From a65e192f0fb4388fc33d8e9bf1807ac540f3003d Mon Sep 17 00:00:00 2001
From: Matthieu Gautier <mgautier@kymeria.fr>
Date: Mon, 12 Aug 2019 13:03:20 +0200
Subject: [PATCH] [JNI] Allow android to know that an article is a redirect.
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Android need to handle the redirection by doing a redirection in the web
view, not by providing the content of the targeted article.

This is already what we do in kiwix-serve or ios.

The API should be far better by returning a Entry but for now,
we just change the given url if the article is a redirection.
---
 src/android/kiwixreader.cpp                     | 17 ++++++++++-------
 .../org/kiwix/kiwixlib/JNIKiwixReader.java      | 16 +++++++++++++++-
 src/android/utils.h                             |  7 +++++++
 3 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/src/android/kiwixreader.cpp b/src/android/kiwixreader.cpp
index 1196f82c5..91dcec78b 100644
--- a/src/android/kiwixreader.cpp
+++ b/src/android/kiwixreader.cpp
@@ -225,7 +225,7 @@ JNIEXPORT jstring JNICALL Java_org_kiwix_kiwixlib_JNIKiwixReader_getMimeType(
 }
 
 JNIEXPORT jbyteArray JNICALL Java_org_kiwix_kiwixlib_JNIKiwixReader_getContent(
-    JNIEnv* env, jobject obj, jstring url, jobject titleObj, jobject mimeTypeObj, jobject sizeObj)
+    JNIEnv* env, jobject obj, jobject url, jobject titleObj, jobject mimeTypeObj, jobject sizeObj)
 {
   /* Default values */
   setStringObjValue("", titleObj, env);
@@ -234,21 +234,24 @@ JNIEXPORT jbyteArray JNICALL Java_org_kiwix_kiwixlib_JNIKiwixReader_getContent(
   jbyteArray data = env->NewByteArray(0);
 
   /* Retrieve the content */
-  std::string cUrl = jni2c(url, env);
+  std::string cUrl = getStringObjValue(url, env);
   unsigned int cSize = 0;
 
   try {
     auto entry = READER->getEntryFromEncodedPath(cUrl);
+    bool isRedirect = entry.isRedirect();
     entry = entry.getFinalEntry();
     cSize = entry.getSize();
     setIntObjValue(cSize, sizeObj, env);
-
-    data = env->NewByteArray(cSize);
-    env->SetByteArrayRegion(
-        data, 0, cSize, reinterpret_cast<const jbyte*>(entry.getBlob().data()));
-
     setStringObjValue(entry.getMimetype(), mimeTypeObj, env);
     setStringObjValue(entry.getTitle(), titleObj, env);
+    if (isRedirect) {
+      setStringObjValue(entry.getPath(), url, env);
+    } else {
+      data = env->NewByteArray(cSize);
+      env->SetByteArrayRegion(
+          data, 0, cSize, reinterpret_cast<const jbyte*>(entry.getBlob().data()));
+    }
   } catch (std::exception& e) {
     __android_log_print(ANDROID_LOG_ERROR, "kiwix", "Unable to get content for url: %s", cUrl.c_str());
     __android_log_print(ANDROID_LOG_ERROR, "kiwix", e.what());
diff --git a/src/android/org/kiwix/kiwixlib/JNIKiwixReader.java b/src/android/org/kiwix/kiwixlib/JNIKiwixReader.java
index e405ef0f4..ea3a3d4b3 100644
--- a/src/android/org/kiwix/kiwixlib/JNIKiwixReader.java
+++ b/src/android/org/kiwix/kiwixlib/JNIKiwixReader.java
@@ -38,7 +38,21 @@ public class JNIKiwixReader
 
   public native String getMimeType(String url);
 
-  public native byte[] getContent(String url,
+  /**
+   * Get the content of a article.
+   *
+   * Return a byte array of the content of the article.
+   * Set the title, mimeType to the title and mimeType of the article.
+   * Set the size to the size of the returned array.
+   *
+   * If the entry doesn't exist :
+   *  - return a empty byte array
+   *  - set all arguments (except url) to empty/0.
+   * If the entry exist but is a redirection :
+   *  - return an empty byte array
+   *  - set all arguments (including url) to information of the targeted article.
+   */
+  public native byte[] getContent(JNIKiwixString url,
                                   JNIKiwixString title,
                                   JNIKiwixString mimeType,
                                   JNIKiwixInt size);
diff --git a/src/android/utils.h b/src/android/utils.h
index 3c164e353..aeb5a4d35 100644
--- a/src/android/utils.h
+++ b/src/android/utils.h
@@ -114,6 +114,13 @@ inline std::string jni2c(const jstring& val, JNIEnv* env)
 
 inline int jni2c(const jint val) { return (int)val; }
 /* Method to deal with variable passed by reference */
+inline std::string getStringObjValue(const jobject obj, JNIEnv* env)
+{
+  jclass objClass = env->GetObjectClass(obj);
+  jfieldID objFid = env->GetFieldID(objClass, "value", "Ljava/lang/String;");
+  jstring jstr = (jstring)env->GetObjectField(obj, objFid);
+  return jni2c(jstr, env);
+}
 inline void setStringObjValue(const std::string& value,
                               const jobject obj,
                               JNIEnv* env)