#include "AP_Networking_Config.h"

#if AP_NETWORKING_ENABLED

#include "AP_Networking.h"
#include "AP_Networking_Backend.h"
#include <GCS_MAVLink/GCS.h>
#include <AP_Math/crc.h>
#include <AP_InternalError/AP_InternalError.h>
#include <AP_Filesystem/AP_Filesystem.h>
#include <AP_HAL/CANIface.h>

extern const AP_HAL::HAL& hal;

#if AP_NETWORKING_BACKEND_CHIBIOS
#include "AP_Networking_ChibiOS.h"
#include <hal_mii.h>
#endif

#include <lwipopts.h>
#include <errno.h>


#include <AP_HAL/utility/Socket.h>

#if AP_NETWORKING_BACKEND_PPP
#include "AP_Networking_PPP.h"
#endif

#if AP_NETWORKING_BACKEND_SITL
#include "AP_Networking_SITL.h"
#endif

const AP_Param::GroupInfo AP_Networking::var_info[] = {
    // @Param: ENABLE
    // @DisplayName: Networking Enable
    // @Description: Networking Enable
    // @Values: 0:Disable,1:Enable
    // @RebootRequired: True
    // @User: Advanced
    AP_GROUPINFO_FLAGS("ENABLE",  1, AP_Networking, param.enabled, 0, AP_PARAM_FLAG_ENABLE),

#if AP_NETWORKING_CONTROLS_HOST_IP_SETTINGS_ENABLED
    // @Group: IPADDR
    // @Path: AP_Networking_address.cpp
    AP_SUBGROUPINFO(param.ipaddr, "IPADDR", 2,  AP_Networking, AP_Networking_IPV4),

    // @Param: NETMASK
    // @DisplayName: IP Subnet mask
    // @Description: Allows setting static subnet mask. The value is a count of consecutive bits. Examples: 24 = 255.255.255.0, 16 = 255.255.0.0
    // @Range: 0 32
    // @RebootRequired: True
    // @User: Advanced
    AP_GROUPINFO("NETMASK", 3,  AP_Networking,    param.netmask,   AP_NETWORKING_DEFAULT_NETMASK),

#if AP_NETWORKING_DHCP_AVAILABLE
    // @Param: DHCP
    // @DisplayName: DHCP client
    // @Description: Enable/Disable DHCP client
    // @Values: 0:Disable, 1:Enable
    // @RebootRequired: True
    // @User: Advanced
    AP_GROUPINFO("DHCP", 4,  AP_Networking,    param.dhcp,   AP_NETWORKING_DEFAULT_DHCP_ENABLE),
#endif

    // @Group: GWADDR
    // @Path: AP_Networking_address.cpp
    AP_SUBGROUPINFO(param.gwaddr, "GWADDR", 5,  AP_Networking, AP_Networking_IPV4),

    // @Group: MACADDR
    // @Path: AP_Networking_macaddr.cpp
    AP_SUBGROUPINFO(param.macaddr, "MACADDR", 6,  AP_Networking, AP_Networking_MAC),
#endif // AP_NETWORKING_CONTROLS_HOST_IP_SETTINGS_ENABLED

#if AP_NETWORKING_TESTS_ENABLED
    // @Param: TESTS
    // @DisplayName: Test enable flags
    // @Description: Enable/Disable networking tests
    // @Bitmask: 0:UDP echo test,1:TCP echo test, 2:TCP discard test, 3:TCP reflect test
    // @RebootRequired: True
    // @User: Advanced
    AP_GROUPINFO("TESTS", 7,  AP_Networking,    param.tests,   0),

    // @Group: TEST_IP
    // @Path: AP_Networking_address.cpp
    AP_SUBGROUPINFO(param.test_ipaddr, "TEST_IP", 8,  AP_Networking, AP_Networking_IPV4),
#endif

    // @Param: OPTIONS
    // @DisplayName: Networking options
    // @Description: Networking options
    // @Bitmask: 0:EnablePPP Ethernet gateway, 1:Enable CAN1 multicast gateway, 2:Enable CAN2 multicast gateway
    // @RebootRequired: True
    // @User: Advanced
    AP_GROUPINFO("OPTIONS", 9,  AP_Networking,    param.options, 0),

