#include <stdint.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netlink/genl/genl.h>
#include <netlink/genl/family.h>
#include <netlink/genl/ctrl.h>
#include <linux/rtnetlink.h>
#include <netpacket/packet.h>
#include <linux/filter.h>
#include <linux/errqueue.h>

#include <linux/pkt_sched.h>
#include <netlink/object-api.h>
#include <netlink/netlink.h>
#include <netlink/socket.h>
#include <netlink/attr.h>
#include <netlink/handlers.h>
#include <netlink/msg.h>

#include <dirent.h>
#include <net/if.h>

#include "sync.h"

#define LOG_TAG  "WifiHAL"

#include <utils/Log.h>

#include "wifi_hal.h"
#include "common.h"
#include "cpp_bindings.h"

/*
 BUGBUG: normally, libnl allocates ports for all connections it makes; but
 being a static library, it doesn't really know how many other netlink connections
 are made by the same process, if connections come from different shared libraries.
 These port assignments exist to solve that problem - temporarily. We need to fix
 libnl to try and allocate ports across the entire process.
 */

#define WIFI_HAL_CMD_SOCK_PORT       644
#define WIFI_HAL_EVENT_SOCK_PORT     645

#define FEATURE_SET                  0
#define FEATURE_SET_MATRIX           1
#define ATTR_NODFS_VALUE             3

static void internal_event_handler(wifi_handle handle, int events);
static int internal_no_seq_check(nl_msg *msg, void *arg);
static int internal_valid_message_handler(nl_msg *msg, void *arg);
static int wifi_get_multicast_id(wifi_handle handle, const char *name, const char *group);
static int wifi_add_membership(wifi_handle handle, const char *group);
static wifi_error wifi_init_interfaces(wifi_handle handle);

typedef enum wifi_attr {
    ANDR_WIFI_ATTRIBUTE_NUM_FEATURE_SET,
    ANDR_WIFI_ATTRIBUTE_FEATURE_SET,
    ANDR_WIFI_ATTRIBUTE_PNO_RANDOM_MAC_OUI
} wifi_attr_t;

/* Initialize/Cleanup */

void wifi_socket_set_local_port(struct nl_sock *sock, uint32_t port)
{
    uint32_t pid = getpid() & 0x3FFFFF;
    nl_socket_set_local_port(sock, pid + (port << 22));
}

static nl_sock * wifi_create_nl_socket(int port)
{
    // ALOGI("Creating socket");
    struct nl_sock *sock = nl_socket_alloc();
    if (sock == NULL) {
        ALOGE("Could not create handle");
        return NULL;
    }

    wifi_socket_set_local_port(sock, port);

    struct sockaddr *addr = NULL;
    // ALOGI("sizeof(sockaddr) = %d, sizeof(sockaddr_nl) = %d", sizeof(*addr), sizeof(*addr_nl));

    // ALOGI("Connecting socket");
    if (nl_connect(sock, NETLINK_GENERIC)) {
        ALOGE("Could not connect handle");
        nl_socket_free(sock);
        return NULL;
    }

    // ALOGI("Making socket nonblocking");
    /*
    if (nl_socket_set_nonblocking(sock)) {
        ALOGE("Could make socket non-blocking");
        nl_socket_free(sock);
        return NULL;
    }
    */

    return sock;
}

wifi_error wifi_initialize(wifi_handle *handle)
{
    srand(getpid());

    ALOGI("Initializing wifi");
    hal_info *info = (hal_info *)malloc(sizeof(hal_info));
    if (info == NULL) {
        ALOGE("Could not allocate hal_info");
        return WIFI_ERROR_UNKNOWN;
    }

    memset(info, 0, sizeof(*info));

