/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "PowerManagerService-JNI"

//#define LOG_NDEBUG 0

#include "JNIHelp.h"
#include "jni.h"
#include <limits.h>
#include <android_runtime/AndroidRuntime.h>
#include <utils/Timers.h>
#include "com_android_server_PowerManagerService.h"

namespace android {

// ----------------------------------------------------------------------------

static struct {
    jclass clazz;

    jmethodID goToSleep;
    jmethodID userActivity;
} gPowerManagerServiceClassInfo;

// ----------------------------------------------------------------------------

static jobject gPowerManagerServiceObj;

static Mutex gPowerManagerLock;
static bool gScreenOn;
static bool gScreenBright;

static nsecs_t gLastEventTime[POWER_MANAGER_LAST_EVENT + 1];

// Throttling interval for user activity calls.
static const nsecs_t MIN_TIME_BETWEEN_USERACTIVITIES = 500 * 1000000L; // 500ms

// ----------------------------------------------------------------------------

static bool checkAndClearExceptionFromCallback(JNIEnv* env, const char* methodName) {
    if (env->ExceptionCheck()) {
        LOGE("An exception was thrown by callback '%s'.", methodName);
        LOGE_EX(env);
        env->ExceptionClear();
        return true;
    }
    return false;
}

bool android_server_PowerManagerService_isScreenOn() {
    AutoMutex _l(gPowerManagerLock);
    return gScreenOn;
}

bool android_server_PowerManagerService_isScreenBright() {
    AutoMutex _l(gPowerManagerLock);
    return gScreenBright;
}

void android_server_PowerManagerService_userActivity(nsecs_t eventTime, int32_t eventType) {
    if (gPowerManagerServiceObj) {
        // Throttle calls into user activity by event type.
        // We're a little conservative about argument checking here in case the caller
        // passes in bad data which could corrupt system state.
        if (eventType >= 0 && eventType <= POWER_MANAGER_LAST_EVENT) {
            nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
            if (eventTime > now) {
                eventTime = now;
            }

            if (gLastEventTime[eventType] + MIN_TIME_BETWEEN_USERACTIVITIES > eventTime) {
                return;
            }
            gLastEventTime[eventType] = eventTime;
        }

        JNIEnv* env = AndroidRuntime::getJNIEnv();

        env->CallVoidMethod(gPowerManagerServiceObj, gPowerManagerServiceClassInfo.userActivity,
                nanoseconds_to_milliseconds(eventTime), false, eventType, false);
        checkAndClearExceptionFromCallback(env, "userActivity");
    }
}

void android_server_PowerManagerService_goToSleep(nsecs_t eventTime) {
    if (gPowerManagerServiceObj) {
        JNIEnv* env = AndroidRuntime::getJNIEnv();

        env->CallVoidMethod(gPowerManagerServiceObj, gPowerManagerServiceClassInfo.goToSleep,
                nanoseconds_to_milliseconds(eventTime));
        checkAndClearExceptionFromCallback(env, "goToSleep");
    }
}

// ----------------------------------------------------------------------------

static void android_server_PowerManagerService_nativeInit(JNIEnv* env, jobject obj) {
    gPowerManagerServiceObj = env->NewGlobalRef(obj);
}

static void android_server_PowerManagerService_nativeSetPowerState(JNIEnv* env,
        jobject serviceObj, jboolean screenOn, jboolean screenBright) {
    AutoMutex _l(gPowerManagerLock);
    gScreenOn = screenOn;
    gScreenBright = screenBright;
}

// ----------------------------------------------------------------------------

static JNINativeMethod gPowerManagerServiceMethods[] = {
    /* name, signature, funcPtr */
    { "nativeInit", "()V",
            (void*) android_server_PowerManagerService_nativeInit },
    { "nativeSetPowerState", "(ZZ)V",
            (void*) android_server_PowerManagerService_nativeSetPowerState },
};

#define FIND_CLASS(var, className) \
        var = env->FindClass(className); \
        LOG_FATAL_IF(! var, "Unable to find class " className); \
        var = jclass(env->NewGlobalRef(var));

#define GET_METHOD_ID(var, clazz, methodName, methodDescriptor) \
        var = env->GetMethodID(clazz, methodName, methodDescriptor); \
        LOG_FATAL_IF(! var, "Unable to find method " methodName);

#define GET_FIELD_ID(var, clazz, fieldName, fieldDescriptor) \
        var = env->GetFieldID(clazz, fieldName, fieldDescriptor); \
        LOG_FATAL_IF(! var, "Unable to find field " fieldName);

int register_android_server_PowerManagerService(JNIEnv* env) {
    int res = jniRegisterNativeMethods(env, "com/android/server/PowerManagerService",
            gPowerManagerServiceMethods, NELEM(gPowerManagerServiceMethods));
    LOG_FATAL_IF(res < 0, "Unable to register native methods.");

    // Callbacks

    FIND_CLASS(gPowerManagerServiceClassInfo.clazz, "com/android/server/PowerManagerService");

    GET_METHOD_ID(gPowerManagerServiceClassInfo.goToSleep, gPowerManagerServiceClassInfo.clazz,
            "goToSleep", "(J)V");

    GET_METHOD_ID(gPowerManagerServiceClassInfo.userActivity, gPowerManagerServiceClassInfo.clazz,
            "userActivity", "(JZIZ)V");

    // Initialize
    for (int i = 0; i < POWER_MANAGER_LAST_EVENT; i++) {
        gLastEventTime[i] = LLONG_MIN;
    }
    gScreenOn = true;
    gScreenBright = true;
    return 0;
}

} /* namespace android */