use config::{Config, ConfigError, Environment, File};
use serde::{Deserialize, Serialize};

mod auth;
mod cors;
mod grpc;
mod log;
mod nginx;

pub use auth::*;
pub use cors::*;
pub use grpc::*;
pub use log::*;
pub use nginx::*;

pub type ValidationError = String;

pub trait Validate {
    fn validate(&self) -> Result<(), ValidationError>;
}

/// Agent settings
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Settings {
    pub agent_id: String,

    pub grpc: GrpcSettings,
    #[serde(default)]
    pub log: LogSettings,
    #[serde(default)]
    pub nginx: NginxSettings,
}

impl Validate for Settings {
    fn validate(&self) -> Result<(), ValidationError> {
        self.grpc.validate()?;
        self.nginx.validate()?;
        Ok(())
    }
}

impl Settings {
    /// Load settings from config files and environment
    pub fn load() -> Result<Self, ConfigError> {
        let run_mode = std::env::var("RUN_MODE").unwrap_or_else(|_| "development".into());

        let settings = Config::builder()
            .add_source(File::with_name("config/default").required(false))
            .add_source(File::with_name(&format!("config/{}", run_mode)).required(false))
            .add_source(File::with_name("config/agent/default").required(false))
            .add_source(File::with_name(&format!("config/agent/{}", run_mode)).required(false))
            .add_source(Environment::with_prefix("NXMESH").separator("__"))
            .build()?;

        let mut settings: Self = settings.try_deserialize()?;

        settings.validate().map_err(ConfigError::Message)?;

        settings.nginx.validate().map_err(ConfigError::Message)?;
        settings.nginx.transform_commands();

        Ok(settings)
    }
}

#[cfg(test)]
mod tests {

    use super::*;

    #[test]
    fn test_ensure_send_and_sync() {
        fn assert_send_sync<T: Send + Sync>() {}
        assert_send_sync::<Settings>();
    }
}