mockforge_http/

state_machine_api.rs

//! State machine API handlers
//!
//! Provides REST endpoints for managing scenario state machines, including
//! CRUD operations, execution, and import/export functionality.

use axum::{
    extract::{Path, Query, State},
    http::StatusCode,
    response::IntoResponse,
    Json,
};
use mockforge_core::intelligent_behavior::{rules::StateMachine, visual_layout::VisualLayout};
use mockforge_scenarios::{
    state_machine::{ScenarioStateMachineManager, StateInstance},
    ScenarioManifest,
};
use serde::{Deserialize, Serialize};
use serde_json::Value;
use std::collections::HashMap;
use std::sync::Arc;
use tokio::sync::RwLock;
use tracing::{debug, error, info, warn};

// Re-export ManagementState for use in handlers
use crate::management::ManagementState;

// ===== Request/Response Types =====

/// Request to create or update a state machine
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct StateMachineRequest {
    /// State machine definition
    pub state_machine: StateMachine,
    /// Optional visual layout
    #[serde(skip_serializing_if = "Option::is_none")]
    pub visual_layout: Option<VisualLayout>,
}

/// Request to execute a state transition
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TransitionRequest {
    /// Resource ID to transition
    pub resource_id: String,
    /// Target state
    pub to_state: String,
    /// Optional context variables for condition evaluation
    #[serde(skip_serializing_if = "Option::is_none")]
    pub context: Option<HashMap<String, Value>>,
}

/// Request to create a state instance
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CreateInstanceRequest {
    /// Resource ID
    pub resource_id: String,
    /// Resource type (must match a state machine resource_type)
    pub resource_type: String,
}

/// Response for state machine operations
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct StateMachineResponse {
    /// State machine definition
    pub state_machine: StateMachine,
    /// Optional visual layout
    #[serde(skip_serializing_if = "Option::is_none")]
    pub visual_layout: Option<VisualLayout>,
}

/// Response for listing state machines
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct StateMachineListResponse {
    /// List of state machines
    pub state_machines: Vec<StateMachineInfo>,
    /// Total count
    pub total: usize,
}

/// Information about a state machine
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct StateMachineInfo {
    /// Resource type
    pub resource_type: String,
    /// Number of states
    pub state_count: usize,
    /// Number of transitions
    pub transition_count: usize,
    /// Number of sub-scenarios
    pub sub_scenario_count: usize,
    /// Whether it has a visual layout
    pub has_visual_layout: bool,
}

/// Response for state instance operations
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct StateInstanceResponse {
    /// Resource ID
    pub resource_id: String,
    /// Current state
    pub current_state: String,
    /// Resource type
    pub resource_type: String,
    /// State history count
    pub history_count: usize,
    /// State data
    pub state_data: HashMap<String, Value>,
}

/// Response for listing state instances
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct StateInstanceListResponse {
    /// List of instances
    pub instances: Vec<StateInstanceResponse>,
    /// Total count
    pub total: usize,
}

/// Response for next states query
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NextStatesResponse {
    /// List of possible next states
    pub next_states: Vec<String>,
}

/// Response for import/export operations
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ImportExportResponse {
    /// State machines
    pub state_machines: Vec<StateMachine>,
    /// Visual layouts by resource type
    pub visual_layouts: HashMap<String, VisualLayout>,
}

// ===== Handlers =====

/// List all state machines
pub async fn list_state_machines(
    State(state): State<ManagementState>,
) -> Result<Json<StateMachineListResponse>, StatusCode> {
    let manager = state.state_machine_manager.read().await;

    // Get all state machines
    let machines = manager.list_state_machines().await;

    let state_machine_list: Vec<_> = machines
        .iter()
        .map(|(resource_type, sm)| StateMachineInfo {
            resource_type: resource_type.clone(),
            state_count: sm.states.len(),
            transition_count: sm.transitions.len(),
            sub_scenario_count: sm.sub_scenarios.len(),
            has_visual_layout: sm.visual_layout.is_some(),
        })
        .collect();

    Ok(Json(StateMachineListResponse {
        state_machines: state_machine_list.clone(),
        total: state_machine_list.len(),
    }))
}

/// Get a state machine by resource type
pub async fn get_state_machine(
    State(state): State<ManagementState>,
    Path(resource_type): Path<String>,
) -> Result<Json<StateMachineResponse>, StatusCode> {
    let manager = state.state_machine_manager.read().await;

    let state_machine =
        manager.get_state_machine(&resource_type).await.ok_or(StatusCode::NOT_FOUND)?;

    let visual_layout = manager.get_visual_layout(&resource_type).await;

    Ok(Json(StateMachineResponse {
        state_machine,
        visual_layout,
    }))
}

