use jzon::JsonValue;

use crate::device::{BDAddr, FormattableDevice};
use std::{
    fmt::{self, Debug, Display},
    time::Instant,
};

#[derive(Debug)]
pub struct MiTempDevice {
    pub name: String,
    pub addr: BDAddr,
    temperature: f32,
    humidity: f32,
    dew_point: f32,
    battery: u8,
    pub last_seen: Instant,
}

impl MiTempDevice {
    pub fn new(addr: BDAddr, name: String) -> Self {
        MiTempDevice {
            name,
            addr,
            temperature: 0.0,
            humidity: 0.0,
            dew_point: 0.0,
            battery: 0,
            last_seen: Instant::now(),
        }
    }

    pub fn update(&mut self, json: &JsonValue) {
        self.last_seen = Instant::now();
        if let Some(temperature) = json["Temperature"].as_number().map(f32::from) {
            self.temperature = temperature;
        }
        if let Some(humidity) = json["Humidity"].as_number().map(f32::from) {
            self.humidity = humidity;
        }
        if let Some(battery) = json["Battery"]
            .as_number()
            .and_then(|num| u8::try_from(num).ok())
        {
            self.battery = battery;
        }
        if let Some(dew_point) = json["DewPoint"].as_number().map(f32::from) {
            self.dew_point = dew_point;
        }
    }
}

impl FormattableDevice for MiTempDevice {
    fn format_open_metrics(&self) -> impl Display + '_ {
        MitempFormatter { device: self }
    }
}

struct MitempFormatter<'a> {
    device: &'a MiTempDevice,
}

impl Display for MitempFormatter<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        if self.device.battery > 0 {
            writeln!(
                f,
                "sensor_battery{{mac=\"{}\", name=\"{}\"}} {}",
                self.device.addr, self.device.name, self.device.battery
            )?;
        }

        if self.device.temperature > 0.0 {
            writeln!(
                f,
                "sensor_temperature{{mac=\"{}\", name=\"{}\"}} {}",
                self.device.addr, self.device.name, self.device.temperature
            )?;
        }

        if self.device.humidity > 0.0 {
            writeln!(
                f,
                "sensor_humidity{{mac=\"{}\", name=\"{}\"}} {}",
                self.device.addr, self.device.name, self.device.humidity
            )?;
        }
        Ok(())
    }
}