configuration.rs

use secrecy::{ExposeSecret, Secret};
use serde_aux::field_attributes::deserialize_number_from_string;
use sqlx::{postgres::PgConnectOptions, ConnectOptions};

pub enum Environment {
    Local,
    Production,
}

impl Environment {
    pub fn as_str(&self) -> &'static str {
        match self {
            Environment::Local => "local",
            Environment::Production => "production",
        }
    }
}

impl TryFrom<String> for Environment {
    type Error = String;

    fn try_from(value: String) -> Result<Self, Self::Error> {
        match value.as_str() {
            "local" => Ok(Environment::Local),
            "production" => Ok(Environment::Production),
            _ => Err(format!(
                "{} is not a supported environment. Use either `local` or `production`.",
                value
            )),
        }
    }
}

#[derive(serde::Deserialize)]
pub struct Settings {
    pub application: ApplicationSettings,
    pub database: DatabaseSettings,
}

#[derive(serde::Deserialize)]
pub struct DatabaseSettings {
    pub username: String,
    pub password: Secret<String>,
    pub host: String,
    #[serde(deserialize_with = "deserialize_number_from_string")]
    pub port: u16,
    pub database_name: String,
    pub require_ssl: bool,
}

#[derive(serde::Deserialize)]
pub struct ApplicationSettings {
    #[serde(deserialize_with = "deserialize_number_from_string")]
    pub port: u16,
    pub host: String,
}

impl DatabaseSettings {
    pub fn with_db(&self) -> PgConnectOptions {
        self.without_db()
            .database(&self.database_name)
            .log_statements(tracing::log::LevelFilter::Trace)
    }

    pub fn without_db(&self) -> PgConnectOptions {
        PgConnectOptions::new()
            .host(&self.host)
            .port(self.port)
            .username(&self.username)
            .password(self.password.expose_secret())
            .ssl_mode(match self.require_ssl {
                true => sqlx::postgres::PgSslMode::Require,
                false => sqlx::postgres::PgSslMode::Prefer,
            })
    }
}

pub fn get_configuration() -> Result<Settings, config::ConfigError> {
    let base_path = std::env::current_dir().expect("Failed to determine the current directory.");
    let configuration_directory = base_path.join("configuration");
    // let environment: Environment = std::env::var("APP_ENVIRONMENT").try_into()?;
    let environment: Environment = std::env::var("APP_ENVIRONMENT")
        .unwrap_or_else(|_| "local".into())
        .try_into()
        .expect("Failed to parse APP_ENVIRONMENT");

    let environment_filename = format!("{}.yml", environment.as_str());
    let settings = config::Config::builder()
        .add_source(config::File::from(configuration_directory.join("base.yml")))
        .add_source(config::File::from(
            configuration_directory.join(environment_filename),
        ))
        .add_source(
            config::Environment::with_prefix("APP")
                .prefix_separator("_")
                .separator("__"),
        )
        .build()?;

    settings.try_deserialize::<Settings>()
}