/*
 * Copyright (C) 2014 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.
 */
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <fcntl.h>
#include <dlfcn.h>
#include <errno.h>
#include <sys/poll.h>
#include <pthread.h>
#include <linux/netlink.h>
#include <stdlib.h>
#include <stdbool.h>

#define LOG_TAG "PowerHAL"
#include <utils/Log.h>

#include <hardware/hardware.h>
#include <hardware/power.h>

#define STATE_ON "state=1"
#define STATE_OFF "state=0"

#define MAX_LENGTH         50
#define BOOST_SOCKET       "/dev/socket/pb"

#define POWERSAVE_MIN_FREQ 384000
#define POWERSAVE_MAX_FREQ 1026000
#define BIAS_PERF_MIN_FREQ 1134000
#define NORMAL_MAX_FREQ 1512000

#define MAX_FREQ_LIMIT_PATH "/sys/kernel/cpufreq_limit/limited_max_freq"
#define MIN_FREQ_LIMIT_PATH "/sys/kernel/cpufreq_limit/limited_min_freq"

static int client_sockfd;
static struct sockaddr_un client_addr;
static int last_state = -1;

static pthread_mutex_t profile_lock = PTHREAD_MUTEX_INITIALIZER;

enum {
    PROFILE_POWER_SAVE = 0,
    PROFILE_BALANCED,
    PROFILE_HIGH_PERFORMANCE,
    PROFILE_BIAS_POWER,
    PROFILE_BIAS_PERFORMANCE,
    PROFILE_MAX
};

static int current_power_profile = PROFILE_BALANCED;

static void socket_init()
{
    if (!client_sockfd) {
        client_sockfd = socket(PF_UNIX, SOCK_DGRAM, 0);
        if (client_sockfd < 0) {
            ALOGE("%s: failed to open: %s", __func__, strerror(errno));
            return;
        }
        memset(&client_addr, 0, sizeof(struct sockaddr_un));
        client_addr.sun_family = AF_UNIX;
        snprintf(client_addr.sun_path, UNIX_PATH_MAX, BOOST_SOCKET);
    }
}

static int sysfs_write(const char *path, char *s)
{
    char buf[80];
    int len;
    int fd = open(path, O_WRONLY);

    if (fd < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error opening %s: %s\n", path, buf);
        return -1;
    }

    len = write(fd, s, strlen(s));
    if (len < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error writing to %s: %s\n", path, buf);
        return -1;
    }

    close(fd);
    return 0;
}

static int sysfs_write_int(char *path, int value)
{
    char buf[80];
    snprintf(buf, 80, "%d", value);
    return sysfs_write(path, buf);
}

static void power_init(__attribute__((unused)) struct power_module *module)
{
    ALOGI("%s", __func__);
    socket_init();
}

static void sync_thread(int off)
{
    int rc;
    pid_t client;
    char data[MAX_LENGTH];

    if (client_sockfd < 0) {
        ALOGE("%s: boost socket not created", __func__);
        return;
    }

    client = getpid();

    if (!off) {
        snprintf(data, MAX_LENGTH, "2:%d", client);
        rc = sendto(client_sockfd, data, strlen(data), 0,
            (const struct sockaddr *)&client_addr, sizeof(struct sockaddr_un));
    } else {
        snprintf(data, MAX_LENGTH, "3:%d", client);
        rc = sendto(client_sockfd, data, strlen(data), 0,
            (const struct sockaddr *)&client_addr, sizeof(struct sockaddr_un));
    }

    if (rc < 0) {
        ALOGE("%s: failed to send: %s", __func__, strerror(errno));
    }
}

static void enc_boost(int off)
{
    int rc;
    pid_t client;
    char data[MAX_LENGTH];

    if (client_sockfd < 0) {
        ALOGE("%s: boost socket not created", __func__);
        return;
    }

    client = getpid();

    if (!off) {
        snprintf(data, MAX_LENGTH, "5:%d", client);
        rc = sendto(client_sockfd, data, strlen(data), 0,
            (const struct sockaddr *)&client_addr, sizeof(struct sockaddr_un));
    } else {
        snprintf(data, MAX_LENGTH, "6:%d", client);
        rc = sendto(client_sockfd, data, strlen(data), 0,
            (const struct sockaddr *)&client_addr, sizeof(struct sockaddr_un));
    }

    if (rc < 0) {
        ALOGE("%s: failed to send: %s", __func__, strerror(errno));
    }
}

static void process_video_encode_hint(void *metadata)
{

    socket_init();

    if (client_sockfd < 0) {
        ALOGE("%s: boost socket not created", __func__);
        return;
    }

    if (!metadata)
        return;

    if (!strncmp(metadata, STATE_ON, sizeof(STATE_ON))) {
        /* Video encode started */
        sync_thread(1);
        enc_boost(1);
    } else if (!strncmp(metadata, STATE_OFF, sizeof(STATE_OFF))) {
        /* Video encode stopped */
        sync_thread(0);
        enc_boost(0);
    }
}

