monorepo/config/src/lib.rs

161 lines
4.9 KiB
Rust

/*
use std::{
collections::HashMap,
fs::File,
hash::Hash,
io::{ErrorKind, Read},
path::PathBuf,
};
*/
pub use config_derive::ConfigOption;
use thiserror::Error;
#[derive(Debug, Error)]
pub enum ConfigReadError {
#[error("Cannot read the configuration file: {0}")]
CannotRead(std::io::Error),
#[error("Cannot open the configuration file for reading: {0}")]
CannotOpen(std::io::Error),
#[error("Invalid json data found in the configurationfile: {0}")]
InvalidJSON(serde_json::Error),
}
#[macro_export]
macro_rules! define_config {
($($name:ident($struct:ident),)+) => (
#[derive(Clone, Debug, Hash, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
pub enum ConfigName {
$($name),+
}
#[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
#[serde(untagged)]
pub enum ConfigOption {
$($name($struct)),+
}
#[derive(Clone, Debug)]
pub struct Config {
values: std::collections::HashMap<ConfigName, ConfigOption>,
}
impl Config {
pub fn new() -> Self {
Self {
values: std::collections::HashMap::new(),
}
}
pub fn from_path(config_path: std::path::PathBuf) -> Result<Self, $crate::ConfigReadError> {
let mut settings = config_path.clone();
settings.push("config");
match std::fs::File::open(settings) {
Ok(mut file) => {
let mut buf = String::new();
std::io::Read::read_to_string(&mut file, &mut buf)
.map_err(|err| $crate::ConfigReadError::CannotRead(err))?;
let values = serde_json::from_str(buf.as_ref())
.map_err(|err| $crate::ConfigReadError::InvalidJSON(err))?;
Ok(Self {
values,
})
}
Err(io_err) => {
match io_err.kind() {
std::io::ErrorKind::NotFound => {
/* create the path and an empty file */
Ok(Self {
values: std::collections::HashMap::new(),
})
}
_ => Err($crate::ConfigReadError::CannotOpen(io_err)),
}
}
}
}
pub fn set(&mut self, val: ConfigOption) {
let _ = match val {
$(ConfigOption::$struct(_) => self.values.insert(ConfigName::$name, val)),+
};
}
pub fn get<'a, T>(&'a self) -> Option<T>
where
Option<T>: From<&'a Self>,
{
self.into()
}
}
)
}
#[cfg(test)]
mod test {
use super::*;
use cool_asserts::assert_matches;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::path::PathBuf;
define_config! {
DatabasePath(DatabasePath),
Me(Me),
}
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, ConfigOption)]
pub struct DatabasePath(PathBuf);
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
enum Rank {
Kyu(i8),
Dan(i8),
}
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, ConfigOption)]
pub struct Me {
name: String,
rank: Option<Rank>,
}
#[test]
fn it_can_set_and_get_options() {
let mut config: Config = Config::new();
config.set(ConfigOption::DatabasePath(DatabasePath(PathBuf::from(
"./fixtures/five_games",
))));
assert_eq!(
Some(DatabasePath(PathBuf::from("./fixtures/five_games"))),
config.get()
);
}
#[test]
fn it_can_serialize_and_deserialize() {
let mut config = Config::new();
config.set(ConfigOption::DatabasePath(DatabasePath(PathBuf::from(
"fixtures/five_games",
))));
config.set(ConfigOption::Me(Me {
name: "Savanni".to_owned(),
rank: Some(Rank::Kyu(10)),
}));
let s = serde_json::to_string(&config.values).unwrap();
println!("{}", s);
let values: HashMap<ConfigName, ConfigOption> = serde_json::from_str(s.as_ref()).unwrap();
println!("options: {:?}", values);
assert_matches!(values.get(&ConfigName::DatabasePath),
Some(ConfigOption::DatabasePath(ref db_path)) =>
assert_eq!(Some(db_path.clone()), config.get())
);
assert_matches!(values.get(&ConfigName::Me), Some(ConfigOption::Me(val)) =>
assert_eq!(Some(val.clone()), config.get())
);
}
}