//! Security System Example for Foxhunt Trading System
//!
//! Demonstrates how to use the comprehensive security features including:
//! - Authentication with username/password and API keys
//! - Role-based access control (RBAC)
//! - Session management
//! - Rate limiting
//! - Audit logging
//! - TLS certificate management

use std::collections::HashMap;
use tli::prelude::*;

// NOTE: Auth module is not implemented yet in TLI
use tokio;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Initialize logging
    tracing_subscriber::fmt::init();

    println!("🔐 Foxhunt Trading System Security Example (PLACEHOLDER)");
    println!("NOTE: This demo shows the intended security API");
    println!("Auth module is not yet implemented in TLI");
    println!("==========================================");

    // 1. Create security configuration
    let security_config = create_security_config();
    println!("✅ Security configuration created");

    // 2. Initialize authentication service
    /*
    let auth_service = match AuthenticationService::new(security_config).await {
        Ok(service) => {
            println!("✅ Authentication service initialized");
            service
        }
        Err(e) => {
            println!("❌ Failed to initialize authentication service: {}", e);
            println!("💡 Note: This example requires proper certificate files for full functionality");
            return Ok(());
        }
    };

    // 3. Demonstrate user authentication
    demonstrate_user_authentication(&auth_service).await?;

    // 4. Demonstrate API key authentication
    demonstrate_api_key_authentication(&auth_service).await?;

    // 5. Demonstrate permission checking
    demonstrate_permission_checking(&auth_service).await?;

    // 6. Demonstrate rate limiting
    demonstrate_rate_limiting(&auth_service).await?;
    */

    println!("\n🎉 Security example completed successfully!");
    println!("📊 Check audit logs for compliance trail");

    Ok(())
}

/// Create comprehensive security configuration
/*
fn create_security_config() -> SecurityConfig {
    SecurityConfig {
        tls: TlsConfig {
            cert_path: "/etc/foxhunt/tls/server.crt".to_string(),
            key_path: "/etc/foxhunt/tls/server.key".to_string(),
            ca_cert_path: "/etc/foxhunt/tls/ca.crt".to_string(),
            require_client_cert: true,
            min_version: "1.3".to_string(),
            cipher_suites: vec![
                "TLS_AES_256_GCM_SHA384".to_string(),
                "TLS_CHACHA20_POLY1305_SHA256".to_string(),
            ],
        },
        session: SessionConfig {
            timeout_seconds: 3600, // 1 hour
            max_sessions_per_user: 3,
            token_length: 32,
            refresh_interval_seconds: 300, // 5 minutes
        },
        rate_limiting: RateLimitConfig {
            authenticated_rpm: 1000,  // 1000 requests per minute for authenticated users
            api_key_rpm: 5000,       // 5000 requests per minute for API keys
            trading_burst: 100,      // Allow 100 trading requests in burst
            window_seconds: 60,      // 1 minute window
        },
        api_keys: ApiKeyConfig {
            key_length: 64,
            default_expiry_days: 90,
            max_keys_per_user: 5,
            rotation_interval_days: 30,
        },
        audit: AuditConfig {
            log_auth_attempts: true,
            log_permission_checks: true,
            log_trading_operations: true,
            retention_days: 2555, // 7 years for financial compliance
            encrypt_logs: true,
        },
        rbac: RbacConfig {
            strict_mode: true,
            cache_permissions: true,
            cache_ttl_seconds: 300,
        },
    }
}
*/
fn create_security_config() -> String {
    // Placeholder for security config
    println!("📊 Would create security configuration with:");
    println!("   - TLS 1.3 with client certificates");
    println!("   - Session timeout: 1 hour");
    println!("   - Rate limiting: 1000 RPM");
    "placeholder_config".to_string()
}

/// Demonstrate user authentication flow
async fn demonstrate_user_authentication(
    auth_service: &AuthenticationService,
) -> Result<(), Box<dyn std::error::Error>> {
    println!("\n👤 User Authentication Demo");
    println!("---------------------------");

    // Attempt authentication with demo credentials
    let client_ip = "127.0.0.1";

    // Try to authenticate admin user (using default credentials)
    match auth_service
        .authenticate_user("admin", "secure_admin_password", client_ip)
        .await
    {
        Ok(auth_result) => {
            println!("✅ Admin authentication successful");
            println!("   User ID: {}", auth_result.user_id);
            println!("   Session expires: {}", auth_result.expires_at);
            println!("   Permissions: {:?}", auth_result.permissions);

            // Validate the session
            match auth_service
                .validate_session(&auth_result.session_token, client_ip)
                .await
            {
                Ok(session_info) => {
                    println!("✅ Session validation successful");
                    println!("   Session ID: {}", session_info.session_id);
                }
                Err(e) => println!("❌ Session validation failed: {}", e),
            }

            // Logout
            if let Err(e) = auth_service.logout(&auth_result.session_token).await {
                println!("⚠️  Logout failed: {}", e);
            } else {
                println!("✅ Logout successful");
            }
        }
        Err(e) => {
            println!("❌ Admin authentication failed: {}", e);
            println!("💡 This is expected - using demo credentials");
        }
    }