static void touch_boost()
{
    int rc;
    pid_t client;
    char data[MAX_LENGTH];

    if (client_sockfd < 0) {
        ALOGE("%s: boost socket not created", __func__);
        return;
    }

    client = getpid();

    snprintf(data, MAX_LENGTH, "1:%d", client);
    rc = sendto(client_sockfd, data, strlen(data), 0,
        (const struct sockaddr *)&client_addr, sizeof(struct sockaddr_un));
    if (rc < 0) {
        ALOGE("%s: failed to send: %s", __func__, strerror(errno));
    }
}

static void power_set_interactive(__attribute__((unused)) struct power_module *module, int on)
{
    if (last_state == on)
        return;

    last_state = on;

    ALOGV("%s %s", __func__, (on ? "ON" : "OFF"));
    if (on) {
        sync_thread(0);
        touch_boost();
    } else {
        sync_thread(1);
    }
}

static void set_power_profile(int profile) {
    int min_freq = POWERSAVE_MIN_FREQ;
    int max_freq = NORMAL_MAX_FREQ;

    ALOGV("%s: profile=%d", __func__, profile);

    switch (profile) {
    case PROFILE_HIGH_PERFORMANCE:
        min_freq = NORMAL_MAX_FREQ;
        max_freq = NORMAL_MAX_FREQ;
        break;
    case PROFILE_BIAS_PERFORMANCE:
        min_freq = BIAS_PERF_MIN_FREQ;
        max_freq = NORMAL_MAX_FREQ;
        break;
    case PROFILE_BIAS_POWER:
        min_freq = POWERSAVE_MIN_FREQ;
        max_freq = POWERSAVE_MAX_FREQ;
        break;
    case PROFILE_POWER_SAVE:
        min_freq = POWERSAVE_MIN_FREQ;
        max_freq = POWERSAVE_MAX_FREQ;
        break;
    default:
        break;
    }

    sysfs_write_int(MIN_FREQ_LIMIT_PATH, min_freq);
    sysfs_write_int(MAX_FREQ_LIMIT_PATH, max_freq);

    current_power_profile = profile;

    ALOGD("%s: set power profile mode: %d", __func__, current_power_profile);
}

static void power_hint( __attribute__((unused)) struct power_module *module,
                      power_hint_t hint, void *data)
{
    if (hint == POWER_HINT_SET_PROFILE) {
        pthread_mutex_lock(&profile_lock);
        set_power_profile(*(int32_t *)data);
        pthread_mutex_unlock(&profile_lock);
        return;
    }

    // Skip other hints in powersave mode
    if (current_power_profile == PROFILE_POWER_SAVE)
        return;

    switch (hint) {
        case POWER_HINT_LAUNCH:
        case POWER_HINT_CPU_BOOST:
            ALOGV("POWER_HINT_INTERACTION");
            touch_boost();
            break;
        case POWER_HINT_VIDEO_ENCODE:
            process_video_encode_hint(data);
            break;
        default:
            break;
    }
}

static int power_open(const hw_module_t *module, const char *name,
                            hw_device_t **device)
{
    ALOGD("%s: enter; name=%s", __FUNCTION__, name);
    int retval = 0; /* 0 is ok; -1 is error */
    if (strcmp(name, POWER_HARDWARE_MODULE_ID) == 0) {
        power_module_t *dev = (power_module_t *)calloc(1,
                sizeof(power_module_t));
        if (dev) {
            /* Common hw_device_t fields */
            dev->common.tag = HARDWARE_MODULE_TAG;
            dev->common.module_api_version = POWER_MODULE_API_VERSION_0_2;
            dev->common.module_api_version = HARDWARE_HAL_API_VERSION;
            dev->init = power_init;
            dev->powerHint = power_hint;
            dev->setInteractive = power_set_interactive;
            *device = (hw_device_t*)dev;
        } else
            retval = -ENOMEM;
    } else {
        retval = -EINVAL;
    }
    ALOGD("%s: exit %d", __FUNCTION__, retval);
    return retval;
}


static struct hw_module_methods_t power_module_methods = {
    .open = power_open,
};

static int get_feature(__attribute__((unused)) struct power_module *module,
                       feature_t feature)
{
    if (feature == POWER_FEATURE_SUPPORTED_PROFILES)
        return PROFILE_MAX;

    return -1;
}

struct power_module HAL_MODULE_INFO_SYM = {
    .common = {
        .tag = HARDWARE_MODULE_TAG,
        .module_api_version = POWER_MODULE_API_VERSION_0_2,
        .hal_api_version = HARDWARE_HAL_API_VERSION,
        .id = POWER_HARDWARE_MODULE_ID,
        .name = "Flo/Deb Power HAL",
        .author = "The Android Open Source Project",
        .methods = &power_module_methods,
    },

    .init = power_init,
    .setInteractive = power_set_interactive,
    .powerHint = power_hint,
    .getFeature = get_feature
};