WARNING: REDESIGN: REMOVED: utils module, functionality moved to rcore module: logging and file-system #4551

[utils] was created long time ago, when [rcore] contained all the platforms code, the purpose of the file was exposing basic filesystem functionality across modules and also logging mechanism but many things have changed since then and there is no need to keep using this module.

 - Logging system has been move to [rcore] module and macros are exposed through `config.h` to other modules
 - File system functionality has also been centralized in [rcore] module that along the years it was already adding more and more file-system functions, now they are all in the same module
 - Android specific code has been moved to `rcore_android.c`, it had no sense to have specific platform code in `utils`, [rcore] is responsible of all platform code.

src/platforms/rcore_android.c

@@ -13,9 +13,6 @@
 *       - Improvement 01
 *       - Improvement 02
 *
-*   ADDITIONAL NOTES:
-*       - TRACELOG() function is located in raylib [utils] module
-*
 *   CONFIGURATION:
 *       #define RCORE_PLATFORM_CUSTOM_FLAG
 *           Custom flag for rcore on target platform -not used-
@@ -48,7 +45,11 @@
 
 #include <android_native_app_glue.h>    // Required for: android_app struct and activity management
 #include <android/window.h>             // Required for: AWINDOW_FLAG_FULLSCREEN definition and others
+#include <android/log.h>                // Required for: Android log system: __android_log_vprint()
+#include <android/asset_manager.h>      // Required for: AAssetManager
 //#include <android/sensor.h>           // Required for: Android sensors functions (accelerometer, gyroscope, light...)
+
+#include <errno.h>                      // Required for: error types
 #include <jni.h>                        // Required for: JNIEnv and JavaVM [Used in OpenURL() and GetCurrentMonitor()]
 
 #include <EGL/egl.h>                    // Native platform windowing system interface
@@ -269,6 +270,17 @@ static GamepadButton AndroidTranslateGamepadButton(int button);
 
 static void SetupFramebuffer(int width, int height); // Setup main framebuffer (required by InitPlatform())
 
+static int android_read(void *cookie, char *buf, int size);
+static int android_write(void *cookie, const char *buf, int size);
+static fpos_t android_seek(void *cookie, fpos_t offset, int whence);
+static int android_close(void *cookie);
+
+FILE *android_fopen(const char *fileName, const char *mode); // Replacement for fopen() -> Read-only!
+FILE *funopen(const void *cookie, int (*readfn)(void *, char *, int), int (*writefn)(void *, const char *, int),
+              fpos_t (*seekfn)(void *, fpos_t, int), int (*closefn)(void *));
+
+#define fopen(name, mode) android_fopen(name, mode)
+
 //----------------------------------------------------------------------------------
 // Module Functions Declaration
 //----------------------------------------------------------------------------------
@@ -819,8 +831,6 @@ int InitPlatform(void)
 
     // Initialize storage system
     //----------------------------------------------------------------------------
-    InitAssetManager(platform.app->activity->assetManager, platform.app->activity->internalDataPath);   // Initialize assets manager
-
     CORE.Storage.basePath = platform.app->activity->internalDataPath;   // Define base path for storage
     //----------------------------------------------------------------------------
 
@@ -1514,4 +1524,66 @@ static void SetupFramebuffer(int width, int height)
     }
 }
 
+// Replacement for fopen()
+// REF: https://developer.android.com/ndk/reference/group/asset
+FILE *android_fopen(const char *fileName, const char *mode)
+{
+    FILE *file = NULL;
+    
+    if (mode[0] == 'w')
+    {
+        // NOTE: fopen() is mapped to android_fopen() that only grants read access to
+        // assets directory through AAssetManager but we want to also be able to
+        // write data when required using the standard stdio FILE access functions
+        // REF: https://stackoverflow.com/questions/11294487/android-writing-saving-files-from-native-code-only
+        #undef fopen
+        file = fopen(TextFormat("%s/%s", platform.app->activity->internalDataPath, fileName), mode);
+        #define fopen(name, mode) android_fopen(name, mode)
+    }
+    else
+    {
+        // NOTE: AAsset provides access to read-only asset
+        AAsset *asset = AAssetManager_open(platform.app->activity->assetManager, fileName, AASSET_MODE_UNKNOWN);
+
+        if (asset != NULL)
+        {
+            // Get pointer to file in the assets
+            file = funopen(asset, android_read, android_write, android_seek, android_close);
+        }
+        else
+        {
+            #undef fopen
+            // Just do a regular open if file is not found in the assets
+            file = fopen(TextFormat("%s/%s", platform.app->activity->internalDataPath, fileName), mode);
+            if (file == NULL) file = fopen(fileName, mode);
+            #define fopen(name, mode) android_fopen(name, mode)
+        }
+    }
+    
+    return file;
+}
+
+static int android_read(void *cookie, char *data, int dataSize)
+{
+    return AAsset_read((AAsset *)cookie, data, dataSize);
+}
+
+static int android_write(void *cookie, const char *data, int dataSize)
+{
+    TRACELOG(LOG_WARNING, "ANDROID: Failed to provide write access to APK");
+
+    return EACCES;
+}
+
+static fpos_t android_seek(void *cookie, fpos_t offset, int whence)
+{
+    return AAsset_seek((AAsset *)cookie, offset, whence);
+}
+
+static int android_close(void *cookie)
+{
+    AAsset_close((AAsset *)cookie);
+    return 0;
+}
+
 // EOF