Start to implement energy consumption backend

central_backend/src/energy/consumption.rs

@@ -0,0 +1,18 @@
+use crate::app_config::{AppConfig, ConsumptionBackend};
+use rand::{thread_rng, Rng};
+
+pub type EnergyConsumption = i32;
+
+/// Get current electrical energy consumption
+pub async fn get_curr_consumption() -> anyhow::Result<EnergyConsumption> {
+    let backend = AppConfig::get()
+        .consumption_backend
+        .as_ref()
+        .unwrap_or(&ConsumptionBackend::Constant { value: 300 });
+
+    match backend {
+        ConsumptionBackend::Constant { value } => Ok(*value),
+
+        ConsumptionBackend::Random { min, max } => Ok(thread_rng().gen_range(*min..*max)),
+    }
+}