    ALOGI("Creating socket");
    struct nl_sock *cmd_sock = wifi_create_nl_socket(WIFI_HAL_CMD_SOCK_PORT);
    if (cmd_sock == NULL) {
        ALOGE("Could not create handle");
        return WIFI_ERROR_UNKNOWN;
    }

    struct nl_sock *event_sock = wifi_create_nl_socket(WIFI_HAL_EVENT_SOCK_PORT);
    if (event_sock == NULL) {
        ALOGE("Could not create handle");
        nl_socket_free(cmd_sock);
        return WIFI_ERROR_UNKNOWN;
    }

    struct nl_cb *cb = nl_socket_get_cb(event_sock);
    if (cb == NULL) {
        ALOGE("Could not create handle");
        return WIFI_ERROR_UNKNOWN;
    }

    // ALOGI("cb->refcnt = %d", cb->cb_refcnt);
    nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, internal_no_seq_check, info);
    nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, internal_valid_message_handler, info);
    nl_cb_put(cb);

    info->cmd_sock = cmd_sock;
    info->event_sock = event_sock;
    info->clean_up = false;
    info->in_event_loop = false;

    info->event_cb = (cb_info *)malloc(sizeof(cb_info) * DEFAULT_EVENT_CB_SIZE);
    info->alloc_event_cb = DEFAULT_EVENT_CB_SIZE;
    info->num_event_cb = 0;

    info->cmd = (cmd_info *)malloc(sizeof(cmd_info) * DEFAULT_CMD_SIZE);
    info->alloc_cmd = DEFAULT_CMD_SIZE;
    info->num_cmd = 0;

    info->nl80211_family_id = genl_ctrl_resolve(cmd_sock, "nl80211");
    if (info->nl80211_family_id < 0) {
        ALOGE("Could not resolve nl80211 familty id");
        nl_socket_free(cmd_sock);
        nl_socket_free(event_sock);
        free(info);
        return WIFI_ERROR_UNKNOWN;
    }

    pthread_mutex_init(&info->cb_lock, NULL);

    *handle = (wifi_handle) info;

    wifi_add_membership(*handle, "scan");
    wifi_add_membership(*handle, "mlme");
    wifi_add_membership(*handle, "regulatory");
    wifi_add_membership(*handle, "vendor");

    wifi_init_interfaces(*handle);
    // ALOGI("Found %d interfaces", info->num_interfaces);


    ALOGI("Initialized Wifi HAL Successfully; vendor cmd = %d", NL80211_CMD_VENDOR);
    return WIFI_SUCCESS;
}

static int wifi_add_membership(wifi_handle handle, const char *group)
{
    hal_info *info = getHalInfo(handle);

    int id = wifi_get_multicast_id(handle, "nl80211", group);
    if (id < 0) {
        ALOGE("Could not find group %s", group);
        return id;
    }

    int ret = nl_socket_add_membership(info->event_sock, id);
    if (ret < 0) {
        ALOGE("Could not add membership to group %s", group);
    }

    // ALOGI("Successfully added membership for group %s", group);
    return ret;
}

static void internal_cleaned_up_handler(wifi_handle handle)
{
    hal_info *info = getHalInfo(handle);
    wifi_cleaned_up_handler cleaned_up_handler = info->cleaned_up_handler;

    if (info->cmd_sock != 0) {
        nl_socket_free(info->cmd_sock);
        nl_socket_free(info->event_sock);
        info->cmd_sock = NULL;
        info->event_sock = NULL;
    }

    (*cleaned_up_handler)(handle);
    pthread_mutex_destroy(&info->cb_lock);
    free(info);

    ALOGI("Internal cleanup completed");
}

void wifi_cleanup(wifi_handle handle, wifi_cleaned_up_handler handler)
{
    hal_info *info = getHalInfo(handle);
    info->cleaned_up_handler = handler;
    info->clean_up = true;

    ALOGI("Wifi cleanup completed");
}

static int internal_pollin_handler(wifi_handle handle)
{
    hal_info *info = getHalInfo(handle);
    struct nl_cb *cb = nl_socket_get_cb(info->event_sock);
    int res = nl_recvmsgs(info->event_sock, cb);
    // ALOGD("nl_recvmsgs returned %d", res);
    nl_cb_put(cb);
    return res;
}

