synapse 1.1.0

//! Synapse Authentication Integration
//! 
//! This module integrates the auth-framework crate to provide federated authentication
//! for Synapse, addressing the security limitations of WebCrypto with enterprise-grade
//! OAuth 2.0, OpenID Connect, and multi-factor authentication support.

#![allow(unused_imports)]

use std::{
    collections::HashMap,
    sync::Arc,
    time::Duration,
    fmt,
};

use anyhow::{Result, anyhow};
use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use tokio::sync::RwLock;

// Only import auth-framework when the "auth" feature is enabled
#[cfg(feature = "auth")]
use auth_framework::{
    self,
    AuthConfig,
    AuthFramework,
    AuthResult,
    AuthToken,
    Credential,
    JwtMethod,
    OAuth2Method,
    OAuthProvider,
    storage::MemoryStorage,
};
use uuid::Uuid;

use crate::blockchain::serialization::{DateTimeWrapper, UuidWrapper};
use crate::error::SynapseError;
use crate::types::SecureMessage;

// Define local types to represent auth-framework functionality
#[cfg(feature = "auth")]
pub struct AuthContext {
    pub user_id: String,
    pub scopes: Vec<String>,
}

#[cfg(feature = "auth")]
pub struct MfaChallenge {
    id: String,
    #[allow(dead_code)]
    challenge_type: String,
}

#[cfg(feature = "auth")]
impl MfaChallenge {
    pub fn id(&self) -> &str {
        &self.id
    }
}

/// Synapse authentication manager that integrates with auth-framework
pub struct SynapseAuthManager {
    #[cfg(feature = "auth")]
    auth_framework: Arc<RwLock<AuthFramework>>,
    
    /// Maps Synapse global IDs to authenticated user profiles
    user_profiles: Arc<RwLock<HashMap<String, SynapseUserProfile>>>,
    
    /// Maps authentication tokens to public keys for message encryption
    #[allow(dead_code)]
    token_to_keys: Arc<RwLock<HashMap<String, String>>>,
    
    /// Configuration for the auth system
    #[allow(dead_code)]
    config: SynapseAuthConfig,
}

/// Synapse-specific user profile with neural network metadata
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SynapseUserProfile {
    /// Unique Synapse global ID (e.g., "alice@ai-lab.example.com")
    pub global_id: String,
    
    /// User's display name
    pub display_name: String,
    
    /// Verified email address
    pub email: String,
    
    /// User's RSA public key for message encryption
    pub public_key: String,
    
    /// Authentication provider used
    pub auth_provider: String,
    
    /// User's roles and permissions
    pub roles: Vec<String>,
    
    /// Whether MFA is enabled/verified
    pub mfa_verified: bool,
    
    /// Trust level based on authentication method
    pub trust_level: TrustLevel,
    
    /// When the user was last authenticated
    pub last_auth: DateTime<Utc>,
    
    /// Additional metadata for neural network features
    pub neural_metadata: NeuralMetadata,
}

/// Neural network specific metadata
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NeuralMetadata {
    /// Whether this user is an AI model
    pub is_ai_model: bool,
    
    /// AI model capabilities if applicable
    pub ai_capabilities: Vec<String>,
    
    /// Preferred communication patterns
    pub communication_preferences: Vec<String>,
    
    /// Topic expertise areas
    pub expertise_areas: Vec<String>,
}

/// Trust levels for authenticated users
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum TrustLevel {
    /// Verified through MFA and trusted provider
    Verified,
    /// Authenticated through trusted provider
    Trusted,
    /// Basic authentication completed
    Authenticated,
    /// Authentication pending/expired
    Unverified,
}

/// Configuration for Synapse authentication
#[derive(Debug, Clone)]
pub struct SynapseAuthConfig {
    /// OAuth providers to support
    pub oauth_providers: Vec<OAuthProviderConfig>,
    
    /// Whether to require MFA for all users
    pub require_mfa: bool,
    
    /// Token lifetime settings
    pub token_lifetime: Duration,
    
    /// Refresh token lifetime
    pub refresh_token_lifetime: Duration,
    
    /// Whether to enable enterprise features
    pub enterprise_mode: bool,
    
    /// Rate limiting configuration
    pub rate_limit_requests: u32,
    pub rate_limit_window: Duration,
}

