#include <stdio.h>
#include <string.h>

#include "wm_include.h"
#include "wm_efuse.h"
#include "wm_watchdog.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h" /* struct netif is only forward-declared by wm_netif2.0.3.h */

#include "light/nl_engine.h"
#include "net/nl_mdns.h"
#include "net/nl_names.h"
#include "net/nl_wifi.h"
#include "net/nl_wifi_sm.h"
#include "sys/nl_app.h"

#define NL_NET_PRIO  35
#define NL_NET_QUEUE 8
#define MSG_NETIF    0x100u /* | netif status */
#define MSG_ONBOARD  0x200u

static u32 s_stack[768];
static tls_os_queue_t *s_queue;
static tls_os_mutex_t *s_lock; /* guards s_sm and the credential buffers */
static nl_wifi_sm_t s_sm;
static bool s_started;
static uint8_t s_mac[6];
static char s_hostname[24];
static char s_ssid[NL_SSID_LEN], s_pass[NL_PASS_LEN];
static char s_test_ssid[NL_SSID_LEN], s_test_pass[NL_PASS_LEN];
static char s_ap_pass[NL_PASS_LEN];
static bool s_ap_create_pending;      /* M3: tls_wifi_softap_create() failed, retry it */
static uint32_t s_ap_create_retry_at;

volatile uint32_t nl_net_beat;

static void lock(void) { tls_os_mutex_acquire(s_lock, 0); }
static void unlock(void) { tls_os_mutex_release(s_lock); }

static void copy(char *dst, const char *src, size_t size)
{
    strncpy(dst, src, size - 1);
    dst[size - 1] = '\0';
}

static bool due_now(uint32_t now, uint32_t at) { return (int32_t)(now - at) >= 0; }

/* SDK system task context: only hand the event over. */
static void netif_event(u8 status)
{
    tls_os_queue_send(s_queue, (void *)(MSG_NETIF | status), 0);
}

/* C2: the SDK sets the SOFTAP bit in TLS_PARAM_ID_WPROTOCOL when tls_wifi_softap_create()
 * runs and persists it to flash; tls_wifi_softap_destroy() only sends a supplicant event
 * and never clears it. As long as the bit stays set, sys_net_status_changed() in
 * sdk/Platform/Sys/tls_sys.c (NETIF_IP_NET_UP case) recreates the AP with the SDK's own
 * (public default) softap params on every station IP-up - independent of our auto-connect
 * flag. Clear the bit (and persist that) whenever we know the AP should be down. */
static void clear_softap_param(void)
{
    u8 proto = 0;

    tls_param_get(TLS_PARAM_ID_WPROTOCOL, &proto, FALSE);
    if (proto & IEEE80211_MODE_AP) {
        proto &= (u8)~IEEE80211_MODE_AP;
        tls_param_set(TLS_PARAM_ID_WPROTOCOL, &proto, TRUE);
        printf("wifi: cleared stale SDK softap param (wprotocol now %u)\r\n", proto);
    }
}

static void start_ap(void)
{
    struct tls_softap_info_t ap;
    struct tls_ip_info_t ip;
    size_t n = strlen(s_ap_pass);
    int r;

    memset(&ap, 0, sizeof ap);
    memset(&ip, 0, sizeof ip);
    copy((char *)ap.ssid, s_hostname, sizeof ap.ssid);
    ap.encrypt = IEEE80211_ENCRYT_CCMP_WPA2;
    ap.channel = 6;
    ap.keyinfo.format = 1; /* ascii */
    ap.keyinfo.index = 1;
    ap.keyinfo.key_len = (u8)n;
    memcpy(ap.keyinfo.key, s_ap_pass, n);
    ip.ip_addr[0] = 192; ip.ip_addr[1] = 168; ip.ip_addr[2] = 4; ip.ip_addr[3] = 1;
    ip.netmask[0] = 255; ip.netmask[1] = 255; ip.netmask[2] = 255; ip.netmask[3] = 0;
    memcpy(ip.dnsname, "local", 6);
    r = tls_wifi_softap_create(&ap, &ip);
    printf("wifi: AP %s %s\r\n", s_hostname, r == WM_SUCCESS ? "up" : "failed");
    /* M3: retry a failed AP create instead of leaving onboarding/fallback without an AP. */
    s_ap_create_pending = r != WM_SUCCESS;
    s_ap_create_retry_at = nl_app_now_ms() + 5000u;
}

