// vapora-backend: Workflow service
// Phase 3: Service layer for workflow management

use std::sync::Arc;

use thiserror::Error;
use tracing::{error, info};

use crate::api::websocket::{WorkflowBroadcaster, WorkflowUpdate};
use crate::audit::{events, AuditEntry, AuditTrail};
use crate::workflow::{EngineError, Workflow, WorkflowEngine};

#[derive(Debug, Error)]
pub enum WorkflowServiceError {
    #[error("Engine error: {0}")]
    EngineError(#[from] EngineError),

    #[error("Workflow not found: {0}")]
    NotFound(String),

    #[error("Invalid operation: {0}")]
    InvalidOperation(String),
}

/// Workflow service provides high-level workflow operations
pub struct WorkflowService {
    engine: Arc<WorkflowEngine>,
    broadcaster: Arc<WorkflowBroadcaster>,
    audit: Arc<AuditTrail>,
}

impl WorkflowService {
    pub fn new(
        engine: Arc<WorkflowEngine>,
        broadcaster: Arc<WorkflowBroadcaster>,
        audit: Arc<AuditTrail>,
    ) -> Self {
        Self {
            engine,
            broadcaster,
            audit,
        }
    }

    /// Create and register a new workflow
    pub async fn create_workflow(
        &self,
        workflow: Workflow,
    ) -> Result<Workflow, WorkflowServiceError> {
        let workflow_id = workflow.id.clone();
        let title = workflow.title.clone();

        // Register with engine
        self.engine.register_workflow(workflow.clone()).await?;

        // Audit event
        self.audit
            .log_event(
                workflow_id.clone(),
                events::WORKFLOW_CREATED.to_string(),
                "system".to_string(),
                serde_json::json!({
                    "title": title,
                    "phases": workflow.phases.len(),
                }),
            )
            .await;

        // Broadcast update
        self.broadcaster.send_update(WorkflowUpdate::new(
            workflow_id.clone(),
            "created".to_string(),
            0,
            format!("Workflow '{}' created", title),
        ));

        info!("Created workflow: {} ({})", workflow_id, title);
        Ok(workflow)
    }

    /// Execute a workflow
    pub async fn execute_workflow(
        &self,
        workflow_id: &str,
    ) -> Result<Workflow, WorkflowServiceError> {
        info!("Executing workflow: {}", workflow_id);

        // Broadcast start
        self.broadcaster.send_update(WorkflowUpdate::new(
            workflow_id.to_string(),
            "starting".to_string(),
            0,
            "Workflow execution started".to_string(),
        ));

        // Audit event
        self.audit
            .log_event(
                workflow_id.to_string(),
                events::WORKFLOW_STARTED.to_string(),
                "system".to_string(),
                serde_json::json!({}),
            )
            .await;

        // Execute workflow
        let result = self.engine.execute_workflow(workflow_id).await;

        match result {
            Ok(workflow) => {
                let status = format!("{:?}", workflow.status);
                let progress = workflow.progress_percent();

                // Broadcast completion
                self.broadcaster.send_update(WorkflowUpdate::new(
                    workflow_id.to_string(),
                    status.clone(),
                    progress,
                    "Workflow execution completed".to_string(),
                ));

                // Audit event
                self.audit
                    .log_event(
                        workflow_id.to_string(),
                        events::WORKFLOW_COMPLETED.to_string(),
                        "system".to_string(),
                        serde_json::json!({
                            "status": status,
                            "progress": progress,
                        }),
                    )
                    .await;

                info!("Workflow {} completed with status: {}", workflow_id, status);
                Ok(workflow)
            }
            Err(e) => {
                let error_msg = format!("{}", e);

                // Broadcast failure
                self.broadcaster.send_update(WorkflowUpdate::new(
                    workflow_id.to_string(),
                    "failed".to_string(),
                    0,
                    format!("Workflow execution failed: {}", error_msg),
                ));

                // Audit event
                self.audit
                    .log_event(
                        workflow_id.to_string(),
                        events::WORKFLOW_FAILED.to_string(),
                        "system".to_string(),
                        serde_json::json!({
                            "error": error_msg,
                        }),
                    )
                    .await;

                error!("Workflow {} failed: {}", workflow_id, error_msg);
                Err(WorkflowServiceError::from(e))
            }
        }
    }

    /// Get workflow by ID
    pub async fn get_workflow(&self, workflow_id: &str) -> Result<Workflow, WorkflowServiceError> {
        self.engine
            .get_workflow(workflow_id)
            .await
            .ok_or_else(|| WorkflowServiceError::NotFound(workflow_id.to_string()))
    }

    /// List all workflows
    pub async fn list_workflows(&self) -> Vec<Workflow> {
        self.engine.list_workflows().await
    }

    /// Rollback a failed workflow
    pub async fn rollback_workflow(&self, workflow_id: &str) -> Result<(), WorkflowServiceError> {
        info!("Rolling back workflow: {}", workflow_id);

        self.engine.rollback_workflow(workflow_id).await?;

