//! Vapora Workflow Engine
//!
//! Orchestrates multi-stage workflows with learning-based agent selection,
//! artifact passing between stages, and cost-aware LLM routing.
//!
//! # Architecture
//!
//! The workflow engine uses a state machine approach where each
//! WorkflowInstance tracks progress through stages. Each stage can execute
//! tasks in parallel or sequentially, with artifacts passed between stages via
//! the Knowledge Graph.
//!
//! # Key Components
//!
//! - `WorkflowOrchestrator`: Main coordinator managing workflow lifecycle
//! - `WorkflowInstance`: State machine tracking individual workflow execution
//! - `StageState`: Manages stage execution and task assignment
//! - `Artifact`: Data passed between stages
//!
//! # Example
//!
//! ```no_run
//! use vapora_workflow_engine::{WorkflowOrchestrator, config::WorkflowsConfig};
//! use std::sync::Arc;
//!
//! # async fn example() -> Result<(), Box<dyn std::error::Error>> {
//! // Initialize dependencies (SwarmCoordinator, KGPersistence, NATS)
//! # let swarm = todo!();
//! # let kg = todo!();
//! # let nats = todo!();
//!
//! // Create orchestrator
//! let orchestrator = Arc::new(
//!     WorkflowOrchestrator::new(
//!         "config/workflows.toml",
//!         swarm,
//!         kg,
//!         nats,
//!     ).await?
//! );
//!
//! // Start event listener
//! orchestrator.clone().start_event_listener().await?;
//!
//! // Start a workflow
//! let workflow_id = orchestrator.start_workflow(
//!     "feature_development",
//!     serde_json::json!({
//!         "task": "Add authentication",
//!         "requirements": ["OAuth2", "JWT"]
//!     })
//! ).await?;
//!
//! println!("Workflow started: {}", workflow_id);
//! # Ok(())
//! # }
//! ```

pub mod artifact;
pub mod config;
pub mod error;
pub mod instance;
pub mod metrics;
pub mod orchestrator;
pub mod stage;

pub use artifact::{Artifact, ArtifactType};
pub use config::{EngineConfig, StageConfig, WorkflowConfig, WorkflowsConfig};
pub use error::{ConfigError, Result, WorkflowError};
pub use instance::{WorkflowInstance, WorkflowStatus};
pub use metrics::WorkflowMetrics;
pub use orchestrator::WorkflowOrchestrator;
pub use stage::{StageState, StageStatus, TaskState, TaskStatus};