def format_value(value, suffix="", decimals=1, missing="--"):
    if value is None:
        return missing

    if isinstance(value, int):
        return f"{value}{suffix}"

    if isinstance(value, float):
        return f"{value:.{decimals}f}{suffix}"

    return f"{value}{suffix}"


def format_bool(value, true_text="ON", false_text="OFF"):
    return true_text if value else false_text


class DashboardViewModel:
    def __init__(self, state, alarms=None):
        self.state = state
        self.alarms = alarms or []

    def top_bar(self):
        soc = format_value(self.state.battery.get("soc"), "%", decimals=0)
        uart = "UART OK" if self.state.network.get("uart_connected") else "UART LOST"
        alarm_count = len(self.alarms)

        return {
            "soc": soc,
            "comms": uart,
            "alarms": alarm_count,
        }

    def battery_summary(self):
        return {
            "voltage": format_value(self.state.battery.get("voltage"), "V", decimals=1),
            "current": format_value(self.state.battery.get("current"), "A", decimals=1),
            "runtime": format_value(self.state.battery.get("runtime_hours"), " hr", decimals=1),
        }

    def fridge_summary(self):
        return {
            "zone_1": format_value(self.state.temps.get("fridge_zone_1"), "°F", decimals=1),
            "zone_2": format_value(self.state.temps.get("fridge_zone_2"), "°F", decimals=1),
        }

    def power_summary(self):
        return {
            "starlink": format_bool(self.state.relays.get("starlink")),
            "fridge": format_bool(self.state.relays.get("fridge")),
        }

    def as_dict(self):
        return {
            "top_bar": self.top_bar(),
            "battery": self.battery_summary(),
            "fridge": self.fridge_summary(),
            "power": self.power_summary(),
        }