#if AP_NETWORKING_PPP_GATEWAY_ENABLED
    // @Group: REMPPP_IP
    // @Path: AP_Networking_address.cpp
    AP_SUBGROUPINFO(param.remote_ppp_ip, "REMPPP_IP", 10,  AP_Networking, AP_Networking_IPV4),
#endif
    
    AP_GROUPEND
};

/*
  constructor
 */
AP_Networking::AP_Networking(void)
{
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
    if (singleton != nullptr) {
        AP_HAL::panic("AP_Networking must be singleton");
    }
#endif
    singleton = this;
    AP_Param::setup_object_defaults(this, var_info);
}

/*
  initialise networking subsystem
 */
void AP_Networking::init()
{
    if (!param.enabled || backend != nullptr) {
        return;
    }

#if AP_NETWORKING_CONTROLS_HOST_IP_SETTINGS_ENABLED
    // set default MAC Address as lower 3 bytes of the CRC of the UID
    uint8_t uid[50];
    uint8_t uid_len = sizeof(uid);
    if (hal.util->get_system_id_unformatted(uid, uid_len)) {
        union {
            uint8_t bytes[4];
            uint32_t value32;
        } crc;
        crc.value32 = crc_crc32(0, uid, uid_len);

        param.macaddr.set_default_address_byte(3, crc.bytes[0]);
        param.macaddr.set_default_address_byte(4, crc.bytes[1]);
        param.macaddr.set_default_address_byte(5, crc.bytes[2]);
    }
#endif

#if AP_NETWORKING_PPP_GATEWAY_ENABLED
    if (option_is_set(OPTION::PPP_ETHERNET_GATEWAY)) {
        /*
          when we are a PPP/Ethernet gateway we bring up the ethernet first
         */
        backend = NEW_NOTHROW AP_Networking_ChibiOS(*this);
        backend_PPP = NEW_NOTHROW AP_Networking_PPP(*this);
    }
#endif


#if AP_NETWORKING_BACKEND_PPP
    if (backend == nullptr && AP::serialmanager().have_serial(AP_SerialManager::SerialProtocol_PPP, 0)) {
        backend = NEW_NOTHROW AP_Networking_PPP(*this);
    }
#endif

#if AP_NETWORKING_BACKEND_CHIBIOS
    if (backend == nullptr) {
        backend = NEW_NOTHROW AP_Networking_ChibiOS(*this);
    }
#endif
#if AP_NETWORKING_BACKEND_SITL
    if (backend == nullptr) {
        backend = NEW_NOTHROW AP_Networking_SITL(*this);
    }
#endif

    if (backend == nullptr) {
        GCS_SEND_TEXT(MAV_SEVERITY_INFO, "NET: backend failed");
        return;
    }

    if (!backend->init()) {
        GCS_SEND_TEXT(MAV_SEVERITY_INFO, "NET: backend init failed");
        // the backend init function creates a thread which references the backend pointer; that thread may be running so don't remove the backend allocation.
        backend = nullptr;
        return;
    }

#if AP_NETWORKING_PPP_GATEWAY_ENABLED
    if (backend_PPP != nullptr && !backend_PPP->init()) {
        GCS_SEND_TEXT(MAV_SEVERITY_INFO, "NET: backend_PPP init failed");
        backend_PPP = nullptr;
    }
#endif

    announce_address_changes();

    GCS_SEND_TEXT(MAV_SEVERITY_INFO,"NET: Initialized");

#if AP_NETWORKING_TESTS_ENABLED
    start_tests();
#endif

#if AP_NETWORKING_CAN_MCAST_ENABLED && !defined(HAL_BOOTLOADER_BUILD)
    if (option_is_set(OPTION::CAN1_MCAST_GATEWAY) || option_is_set(OPTION::CAN2_MCAST_GATEWAY)) {
        // get mask of enabled buses
        uint8_t bus_mask = 0;
        if (option_is_set(OPTION::CAN1_MCAST_GATEWAY)) {
            bus_mask |= (1U<<0);
        }
        if (option_is_set(OPTION::CAN2_MCAST_GATEWAY)) {
            bus_mask |= (1U<<1);
        }
        mcast_server.start(bus_mask);
    }
#endif
    