static void connect_station(bool test)
{
    char ssid[NL_SSID_LEN], pass[NL_PASS_LEN];
    int r;

    lock();
    copy(ssid, test ? s_test_ssid : s_ssid, sizeof ssid);
    copy(pass, test ? s_test_pass : s_pass, sizeof pass);
    unlock();
    printf("wifi: connecting to %s\r\n", ssid);
    r = tls_wifi_connect((u8 *)ssid, (u8)strlen(ssid), (u8 *)pass, (u8)strlen(pass));
    if (r != WM_SUCCESS) /* M2: surface connect-call failures, not just later join events */
        printf("wifi: tls_wifi_connect failed, err=%d\r\n", r);
}

static void pulse(bool on)
{
    nl_app_lock();
    nl_engine_pulse(on);
    nl_app_unlock();
}

static void execute(nl_wifi_actions_t a)
{
    if (a.save_test_creds) {
        char ssid[NL_SSID_LEN], pass[NL_PASS_LEN];
        lock();
        copy(s_ssid, s_test_ssid, sizeof s_ssid);
        copy(s_pass, s_test_pass, sizeof s_pass);
        copy(ssid, s_ssid, sizeof ssid);
        copy(pass, s_pass, sizeof pass);
        unlock();
        printf("wifi: onboarding ok, saving credentials for %s\r\n", ssid);
        nl_app_set_wifi_credentials(ssid, pass);
    }
    if (a.pulse_on)
        pulse(true);
    if (a.pulse_off)
        pulse(false);
    if (a.start_ap)
        start_ap();
    if (a.stop_ap) {
        printf("wifi: AP down\r\n");
        tls_wifi_softap_destroy();
        s_ap_create_pending = false;
        clear_softap_param(); /* C2: every softap teardown clears the persisted SOFTAP bit */
    }
    if (a.disconnect) {
        printf("wifi: dropping stray/failed station attempt\r\n");
        tls_wifi_disconnect();
    }
    if (a.connect)
        connect_station(a.use_test_creds);
}

static nl_wifi_error_t join_error(void)
{
    switch (tls_wifi_get_errno()) {
    case WM_WIFI_EKEY: return NL_WIFI_ERR_AUTH;
    case WM_WIFI_ENOAP: return NL_WIFI_ERR_NOT_FOUND;
    default: return NL_WIFI_ERR_TIMEOUT;
    }
}

static void net_task(void *arg)
{
    (void)arg;
    for (;;) {
        void *msg = NULL;
        nl_wifi_actions_t ev, tick;
        uint32_t m = 0, now;
        bool got_ip_event = false, connected_now, ap_wanted, unexpected_softap;

        memset(&ev, 0, sizeof ev);
        if (tls_os_queue_receive(s_queue, &msg, 0, HZ / 10) == TLS_OS_SUCCESS)
            m = (uint32_t)msg;
        now = nl_app_now_ms();

        lock();
        if (m == (MSG_NETIF | NETIF_IP_NET_UP)) {
            ev = nl_wifi_sm_event(&s_sm, NL_WIFI_EV_CONNECTED, NL_WIFI_ERR_NONE, now);
            got_ip_event = true;
        } else if (m == (MSG_NETIF | NETIF_WIFI_JOIN_FAILED)) {
            ev = nl_wifi_sm_event(&s_sm, NL_WIFI_EV_JOIN_FAILED, join_error(), now);
        } else if (m == (MSG_NETIF | NETIF_WIFI_DISCONNECTED)) {
            ev = nl_wifi_sm_event(&s_sm, NL_WIFI_EV_DISCONNECTED, NL_WIFI_ERR_NONE, now);
        } else if (m == MSG_ONBOARD) {
            ev = nl_wifi_sm_onboard(&s_sm, now);
        }
        tick = nl_wifi_sm_tick(&s_sm, now);
        /* I1: a late/stray IP-up must not announce mDNS unless the SM actually settled on STA_CONNECTED. */
        connected_now = s_sm.state == NL_WIFI_ST_STA_CONNECTED;
        ap_wanted = s_sm.ap_up;
        /* C2 backstop: the SDK brought its own softap up behind our back (e.g. the clear in
         * nl_wifi_start raced a pending sys_net_status_changed()) while our state machine
         * does not want an AP. Only latch the fact here; tls_wifi_softap_destroy() and
         * clear_softap_param() touch the SDK's own state and must not run while s_lock
         * (which only guards s_sm and the credential buffers) is held. */
        unexpected_softap = m == (MSG_NETIF | NETIF_WIFI_SOFTAP_SUCCESS) && !ap_wanted;
        unlock();

