rs-zero 0.2.9

use std::{collections::BTreeMap, net::SocketAddr, time::Duration};

use serde::Deserialize;

use crate::core::{
    ConfigFeatureWarning, CoreError, CoreResult, DatabaseSection, LogConfig, LogSection,
    RpcClientSection, ServiceConfig, dependency_feature_warnings, load_config,
};

/// REST service configuration loaded by generated services.
#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
#[serde(default, deny_unknown_fields)]
pub struct RestServiceConfig {
    /// Service name.
    pub name: String,
    /// Deployment mode.
    pub mode: String,
    /// Server listener and request limits.
    pub server: RestServerSection,
    /// Logging configuration.
    pub log: LogSection,
    /// Optional JWT auth configuration.
    pub auth: Option<RestAuthSection>,
    /// Middleware toggles.
    pub middlewares: RestMiddlewaresSection,
    /// Outbound RPC clients used by this REST service.
    pub rpc_clients: BTreeMap<String, RpcClientSection>,
    /// Optional database used by model repositories.
    pub database: Option<DatabaseSection>,
}

impl Default for RestServiceConfig {
    fn default() -> Self {
        let service = ServiceConfig::default();
        Self {
            name: service.name,
            mode: service.mode,
            server: RestServerSection::default(),
            log: service.log,
            auth: None,
            middlewares: RestMiddlewaresSection::default(),
            rpc_clients: BTreeMap::new(),
            database: None,
        }
    }
}

impl RestServiceConfig {
    /// Loads REST service configuration from `basename` and env vars with `env_prefix`.
    pub fn load(basename: &str, env_prefix: &str) -> Result<Self, config::ConfigError> {
        load_config(basename, env_prefix)
    }

    /// Returns the listening address.
    pub fn addr(&self) -> CoreResult<SocketAddr> {
        format!("{}:{}", self.server.host, self.server.port)
            .parse()
            .map_err(|error| {
                config::ConfigError::Message(format!("invalid REST listen address: {error}")).into()
            })
    }

    /// Converts to runtime logging config.
    pub fn log_config(&self) -> LogConfig {
        self.log.to_log_config(&self.name)
    }

    /// Converts to runtime REST config.
    pub fn rest_config(&self) -> crate::rest::RestConfig {
        let mut config = if self.middlewares.resilience || self.middlewares.metrics {
            crate::rest::RestConfig::production_defaults(self.name.clone())
        } else {
            crate::rest::RestConfig {
                name: self.name.clone(),
                ..crate::rest::RestConfig::default()
            }
        };
        config.timeout = Duration::from_millis(self.server.timeout_ms);
        config.max_body_bytes = self.server.max_body_bytes;
        config.middlewares.metrics.enabled = self.middlewares.metrics;
        if !self.middlewares.resilience {
            config.middlewares.resilience = crate::rest::RestResilienceConfig::default();
        }
        config.auth = self.auth.as_ref().and_then(RestAuthSection::auth_config);
        config
    }

    /// Returns warnings for config options that are unavailable in this Cargo feature build.
    pub fn validate_features(&self) -> Vec<ConfigFeatureWarning> {
        let mut warnings = Vec::new();
        if self.middlewares.metrics && !cfg!(feature = "observability") {
            warnings.push(ConfigFeatureWarning::ignored(
                "middlewares.metrics",
                "observability",
            ));
        }
        if self.middlewares.resilience && !cfg!(feature = "resil") {
            warnings.push(ConfigFeatureWarning::ignored(
                "middlewares.resilience",
                "resil",
            ));
        }
        warnings.extend(dependency_feature_warnings(
            &self.rpc_clients,
            self.database.as_ref(),
        ));
        warnings
    }

    /// Returns configured JWT expiration in seconds, with `JWT_AUTH_EXPIRES` precedence.
    pub fn jwt_expires(&self) -> Option<u64> {
        self.auth.as_ref().map(RestAuthSection::jwt_expires)
    }

    /// Returns one outbound RPC client dependency by logical name.
    pub fn rpc_client(&self, name: &str) -> CoreResult<&RpcClientSection> {
        self.rpc_clients.get(name).ok_or_else(|| {
            CoreError::Config(config::ConfigError::Message(format!(
                "missing rpc client config: {name}"
            )))
        })
    }

    /// Converts one outbound RPC client dependency to runtime RPC config.
    #[cfg(feature = "rpc")]
    pub fn rpc_client_config(&self, name: &str) -> CoreResult<crate::rpc::RpcClientConfig> {
        self.rpc_client(name)?.to_rpc_client_config()
    }

    /// Converts the optional database dependency to runtime database config.
    #[cfg(feature = "db")]
    pub fn database_config(&self) -> Option<crate::db::DatabaseConfig> {
        self.database
            .as_ref()
            .map(DatabaseSection::to_database_config)
    }
}

/// REST listener section.
#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
#[serde(default, deny_unknown_fields)]
pub struct RestServerSection {
    pub host: String,
    pub port: u16,
    pub timeout_ms: u64,
    pub max_body_bytes: usize,
}

impl Default for RestServerSection {
    fn default() -> Self {
        Self {
            host: "127.0.0.1".to_string(),
            port: 8080,
            timeout_ms: 5000,
            max_body_bytes: 1024 * 1024,
        }
    }
}

/// REST JWT auth section.
#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
#[serde(default, deny_unknown_fields)]
pub struct RestAuthSection {
    pub jwt_secret: String,
    pub jwt_expires: u64,
    pub public_paths: Vec<String>,
}

impl Default for RestAuthSection {
    fn default() -> Self {
        Self {
            jwt_secret: String::new(),
            jwt_expires: 7200,
            public_paths: Vec::new(),
        }
    }
}

impl RestAuthSection {
    fn secret(&self) -> String {
        std::env::var("JWT_AUTH_SECRET").unwrap_or_else(|_| self.jwt_secret.clone())
    }

    fn jwt_expires(&self) -> u64 {
        std::env::var("JWT_AUTH_EXPIRES")
            .ok()
            .and_then(|value| value.parse().ok())
            .unwrap_or(self.jwt_expires)
    }

    fn auth_config(&self) -> Option<crate::rest::AuthConfig> {
        let secret = self.secret();
        (!secret.is_empty()).then(|| crate::rest::AuthConfig {
            secret,
            public_paths: self.public_paths.clone(),
        })
    }
}

/// REST middleware toggles.
#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
#[serde(default, deny_unknown_fields)]
pub struct RestMiddlewaresSection {
    pub metrics: bool,
    pub resilience: bool,
}

impl Default for RestMiddlewaresSection {
    fn default() -> Self {
        Self {
            metrics: true,
            resilience: true,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::RestServiceConfig;

    #[test]
    fn maps_runtime_values() {
        let config = RestServiceConfig::default();
        let runtime = config.rest_config();
        assert_eq!(runtime.name, "rs-zero");
        assert_eq!(runtime.timeout, std::time::Duration::from_millis(5000));
        assert!(runtime.middlewares.metrics.enabled);
    }

    #[test]
    fn validate_features_reflects_compile_time_features() {
        let warnings = RestServiceConfig::default().validate_features();
        assert_eq!(
            warnings
                .iter()
                .any(|warning| warning.required_feature == "observability"),
            !cfg!(feature = "observability")
        );
        assert_eq!(
            warnings
                .iter()
                .any(|warning| warning.required_feature == "resil"),
            !cfg!(feature = "resil")
        );
    }
}