/* Run event handler */
void wifi_event_loop(wifi_handle handle)
{
    hal_info *info = getHalInfo(handle);
    if (info->in_event_loop) {
        return;
    } else {
        info->in_event_loop = true;
    }

    pollfd pfd;
    memset(&pfd, 0, sizeof(pfd));

    pfd.fd = nl_socket_get_fd(info->event_sock);
    pfd.events = POLLIN;

    /* TODO: Add support for timeouts */

    do {
        int timeout = -1;                   /* Infinite timeout */
        pfd.revents = 0;
        // ALOGI("Polling socket");
        int result = poll(&pfd, 1, -1);
        if (result < 0) {
            ALOGE("Error polling socket");
        } else if (pfd.revents & POLLERR) {
            ALOGE("POLL Error; error no = %d", errno);
            char buf[2048];
            int result2 = read(pfd.fd, buf, sizeof(buf));
            ALOGE("Read after POLL returned %d, error no = %d", result2, errno);
        } else if (pfd.revents & POLLHUP) {
            ALOGE("Remote side hung up");
            break;
        } else if (pfd.revents & POLLIN) {
            // ALOGI("Found some events!!!");
            internal_pollin_handler(handle);
        } else {
            ALOGE("Unknown event - %0x", pfd.revents);
        }
    } while (!info->clean_up);


    ALOGI("Cleaning up");
    internal_cleaned_up_handler(handle);
}

///////////////////////////////////////////////////////////////////////////////////////

static int internal_no_seq_check(struct nl_msg *msg, void *arg)
{
    return NL_OK;
}

static int internal_valid_message_handler(nl_msg *msg, void *arg)
{
    wifi_handle handle = (wifi_handle)arg;
    hal_info *info = getHalInfo(handle);

    WifiEvent event(msg);
    int res = event.parse();
    if (res < 0) {
        ALOGE("Failed to parse event: %d", res);
        return NL_SKIP;
    }

    int cmd = event.get_cmd();
    uint32_t vendor_id = 0;
    int subcmd = 0;

    if (cmd == NL80211_CMD_VENDOR) {
        vendor_id = event.get_u32(NL80211_ATTR_VENDOR_ID);
        subcmd = event.get_u32(NL80211_ATTR_VENDOR_SUBCMD);
        ALOGI("event received %s, vendor_id = 0x%0x, subcmd = 0x%0x",
                event.get_cmdString(), vendor_id, subcmd);
    } else {
        // ALOGI("event received %s", event.get_cmdString());
    }

    // ALOGI("event received %s, vendor_id = 0x%0x", event.get_cmdString(), vendor_id);
    // event.log();

    bool dispatched = false;

    pthread_mutex_lock(&info->cb_lock);

    for (int i = 0; i < info->num_event_cb; i++) {
        if (cmd == info->event_cb[i].nl_cmd) {
            if (cmd == NL80211_CMD_VENDOR
                && ((vendor_id != info->event_cb[i].vendor_id)
                || (subcmd != info->event_cb[i].vendor_subcmd)))
            {
                /* event for a different vendor, ignore it */
                continue;
            }

            cb_info *cbi = &(info->event_cb[i]);
            nl_recvmsg_msg_cb_t cb_func = cbi->cb_func;
            void *cb_arg = cbi->cb_arg;
            WifiCommand *cmd = (WifiCommand *)cbi->cb_arg;
            if (cmd != NULL) {
                cmd->addRef();
            }

            pthread_mutex_unlock(&info->cb_lock);

