/*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "webrtc/modules/video_capture/android/device_info_android.h"

#include <algorithm>
#include <sstream>
#include <vector>

#include "json/json.h"
#include "third_party/icu/source/common/unicode/unistr.h"
#include "webrtc/modules/video_capture/android/video_capture_android.h"
#include "webrtc/system_wrappers/interface/logging.h"
#include "webrtc/system_wrappers/interface/ref_count.h"
#include "webrtc/system_wrappers/interface/trace.h"

namespace webrtc {

namespace videocapturemodule {

// Helper for storing lists of pairs of ints.  Used e.g. for resolutions & FPS
// ranges.
typedef std::pair<int, int> IntPair;
typedef std::vector<IntPair> IntPairs;

static std::string IntPairsToString(const IntPairs& pairs, char separator) {
  std::stringstream stream;
  for (size_t i = 0; i < pairs.size(); ++i) {
    if (i > 0)
      stream << ", ";
    stream << "(" << pairs[i].first << separator << pairs[i].second << ")";
  }
  return stream.str();
}

struct AndroidCameraInfo {
  std::string name;
  bool front_facing;
  int orientation;
  IntPairs resolutions;  // Pairs are: (width,height).
  // Pairs are (min,max) in units of FPS*1000 ("milli-frame-per-second").
  IntPairs mfpsRanges;

  std::string ToString() {
    std::stringstream stream;
    stream << "Name: [" << name << "], MFPS ranges: ["
           << IntPairsToString(mfpsRanges, ':')
           << "], front_facing: " << front_facing
           << ", orientation: " << orientation << ", resolutions: ["
           << IntPairsToString(resolutions, 'x') << "]";
    return stream.str();
  }
};

// Camera info; populated during DeviceInfoAndroid::Initialize() and immutable
// thereafter.
static std::vector<AndroidCameraInfo>* g_camera_info = NULL;

// Set |*index| to the index of |name| in g_camera_info or return false if no
// match found.
static bool FindCameraIndexByName(const std::string& name, size_t* index) {
  for (size_t i = 0; i < g_camera_info->size(); ++i) {
    if (g_camera_info->at(i).name == name) {
      *index = i;
      return true;
    }
  }
  return false;
}

// Returns a pointer to the named member of g_camera_info, or NULL if no match
// is found.
static AndroidCameraInfo* FindCameraInfoByName(const std::string& name) {
  size_t index = 0;
  if (FindCameraIndexByName(name, &index))
    return &g_camera_info->at(index);
  return NULL;
}

// static
void DeviceInfoAndroid::Initialize(JNIEnv* jni) {
  // TODO(henrike): this "if" would make a lot more sense as an assert, but
  // Java_org_webrtc_videoengineapp_ViEAndroidJavaAPI_GetVideoEngine() and
  // Java_org_webrtc_videoengineapp_ViEAndroidJavaAPI_Terminate() conspire to
  // prevent this.  Once that code is made to only
  // VideoEngine::SetAndroidObjects() once per process, this can turn into an
  // assert.
  if (g_camera_info)
    return;

  g_camera_info = new std::vector<AndroidCameraInfo>();
  jclass j_info_class =
      jni->FindClass("org/webrtc/videoengine/VideoCaptureDeviceInfoAndroid");
  assert(j_info_class);
  jmethodID j_initialize = jni->GetStaticMethodID(
      j_info_class, "getDeviceInfo", "()Ljava/lang/String;");
  jstring j_json_info = static_cast<jstring>(
      jni->CallStaticObjectMethod(j_info_class, j_initialize));

  const jchar* jchars = jni->GetStringChars(j_json_info, NULL);
  icu::UnicodeString ustr(jchars, jni->GetStringLength(j_json_info));
  jni->ReleaseStringChars(j_json_info, jchars);
  std::string json_info;
  ustr.toUTF8String(json_info);

  Json::Value cameras;
  Json::Reader reader(Json::Features::strictMode());
  bool parsed = reader.parse(json_info, cameras);
  if (!parsed) {
    std::stringstream stream;
    stream << "Failed to parse configuration:\n"
           << reader.getFormattedErrorMessages();
    assert(false);
    return;
  }
  for (Json::ArrayIndex i = 0; i < cameras.size(); ++i) {
    const Json::Value& camera = cameras[i];
    AndroidCameraInfo info;
    info.name = camera["name"].asString();
    info.front_facing = camera["front_facing"].asBool();
    info.orientation = camera["orientation"].asInt();
    Json::Value sizes = camera["sizes"];
    for (Json::ArrayIndex j = 0; j < sizes.size(); ++j) {
      const Json::Value& size = sizes[j];
      info.resolutions.push_back(std::make_pair(
          size["width"].asInt(), size["height"].asInt()));
    }
    Json::Value mfpsRanges = camera["mfpsRanges"];
    for (Json::ArrayIndex j = 0; j < mfpsRanges.size(); ++j) {
      const Json::Value& mfpsRange = mfpsRanges[j];
      info.mfpsRanges.push_back(std::make_pair(mfpsRange["min_mfps"].asInt(),
                                               mfpsRange["max_mfps"].asInt()));
    }
    g_camera_info->push_back(info);
  }
}

void DeviceInfoAndroid::DeInitialize() {
  if (g_camera_info) {
    delete g_camera_info;
    g_camera_info = NULL;
  }
}