        if (unexpected_softap) {
            printf("wifi: unexpected SDK softap while AP should be down, destroying it\r\n");
            tls_wifi_softap_destroy();
            clear_softap_param();
        }

        if (m & MSG_NETIF)
            printf("wifi: netif event %u\r\n", (unsigned)(m & 0xFFu));
        execute(ev);
        execute(tick);
        if (got_ip_event && connected_now)
            nl_mdns_on_ip_up();

        /* M3: retry a softap create that failed, as long as the SM still wants the AP up. */
        if (s_ap_create_pending && ap_wanted && due_now(now, s_ap_create_retry_at)) {
            printf("wifi: retrying AP create\r\n");
            start_ap();
        }
        nl_net_beat++;
    }
}

void nl_wifi_start(const char *ssid, const char *pass, const char *ap_pass)
{
    u8 auto_mode = WIFI_AUTO_CNT_OFF;
    nl_wifi_actions_t a;
    struct netif *nif;

    clear_softap_param(); /* C2: drop any softap bit left over from a previous onboarding/fallback */

    tls_get_mac_addr(s_mac);
    nl_names_hostname(s_mac, s_hostname, sizeof s_hostname);
    copy(s_ssid, ssid, sizeof s_ssid);
    copy(s_pass, pass, sizeof s_pass);
    copy(s_ap_pass, ap_pass, sizeof s_ap_pass);

    /* The SDK would otherwise reconnect on its own with credentials from its parameter area. */
    tls_wifi_auto_connect_flag(WIFI_AUTO_CNT_FLAG_GET, &auto_mode);
    if (auto_mode != WIFI_AUTO_CNT_OFF) {
        auto_mode = WIFI_AUTO_CNT_OFF;
        tls_wifi_auto_connect_flag(WIFI_AUTO_CNT_FLAG_SET, &auto_mode);
    }
    tls_wifi_disconnect();
    if (tls_wifi_softap_get_state() != WM_WIFI_DISCONNECTED) {
        /* C2: the SDK already brought up its own softap (e.g. from NETIF_IP_NET_UP before
         * we got a chance to run) - tear it down, our state machine owns AP lifecycle. */
        printf("wifi: destroying SDK-created softap left over from boot\r\n");
        tls_wifi_softap_destroy();
        clear_softap_param();
    }
    nif = tls_get_netif();
    if (nif)
        nif->hostname = s_hostname; /* DHCP host name */

    tls_os_mutex_create(0, &s_lock);
    tls_os_queue_create(&s_queue, NL_NET_QUEUE);
    tls_netif_add_status_event(netif_event);

    lock();
    a = nl_wifi_sm_start(&s_sm, s_ssid[0] != '\0', nl_app_now_ms());
    unlock();
    s_started = true;
    printf("wifi: %s, hostname %s\r\n", s_ssid[0] ? "station" : "onboarding AP", s_hostname);
    execute(a);
    tls_os_task_create(NULL, "nl_net", net_task, NULL, (u8 *)s_stack, sizeof(s_stack), NL_NET_PRIO, 0);
}

int nl_wifi_request_onboard(const char *ssid, const char *pass)
{
    bool busy;