#if AP_NETWORKING_REGISTER_PORT_ENABLED
    // init network mapped serialmanager ports
    ports_init();
#endif
}

/*
  check if we should announce changes to IP addresses
 */
void AP_Networking::announce_address_changes()
{
    const auto &as = backend->activeSettings;

    if (as.last_change_ms == 0 || as.last_change_ms == announce_ms) {
        // nothing changed and we've already printed it at least once. Nothing to do.
        return;
    }

#if AP_HAVE_GCS_SEND_TEXT
    char ipstr[16];
    GCS_SEND_TEXT(MAV_SEVERITY_INFO, "NET: IP      %s", SocketAPM::inet_addr_to_str(get_ip_active(), ipstr, sizeof(ipstr)));
    GCS_SEND_TEXT(MAV_SEVERITY_INFO, "NET: Mask    %s", SocketAPM::inet_addr_to_str(get_netmask_active(), ipstr, sizeof(ipstr)));
    GCS_SEND_TEXT(MAV_SEVERITY_INFO, "NET: Gateway %s", SocketAPM::inet_addr_to_str(get_gateway_active(), ipstr, sizeof(ipstr)));
#endif

    announce_ms = as.last_change_ms;
}

/*
  update called at 10Hz
 */
void AP_Networking::update()
{
    if (!is_healthy()) {
        return;
    }
    backend->update();
    announce_address_changes();
}

uint32_t AP_Networking::convert_netmask_bitcount_to_ip(const uint32_t netmask_bitcount)
{
    if (netmask_bitcount >= 32) {
        return 0xFFFFFFFFU;
    }
    return ~((1U<<(32U-netmask_bitcount))-1U);
}

uint8_t AP_Networking::convert_netmask_ip_to_bitcount(const uint32_t netmask_ip)
{
    uint32_t netmask_bitcount = 0;
    for (uint32_t i=0; i<32; i++) {
        // note, netmask LSB is IP MSB
        if ((netmask_ip & (1UL<<i)) == 0) {
            break;
        }
        netmask_bitcount++;
    }
    return netmask_bitcount;
}

/*
  convert a string to an ethernet MAC address
 */
bool AP_Networking::convert_str_to_macaddr(const char *mac_str, uint8_t addr[6])
{
    if (strlen(mac_str) != 17) {
        return false;
    }
    char s2[18];
    strncpy(s2, mac_str, sizeof(s2)-1);
    s2[17] = 0;
    char *ptr = nullptr;
    const char *s = strtok_r(s2, ":", &ptr);
    for (uint8_t i=0; i<6; i++) {
        if (s == nullptr) {
            return false;
        }
        auto v = strtoul(s, nullptr, 16);
        if (v > 255) {
            return false;
        }
        addr[i] = v;
        s = strtok_r(nullptr, ":", &ptr);
    }
    return true;
}

// returns the 32bit value of the active IP address that is currently in use
uint32_t AP_Networking::get_ip_active() const
{
    return backend?backend->activeSettings.ip:0;
}

// returns the 32bit value of the active Netmask that is currently in use
uint32_t AP_Networking::get_netmask_active() const
{
    return backend?backend->activeSettings.nm:0;
}

uint32_t AP_Networking::get_gateway_active() const
{
    return backend?backend->activeSettings.gw:0;
}

/*
  wait for networking to be active
 */
void AP_Networking::startup_wait(void) const
{
    if (hal.scheduler->in_main_thread()) {
        INTERNAL_ERROR(AP_InternalError::error_t::flow_of_control);
        return;
    }
    while (!hal.scheduler->is_system_initialized()) {
        hal.scheduler->delay(100);
    }
#if AP_NETWORKING_BACKEND_CHIBIOS
    do {
        hal.scheduler->delay(250);
    } while (get_ip_active() == 0);
#endif
}

