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use std::fs;
use std::io;
use std::path::Path;
use std::path::PathBuf;
use serde::{de::DeserializeOwned, Serialize};
use snafu::{ResultExt, Snafu};
use polyglot::Format;
#[derive(Debug, Snafu)]
pub enum Error {
#[snafu(display("Unknown config directory"))]
UnknownConfigDirectory,
FailedToCreateConfigDir {
source: io::Error,
},
FailedToCreateDefaultConfigFile {
source: io::Error,
},
FailedToSerializeDefaultConfig {
source: polyglot::Error,
},
#[snafu(display("Failed to find config file"))]
FailedToFindConfigFile,
FailedToOpenConfigFile {
source: io::Error,
},
FailedToDeserializeConfigFile {
source: polyglot::Error,
},
}
type Result<T> = std::result::Result<T, Error>;
fn deser<T: DeserializeOwned>(file: &Path, format: Format) -> Result<T> {
let f = fs::File::open(file).context(FailedToOpenConfigFile)?;
polyglot::from_reader(f, format).context(FailedToDeserializeConfigFile)
}
fn find_config_file(namespace: &str, name: &str) -> Result<Option<(PathBuf, Format)>> {
let config_dir = dirs::config_dir().ok_or(Error::UnknownConfigDirectory)?;
let file_path = config_dir.join(namespace).join(name);
let (ext, format) = if file_path.with_extension("toml").exists() {
("toml", Format::TOML)
} else if file_path.with_extension("json").exists() {
("json", Format::JSON)
} else if file_path.with_extension("yml").exists() {
("yml", Format::YAML)
} else {
return Ok(None);
};
Ok(Some((file_path.with_extension(ext), format)))
}
pub fn load<T: DeserializeOwned>(namespace: &str, name: &str) -> Result<T> {
let (file_path, format) =
find_config_file(namespace, name)?.ok_or(Error::FailedToFindConfigFile)?;
deser(&file_path, format)
}
pub fn load_or_default<T: DeserializeOwned + Serialize>(
namespace: &str,
name: &str,
default: T,
) -> Result<T> {
if let Some((file, format)) = find_config_file(namespace, name)? {
deser(&file, format)
} else {
let config_dir = dirs::config_dir().ok_or(Error::UnknownConfigDirectory)?;
let namespace_dir = config_dir.join(namespace);
fs::create_dir_all(&namespace_dir).context(FailedToCreateConfigDir)?;
let file_path = namespace_dir.join(name).with_extension("toml");
let f = fs::File::create(&file_path).context(FailedToCreateDefaultConfigFile)?;
polyglot::to_writer(f, &default, Format::TOML).context(FailedToSerializeDefaultConfig)?;
Ok(default)
}
}