    if (!s_started)
        return -1;
    lock();
    busy = s_sm.state == NL_WIFI_ST_ONBOARD_TEST;
    if (!busy) {
        copy(s_test_ssid, ssid, sizeof s_test_ssid);
        copy(s_test_pass, pass, sizeof s_test_pass);
    }
    unlock();
    if (busy) /* M1: API returns 503 "wifi busy" instead of queuing on top of a running test */
        return -1;
    return tls_os_queue_send(s_queue, (void *)MSG_ONBOARD, 0) == TLS_OS_SUCCESS ? 0 : -1;
}

bool nl_wifi_open_access(void)
{
    bool r;
    if (!s_started)
        return false;
    lock();
    r = nl_wifi_sm_open_access(&s_sm);
    unlock();
    return r;
}

void nl_wifi_status(nl_wifi_status_t *out)
{
    struct tls_ethif *e = tls_netif_get_ethif();
    bool ap_up = false;

    memset(out, 0, sizeof *out);
    out->mode = "sta";
    if (s_started) {
        lock();
        out->mode = nl_wifi_sm_mode(&s_sm);
        out->error = nl_wifi_error_name(s_sm.error);
        copy(out->ssid, s_ssid, sizeof out->ssid);
        ap_up = s_sm.ap_up || s_sm.state == NL_WIFI_ST_AP_ONBOARDING;
        unlock();
    }
    if (e && e->status) {
        struct tls_curr_bss_t bss;
        ip4addr_ntoa_r(ip_2_ip4(&e->ip_addr), out->sta_ip, sizeof out->sta_ip);
        memset(&bss, 0, sizeof bss);
        tls_wifi_get_current_bss(&bss);
        /* W600 SDK reports RSSI magnitude as unsigned; EVK ninIOT measured ~-50 dBm as 50.
         * Report negative for 0 < bss.rssi <= 127, unchanged for > 127 (already two's complement). */
        out->rssi = (bss.rssi > 0 && bss.rssi <= 127) ? -(int)bss.rssi : (int)(int8_t)bss.rssi;
    }
    if (out->sta_ip[0])
        copy(out->ip, out->sta_ip, sizeof out->ip);
    else if (ap_up)
        copy(out->ip, "192.168.4.1", sizeof out->ip);
}

const char *nl_wifi_hostname(void) { return s_hostname; }

void nl_wifi_mac(uint8_t mac[6]) { memcpy(mac, s_mac, 6); }

/* --- boot recovery: join a station directly, ahead of nl_wifi_start()/nl_wifi_sm --- */

static volatile bool s_recovery_join_done;
static volatile bool s_recovery_join_ok;

static void recovery_join_event(u8 status)
{
    if (status == NETIF_IP_NET_UP) {
        s_recovery_join_ok = true;
        s_recovery_join_done = true;
    } else if (status == NETIF_WIFI_JOIN_FAILED) {
        s_recovery_join_done = true;
    }
}

bool nl_wifi_join_blocking(const char *ssid, const char *pass, uint32_t timeout_ms)
{
    uint32_t waited = 0;

    /* C2: if a stale SDK softap bit from a previous onboarding/fallback boot is still set
     * in TLS_PARAM_ID_WPROTOCOL, sys_net_status_changed() (sdk/Platform/Sys/tls_sys.c)
     * recreates the SDK's own default-params softap the moment this join reaches
     * NETIF_IP_NET_UP - exactly the "lamp stuck in onboarding" case recovery exists for.
     * Clear it once, up front, same as nl_wifi_start() does. */
    clear_softap_param();

    s_recovery_join_done = false;
    s_recovery_join_ok = false;
    tls_netif_add_status_event(recovery_join_event);
    if (tls_wifi_connect((u8 *)ssid, (u8)strlen(ssid), (u8 *)pass, (u8)strlen(pass)) != WM_SUCCESS) {
        tls_netif_remove_status_event(recovery_join_event);
        return false;
    }
    while (!s_recovery_join_done && waited < timeout_ms) {
        tls_watchdog_clr(); /* boot phase: called before app_task's own heartbeat gate exists */
        tls_os_time_delay(HZ / 10);
        waited += 100;
    }
    tls_netif_remove_status_event(recovery_join_event);
    if (!s_recovery_join_ok) {
        tls_wifi_disconnect(); /* cancel a stuck/timed-out join attempt */
        return false;
    }
    return true;
}