use std::{env::var, fs::read_to_string, path::PathBuf};

use directories::ProjectDirs;
use serde::Deserialize;

use crate::{constants::*, errors::McError};
#[allow(dead_code)]
#[derive(Debug, Deserialize)]
pub struct Config {
    pub username: String,
    pub uuid: String,
    pub version: String,
    pub java_path: String,
    pub max_memory_mb: u32,
    pub data_dir: PathBuf,
    pub cache_dir: PathBuf,
    pub config_dir: PathBuf,
    #[serde(default)]
    pub jvm_args: Vec<String>,
}
impl Config {
    pub fn load() -> Result<Self, McError> {
        let cfg_path = default_config_path()?;
        let mut cfg: Config = if cfg_path.exists() {
            let txt = read_to_string(&cfg_path)?;
            toml::from_str(&txt).map_err(|e| McError::Config(e.to_string()))?
        } else {
            Self::default()
        };
        if let Ok(v) = var("MC_USERNAME") {
            cfg.username = v;
        }
        if let Ok(v) = var("MC_VERSION") {
            cfg.version = v;
        }
        if let Ok(v) = var("MC_JAVA_PATH") {
            cfg.java_path = v;
        }
        if let Ok(v) = var("MC_MAX_MEMORY_MB") {
            cfg.max_memory_mb = v.parse().unwrap_or(cfg.max_memory_mb);
        }
        Ok(cfg)
    }

    fn default() -> Self {
        let base =
            ProjectDirs::from("com", "example", "dml").expect("platform dirs");
        Self {
            username: "Player".into(),
            uuid: uuid::Uuid::new_v4().to_string(),
            version: DEFAULT_VERSION.into(),
            java_path: DEFAULT_JAVA_PATH.into(),
            max_memory_mb: DEFAULT_MAX_MEMORY_MB,
            data_dir: base.data_dir().into(),
            cache_dir: base.cache_dir().into(),
            config_dir: base.config_dir().into(),
            jvm_args: vec![],
        }
    }
}
fn default_config_path() -> Result<PathBuf, McError> {
    let base = ProjectDirs::from("com", "example", "dml")
        .ok_or_else(|| McError::Config("cannot determine config dir".into()))?;
    Ok(base.config_dir().join("config.toml"))
}