Add function to create mock component graph structure

... to pytest utils folder.
The behaviour is copied from the MockMicrogrid.
I moved it to another module to make for readable.

Signed-off-by: ela-kotulska-frequenz <[email protected]>

Author: ela-kotulska-frequenz

tests/utils/component_graph_utils.py

@@ -0,0 +1,95 @@
+# License: MIT
+# Copyright © 2023 Frequenz Energy-as-a-Service GmbH
+
+"""Utils for tests that uses component graph."""
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from frequenz.sdk.microgrid.client import Connection
+from frequenz.sdk.microgrid.component import Component, ComponentCategory, InverterType
+
+
+@dataclass
+class ComponentGraphConfig:
+    """Config with information how the component graph should be created."""
+
+    grid_side_meter: bool = True
+    """True if the main meter should be by grid side."""
+
+    batteries_num: int = 0
+    """Number of batteries in the component graph.
+
+    Each battery will have its own inverter and meter connected.
+    """
+
+    solar_inverters_num: int = 0
+    """Number of pv inverters in the component graph.
+
+    Each pv inverter will have its own pv meter connected.
+    """
+
+    ev_chargers: int = 0
+    """Number of ev chargers in the component graph."""
+
+
+def create_component_graph_structure(
+    component_graph_config: ComponentGraphConfig,
+) -> tuple[set[Component], set[Connection]]:
+    """Create structure of components graph.
+
+    Args:
+        component_graph_config: config that tells what graph should have.
+
+    Returns:
+        Create set of components and set of connections between them.
+    """
+    grid_id = 1
+    main_meter_id = 2
+
+    components = {
+        Component(grid_id, ComponentCategory.GRID),
+        Component(main_meter_id, ComponentCategory.METER),
+    }
+    connections = {Connection(grid_id, main_meter_id)}
+
+    junction_id: int = grid_id
+    if component_graph_config.grid_side_meter:
+        junction_id = main_meter_id
+
+    start_idx = 3
+    for _ in range(component_graph_config.batteries_num):
+        meter_id = start_idx
+        inv_id = start_idx + 1
+        battery_id = start_idx + 2
+        start_idx += 3
+
+        components.add(Component(meter_id, ComponentCategory.METER))
+        components.add(Component(battery_id, ComponentCategory.BATTERY))
+        components.add(
+            Component(inv_id, ComponentCategory.INVERTER, InverterType.BATTERY)
+        )
+
+        connections.add(Connection(junction_id, meter_id))
+        connections.add(Connection(meter_id, inv_id))
+        connections.add(Connection(inv_id, battery_id))
+
+    for _ in range(component_graph_config.solar_inverters_num):
+        meter_id = start_idx
+        inv_id = start_idx + 1
+        start_idx += 2
+
+        components.add(Component(meter_id, ComponentCategory.METER))
+        components.add(
+            Component(inv_id, ComponentCategory.INVERTER, InverterType.SOLAR)
+        )
+        connections.add(Connection(junction_id, meter_id))
+        connections.add(Connection(meter_id, inv_id))
+
+    for _ in range(component_graph_config.ev_chargers):
+        ev_id = start_idx
+        start_idx += 1
+
+        components.add(Component(ev_id, ComponentCategory.EV_CHARGER))
+        connections.add(Connection(junction_id, ev_id))
+    return components, connections