/// Create or update a state machine
pub async fn create_state_machine(
    State(state): State<ManagementState>,
    Json(request): Json<StateMachineRequest>,
) -> Result<Json<StateMachineResponse>, StatusCode> {
    let mut manager = state.state_machine_manager.write().await;

    // Validate state machine
    if let Err(e) = manager.validate_state_machine(&request.state_machine) {
        error!("Invalid state machine: {}", e);
        return Err(StatusCode::BAD_REQUEST);
    }

    // Store state machine (we'd need to add a method to store directly)
    // For now, we'll create a minimal manifest and load it
    let mut manifest = ScenarioManifest::new(
        "api".to_string(),
        "1.0.0".to_string(),
        "API State Machine".to_string(),
        "State machine created via API".to_string(),
    );
    manifest.state_machines.push(request.state_machine.clone());

    if let Some(layout) = &request.visual_layout {
        manifest
            .state_machine_graphs
            .insert(request.state_machine.resource_type.clone(), layout.clone());
    }

    if let Err(e) = manager.load_from_manifest(&manifest).await {
        error!("Failed to load state machine: {}", e);
        return Err(StatusCode::INTERNAL_SERVER_ERROR);
    }

    // Set visual layout if provided
    let visual_layout = request.visual_layout.clone();
    if let Some(layout) = &visual_layout {
        manager
            .set_visual_layout(&request.state_machine.resource_type, layout.clone())
            .await;
    }

    // Broadcast WebSocket event
    if let Some(ref ws_tx) = state.ws_broadcast {
        let event = crate::management_ws::MockEvent::state_machine_updated(
            request.state_machine.resource_type.clone(),
            request.state_machine.clone(),
        );
        let _ = ws_tx.send(event);
    }

    Ok(Json(StateMachineResponse {
        state_machine: request.state_machine,
        visual_layout,
    }))
}

/// Delete a state machine
pub async fn delete_state_machine(
    State(state): State<ManagementState>,
    Path(resource_type): Path<String>,
) -> Result<StatusCode, StatusCode> {
    let mut manager = state.state_machine_manager.write().await;

    // Delete the state machine
    let deleted = manager.delete_state_machine(&resource_type).await;

    if !deleted {
        return Err(StatusCode::NOT_FOUND);
    }

    // Broadcast WebSocket event
    if let Some(ref ws_tx) = state.ws_broadcast {
        let event = crate::management_ws::MockEvent::state_machine_deleted(resource_type);
        let _ = ws_tx.send(event);
    }

    Ok(StatusCode::NO_CONTENT)
}

/// List all state instances
pub async fn list_instances(
    State(state): State<ManagementState>,
) -> Result<Json<StateInstanceListResponse>, StatusCode> {
    let manager = state.state_machine_manager.read().await;

    let instances = manager.list_instances().await;

    let instance_responses: Vec<StateInstanceResponse> = instances
        .iter()
        .map(|i| StateInstanceResponse {
            resource_id: i.resource_id.clone(),
            current_state: i.current_state.clone(),
            resource_type: i.resource_type.clone(),
            history_count: i.state_history.len(),
            state_data: i.state_data.clone(),
        })
        .collect();

    Ok(Json(StateInstanceListResponse {
        instances: instance_responses,
        total: instances.len(),
    }))
}

/// Get a state instance by resource ID
pub async fn get_instance(
    State(state): State<ManagementState>,
    Path(resource_id): Path<String>,
) -> Result<Json<StateInstanceResponse>, StatusCode> {
    let manager = state.state_machine_manager.read().await;

    let instance = manager.get_instance(&resource_id).await.ok_or(StatusCode::NOT_FOUND)?;

    Ok(Json(StateInstanceResponse {
        resource_id: instance.resource_id,
        current_state: instance.current_state,
        resource_type: instance.resource_type,
        history_count: instance.state_history.len(),
        state_data: instance.state_data,
    }))
}

/// Create a new state instance
pub async fn create_instance(
    State(state): State<ManagementState>,
    Json(request): Json<CreateInstanceRequest>,
) -> Result<Json<StateInstanceResponse>, StatusCode> {
    let manager = state.state_machine_manager.write().await;

    if let Err(e) = manager.create_instance(&request.resource_id, &request.resource_type).await {
        error!("Failed to create instance: {}", e);
        return Err(StatusCode::BAD_REQUEST);
    }

    let instance = manager
        .get_instance(&request.resource_id)
        .await
        .ok_or(StatusCode::INTERNAL_SERVER_ERROR)?;

    // Broadcast WebSocket event
    if let Some(ref ws_tx) = state.ws_broadcast {
        let event = crate::management_ws::MockEvent::state_instance_created(
            instance.resource_id.clone(),
            instance.resource_type.clone(),
            instance.current_state.clone(),
        );
        let _ = ws_tx.send(event);
    }

    Ok(Json(StateInstanceResponse {
        resource_id: instance.resource_id,
        current_state: instance.current_state,
        resource_type: instance.resource_type,
        history_count: instance.state_history.len(),
        state_data: instance.state_data,
    }))
}

