Query instance for max_toot_chars.

include/instance.hpp

@@ -19,12 +19,14 @@
 
 #include "curl_wrapper.hpp"
 
+#include <cstdint>
 #include <string>
 #include <string_view>
 
 namespace mastodonpp
 {
 
+using std::uint64_t;
 using std::string;
 using std::string_view;
 
@@ -41,6 +43,8 @@ public:
     /*!
      *  @brief  Construct a new Instance object.
      *
+     *  Also queries `/api/v1/instance` for `max_toot_chars'.
+     *
      *  @param  hostname     The hostname of the instance.
      *  @param  access_token Your access token.
      *
@@ -83,10 +87,22 @@ public:
         return _access_token;
     }
 
+    /*!
+     *  @brief  Returns the maximum number of characters per post.
+     *
+     *  @since  0.1.0
+     */
+    [[nodiscard]]
+    inline uint64_t get_max_chars() const
+    {
+        return _max_chars;
+    }
+
 private:
     const string _hostname;
     const string _baseuri;
     string _access_token;
+    uint64_t _max_chars;
 };
 
 } // namespace mastodonpp

src/instance.cpp

@@ -15,6 +15,8 @@
  */
 
 #include "instance.hpp"
+#include "log.hpp"
+#include "return_types.hpp"
 
 #include <utility>
 
@@ -27,6 +29,35 @@ Instance::Instance(string hostname, string access_token)
     : _hostname{move(hostname)}
     , _baseuri{"https://" + _hostname}
     , _access_token{move(access_token)}
-{}
+    , _max_chars{500}
+{
+    try
+    {
+        const auto answer{make_request(http_method::GET,
+                                       _baseuri + "/api/v1/instance")};
+        if (answer)
+        {
+            debuglog << "Querying instance for max_toot_chars…\n";
+            auto &body{answer.body};
+            size_t pos_start{body.find("max_toot_chars")};
+            if (pos_start == string::npos)
+            {
+                debuglog << "max_toot_chars not found.";
+                return;
+            }
+            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)};
+            _max_chars = std::stoull(max_toot_chars);
+            debuglog << "Set _max_chars to: " << _max_chars << '\n';
+        }
+    }
+    catch (const std::exception &e)
+    {
+        debuglog << "Unexpected exception: " << e.what() << '\n';
+    }
+}
 
 } // namespace mastodonpp