radicle-native-ci/src/config.rs

use std::path::{Path, PathBuf};

use log::{debug, error};
use serde::Deserialize;

use crate::logfile::{LogError, LogFile};

const DEFAULT_TIMEOUT: usize = 3600;

/// Configuration file for `radicle-native-ci`.
#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct Config {
    /// Directory where per-run directories are stored. Each run gets
    /// its own dedicated subdirectory.
    pub state: PathBuf,

    /// File where native CI should write a log.
    pub log: PathBuf,

    /// Optional maximum duration of a CI run.
    pub timeout: Option<usize>,
}

impl Config {
    pub fn load_via_env() -> Result<Self, ConfigError> {
        const ENV: &str = "RADICLE_NATIVE_CI";
        let filename = std::env::var(ENV).map_err(|e| ConfigError::GetEnv(ENV, e))?;
        let filename = Path::new(&filename);
        let config = Config::read(filename)?;
        debug!("configuration from {}: {:#?}", filename.display(), config);
        Ok(config)
    }

    pub fn open_log(&self) -> Result<LogFile, ConfigError> {
        Ok(LogFile::open(&self.log)?)
    }

    /// Read configuration specification from a file.
    pub fn read(filename: &Path) -> Result<Self, ConfigError> {
        let file = std::fs::File::open(filename)
            .map_err(|e| ConfigError::ReadConfig(filename.into(), e))?;
        let mut config: Self = serde_yaml::from_reader(&file)
            .map_err(|e| ConfigError::ParseConfig(filename.into(), e))?;
        if config.timeout.is_none() {
            config.timeout = Some(DEFAULT_TIMEOUT);
        }
        Ok(config)
    }
}

#[derive(Debug, thiserror::Error)]
pub enum ConfigError {
    #[error("failed to read configuration file {0}")]
    ReadConfig(PathBuf, #[source] std::io::Error),

    #[error("failed to parse configuration file as YAML: {0}")]
    ParseConfig(PathBuf, #[source] serde_yaml::Error),

    #[error("failed to get environment variable {0}")]
    GetEnv(&'static str, #[source] std::env::VarError),

    #[error(transparent)]
    Log(#[from] LogError),
}