use config::{Config, FileFormat};
use err_derive::Error;
use log::{error, info};
use serde::{Deserialize, Serialize};
use std::fs::File;
use std::io::Write;

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct AppConfig {
    pub camera_ip: String,
    pub camera_port: u32,

    pub tracker_ip: String,
    pub tracker_port: u32,
    pub tracker_refresh_rate_millis: u32,
}

impl Default for AppConfig {
    fn default() -> Self {
        AppConfig {
            camera_ip: "10.0.0.33".to_string(),
            camera_port: 8765,

            tracker_ip: "10.0.0.210".to_string(),
            tracker_port: 6543,
            tracker_refresh_rate_millis: 100,
        }
    }
}

pub fn load_config() -> AppConfig {
    let settings = Config::builder()
        .add_source(config::File::new("./settings.toml", FileFormat::Toml))
        .build();

    settings
        .and_then(|val| val.try_deserialize())
        .unwrap_or_default()
}

#[derive(Error, Debug)]
pub enum SaveConfigError {
    #[error(display = "Could not serialize app state: {:?}", _0)]
    SerdeError(#[cause] toml::ser::Error),
    #[error(display = "Could not write app state to file: {:?}", _0)]
    IoError(#[cause] std::io::Error),
}

pub fn save_config(config: &AppConfig) -> Result<(), SaveConfigError> {
    let toml_str = toml::to_string(&config)?;
    let mut file = File::create("./settings.toml")?;
    file.write_all(toml_str.as_bytes())?;
    info!("Config file saved successfully");
    Ok(())
}