            (*cb_func)(msg, cb_arg);
            if (cmd != NULL) {
                cmd->releaseRef();
            }

            return NL_OK;
        }
    }

    pthread_mutex_unlock(&info->cb_lock);
    return NL_OK;
}

///////////////////////////////////////////////////////////////////////////////////////

class GetMulticastIdCommand : public WifiCommand
{
private:
    const char *mName;
    const char *mGroup;
    int   mId;
public:
    GetMulticastIdCommand(wifi_handle handle, const char *name, const char *group)
        : WifiCommand(handle, 0)
    {
        mName = name;
        mGroup = group;
        mId = -1;
    }

    int getId() {
        return mId;
    }

    virtual int create() {
        int nlctrlFamily = genl_ctrl_resolve(mInfo->cmd_sock, "nlctrl");
        // ALOGI("ctrl family = %d", nlctrlFamily);
        int ret = mMsg.create(nlctrlFamily, CTRL_CMD_GETFAMILY, 0, 0);
        if (ret < 0) {
            return ret;
        }
        ret = mMsg.put_string(CTRL_ATTR_FAMILY_NAME, mName);
        return ret;
    }

    virtual int handleResponse(WifiEvent& reply) {

        // ALOGI("handling reponse in %s", __func__);

        struct nlattr **tb = reply.attributes();
        struct genlmsghdr *gnlh = reply.header();
        struct nlattr *mcgrp = NULL;
        int i;

        if (!tb[CTRL_ATTR_MCAST_GROUPS]) {
            ALOGI("No multicast groups found");
            return NL_SKIP;
        } else {
            // ALOGI("Multicast groups attr size = %d", nla_len(tb[CTRL_ATTR_MCAST_GROUPS]));
        }

        for_each_attr(mcgrp, tb[CTRL_ATTR_MCAST_GROUPS], i) {

            // ALOGI("Processing group");
            struct nlattr *tb2[CTRL_ATTR_MCAST_GRP_MAX + 1];
            nla_parse(tb2, CTRL_ATTR_MCAST_GRP_MAX, (nlattr *)nla_data(mcgrp),
                nla_len(mcgrp), NULL);
            if (!tb2[CTRL_ATTR_MCAST_GRP_NAME] || !tb2[CTRL_ATTR_MCAST_GRP_ID]) {
                continue;
            }

            char *grpName = (char *)nla_data(tb2[CTRL_ATTR_MCAST_GRP_NAME]);
            int grpNameLen = nla_len(tb2[CTRL_ATTR_MCAST_GRP_NAME]);

            // ALOGI("Found group name %s", grpName);

            if (strncmp(grpName, mGroup, grpNameLen) != 0)
                continue;

            mId = nla_get_u32(tb2[CTRL_ATTR_MCAST_GRP_ID]);
            break;
        }

        return NL_SKIP;
    }

};

class SetPnoMacAddrOuiCommand : public WifiCommand {

private:
    byte *mOui;
    feature_set *fset;
    feature_set *feature_matrix;
    int *fm_size;
    int set_size_max;
public:
    SetPnoMacAddrOuiCommand(wifi_interface_handle handle, oui scan_oui)
        : WifiCommand(handle, 0)
    {
        mOui = scan_oui;
    }

    int createRequest(WifiRequest& request, int subcmd, byte *scan_oui) {
        int result = request.create(GOOGLE_OUI, subcmd);
        if (result < 0) {
            return result;
        }

        nlattr *data = request.attr_start(NL80211_ATTR_VENDOR_DATA);
        result = request.put(ANDR_WIFI_ATTRIBUTE_PNO_RANDOM_MAC_OUI, scan_oui, DOT11_OUI_LEN);
        if (result < 0) {
            return result;
        }

        request.attr_end(data);
        return WIFI_SUCCESS;

    }

    int start() {
        ALOGD("Sending mac address OUI");
        WifiRequest request(familyId(), ifaceId());
        int result = createRequest(request, WIFI_SUBCMD_SET_PNO_RANDOM_MAC_OUI, mOui);
        if (result != WIFI_SUCCESS) {
            ALOGE("failed to create request; result = %d", result);
            return result;
        }

        result = requestResponse(request);
        if (result != WIFI_SUCCESS) {
            ALOGE("failed to set scanning mac OUI; result = %d", result);
        }

