// POST /api/devices/register — Register a new device by MAC
// Body: {"mac": "AA:BB:CC:DD:EE:FF"}

#include "cJSON.h"
#include "esp_http_server.h"
#include "esp_log.h"

#include "types.hpp"
#include "device.hpp"

internal const char *kTagDeviceRegister = "API_DEV_REG";

internal esp_err_t api_devices_register_handler(httpd_req_t *req)
{
  httpd_resp_set_type(req, "application/json");
  httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");

  char buf[128];
  int received = httpd_req_recv(req, buf, sizeof(buf) - 1);
  if (received <= 0)
  {
    httpd_resp_send_err(req, HTTPD_400_BAD_REQUEST, "Empty body");
    return ESP_FAIL;
  }
  buf[received] = '\0';

  cJSON *body = cJSON_Parse(buf);
  if (!body)
  {
    httpd_resp_send_err(req, HTTPD_400_BAD_REQUEST, "Invalid JSON");
    return ESP_FAIL;
  }

  cJSON *mac_item = cJSON_GetObjectItem(body, "mac");
  if (!cJSON_IsString(mac_item) || !mac_item->valuestring || strlen(mac_item->valuestring) == 0)
  {
    cJSON_Delete(body);
    httpd_resp_send_err(req, HTTPD_400_BAD_REQUEST, "Missing 'mac'");
    return ESP_FAIL;
  }

  bool was_new = false;
  device_t *dev = register_device(mac_item->valuestring, &was_new);

  if (!dev)
  {
    cJSON_Delete(body);
    httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, "Device limit reached");
    return ESP_FAIL;
  }

  cJSON *resp = cJSON_CreateObject();
  if (was_new)
  {
    cJSON_AddStringToObject(resp, "status", "ok");
    ESP_LOGI(kTagDeviceRegister, "Registered new device: %s", dev->mac);
  }
  else
  {
    cJSON_AddStringToObject(resp, "status", "already_registered");
  }
  cJSON_AddStringToObject(resp, "mac", dev->mac);

  cJSON_Delete(body);

  const char *json = cJSON_PrintUnformatted(resp);
  httpd_resp_sendstr(req, json);

  free((void *)json);
  cJSON_Delete(resp);

  return ESP_OK;
}

internal const httpd_uri_t api_devices_register_uri = {
    .uri = "/api/devices/register",
    .method = HTTP_POST,
    .handler = api_devices_register_handler,
    .user_ctx = NULL};