use bytesize::ByteSize;
use figment::{
    error::Result,
    providers::{Env, Format, Serialized, Toml},
    value::{Dict, Map},
    Figment, Metadata, Profile, Provider,
};
use serde::{Deserialize, Serialize};
use std::path::PathBuf;

#[derive(Debug, Clone, Deserialize, Serialize)]
pub struct Config {
    pub quota: ByteSize,
    pub pool_name: String,
    pub mountpoint: PathBuf,
}

impl Default for Config {
    fn default() -> Self {
        Config {
            quota: ByteSize::gb(16),
            pool_name: String::from("pool"),
            mountpoint: PathBuf::from("/srv"),
        }
    }
}

impl Config {
    pub fn from<T: Provider>(provider: T) -> Result<Config> {
        Figment::from(provider).extract()
    }

    pub fn figment() -> Figment {
        Figment::from(Config::default())
            .merge(Toml::file(Env::var_or("ZFS_CONFIG", "ZFS.toml")).nested())
            .merge(Env::prefixed("ZFS_").global())
    }
}

impl Provider for Config {
    fn metadata(&self) -> Metadata {
        Metadata::named("ZFS Config")
    }

    fn data(&self) -> Result<Map<Profile, Dict>> {
        Serialized::defaults(Config::default()).data()
    }
}