/// OAuth provider configuration
#[derive(Debug, Clone)]
pub struct OAuthProviderConfig {
    pub provider: String,
    pub client_id: String,
    pub client_secret: String,
    pub redirect_uri: String,
    pub scopes: Vec<String>,
    pub enabled: bool,
}

/// Authentication result for Synapse
#[derive(Debug)]
pub enum SynapseAuthResult {
    /// Authentication successful with user profile
    Success(SynapseUserProfile),
    
    /// MFA required - includes challenge
    MfaRequired {
        challenge_id: String,
        challenge_type: String,
        expires_at: DateTime<Utc>,
    },
    
    /// Device flow required - includes device code
    DeviceFlowRequired {
        device_code: String,
        user_code: String,
        verification_uri: String,
        expires_at: DateTime<Utc>,
    },
    
    /// Authentication failed
    Failed {
        reason: String,
        can_retry: bool,
    },
}

impl Default for SynapseAuthConfig {
    fn default() -> Self {
        Self {
            oauth_providers: vec![],
            require_mfa: false,
            token_lifetime: Duration::from_secs(3600), // 1 hour
            refresh_token_lifetime: Duration::from_secs(86400 * 7), // 7 days
            enterprise_mode: false,
            rate_limit_requests: 100,
            rate_limit_window: Duration::from_secs(60),
        }
    }
}

impl SynapseAuthManager {
    /// Create a new Synapse authentication manager
    pub async fn new(config: SynapseAuthConfig) -> Result<Self> {
        #[cfg(feature = "auth")]
        {
            // Configure auth-framework
            let auth_config = AuthConfig::new()
                .token_lifetime(config.token_lifetime)
                .refresh_token_lifetime(config.refresh_token_lifetime)
                .enable_multi_factor(config.require_mfa);
            
            let _storage = Arc::new(MemoryStorage::new());
            let mut auth_framework = AuthFramework::new(auth_config);
            
            // Register OAuth providers
            for provider_config in &config.oauth_providers {
                let oauth_method = Self::create_oauth_method(provider_config)?;
                auth_framework.register_method(&provider_config.provider, Box::new(oauth_method));
            }
            
            // Register JWT method for internal tokens
            let jwt_method = JwtMethod::new()
                .secret_key("synapse-jwt-secret") // In production, use a secure secret
                .issuer("synapse");
            auth_framework.register_method("jwt", Box::new(jwt_method));
            
            // Initialize the framework
            auth_framework.initialize().await?;
            
            Ok(Self {
                auth_framework: Arc::new(RwLock::new(auth_framework)),
                user_profiles: Arc::new(RwLock::new(HashMap::new())),
                token_to_keys: Arc::new(RwLock::new(HashMap::new())),
                config,
            })
        }
        
        #[cfg(not(feature = "auth"))]
        {
            Ok(Self {
                user_profiles: Arc::new(RwLock::new(HashMap::new())),
                token_to_keys: Arc::new(RwLock::new(HashMap::new())),
                config,
            })
        }
    }
    
    /// Authenticate a user with OAuth provider
    pub async fn authenticate_oauth(
        &self,
        provider: &str,
        authorization_code: &str,
    ) -> Result<SynapseAuthResult> {
        #[cfg(feature = "auth")]
        {
            let auth_framework = self.auth_framework.read().await;
            
            let credential = Credential::oauth_code(authorization_code);
            let result = auth_framework.authenticate(provider, credential).await?;
            
            match result {
                AuthResult::Success(token) => {
                    let profile = self.create_synapse_profile_from_token(&token, provider).await?;
                    self.store_user_profile(&profile).await?;
                    Ok(SynapseAuthResult::Success(profile))
                }
                AuthResult::MfaRequired(challenge) => {
                    use crate::blockchain::serialization::DateTimeWrapper;

                    Ok(SynapseAuthResult::MfaRequired {
                        challenge_id: challenge.id().to_string(),
                        challenge_type: "totp".to_string(), // Simplified for now
                        expires_at: Utc::now() + chrono::Duration::minutes(5),
                    })
                }
                AuthResult::Failure(reason) => {
                    Ok(SynapseAuthResult::Failed {
                        reason,
                        can_retry: true,
                    })
                }
            }
        }
        
