elura-cli 0.1.0

use std::{env, fs, sync::Arc};

use elura::adapters::discovery::DnsWorldDiscoveryConfig;
use elura::prelude::*;
use serde::Deserialize;

/// Application-owned configuration. Elura never chooses an adapter or reads
/// this file/environment on the application's behalf.
#[derive(Deserialize)]
#[serde(deny_unknown_fields)]
struct AppConfig {
    runtime: GatewayLaunchConfig,
    discovery: DnsWorldDiscoveryConfig,
}

impl AppConfig {
    fn load() -> elura::Result<Self> {
        let path = env::var("APP_GATEWAY_CONFIG").unwrap_or_else(|_| "config/gateway.json".into());
        let mut config: Self = serde_json::from_slice(&fs::read(path)?)?;
        config.runtime.ticket.key = required_env("APP_TICKET_KEY")?;
        config.runtime.internal_token = required_env("APP_INTERNAL_TOKEN")?;
        if let Some(value) = optional_env("APP_GATEWAY_ADDR") {
            config.runtime.gateway.listen = parse_address("APP_GATEWAY_ADDR", &value)?;
        }
        if let Some(value) = optional_env("APP_GATEWAY_ADMIN_ADDR") {
            config.runtime.admin.listen = parse_address("APP_GATEWAY_ADMIN_ADDR", &value)?;
        }
        config.runtime.admin.token = optional_env("APP_ADMIN_TOKEN");
        if let Some(value) = optional_env("APP_INSTANCE_ID") {
            config.runtime.admin.instance_id = value;
        }
        Ok(config)
    }
}

#[tokio::main]
async fn main() -> elura::Result<()> {
    let app = AppConfig::load()?;
    let discovery = Arc::new(app.discovery.build()?);
    GatewayLauncher::new(app.runtime)?
        .with_world_discovery(discovery)
        .run()
        .await
}

fn required_env(name: &str) -> elura::Result<String> {
    env::var(name).map_err(|_| elura::Error::InvalidConfig(format!("{name} is required")))
}

fn optional_env(name: &str) -> Option<String> {
    env::var(name).ok().filter(|value| !value.trim().is_empty())
}

fn parse_address(name: &str, value: &str) -> elura::Result<std::net::SocketAddr> {
    value
        .parse()
        .map_err(|_| elura::Error::InvalidConfig(format!("invalid {name}")))
}