add(web_server): init basic webserver

components/web_server/src/wifi.c

@@ -0,0 +1,89 @@
+#include "wifi.h"
+
+#include <string.h>
+
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_netif.h"
+#include "esp_wifi.h"
+#include "nvs_flash.h"
+
+static const char *TAG = "WIFI";
+static bool s_wifi_started = false;
+
+esp_err_t wifi_start_ap(const char *ssid, const char *password, uint8_t channel, uint8_t max_connections)
+{
+  if (s_wifi_started)
+  {
+    return ESP_OK;
+  }
+
+  if (!ssid || strlen(ssid) == 0 || strlen(ssid) > 32)
+  {
+    return ESP_ERR_INVALID_ARG;
+  }
+
+  const bool has_password = password && strlen(password) > 0;
+  if (has_password && strlen(password) < 8)
+  {
+    return ESP_ERR_INVALID_ARG;
+  }
+
+  esp_err_t err = nvs_flash_init();
+  if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND)
+  {
+    ESP_ERROR_CHECK(nvs_flash_erase());
+    err = nvs_flash_init();
+  }
+  if (err != ESP_OK)
+  {
+    return err;
+  }
+
+  ESP_ERROR_CHECK(esp_netif_init());
+  ESP_ERROR_CHECK(esp_event_loop_create_default());
+  esp_netif_create_default_wifi_ap();
+
+  wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+  ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+
+  wifi_config_t wifi_config = {
+      .ap = {
+          .channel = channel,
+          .max_connection = max_connections,
+          .authmode = has_password ? WIFI_AUTH_WPA2_PSK : WIFI_AUTH_OPEN,
+          .pmf_cfg = {
+              .required = false,
+          },
+      },
+  };
+
+  strlcpy((char *)wifi_config.ap.ssid, ssid, sizeof(wifi_config.ap.ssid));
+  wifi_config.ap.ssid_len = strlen(ssid);
+
+  if (has_password)
+  {
+    strlcpy((char *)wifi_config.ap.password, password, sizeof(wifi_config.ap.password));
+  }
+
+  ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
+  ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_AP, &wifi_config));
+  ESP_ERROR_CHECK(esp_wifi_start());
+
+  s_wifi_started = true;
+  ESP_LOGI(TAG, "WiFi AP started: SSID=%s channel=%u", ssid, channel);
+  return ESP_OK;
+}
+
+void wifi_stop_ap(void)
+{
+  if (!s_wifi_started)
+  {
+    return;
+  }
+
+  esp_wifi_stop();
+  esp_wifi_deinit();
+  s_wifi_started = false;
+  ESP_LOGI(TAG, "WiFi AP stopped");
+}