VideoCaptureModule::DeviceInfo* VideoCaptureImpl::CreateDeviceInfo(
    const int32_t id) {
  return new videocapturemodule::DeviceInfoAndroid(id);
}

DeviceInfoAndroid::DeviceInfoAndroid(const int32_t id) :
    DeviceInfoImpl(id) {
}

DeviceInfoAndroid::~DeviceInfoAndroid() {
}

bool DeviceInfoAndroid::FindCameraIndex(const char* deviceUniqueIdUTF8,
                                        size_t* index) {
  return FindCameraIndexByName(deviceUniqueIdUTF8, index);
}

int32_t DeviceInfoAndroid::Init() {
  return 0;
}

uint32_t DeviceInfoAndroid::NumberOfDevices() {
  return g_camera_info->size();
}

int32_t DeviceInfoAndroid::GetDeviceName(
    uint32_t deviceNumber,
    char* deviceNameUTF8,
    uint32_t deviceNameLength,
    char* deviceUniqueIdUTF8,
    uint32_t deviceUniqueIdUTF8Length,
    char* /*productUniqueIdUTF8*/,
    uint32_t /*productUniqueIdUTF8Length*/) {
  if (deviceNumber >= g_camera_info->size())
    return -1;
  const AndroidCameraInfo& info = g_camera_info->at(deviceNumber);
  if (info.name.length() + 1 > deviceNameLength ||
      info.name.length() + 1 > deviceUniqueIdUTF8Length) {
    return -1;
  }
  memcpy(deviceNameUTF8, info.name.c_str(), info.name.length() + 1);
  memcpy(deviceUniqueIdUTF8, info.name.c_str(), info.name.length() + 1);
  return 0;
}

int32_t DeviceInfoAndroid::CreateCapabilityMap(
    const char* deviceUniqueIdUTF8) {
  _captureCapabilities.clear();
  const AndroidCameraInfo* info = FindCameraInfoByName(deviceUniqueIdUTF8);
  if (info == NULL)
    return -1;

  for (size_t i = 0; i < info->resolutions.size(); ++i) {
    for (size_t j = 0; j < info->mfpsRanges.size(); ++j) {
      const IntPair& size = info->resolutions[i];
      const IntPair& mfpsRange = info->mfpsRanges[j];
      VideoCaptureCapability cap;
      cap.width = size.first;
      cap.height = size.second;
      cap.maxFPS = mfpsRange.second / 1000;
      cap.expectedCaptureDelay = kExpectedCaptureDelay;
      cap.rawType = kVideoNV21;
      _captureCapabilities.push_back(cap);
    }
  }
  return _captureCapabilities.size();
}

int32_t DeviceInfoAndroid::GetOrientation(const char* deviceUniqueIdUTF8,
                                          VideoRotation& orientation) {
  const AndroidCameraInfo* info = FindCameraInfoByName(deviceUniqueIdUTF8);
  if (info == NULL ||
      VideoCaptureImpl::RotationFromDegrees(info->orientation,
                                            &orientation) != 0) {
    return -1;
  }
  return 0;
}

void DeviceInfoAndroid::GetMFpsRange(const char* deviceUniqueIdUTF8,
                                     int max_fps_to_match,
                                     int* min_mfps, int* max_mfps) {
  const AndroidCameraInfo* info = FindCameraInfoByName(deviceUniqueIdUTF8);
  if (info == NULL)
    return;
  int desired_mfps = max_fps_to_match * 1000;
  int best_diff_mfps = 0;
  LOG(LS_INFO) << "Search for best target mfps " << desired_mfps;
  // Search for best fps range with preference shifted to constant fps modes.
  for (size_t i = 0; i < info->mfpsRanges.size(); ++i) {
    int diff_mfps = abs(info->mfpsRanges[i].first - desired_mfps) +
        abs(info->mfpsRanges[i].second - desired_mfps) +
        (info->mfpsRanges[i].second - info->mfpsRanges[i].first) / 2;
    LOG(LS_INFO) << "Fps range " << info->mfpsRanges[i].first << ":" <<
        info->mfpsRanges[i].second << ". Distance: " << diff_mfps;
    if (i == 0 || diff_mfps < best_diff_mfps) {
      best_diff_mfps = diff_mfps;
      *min_mfps = info->mfpsRanges[i].first;
      *max_mfps = info->mfpsRanges[i].second;
    }
  }
}

}  // namespace videocapturemodule
}  // namespace webrtc