        // Broadcast rollback
        self.broadcaster.send_update(WorkflowUpdate::new(
            workflow_id.to_string(),
            "rolled_back".to_string(),
            0,
            "Workflow rolled back".to_string(),
        ));

        // Audit event
        self.audit
            .log_event(
                workflow_id.to_string(),
                events::WORKFLOW_ROLLED_BACK.to_string(),
                "system".to_string(),
                serde_json::json!({}),
            )
            .await;

        Ok(())
    }

    /// Get audit trail for workflow
    pub async fn get_audit_trail(&self, workflow_id: &str) -> Vec<AuditEntry> {
        self.audit.get_workflow_audit(workflow_id).await
    }

    /// Get broadcaster reference
    pub fn broadcaster(&self) -> Arc<WorkflowBroadcaster> {
        Arc::clone(&self.broadcaster)
    }
}

#[cfg(test)]
mod tests {
    use vapora_agents::{
        config::{AgentConfig, RegistryConfig},
        coordinator::AgentCoordinator,
        registry::AgentRegistry,
    };

    use super::*;
    use crate::workflow::{
        executor::StepExecutor,
        state::{Phase, StepStatus, WorkflowStep},
    };

    fn create_test_workflow() -> Workflow {
        Workflow::new(
            "test-wf-1".to_string(),
            "Test Workflow".to_string(),
            vec![Phase {
                id: "phase1".to_string(),
                name: "Phase 1".to_string(),
                status: StepStatus::Pending,
                parallel: false,
                estimated_hours: 1.0,
                steps: vec![WorkflowStep {
                    id: "step1".to_string(),
                    name: "Step 1".to_string(),
                    agent_role: "developer".to_string(),
                    status: StepStatus::Pending,
                    depends_on: vec![],
                    can_parallelize: true,
                    started_at: None,
                    completed_at: None,
                    result: None,
                    error: None,
                }],
            }],
        )
    }

    #[tokio::test]
    async fn test_service_creation() {
        let registry = Arc::new(AgentRegistry::new(5));
        let config = AgentConfig {
            registry: RegistryConfig {
                max_agents_per_role: 5,
                health_check_interval: 30,
                agent_timeout: 300,
            },
            agents: vec![],
        };
        let coordinator = Arc::new(
            AgentCoordinator::new(config, registry)
                .await
                .expect("coordinator creation failed"),
        );
        let executor = StepExecutor::new(coordinator);
        let engine = Arc::new(WorkflowEngine::new(executor));
        let broadcaster = Arc::new(WorkflowBroadcaster::new());
        let audit = Arc::new(AuditTrail::new());

        let service = WorkflowService::new(engine, broadcaster, audit);
        assert!(service.list_workflows().await.is_empty());
    }

    #[tokio::test]
    async fn test_create_workflow() {
        let registry = Arc::new(AgentRegistry::new(5));
        let config = AgentConfig {
            registry: RegistryConfig {
                max_agents_per_role: 5,
                health_check_interval: 30,
                agent_timeout: 300,
            },
            agents: vec![],
        };
        let coordinator = Arc::new(
            AgentCoordinator::new(config, registry)
                .await
                .expect("coordinator creation failed"),
        );
        let executor = StepExecutor::new(coordinator);
        let engine = Arc::new(WorkflowEngine::new(executor));
        let broadcaster = Arc::new(WorkflowBroadcaster::new());
        let audit = Arc::new(AuditTrail::new());

        let service = WorkflowService::new(engine, broadcaster, audit);

        let workflow = create_test_workflow();
        let id = workflow.id.clone();

        let result: Result<Workflow, WorkflowServiceError> =
            service.create_workflow(workflow).await;
        assert!(result.is_ok());

        let retrieved: Result<Workflow, WorkflowServiceError> = service.get_workflow(&id).await;
        assert!(retrieved.is_ok());
        assert_eq!(retrieved.unwrap().id, id);
    }

    #[tokio::test]
    async fn test_audit_trail_logging() {
        let registry = Arc::new(AgentRegistry::new(5));
        let config = AgentConfig {
            registry: RegistryConfig {
                max_agents_per_role: 5,
                health_check_interval: 30,
                agent_timeout: 300,
            },
            agents: vec![],
        };
        let coordinator = Arc::new(
            AgentCoordinator::new(config, registry)
                .await
                .expect("coordinator creation failed"),
        );
        let executor = StepExecutor::new(coordinator);
        let engine = Arc::new(WorkflowEngine::new(executor));
        let broadcaster = Arc::new(WorkflowBroadcaster::new());
        let audit = Arc::new(AuditTrail::new());

        let service = WorkflowService::new(engine, broadcaster, audit);

        let workflow = create_test_workflow();
        let id = workflow.id.clone();

        let _: Result<Workflow, WorkflowServiceError> = service.create_workflow(workflow).await;

        let audit_entries: Vec<_> = service.get_audit_trail(&id).await;
        assert!(!audit_entries.is_empty());
        assert_eq!(audit_entries[0].event_type, events::WORKFLOW_CREATED);
    }
}