work: добавил автоматический режим

app/auto/co2_policy.py

@@ -0,0 +1,129 @@
+class Co2SpeedPolicy:
+
+    def __init__(
+        self,
+        *,
+        base_speed: int,
+        thresholds: tuple[
+            tuple[int, int],
+            ...
+        ],
+        hysteresis: int,
+    ):
+        if hysteresis < 0:
+            raise ValueError(
+                "hysteresis must be >= 0"
+            )
+
+        if not thresholds:
+            raise ValueError(
+                "thresholds cannot be empty"
+            )
+
+        previous_ppm = None
+
+        speeds = [base_speed]
+
+        for ppm, speed in thresholds:
+
+            if previous_ppm is not None:
+                if ppm <= previous_ppm:
+                    raise ValueError(
+                        "CO2 thresholds must "
+                        "be strictly increasing"
+                    )
+
+            if speed in speeds:
+                raise ValueError(
+                    "AUTO speeds must be unique"
+                )
+
+            speeds.append(speed)
+            previous_ppm = ppm
+
+        self._base_speed = base_speed
+        self._thresholds = thresholds
+        self._hysteresis = hysteresis
+        self._speeds = tuple(speeds)
+
+
+    def select_speed(self, co2: int, current_speed: int | None) -> int:
+
+        if co2 < 0:
+            raise ValueError(
+                "CO2 cannot be negative"
+            )
+
+        # --------------------------------------------------
+        # Первое решение AUTO.
+        #
+        # Гистерезис пока применять не к чему:
+        # предыдущей AUTO-скорости ещё нет.
+        # --------------------------------------------------
+
+        if (
+            current_speed is None
+            or current_speed not in self._speeds
+        ):
+            return self._select_initial_speed(co2)
+
+        index = self._speeds.index(current_speed)
+
+        # --------------------------------------------------
+        # CO2 растёт.
+        #
+        # Проверяем пороги перехода вверх.
+        # За один вызов можем перепрыгнуть
+        # сразу несколько скоростей.
+        # --------------------------------------------------
+
+        while index < len(
+            self._thresholds
+        ):
+
+            ppm, _ = self._thresholds[index]
+
+            if co2 < ppm:
+                break
+
+            index += 1
+
+        # --------------------------------------------------
+        # CO2 падает.
+        #
+        # Для перехода вниз используем:
+        #
+        # threshold - hysteresis
+        #
+        # Поэтому скорость не будет прыгать
+        # туда-сюда около одного порога.
+        # --------------------------------------------------
+
+        while index > 0:
+
+            ppm, _ = self._thresholds[index - 1]
+
+            down_threshold = ppm - self._hysteresis
+
+            if co2 > down_threshold:
+                break
+
+            index -= 1
+
+        return self._speeds[index]
+
+
+    def _select_initial_speed(self, co2: int) -> int:
+
+        speed = self._base_speed
+
+        for ppm, candidate_speed in (
+            self._thresholds
+        ):
+
+            if co2 < ppm:
+                break
+
+            speed = candidate_speed
+
+        return speed