/*
  send the rest of a file to a socket
 */
bool AP_Networking::sendfile(SocketAPM *sock, int fd)
{
    WITH_SEMAPHORE(sem);
    if (sendfile_buf == nullptr) {
        uint32_t bufsize = AP_NETWORKING_SENDFILE_BUFSIZE;
        do {
            sendfile_buf = (uint8_t *)hal.util->malloc_type(bufsize, AP_HAL::Util::MEM_FILESYSTEM);
            if (sendfile_buf != nullptr) {
                sendfile_bufsize = bufsize;
                break;
            }
            bufsize /= 2;
        } while (bufsize >= 4096);
        if (sendfile_buf == nullptr) {
            return false;
        }
    }
    if (!sendfile_thread_started) {
        if (!hal.scheduler->thread_create(FUNCTOR_BIND_MEMBER(&AP_Networking::sendfile_check, void),
                                          "sendfile",
                                          2048, AP_HAL::Scheduler::PRIORITY_UART, 0)) {
            return false;
        }
        sendfile_thread_started = true;
    }
    for (auto &s : sendfiles) {
        if (s.sock == nullptr) {
            s.sock = sock->duplicate();
            if (s.sock == nullptr) {
                return false;
            }
            s.fd = fd;
            return true;
        }
    }
    return false;
}

void AP_Networking::SendFile::close(void)
{
    AP::FS().close(fd);
    delete sock;
    sock = nullptr;
}

#include <stdio.h>
/*
  check for sendfile updates
 */
void AP_Networking::sendfile_check(void)
{
    while (true) {
        hal.scheduler->delay(1);
        WITH_SEMAPHORE(sem);
        bool none_active = true;
        for (auto &s : sendfiles) {
            if (s.sock == nullptr) {
                continue;
            }
            none_active = false;
            if (!s.sock->pollout(0)) {
                continue;
            }
            const auto nread = AP::FS().read(s.fd, sendfile_buf, sendfile_bufsize);
            if (nread <= 0) {
                s.close();
                continue;
            }
            const auto nsent = s.sock->send(sendfile_buf, nread);
            if (nsent <= 0) {
                s.close();
                continue;
            }
            if (nsent < nread) {
                AP::FS().lseek(s.fd, nsent - nread, SEEK_CUR);
            }
        }
        if (none_active) {
            free(sendfile_buf);
            sendfile_buf = nullptr;
        }
    }
}

AP_Networking *AP_Networking::singleton;

namespace AP
{
AP_Networking &network()
{
    return *AP_Networking::get_singleton();
}
}

/*
  debug printfs from LWIP
 */
int ap_networking_printf(const char *fmt, ...)
{
    WITH_SEMAPHORE(AP::network().get_semaphore());
#ifdef AP_NETWORKING_LWIP_DEBUG_FILE
    static int fd = -1;
    if (fd == -1) {
        fd = AP::FS().open(AP_NETWORKING_LWIP_DEBUG_FILE, O_WRONLY|O_CREAT|O_TRUNC, 0644);
        if (fd == -1) {
            return -1;
        }
    }
    va_list ap;
    va_start(ap, fmt);
    vdprintf(fd, fmt, ap);
    va_end(ap);
#else
    va_list ap;
    va_start(ap, fmt);
    hal.console->vprintf(fmt, ap);
    va_end(ap);
#endif
    return 0;
}

// address to string using a static return buffer
const char *AP_Networking::address_to_str(uint32_t addr)
{
    static char buf[16]; // 16 for aaa.bbb.ccc.ddd
    return SocketAPM::inet_addr_to_str(addr, buf, sizeof(buf));
}

#ifdef LWIP_PLATFORM_ASSERT
void ap_networking_platform_assert(const char *msg, int line, const char *file)
{
    AP_HAL::panic("LWIP: %s: %s:%u", msg, file, line);
}
#endif

#endif // AP_NETWORKING_ENABLED