    // Try to authenticate trader user
    match auth_service
        .authenticate_user("trader", "secure_trader_password", client_ip)
        .await
    {
        Ok(auth_result) => {
            println!("✅ Trader authentication successful");
            println!("   Permissions: {:?}", auth_result.permissions);
        }
        Err(e) => println!("❌ Trader authentication failed: {}", e),
    }

    Ok(())
}

/// Demonstrate API key authentication
async fn demonstrate_api_key_authentication(
    auth_service: &AuthenticationService,
) -> Result<(), Box<dyn std::error::Error>> {
    println!("\n🔑 API Key Authentication Demo");
    println!("------------------------------");

    // Create API key for trader
    let permissions = vec![
        "api:access".to_string(),
        "trade:view".to_string(),
        "order:place".to_string(),
        "market_data:view".to_string(),
    ];

    match auth_service
        .create_api_key("trader_user_id", "Trading Bot Key", permissions, Some(30))
        .await
    {
        Ok(api_key_result) => {
            println!("✅ API key created successfully");
            println!("   Key ID: {}", api_key_result.id);
            println!("   Key: {}...", &api_key_result.key[..20]); // Show only first 20 chars
            println!("   Permissions: {:?}", api_key_result.permissions);
            println!("   Expires: {}", api_key_result.expires_at);

            // Test API key authentication
            let client_ip = "127.0.0.1";
            match auth_service
                .authenticate_api_key(&api_key_result.key, client_ip)
                .await
            {
                Ok(auth_result) => {
                    println!("✅ API key authentication successful");
                    println!("   User ID: {}", auth_result.user_id);
                    println!("   Permissions: {:?}", auth_result.permissions);
                }
                Err(e) => println!("❌ API key authentication failed: {}", e),
            }

            // Revoke the API key
            if let Err(e) = auth_service
                .revoke_api_key("trader_user_id", &api_key_result.id)
                .await
            {
                println!("⚠️  API key revocation failed: {}", e);
            } else {
                println!("✅ API key revoked successfully");
            }
        }
        Err(e) => println!("❌ API key creation failed: {}", e),
    }

    Ok(())
}

/// Demonstrate permission checking
async fn demonstrate_permission_checking(
    auth_service: &AuthenticationService,
) -> Result<(), Box<dyn std::error::Error>> {
    println!("\n🛡️  Permission Checking Demo");
    println!("----------------------------");

    let test_permissions = vec![
        ("system:admin", "System administration"),
        ("trade:execute", "Execute trades"),
        ("order:place", "Place orders"),
        ("risk:override", "Override risk limits"),
        ("audit:view", "View audit logs"),
        ("invalid:permission", "Invalid permission"),
    ];

    for (permission, description) in test_permissions {
        match auth_service
            .check_permission("admin_user_id", permission, None)
            .await
        {
            Ok(has_permission) => {
                let status = if has_permission {
                    "✅ GRANTED"
                } else {
                    "❌ DENIED"
                };
                println!("   {} {}: {}", status, permission, description);
            }
            Err(e) => println!("   ⚠️  {} (error: {})", permission, e),
        }
    }

    Ok(())
}

/// Demonstrate rate limiting
async fn demonstrate_rate_limiting(
    auth_service: &AuthenticationService,
) -> Result<(), Box<dyn std::error::Error>> {
    println!("\n🚦 Rate Limiting Demo");
    println!("---------------------");

    let client_ip = "192.168.1.100";

    // Make several authentication attempts to test rate limiting
    for i in 1..=5 {
        match auth_service
            .authenticate_user("test_user", "wrong_password", client_ip)
            .await
        {
            Ok(_) => println!("   Attempt {}: ✅ Unexpected success", i),
            Err(AuthError::RateLimitExceeded { limit, window }) => {
                println!(
                    "   Attempt {}: 🚦 Rate limit exceeded ({} requests per {:?})",
                    i, limit, window
                );
                break;
            }
            Err(e) => println!("   Attempt {}: ❌ Failed ({})", i, e),
        }
    }

    Ok(())
}

/// Example of security middleware for gRPC services
pub struct SecurityMiddleware {
    auth_service: AuthenticationService,
}

impl SecurityMiddleware {
    pub async fn new(config: SecurityConfig) -> Result<Self, AuthError> {
        let auth_service = AuthenticationService::new(config).await?;
        Ok(Self { auth_service })
    }

    /// Authenticate and authorize gRPC request
    pub async fn authenticate_request(
        &self,
        session_token: Option<&str>,
        api_key: Option<&str>,
        client_ip: &str,
        required_permission: &str,
    ) -> Result<String, AuthError> {
        // Try session token first
        if let Some(token) = session_token {
            let session_info = self.auth_service.validate_session(token, client_ip).await?;

            if session_info
                .permissions
                .contains(&required_permission.to_string())
            {
                return Ok(session_info.user_id);
            } else {
                return Err(AuthError::AccessDenied {
                    operation: required_permission.to_string(),
                });
            }
        }

        // Try API key
        if let Some(key) = api_key {
            let auth_result = self
                .auth_service
                .authenticate_api_key(key, client_ip)
                .await?;

            if auth_result
                .permissions
                .contains(&required_permission.to_string())
            {
                return Ok(auth_result.user_id);
            } else {
                return Err(AuthError::AccessDenied {
                    operation: required_permission.to_string(),
                });
            }
        }

        Err(AuthError::InvalidCredentials)
    }
}