feat: Adds support for Reader to_folder method

include/c2pa.h

@@ -318,6 +318,19 @@ int c2pa_reader_resource_to_stream(struct C2paReader *reader_ptr,
                                    const char *uri,
                                    struct CStream *stream);
 
+/**
+ * Writes all the resources in a Reader to a folder.
+ *
+ * # Parameters
+ * * reader_ptr: pointer to a Reader.
+ * * folder_path: pointer to a C string with the path to the folder.
+ *
+ * # Errors
+ * Returns -1 if there were errors, otherwise returns 0.
+ * The error string can be retrieved by calling c2pa_error.
+ */
+IMPORT extern int c2pa_reader_to_folder(struct C2paReader *reader_ptr, const char *folder_path);
+
 /**
  * Creates a C2paBuilder from a JSON manifest definition string.
  *
@@ -662,7 +675,7 @@ struct CStream *c2pa_create_stream(struct StreamContext *context,
 IMPORT extern void c2pa_release_stream(struct CStream *stream);
 
 #ifdef __cplusplus
-} // extern "C"
-#endif // __cplusplus
+}  // extern "C"
+#endif  // __cplusplus
 
-#endif /* c2pa_bindings_h */
+#endif  /* c2pa_bindings_h */

include/c2pa.hpp

@@ -152,6 +152,13 @@ namespace c2pa
         /// @return The number of bytes written.
         /// @throws C2pa::Exception for errors encountered by the C2PA library.
         int get_resource(const string &uri, std::ostream &stream);
+
+        /// @brief Write the manifest json and all resources to a folder.
+        /// @details There is no stream version of this function.
+        /// @param path The path to write the folder to.
+        ///
+        /// @throws C2pa::Exception for errors encountered by the C2PA library.
+        void to_folder(const std::filesystem::path &path);
     };
 
     /// @brief  Signer Callback function type.

src/c2pa.cpp

@@ -527,6 +527,15 @@ namespace c2pa
         return result;
     }
 
+    void Reader::to_folder(const std::filesystem::path &path)
+    {
+        int result = c2pa_reader_to_folder(c2pa_reader, path.c_str());
+        if (result < 0)
+        {
+            throw Exception();
+        }
+    }
+
     intptr_t signer_passthrough(const void *context, const unsigned char *data, uintptr_t len, unsigned char *signature, uintptr_t sig_max_len)
     {
         try

src/c_api.rs

@@ -465,6 +465,33 @@ pub unsafe extern "C" fn c2pa_reader_resource_to_stream(
     }
 }
 
+/// Writes all the resources in a Reader to a folder.
+///
+/// # Parameters
+/// * reader_ptr: pointer to a Reader.
+/// * folder_path: pointer to a C string with the path to the folder.
+///
+/// # Errors
+/// Returns -1 if there were errors, otherwise returns 0.
+/// The error string can be retrieved by calling c2pa_error.
+#[no_mangle]
+pub unsafe extern "C" fn c2pa_reader_to_folder(
+    reader_ptr: *mut C2paReader,
+    folder_path: *const c_char,
+) -> c_int {
+    let c2pa_reader: Box<C2paReader> = Box::from_raw(reader_ptr);
+    let folder_path = from_cstr_null_check_int!(folder_path);
+    let result = c2pa_reader.to_folder(folder_path);
+    let _ = Box::into_raw(c2pa_reader);
+    match result {
+        Ok(_) => 0,
+        Err(err) => {
+            Error::from_c2pa_error(err).set_last();
+            -1
+        }
+    }
+}
+
 /// Creates a C2paBuilder from a JSON manifest definition string.
 ///
 /// # Errors

tests/builder.test.cpp

@@ -104,7 +104,7 @@ TEST(Builder, SignStream)
         dest.seekp(0, std::ios::beg);
         auto reader = c2pa::Reader("image/jpeg", dest);
         auto json = reader.json();
-        ASSERT_TRUE(json.find("c2pa.training-mining") != std::string::npos);
+        ASSERT_TRUE(json.find("cawg.training-mining") != std::string::npos);
     }
     catch (c2pa::Exception const &e)
     {

tests/reader.test.cpp

@@ -10,9 +10,14 @@
 // specific language governing permissions and limitations under
 // each license.
 
-#include <c2pa.hpp>
+
 #include <gtest/gtest.h>
+#include <filesystem>
+#include <fstream>
 #include <nlohmann/json.hpp>
+#include <c2pa.hpp>
+
+namespace fs = std::filesystem;
 
 using nlohmann::json;
 
@@ -33,6 +38,24 @@ TEST(Reader, FileWithManifest)
     EXPECT_TRUE(manifest_store_json.find("C.jpg") != std::string::npos);
 };
 
+TEST(Reader, ToFolder)
+{
+    // Define the target directory
+    fs::path target_dir = "../../target/dest";
+
+    // Delete the target directory if it exists
+    if (fs::exists(target_dir)) {
+        fs::remove_all(target_dir);
+    }
+
+    auto reader = c2pa::Reader("../../tests/fixtures/C.jpg");
+
+    reader.to_folder(target_dir);
+
+        // Expect the manifest.json file to exist in the target directory
+    EXPECT_TRUE(fs::exists(target_dir / "manifest.json"));
+};
+
 TEST(Reader, FileNoManifest)
 {
     EXPECT_THROW({ auto reader = c2pa::Reader("../../tests/fixtures/A.jpg"); }, c2pa::Exception);