        return result;
    }
protected:
    virtual int handleResponse(WifiEvent& reply) {
         ALOGD("Request complete!");
        /* Nothing to do on response! */
        return NL_SKIP;
    }
};

class SetNodfsCommand : public WifiCommand {

private:
    u32 mNoDfs;
public:
    SetNodfsCommand(wifi_interface_handle handle, u32 nodfs)
        : WifiCommand(handle, 0) {
        mNoDfs = nodfs;
    }
    virtual int create() {
        int ret;

        ret = mMsg.create(GOOGLE_OUI, WIFI_SUBCMD_NODFS_SET);
        if (ret < 0) {
            ALOGE("Can't create message to send to driver - %d", ret);
            return ret;
        }

        nlattr *data = mMsg.attr_start(NL80211_ATTR_VENDOR_DATA);
        ret = mMsg.put_u32(ATTR_NODFS_VALUE, mNoDfs);
        if (ret < 0) {
             return ret;
        }

        mMsg.attr_end(data);
        return WIFI_SUCCESS;
    }
};

class GetFeatureSetCommand : public WifiCommand {

private:
    int feature_type;
    feature_set *fset;
    feature_set *feature_matrix;
    int *fm_size;
    int set_size_max;
public:
    GetFeatureSetCommand(wifi_interface_handle handle, int feature, feature_set *set,
         feature_set set_matrix[], int *size, int max_size)
        : WifiCommand(handle, 0)
    {
        feature_type = feature;
        fset = set;
        feature_matrix = set_matrix;
        fm_size = size;
        set_size_max = max_size;
    }

    virtual int create() {
        int ret;

        if(feature_type == FEATURE_SET) {
            ret = mMsg.create(GOOGLE_OUI, WIFI_SUBCMD_GET_FEATURE_SET);
        } else if (feature_type == FEATURE_SET_MATRIX) {
            ret = mMsg.create(GOOGLE_OUI, WIFI_SUBCMD_GET_FEATURE_SET_MATRIX);
        } else {
            ALOGE("Unknown feature type %d", feature_type);
            return -1;
        }

        if (ret < 0) {
            ALOGE("Can't create message to send to driver - %d", ret);
        }

        return ret;
    }

protected:
    virtual int handleResponse(WifiEvent& reply) {

        ALOGD("In GetFeatureSetCommand::handleResponse");

        if (reply.get_cmd() != NL80211_CMD_VENDOR) {
            ALOGD("Ignoring reply with cmd = %d", reply.get_cmd());
            return NL_SKIP;
        }

        int id = reply.get_vendor_id();
        int subcmd = reply.get_vendor_subcmd();

        nlattr *vendor_data = reply.get_attribute(NL80211_ATTR_VENDOR_DATA);
        int len = reply.get_vendor_data_len();

        ALOGD("Id = %0x, subcmd = %d, len = %d", id, subcmd, len);
        if (vendor_data == NULL || len == 0) {
            ALOGE("no vendor data in GetFeatureSetCommand response; ignoring it");
            return NL_SKIP;
        }
        if(feature_type == FEATURE_SET) {
            void *data = reply.get_vendor_data();
            if(!fset) {
                ALOGE("Buffers pointers not set");
                return NL_SKIP;
            }
            memcpy(fset, data, min(len, (int) sizeof(*fset)));
        } else {
            int num_features_set = 0;
            int i = 0;

            if(!feature_matrix || !fm_size) {
                ALOGE("Buffers pointers not set");
                return NL_SKIP;
            }

            for (nl_iterator it(vendor_data); it.has_next(); it.next()) {
                if (it.get_type() == ANDR_WIFI_ATTRIBUTE_NUM_FEATURE_SET) {
                    num_features_set = it.get_u32();
                    ALOGI("Got feature list with %d concurrent sets", num_features_set);
                    if(set_size_max && (num_features_set > set_size_max))
                        num_features_set = set_size_max;
                    *fm_size = num_features_set;
                } else if ((it.get_type() == ANDR_WIFI_ATTRIBUTE_FEATURE_SET) &&
                             i < num_features_set) {
                    feature_matrix[i] = it.get_u32();
                    i++;
                } else {
                    ALOGW("Ignoring invalid attribute type = %d, size = %d",
                            it.get_type(), it.get_len());
                }
            }