        #[cfg(not(feature = "auth"))]
        {
            Ok(SynapseAuthResult::Failed {
                reason: "Authentication feature not enabled".to_string(),
                can_retry: false,
            })
        }
    }
    
    /// Start device flow authentication
    pub async fn start_device_flow(&self, _provider: &str) -> Result<SynapseAuthResult> {
        #[cfg(feature = "auth")]
        {
            // Implementation would use auth-framework's device flow
            // This is a simplified example

            use crate::blockchain::serialization::DateTimeWrapper;
            Ok(SynapseAuthResult::DeviceFlowRequired {
                device_code: "device_123".to_string(),
                user_code: "USER-CODE".to_string(),
                verification_uri: "https://github.com/login/device".to_string(),
                expires_at: Utc::now() + chrono::Duration::seconds(900),
            })
        }
        
        #[cfg(not(feature = "auth"))]
        {
            Ok(SynapseAuthResult::Failed {
                reason: "Authentication feature not enabled".to_string(),
                can_retry: false,
            })
        }
    }
    
    /// Validate an authentication token
    pub async fn validate_token(&self, token: &str) -> Result<Option<SynapseUserProfile>> {
        #[cfg(feature = "auth")]
        {
            let auth_framework = self.auth_framework.read().await;
            
            // Create a JWT credential for validation
            let credential = Credential::jwt(token);
            
            // Try to authenticate with the JWT token
            if let Ok(AuthResult::Success(auth_token)) = auth_framework.authenticate("jwt", credential).await {
                // Look up user profile
                let profiles = self.user_profiles.read().await;
                return Ok(profiles.get(&auth_token.user_id).cloned());
            }
            
            Ok(None)
        }
        
        #[cfg(not(feature = "auth"))]
        {
            Ok(None)
        }
    }
    
    /// Check if a user has permission for an action
    pub async fn check_permission(
        &self,
        user_id: &str,
        permission: &str,
        resource: &str,
    ) -> Result<bool> {
        #[cfg(feature = "auth")]
        {
            let auth_framework = self.auth_framework.read().await;
            
            // Get user's token
            if let Some(profile) = self.get_user_profile(user_id).await? {
                // Create a temporary token for permission checking
                let token = auth_framework.create_auth_token(
                    user_id,
                    profile.roles.clone(),
                    "jwt",
                    None,
                ).await?;
                
                return Ok(auth_framework.check_permission(&token, permission, resource).await?);
            }
            
            Ok(false)
        }
        
        #[cfg(not(feature = "auth"))]
        {
            Ok(false)
        }
    }
    
    /// Get user profile by global ID
    pub async fn get_user_profile(&self, global_id: &str) -> Result<Option<SynapseUserProfile>> {
        let profiles = self.user_profiles.read().await;
        Ok(profiles.get(global_id).cloned())
    }
    
    /// Exchange user credentials for public key for message encryption
    pub async fn get_public_key_for_user(&self, global_id: &str) -> Result<Option<String>> {
        let profiles = self.user_profiles.read().await;
        Ok(profiles.get(global_id).map(|p| p.public_key.clone()))
    }
    
    /// Create OAuth method for a provider
    #[cfg(feature = "auth")]
    fn create_oauth_method(config: &OAuthProviderConfig) -> Result<OAuth2Method> {
        let provider = match config.provider.as_str() {
            "github" => OAuthProvider::GitHub,
            "google" => OAuthProvider::Google,
            "microsoft" => OAuthProvider::Microsoft,
            _ => return Err(anyhow::anyhow!("Unsupported OAuth provider: {}", config.provider)),
        };
        
        let oauth_method = OAuth2Method::new()
            .provider(provider)
            .client_id(&config.client_id)
            .client_secret(&config.client_secret)
            .redirect_uri(&config.redirect_uri);
        
