use std::{env, path::PathBuf, sync::atomic::AtomicBool};

use directories::ProjectDirs;
use dotenv::from_path;
use thiserror::Error;

const CONFIG_FILE_NAME: &str = ".env";

static CONFIG_INITIALIZED: AtomicBool = AtomicBool::new(false);

#[derive(Debug, Error)]
pub enum ConfigError {
    #[error("No config file {0} found in the following directories: {1:#?}")]
    ConfigFileNotFound(String, Vec<PathBuf>),
    #[error("Failed to load config file: {0}")]
    LoadConfigError(#[from] dotenv::Error),
    #[error("Environment variable error: {0}")]
    EnvVarError(#[from] std::env::VarError),
}

pub fn get_config_dirs() -> Vec<PathBuf> {
    let mut config_dirs = vec![
        PathBuf::from(""), // Current directory
    ];
    if let Ok(manifest_dir) = env::var("CARGO_MANIFEST_DIR") {
        config_dirs.push(PathBuf::from(manifest_dir));
    }
    if let Some(proj_dirs) = ProjectDirs::from("org", "P4pillon", "Krys4lide") {
        config_dirs.push(proj_dirs.config_dir().to_path_buf());
    }
    config_dirs
}

pub fn get_config_files() -> Result<Vec<PathBuf>, ConfigError> {
    let config_dirs = get_config_dirs();
    let mut config_files = Vec::new();
    for config_dir in config_dirs.iter() {
        let config_file = config_dir.join(CONFIG_FILE_NAME);
        if config_file.exists() {
            config_files.push(config_file);
        }
    }
    if config_files.is_empty() {
        return Err(ConfigError::ConfigFileNotFound(
            CONFIG_FILE_NAME.to_string(),
            config_dirs,
        ));
    }
    Ok(config_files)
}

pub fn load_config(force: Option<bool>) -> Result<(), ConfigError> {
    let force = force.unwrap_or(false);
    if CONFIG_INITIALIZED.load(std::sync::atomic::Ordering::Relaxed) && force {
        println!("DEBUG: Config already initialized, skipping");
        return Ok(());
    }
    let config_files = get_config_files()?;
    // Load the first config file found
    // TODO: add a verbose log to list all config files found
    println!(
        "DEBUG: Config files found (1st loaded): {:#?}",
        config_files
    );
    from_path(config_files[0].as_path()).map_err(ConfigError::LoadConfigError)?;
    CONFIG_INITIALIZED.store(true, std::sync::atomic::Ordering::Relaxed);
    Ok(())
}