#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "nvs.h"
#include "esp_netif.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "wifi_cfg.h"

// Removed unused TAG

static esp_netif_t *sta_netif = NULL;

// --- Helper: NVS Write ---
static void nvs_write_str(const char *key, const char *val) {
    nvs_handle_t h;
    if (nvs_open("netcfg", NVS_READWRITE, &h) == ESP_OK) {
        if (val) nvs_set_str(h, key, val);
        else nvs_erase_key(h, key);
        nvs_commit(h);
        nvs_close(h);
    }
}

static void nvs_write_u8(const char *key, uint8_t val) {
    nvs_handle_t h;
    if (nvs_open("netcfg", NVS_READWRITE, &h) == ESP_OK) {
        nvs_set_u8(h, key, val);
        nvs_commit(h);
        nvs_close(h);
    }
}

// --- Public Setters ---

void wifi_cfg_set_credentials(const char* ssid, const char* pass) {
    nvs_write_str("ssid", ssid);
    nvs_write_str("pass", pass);
}

void wifi_cfg_set_static_ip(const char* ip, const char* mask, const char* gw) {
    nvs_write_str("ip", ip);
    nvs_write_str("mask", mask);
    nvs_write_str("gw", gw);
}

void wifi_cfg_set_dhcp(bool enable) {
    nvs_write_u8("dhcp", enable ? 1 : 0);
}

// --- Init & Load ---

void wifi_cfg_init(void) {
    nvs_flash_init();
}

static bool load_cfg(char* ssid, size_t ssz, char* pass, size_t psz,
                     char* ip, size_t isz, char* mask, size_t msz, char* gw, size_t gsz,
                     char* band, size_t bsz, char* bw, size_t bwsz, char* powersave, size_t pssz,
                     char* mode, size_t modesz, uint8_t* mon_ch, bool* dhcp){
    nvs_handle_t h;
    if (nvs_open("netcfg", NVS_READONLY, &h) != ESP_OK) return false;

    size_t len;
    // Load SSID (Mandatory)
    len = ssz;
    if (nvs_get_str(h, "ssid", ssid, &len) != ESP_OK) { nvs_close(h); return false; }

    // Load Optionals
    len = psz; if (nvs_get_str(h, "pass", pass, &len) != ESP_OK) pass[0]=0;
    len = isz; if (nvs_get_str(h, "ip", ip, &len) != ESP_OK) ip[0]=0;
    len = msz; if (nvs_get_str(h, "mask", mask, &len) != ESP_OK) mask[0]=0;
    len = gsz; if (nvs_get_str(h, "gw", gw, &len) != ESP_OK) gw[0]=0;

    // Defaults
    len = bsz; if (nvs_get_str(h, "band", band, &len) != ESP_OK) strcpy(band, "2.4G");
    len = bwsz; if (nvs_get_str(h, "bw", bw, &len) != ESP_OK) strcpy(bw, "HT20");
    len = pssz; if (nvs_get_str(h, "powersave", powersave, &len) != ESP_OK) strcpy(powersave, "NONE");
    len = modesz; if (nvs_get_str(h, "mode", mode, &len) != ESP_OK) strcpy(mode, "STA");

    uint8_t ch=36; nvs_get_u8(h, "mon_ch", &ch); *mon_ch = ch;
    uint8_t d=1; nvs_get_u8(h, "dhcp", &d); *dhcp = (d!=0);

    nvs_close(h);
    return true;
}

static void apply_ip_static(const char* ip, const char* mask, const char* gw){
    if (!sta_netif) return;
    if (!ip || !ip[0]) return;

    esp_netif_ip_info_t info = {0};
    esp_netif_dhcpc_stop(sta_netif);

    info.ip.addr      = esp_ip4addr_aton(ip);
    info.netmask.addr = (mask && mask[0]) ? esp_ip4addr_aton(mask) : esp_ip4addr_aton("255.255.255.0");
    info.gw.addr      = (gw && gw[0]) ? esp_ip4addr_aton(gw) : 0;

    esp_netif_set_ip_info(sta_netif, &info);
}

bool wifi_cfg_apply_from_nvs(void) {
    char ssid[64]={0}, pass[64]={0}, ip[32]={0}, mask[32]={0}, gw[32]={0};
    char band[16]={0}, bw[16]={0}, powersave[16]={0}, mode[16]={0};
    uint8_t mon_ch = 36; bool dhcp = true;

    if (!load_cfg(ssid,sizeof(ssid), pass,sizeof(pass), ip,sizeof(ip), mask,sizeof(mask), gw,sizeof(gw),
                  band,sizeof(band), bw,sizeof(bw), powersave,sizeof(powersave), mode,sizeof(mode), &mon_ch, &dhcp)){
        return false;
    }

    if (sta_netif == NULL) sta_netif = esp_netif_create_default_wifi_sta();

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    esp_wifi_init(&cfg);

    wifi_config_t wcfg = {0};
    strlcpy((char*)wcfg.sta.ssid, ssid, sizeof(wcfg.sta.ssid));
    strlcpy((char*)wcfg.sta.password, pass, sizeof(wcfg.sta.password));
    wcfg.sta.threshold.authmode = WIFI_AUTH_WPA2_PSK;
    wcfg.sta.sae_pwe_h2e = WPA3_SAE_PWE_BOTH;
    wcfg.sta.scan_method = WIFI_ALL_CHANNEL_SCAN;

    esp_wifi_set_mode(WIFI_MODE_STA);
    esp_wifi_set_config(WIFI_IF_STA, &wcfg);

    if (!dhcp && ip[0]) apply_ip_static(ip, mask, gw);
    else esp_netif_dhcpc_start(sta_netif);

    esp_wifi_start();
    esp_wifi_connect();
    return true;
}

wifi_ps_type_t wifi_cfg_get_power_save_mode(void) {
    return WIFI_PS_NONE;
}

bool wifi_cfg_get_bandwidth(char *buf, size_t buf_size) {
    if (buf) strncpy(buf, "HT20", buf_size);
    return true;
}

bool wifi_cfg_get_mode(char *mode, uint8_t *mon_ch) {
    nvs_handle_t h;
    if (nvs_open("netcfg", NVS_READONLY, &h) != ESP_OK) return false;
    size_t len = 16;
    if (nvs_get_str(h, "mode", mode, &len) != ESP_OK) strcpy(mode, "STA");
    nvs_get_u8(h, "mon_ch", mon_ch);
    nvs_close(h);
    return true;
}

// --- State Checkers ---

bool wifi_cfg_monitor_channel_is_unsaved(uint8_t ram_value) {
    nvs_handle_t h;
    if (nvs_open("netcfg", NVS_READONLY, &h) != ESP_OK) return true; // Assume dirty if error

    uint8_t nvs_val = 0;
    esp_err_t err = nvs_get_u8(h, "mon_ch", &nvs_val);
    nvs_close(h);

    if (err != ESP_OK) return true; // Key missing = dirty (using default)
    return (nvs_val != ram_value);
}

// --- Setters ---

bool wifi_cfg_set_monitor_channel(uint8_t channel) {
    nvs_handle_t h;
    if (nvs_open("netcfg", NVS_READWRITE, &h) != ESP_OK) return false;

    uint8_t current = 0;
    // Check if write is necessary
    if (nvs_get_u8(h, "mon_ch", &current) == ESP_OK) {
        if (current == channel) {
            nvs_close(h);
            return false; // No change needed
        }
    }

    nvs_set_u8(h, "mon_ch", channel);
    nvs_commit(h);
    nvs_close(h);
    return true; // Write occurred
}