        Ok(oauth_method)
    }
    
    /// Create Synapse profile from auth token
    #[cfg(feature = "auth")]
    async fn create_synapse_profile_from_token(
        &self,
        token: &AuthToken,
        provider: &str,
    ) -> Result<SynapseUserProfile> {
        // Generate RSA key pair for this user

        use crate::blockchain::serialization::DateTimeWrapper;
        let (_private_key, public_key) = self.generate_keypair_for_user(&token.user_id).await?;
        
        // Create Synapse profile
        let profile = SynapseUserProfile {
            global_id: format!("{}@{}", token.user_id, provider),
            display_name: token.user_id.clone(),
            email: format!("{}@{}", token.user_id, provider), // In practice, get from OAuth
            public_key,
            auth_provider: provider.to_string(),
            roles: token.scopes.clone(),
            mfa_verified: false, // Would be set based on token claims
            trust_level: TrustLevel::Authenticated,
            last_auth: Utc::now(),
            neural_metadata: NeuralMetadata {
                is_ai_model: false,
                ai_capabilities: vec![],
                communication_preferences: vec![],
                expertise_areas: vec![],
            },
        };
        
        Ok(profile)
    }
    
    /// Generate RSA key pair for a user
    async fn generate_keypair_for_user(&self, user_id: &str) -> Result<(String, String)> {
        // This would integrate with Synapse's existing crypto system
        // For now, return placeholder keys
        Ok((
            format!("private_key_for_{}", user_id),
            format!("public_key_for_{}", user_id),
        ))
    }
    
    /// Store user profile
    async fn store_user_profile(&self, profile: &SynapseUserProfile) -> Result<()> {
        let mut profiles = self.user_profiles.write().await;
        profiles.insert(profile.global_id.clone(), profile.clone());
        Ok(())
    }
}

/// Helper functions for integrating with existing Synapse systems
impl SynapseAuthManager {
    /// Create a secure message with authenticated sender
    pub async fn create_authenticated_message(
        &self,
        sender_id: &str,
        recipient_id: &str,
        content: &str,
    ) -> Result<SecureMessage> {
        // Verify sender is authenticated
        let sender_profile = self.get_user_profile(sender_id).await?
            .ok_or_else(|| anyhow::anyhow!("Sender not authenticated"))?;
        
        // Get recipient's public key
        let _recipient_key = self.get_public_key_for_user(recipient_id).await?
            .ok_or_else(|| anyhow::anyhow!("Recipient public key not found"))?;
        
        // Create secure message (integrate with existing crypto system)
        let secure_message = SecureMessage {
            message_id: UuidWrapper::new(Uuid::new_v4()),
            from_global_id: sender_profile.global_id.clone(),
            to_global_id: recipient_id.to_string(),
            encrypted_content: content.as_bytes().to_vec(), // Simplified - should be encrypted
            signature: vec![], // Simplified - should be signed
            timestamp: DateTimeWrapper::new(Utc::now()),
            security_level: crate::types::SecurityLevel::Secure,
            routing_path: vec![],
            metadata: HashMap::new(),
        };
        
        Ok(secure_message)
    }
    
    /// Verify message sender authentication
    pub async fn verify_message_sender(&self, message: &SecureMessage) -> Result<bool> {
        // Check if sender is authenticated
        let sender_profile = self.get_user_profile(&message.from_global_id).await?;
        
        match sender_profile {
            Some(profile) => {
                // Verify the sender's trust level and authentication status
                Ok(matches!(profile.trust_level, TrustLevel::Verified | TrustLevel::Trusted))
            }
            None => Ok(false),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    
    #[tokio::test]
    async fn test_auth_manager_creation() {
        let config = SynapseAuthConfig::default();
        let auth_manager = SynapseAuthManager::new(config).await.unwrap();
        
        // Test basic functionality
        let profile = auth_manager.get_user_profile("test@example.com").await.unwrap();
        assert!(profile.is_none());
    }
    
    #[tokio::test]
    async fn test_permission_checking() {
        let config = SynapseAuthConfig::default();
        let auth_manager = SynapseAuthManager::new(config).await.unwrap();
        
        // Test permission checking
        let has_permission = auth_manager
            .check_permission("test@example.com", "read", "messages")
            .await
            .unwrap();
        
        assert!(!has_permission); // User not authenticated
    }
}