basic of display management. Backend to register and give image for the device. front end to manage displays etc.

Provider/main/api/devices/screen.cpp

@@ -0,0 +1,59 @@
+// GET /api/devices/screen?mac=XX — Return the image URL for a device's current screen
+
+#include "cJSON.h"
+#include "esp_http_server.h"
+
+#include "types.hpp"
+#include "device.hpp"
+
+internal esp_err_t api_devices_screen_handler(httpd_req_t *req)
+{
+  httpd_resp_set_type(req, "application/json");
+  httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");
+
+  // Extract mac query parameter
+  char mac[18] = {};
+  size_t buf_len = httpd_req_get_url_query_len(req) + 1;
+  if (buf_len > 1)
+  {
+    char query[64] = {};
+    if (httpd_req_get_url_query_str(req, query, sizeof(query)) == ESP_OK)
+    {
+      httpd_query_key_value(query, "mac", mac, sizeof(mac));
+    }
+  }
+
+  if (mac[0] == '\0')
+  {
+    httpd_resp_send_err(req, HTTPD_400_BAD_REQUEST, "Missing 'mac' query param");
+    return ESP_FAIL;
+  }
+
+  device_t *dev = find_device(mac);
+  if (!dev)
+  {
+    httpd_resp_send_err(req, HTTPD_404_NOT_FOUND, "Device not registered");
+    return ESP_FAIL;
+  }
+
+  // Build image_url: /api/devices/screen.png?mac=XX
+  char image_url[64];
+  snprintf(image_url, sizeof(image_url), "/api/devices/screen.png?mac=%s", mac);
+
+  cJSON *resp = cJSON_CreateObject();
+  cJSON_AddStringToObject(resp, "image_url", image_url);
+
+  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_screen_info_uri = {
+    .uri = "/api/devices/screen",
+    .method = HTTP_GET,
+    .handler = api_devices_screen_handler,
+    .user_ctx = NULL};