darkwing/

config.rs

//! Configuration management for the Darkwing application.
//!
//! This module handles all configuration settings that can be set via
//! environment variables or command line arguments using the `clap` crate. It
//! provides structured access to application settings including:
//!
//! - Environment selection (Development/Test/Production)
//! - Server configuration
//! - Database settings
//! - Redis cache settings
//! - JWT authentication settings
//! - AWS S3 configuration for both primary and backup storage
//! - Encryption keys and security settings
//! - Rate limiting parameters
//! - Monitoring configuration (Sentry)

use std::{str::FromStr, time::Duration};

use anyhow::Context;
use jsonwebtoken::Algorithm;

/// Represents the running environment of the application.
///
/// This enum is used to determine the behavior and settings of the application
/// based on its deployment environment.
#[derive(clap::ValueEnum, Clone, Debug, Copy, Default, PartialEq)]
pub enum CargoEnv {
  /// Development environment for local development and testing
  #[default]
  Development,
  /// Test environment for running automated tests
  Test,
  /// Production environment for deployed applications
  Production,
}

/// Main configuration structure for the Darkwing application.
///
/// This struct is populated using command line arguments or environment
/// variables through the `clap` crate's derive functionality. Each field
/// corresponds to a configurable aspect of the application.
#[derive(clap::Parser, Clone, Debug, Default)]
pub struct DarkwingConfig {
  /// The environment in which the application is running
  #[clap(long, env = "CARGO_ENV", value_enum)]
  pub cargo_env: CargoEnv,

  /// Port number on which the server will listen
  #[clap(long, env = "PORT", default_value = "1337")]
  pub port: u16,

  /// Database connection string
  #[clap(long, env = "DATABASE_URL")]
  pub database_url: String,

  /// Maximum number of connections in the database connection pool
  #[clap(long, env = "DATABASE_CONNECTION_POOL_SIZE", default_value = "5")]
  pub database_connection_pool_size: u32,

  /// Redis server connection string
  #[clap(long, env = "REDIS_URL")]
  pub redis_url: String,

  /// Maximum number of connections in the Redis connection pool
  #[clap(long, env = "REDIS_CONNECTION_POOL_SIZE", default_value = "5")]
  pub redis_connection_pool_size: u32,

  /// Default timeout for Redis operations in seconds
  #[clap(long, env = "REDIS_DEFAULT_TIMEOUT_SECONDS", default_value = "5")]
  pub redis_default_timeout_seconds: u64,

  /// Time-to-live for Redis cache entries in seconds
  #[clap(long, env = "REDIS_EXPIRATION_SECONDS", default_value = "3600")]
  pub redis_expiration_seconds: u64,

  /// Public key used for JWT token verification
  #[clap(long, env = "JWT_TOKEN_PUBLIC_KEY")]
  pub jwt_token_public_key: String,

  /// Algorithm used for JWT token signing/verification (e.g., "RS256")
  #[clap(long, env = "JWT_TOKEN_ALGORITHM", default_value = "RS256")]
  pub jwt_token_algorithm: String,

  /// Key used for encrypting configuration values
  #[clap(long, env = "CONFIG_ENCRYPTION_KEY")]
  pub config_encryption_key: String,

  /// Maximum number of requests allowed per second for rate limiting
  #[clap(long, env = "RATE_LIMIT_PER_SECOND", default_value = "100")]
  pub rate_limit_per_second: u64,

  /// AWS S3 access key ID for primary storage
  #[clap(long, env = "AWS_S3_ACCESS_KEY_ID")]
  pub aws_s3_access_key_id: String,

  /// AWS S3 secret access key for primary storage
  #[clap(long, env = "AWS_S3_SECRET_ACCESS_KEY")]
  pub aws_s3_secret_access_key: String,

  /// AWS S3 endpoint URL for primary storage
  #[clap(long, env = "AWS_S3_ENDPOINT")]
  pub aws_s3_endpoint: String,

  /// AWS S3 bucket name for primary storage
  #[clap(long, env = "AWS_S3_BUCKET")]
  pub aws_s3_bucket: String,

  /// AWS S3 region for primary storage
  #[clap(long, env = "AWS_S3_REGION")]
  pub aws_s3_region: String,

  /// Public URL for accessing S3 objects
  #[clap(long, env = "AWS_S3_PUBLIC_URL")]
  pub aws_s3_public_url: String,

  /// AWS S3 access key ID for backup storage
  #[clap(long, env = "AWS_S3_BACKUP_ACCESS_KEY_ID")]
  pub aws_s3_backup_access_key_id: String,

  /// AWS S3 secret access key for backup storage
  #[clap(long, env = "AWS_S3_BACKUP_SECRET_ACCESS_KEY")]
  pub aws_s3_backup_secret_access_key: String,

  /// AWS S3 endpoint URL for backup storage
  #[clap(long, env = "AWS_S3_BACKUP_ENDPOINT")]
  pub aws_s3_backup_endpoint: String,

  /// AWS S3 bucket name for backup storage
  #[clap(long, env = "AWS_S3_BACKUP_BUCKET")]
  pub aws_s3_backup_bucket: String,

  /// AWS S3 region for backup storage
  #[clap(long, env = "AWS_S3_BACKUP_REGION")]
  pub aws_s3_backup_region: String,

  /// First part of the database encryption key (split for security)
  #[clap(long, env = "DATABASE_ENCRYPTION_KEY_PART_1")]
  pub database_encryption_key_part_1: String,

  /// Second part of the database encryption key (split for security)
  #[clap(long, env = "DATABASE_ENCRYPTION_KEY_PART_2")]
  pub database_encryption_key_part_2: String,

  /// Expiration time in seconds for S3 presigned URLs
  #[clap(
    long,
    env = "AWS_S3_PRESIGNED_URL_EXPIRATION_SECONDS",
    default_value = "300"
  )]
  pub aws_s3_presigned_url_expiration_seconds: u64,

  /// Encryption key for S3 path encryption
  #[clap(long, env = "S3_PATH_ENCRYPTION_KEY")]
  pub s3_path_encryption_key: String,

  /// Optional Sentry DSN for error tracking
  #[clap(long, env = "SENTRY_DSN")]
  pub sentry_dsn: Option<String>,
}

impl DarkwingConfig {
  /// Converts the JWT algorithm string to the corresponding Algorithm enum
  /// value.
  pub fn get_jwt_token_algorithm(&self) -> anyhow::Result<Algorithm> {
    Algorithm::from_str(&self.jwt_token_algorithm)
      .context("Invalid JWT token algorithm in config transform")
  }

  /// Returns the Redis timeout duration.
  pub fn redis_timeout(&self) -> Duration {
    Duration::from_secs(self.redis_default_timeout_seconds)
  }

  /// Returns the expiration duration for presigned URLs.
  pub fn presigned_url_expiration(&self) -> Duration {
    Duration::from_secs(self.aws_s3_presigned_url_expiration_seconds)
  }
}