/// Execute a state transition
pub async fn execute_transition(
    State(state): State<ManagementState>,
    Json(request): Json<TransitionRequest>,
) -> Result<Json<StateInstanceResponse>, StatusCode> {
    let manager = state.state_machine_manager.write().await;

    if let Err(e) = manager
        .execute_transition(&request.resource_id, &request.to_state, request.context)
        .await
    {
        error!("Failed to execute transition: {}", e);
        return Err(StatusCode::BAD_REQUEST);
    }

    let instance = manager.get_instance(&request.resource_id).await.ok_or(StatusCode::NOT_FOUND)?;

    // Get the previous state from history if available
    let from_state = instance
        .state_history
        .last()
        .map(|h| h.from_state.clone())
        .unwrap_or_else(|| instance.current_state.clone());

    // Broadcast WebSocket event
    if let Some(ref ws_tx) = state.ws_broadcast {
        let event = crate::management_ws::MockEvent::state_transitioned(
            instance.resource_id.clone(),
            instance.resource_type.clone(),
            from_state,
            instance.current_state.clone(),
            instance.state_data.clone(),
        );
        let _ = ws_tx.send(event);
    }

    Ok(Json(StateInstanceResponse {
        resource_id: instance.resource_id,
        current_state: instance.current_state,
        resource_type: instance.resource_type,
        history_count: instance.state_history.len(),
        state_data: instance.state_data,
    }))
}

/// Get next possible states for a resource
pub async fn get_next_states(
    State(state): State<ManagementState>,
    Path(resource_id): Path<String>,
) -> Result<Json<NextStatesResponse>, StatusCode> {
    let manager = state.state_machine_manager.read().await;

    let next_states =
        manager.get_next_states(&resource_id).await.map_err(|_| StatusCode::NOT_FOUND)?;

    Ok(Json(NextStatesResponse { next_states }))
}

/// Get current state of a resource
pub async fn get_current_state(
    State(state): State<ManagementState>,
    Path(resource_id): Path<String>,
) -> Result<Json<serde_json::Value>, StatusCode> {
    let manager = state.state_machine_manager.read().await;

    let current_state =
        manager.get_current_state(&resource_id).await.ok_or(StatusCode::NOT_FOUND)?;

    Ok(Json(serde_json::json!({
        "resource_id": resource_id,
        "current_state": current_state
    })))
}

/// Export state machines as JSON
pub async fn export_state_machines(
    State(state): State<ManagementState>,
) -> Result<Json<ImportExportResponse>, StatusCode> {
    let manager = state.state_machine_manager.read().await;

    // Export all state machines and visual layouts
    let (state_machines, visual_layouts) = manager.export_all().await;

    Ok(Json(ImportExportResponse {
        state_machines,
        visual_layouts,
    }))
}

/// Import state machines from JSON
pub async fn import_state_machines(
    State(state): State<ManagementState>,
    Json(request): Json<ImportExportResponse>,
) -> Result<StatusCode, StatusCode> {
    let mut manager = state.state_machine_manager.write().await;

    // Create a manifest from imported data
    let mut manifest = ScenarioManifest::new(
        "imported".to_string(),
        "1.0.0".to_string(),
        "Imported State Machines".to_string(),
        "State machines imported via API".to_string(),
    );
    manifest.state_machines = request.state_machines.clone();
    manifest.state_machine_graphs = request.visual_layouts.clone();

    if let Err(e) = manager.load_from_manifest(&manifest).await {
        error!("Failed to import state machines: {}", e);
        return Err(StatusCode::BAD_REQUEST);
    }

    // Set visual layouts
    for (resource_type, layout) in request.visual_layouts {
        manager.set_visual_layout(&resource_type, layout).await;
    }

    Ok(StatusCode::CREATED)
}

/// Create the state machine API router
///
/// This function creates routes that use ManagementState, so they can be
/// nested within the management router.
pub fn create_state_machine_routes() -> axum::Router<ManagementState> {
    use axum::routing::{delete, get, post, put};

    axum::Router::new()
        // State machine CRUD
        .route("/", get(list_state_machines))
        .route("/", post(create_state_machine))
        .route("/:resource_type", get(get_state_machine))
        .route("/:resource_type", put(create_state_machine))
        .route("/:resource_type", delete(delete_state_machine))

        // State instance operations
        .route("/instances", get(list_instances))
        .route("/instances", post(create_instance))
        .route("/instances/:resource_id", get(get_instance))
        .route("/instances/:resource_id/state", get(get_current_state))
        .route("/instances/:resource_id/next-states", get(get_next_states))
        .route("/instances/:resource_id/transition", post(execute_transition))

        // Import/Export
        .route("/export", get(export_state_machines))
        .route("/import", post(import_state_machines))
}