// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/spellcheck/browser/spellchecker_session_bridge_android.h"

#include <stddef.h>

#include <utility>

#include "base/android/jni_array.h"
#include "base/android/jni_string.h"
#include "base/android/scoped_java_ref.h"
#include "base/feature_list.h"
#include "base/logging.h"
#include "components/spellcheck/common/spellcheck_decoration.h"
#include "components/spellcheck/common/spellcheck_features.h"
#include "components/spellcheck/common/spellcheck_result.h"
#include "components/spellcheck/common/spelling_marker.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/render_process_host.h"
#include "third_party/blink/public/common/features.h"

// Must come after all headers that specialize FromJniType() / ToJniType().
#include "components/spellcheck/browser/android/jni_headers/SpellCheckerSessionBridge_jni.h"

using base::android::JavaRef;

SpellCheckerSessionBridge::SpellCheckerSessionBridge()
    : java_object_initialization_failed_(false) {}

SpellCheckerSessionBridge::~SpellCheckerSessionBridge() {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  // Clean-up java side to avoid any stale JNI callbacks.
  DisconnectSession();
}

void SpellCheckerSessionBridge::RequestTextCheck(
    const std::u16string& text,
    const std::vector<spellcheck::SpellingMarker>& spelling_markers,
    RequestTextCheckCallback callback) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

  // This allows us to discard |callback| safely in case it's not run due to
  // failures in initialization of |java_object_|.
  std::unique_ptr<SpellingRequest> incoming_request =
      std::make_unique<SpellingRequest>(text, spelling_markers,
                                        std::move(callback));

  // SpellCheckerSessionBridge#create() will return null if spell checker
  // service is unavailable.
  if (java_object_initialization_failed_) {
    return;
  }

  // RequestTextCheck API call arrives at the SpellCheckHost before
  // DisconnectSessionBridge when the user focuses an input field that already
  // contains completed text.  We need to initialize the spellchecker here
  // rather than in response to DisconnectSessionBridge so that the existing
  // text will be spellchecked immediately.
  //
  // AndroidSpellcheckFullApiBlink gives input methods inside Android enough
  // info to render a custom suggestion menu. We should only allow hiding the
  // suggestion menu from the Clank side when we are sure that the Android
  // input methods have enough information to render an alternative menu.
  if (java_object_.is_null()) {
    java_object_.Reset(Java_SpellCheckerSessionBridge_create(
        base::android::AttachCurrentThread(), reinterpret_cast<intptr_t>(this),
        base::FeatureList::IsEnabled(spellcheck::kAndroidGrammarCheck),
        /* allowHideSuggestionMenuAttribute= */
        base::FeatureList::IsEnabled(
            blink::features::kAndroidSpellcheckFullApiBlink)));
    if (java_object_.is_null()) {
      java_object_initialization_failed_ = true;
      return;
    }
  }

  // Save incoming requests to run at the end of the currently active request.
  // If multiple requests arrive during one active request, only the most
  // recent request will run (the others get overwritten).
  if (active_request_) {
    pending_request_ = std::move(incoming_request);
    return;
  }

  active_request_ = std::move(incoming_request);

  JNIEnv* env = base::android::AttachCurrentThread();
  Java_SpellCheckerSessionBridge_requestTextCheck(
      env, java_object_, base::android::ConvertUTF16ToJavaString(env, text),
      spelling_markers);
}

void SpellCheckerSessionBridge::ProcessSpellCheckResults(
    JNIEnv* env,
    const JavaRef<jintArray>& offset_array,
    const JavaRef<jintArray>& length_array,
    const JavaRef<jobjectArray>& suggestions_array,
    const JavaRef<jintArray>& spellcheck_result_decorations_array,
    const JavaRef<jbooleanArray>& hide_suggestion_menu_booleans_array) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  std::vector<int> offsets;
  std::vector<int> lengths;
  std::vector<int> spellcheck_result_decorations;
  std::vector<bool> hide_suggestion_menu_booleans;

  base::android::JavaIntArrayToIntVector(env, offset_array, &offsets);
  base::android::JavaIntArrayToIntVector(env, length_array, &lengths);
  base::android::JavaIntArrayToIntVector(
      env, spellcheck_result_decorations_array, &spellcheck_result_decorations);
  base::android::JavaBooleanArrayToBoolVector(
      env, hide_suggestion_menu_booleans_array, &hide_suggestion_menu_booleans);

  std::vector<SpellCheckResult> results;
  for (size_t i = 0; i < offsets.size(); i++) {
    auto suggestions_for_word_array = jni_zero::AdoptRef(
        env, static_cast<jobjectArray>(
                 env->GetObjectArrayElement(suggestions_array.obj(), i)));
    std::vector<std::u16string> suggestions_for_word;
    base::android::AppendJavaStringArrayToStringVector(
        env, suggestions_for_word_array, &suggestions_for_word);
    spellcheck::Decoration decoration =
        static_cast<spellcheck::Decoration>(spellcheck_result_decorations[i]);
    results.emplace_back(decoration, offsets[i], lengths[i],
                         suggestions_for_word,
                         hide_suggestion_menu_booleans[i]);
  }

  std::move(active_request_->callback_).Run(results);

  active_request_ = std::move(pending_request_);
  if (active_request_) {
    Java_SpellCheckerSessionBridge_requestTextCheck(
        env, java_object_,
        base::android::ConvertUTF16ToJavaString(env, active_request_->text_),
        active_request_->spelling_markers_);
  }
}

void SpellCheckerSessionBridge::DisconnectSession() {
  // Needs to be executed on the same thread as the RequestTextCheck and
  // ProcessSpellCheckResults methods, which is the UI thread.
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

  active_request_.reset();
  pending_request_.reset();

  if (!java_object_.is_null()) {
    Java_SpellCheckerSessionBridge_disconnect(
        base::android::AttachCurrentThread(), java_object_);
    java_object_.Reset();
  }
}

SpellCheckerSessionBridge::SpellingRequest::SpellingRequest(
    const std::u16string& text,
    const std::vector<spellcheck::SpellingMarker>& spelling_markers,
    RequestTextCheckCallback callback)
    : text_(text),
      spelling_markers_(spelling_markers),
      callback_(std::move(callback)) {}

SpellCheckerSessionBridge::SpellingRequest::~SpellingRequest() {
  // Ensure that we don't clear an uncalled RequestTextCheckCallback
  if (callback_)
    std::move(callback_).Run(std::vector<SpellCheckResult>());
}

base::android::ScopedJavaLocalRef<jobject> ToJavaSpellingMarker(
    JNIEnv* env,
    const spellcheck::SpellingMarker& spelling_marker) {
  base::android::ScopedJavaLocalRef<jobject> j_spelling_marker =
      Java_SpellCheckerSessionBridge_createSpellingMarker(
          env, spelling_marker.start, spelling_marker.end,
          spelling_marker.marker_type);
  if (j_spelling_marker.is_null()) {
    LOG(ERROR) << "Failed to create a spelling marker with range ["
               << spelling_marker.start << ", " << spelling_marker.end << "];";
  }
  return j_spelling_marker;
}

DEFINE_JNI(SpellCheckerSessionBridge)