        }
        return NL_OK;
    }

};

static int wifi_get_multicast_id(wifi_handle handle, const char *name, const char *group)
{
    GetMulticastIdCommand cmd(handle, name, group);
    int res = cmd.requestResponse();
    if (res < 0)
        return res;
    else
        return cmd.getId();
}

/////////////////////////////////////////////////////////////////////////

static bool is_wifi_interface(const char *name)
{
    if (strncmp(name, "wlan", 4) != 0 && strncmp(name, "p2p", 3) != 0) {
        /* not a wifi interface; ignore it */
        return false;
    } else {
        return true;
    }
}

static int get_interface(const char *name, interface_info *info)
{
    strcpy(info->name, name);
    info->id = if_nametoindex(name);
    // ALOGI("found an interface : %s, id = %d", name, info->id);
    return WIFI_SUCCESS;
}

wifi_error wifi_init_interfaces(wifi_handle handle)
{
    hal_info *info = (hal_info *)handle;

    struct dirent *de;

    DIR *d = opendir("/sys/class/net");
    if (d == 0)
        return WIFI_ERROR_UNKNOWN;

    int n = 0;
    while ((de = readdir(d))) {
        if (de->d_name[0] == '.')
            continue;
        if (is_wifi_interface(de->d_name) ) {
            n++;
        }
    }

    closedir(d);

    d = opendir("/sys/class/net");
    if (d == 0)
        return WIFI_ERROR_UNKNOWN;

    info->interfaces = (interface_info **)malloc(sizeof(interface_info *) * n);

    int i = 0;
    while ((de = readdir(d))) {
        if (de->d_name[0] == '.')
            continue;
        if (is_wifi_interface(de->d_name)) {
            interface_info *ifinfo = (interface_info *)malloc(sizeof(interface_info));
            if (get_interface(de->d_name, ifinfo) != WIFI_SUCCESS) {
                free(ifinfo);
                continue;
            }
            ifinfo->handle = handle;
            info->interfaces[i] = ifinfo;
            i++;
        }
    }

    closedir(d);

    info->num_interfaces = n;
    return WIFI_SUCCESS;
}

wifi_error wifi_get_ifaces(wifi_handle handle, int *num, wifi_interface_handle **interfaces)
{
    hal_info *info = (hal_info *)handle;

    *interfaces = (wifi_interface_handle *)info->interfaces;
    *num = info->num_interfaces;

    return WIFI_SUCCESS;
}

wifi_error wifi_get_iface_name(wifi_interface_handle handle, char *name, size_t size)
{
    interface_info *info = (interface_info *)handle;
    strcpy(name, info->name);
    return WIFI_SUCCESS;
}

wifi_error wifi_get_supported_feature_set(wifi_interface_handle handle, feature_set *set)
{
    GetFeatureSetCommand command(handle, FEATURE_SET, set, NULL, NULL, 1);
    return (wifi_error) command.requestResponse();
}

wifi_error wifi_get_concurrency_matrix(wifi_interface_handle handle, int set_size_max,
       feature_set set[], int *set_size)
{
    GetFeatureSetCommand command(handle, FEATURE_SET_MATRIX, NULL, set, set_size, set_size_max);
    return (wifi_error) command.requestResponse();
}

wifi_error wifi_set_scanning_mac_oui(wifi_interface_handle handle, oui scan_oui)
{
    SetPnoMacAddrOuiCommand command(handle, scan_oui);
    return (wifi_error)command.start();

}

wifi_error wifi_set_nodfs_flag(wifi_interface_handle handle, u32 nodfs)
{
    SetNodfsCommand command(handle, nodfs);
    return (wifi_error) command.requestResponse();
}

/////////////////////////////////////////////////////////////////////////////