot_chars));
+        }();
+        debuglog << "Set _max_chars to: " << _max_chars << '\n';
+    }
+    catch (const exception &e)
+    {
+        debuglog << "Unexpected exception: " << e.what() << '\n';
+        return default_max_chars;
     }
 
     return _max_chars;
@@ -107,7 +106,7 @@ answer_type Instance::get_nodeinfo()
     return make_request(http_method::GET, hrefs.back(), {});
 }
 
-vector<string> Instance::get_post_formats()
+vector<string> Instance::get_post_formats() noexcept
 {
     constexpr auto default_value{"text/plain"};
 
@@ -116,36 +115,128 @@ vector<string> Instance::get_post_formats()
         return _post_formats;
     }
 
-    debuglog << "Querying " << _hostname << " for postFormats…\n";
+    try
-    const auto answer{get_nodeinfo()};
-    if (!answer)
     {
-        debuglog << "Couldn't get NodeInfo.\n";
+        debuglog << "Querying " << _hostname << " for postFormats…\n";
-        _post_formats = {default_value};
+        const auto answer{get_nodeinfo()};
-        return _post_formats;
+        if (!answer)
-    }
+        {
+            debuglog << "Couldn't get NodeInfo.\n";
+            _post_formats = {default_value};
+            return _post_formats;
+        }
 
-    constexpr string_view searchstring{R"("postFormats":[)"};
+        constexpr string_view searchstring{R"("postFormats":[)"};
-    auto pos{answer.body.find(searchstring)};
+        auto pos{answer.body.find(searchstring)};
-    if (pos == string::npos)
+        if (pos == string::npos)
-    {
+        {
-        debuglog << "Couldn't find metadata.postFormats.\n";
+            debuglog << "Couldn't find metadata.postFormats.\n";
-        _post_formats = {default_value};
+            _post_formats = {default_value};
-        return _post_formats;
+            return _post_formats;
-    }
+        }
-    pos += searchstring.size();
+        pos += searchstring.size();
-    auto endpos{answer.body.find("],", pos)};
+        auto endpos{answer.body.find("],", pos)};
-    string formats{answer.body.substr(pos, endpos - pos)};
+        string formats{answer.body.substr(pos, endpos - pos)};
-    debuglog << "Extracted postFormats: " << formats << '\n';
+        debuglog << "Extracted postFormats: " << formats << '\n';
 
-    while ((pos = formats.find('"', 1)) != string::npos)
+        while ((pos = formats.find('"', 1)) != string::npos)
+        {
+            _post_formats.push_back(formats.substr(1, pos - 1));
+            formats.erase(0, pos + 2); // 2 is the length of: ",
+            debuglog << "Found postFormat: " << _post_formats.back() << '\n';
+        }
+    }
+    catch (const std::exception &e)
     {
-        _post_formats.push_back(formats.substr(1, pos - 1));
+        debuglog << "Unexpected exception: " << e.what() << '\n';
-        formats.erase(0, pos + 2); // 2 is the length of: ",
+        return {default_value};
-        debuglog << "Found postFormat: " << _post_formats.back() << '\n';
     }
 
     return _post_formats;
 }
 
+answer_type Instance::ObtainToken::step_1(const string_view client_name,
+                                          const string_view scopes,
+                                          const string_view website)
+{
+    parametermap parameters
+        {
+            {"client_name", client_name},
+            {"redirect_uris", "urn:ietf:wg:oauth:2.0:oob"}
+        };
+    if (!scopes.empty())
+    {
+        _scopes = scopes;
+        parameters.insert({"scopes", scopes});
+    }
+    if (!website.empty())
+    {
+        parameters.insert({"website", website});
+    }
+
+    auto answer{make_request(http_method::POST, _baseuri + "/api/v1/apps",
+                             parameters)};
+    if (answer)
+    {
+        const regex re_id{R"("client_id"\s*:\s*"([^"]+)\")"};
+        const regex re_secret{R"("client_secret"\s*:\s*"([^"]+)\")"};
+        smatch match;
+
+        if (regex_search(answer.body, match, re_id))
+        {
+            _client_id = match[1].str();
+        }
+        if (regex_search(answer.body, match, re_secret))
+        {
+            _client_secret = match[1].str();
+        }
+
+        string uri{_baseuri + "/oauth/authorize?scope=" + escape_url(scopes)
+            + "&response_type=code"
+            "&redirect_uri=" + escape_url("urn:ietf:wg:oauth:2.0:oob")
+            + "&client_id=" + _client_id};
+        if (!website.empty())
+        {
+            uri += "&website=" + escape_url(website);
+        }
+        answer.body = uri;
+        debuglog << "Built URI.";
+    }
+
+    return answer;
+}
+
+answer_type Instance::ObtainToken::step_2(const string_view code)
+{
+    parametermap parameters
+        {
+            {"client_id", _client_id},
+            {"client_secret", _client_secret},
+            {"redirect_uri", "urn:ietf:wg:oauth:2.0:oob"},
+            {"code", code},
+            {"grant_type", "client_credentials"}
+        };
+    if (!_scopes.empty())
+    {
+        parameters.insert({"scope", _scopes});
+    }
+
+    auto answer{make_request(http_method::POST, _baseuri + "/oauth/token",
+                             parameters)};
+    if (answer)
+    {
+        const regex re_token{R"("access_token"\s*:\s*"([^"]+)\")"};
+        smatch match;
+
+        if (regex_search(answer.body, match, re_token))
+        {
+            answer.body = match[1].str();
+            debuglog << "Got access token.\n";
+            _instance.set_access_token(answer.body);
+        }
+    }
+
+    return answer;
+}
+
 } // namespace mastodonpp