use config::{Config, FileFormat};
use serde::{Deserialize, Serialize};
use snafu::prelude::*;
use std::fs::File;
use std::io::Write;
use tracing::{info, instrument};

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct AppConfig {
    pub destination_ip: String,
    pub destination_port: u32,
    pub aspect_ratio: f64,
}

impl Default for AppConfig {
    fn default() -> Self {
        AppConfig {
            destination_ip: "localhost".to_string(),
            destination_port: 7891,

            aspect_ratio: 16.0 / 9.0,
        }
    }
}

pub fn load_config() -> AppConfig {
    Config::builder()
        .add_source(config::File::new("./settings.toml", FileFormat::Toml))
        .build()
        .and_then(|val| val.try_deserialize())
        .unwrap_or_default()
}

#[derive(Debug, Snafu)]
pub enum SaveConfigError {
    #[snafu(display("Could not serialize app state: {source}"))]
    SerdeError { source: toml::ser::Error },
    #[snafu(display("Could not write app state to file: {path}"))]
    IoError {
        source: std::io::Error,
        path: String,
    },
}

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