qail-gateway 0.1.0

//! Row-level security policy engine
//!
//! Parses and evaluates security policies defined in policies.qail.

use crate::auth::AuthContext;
use crate::error::GatewayError;

/// A security policy rule
#[derive(Debug, Clone)]
pub struct Policy {
    /// Policy name
    pub name: String,
    
    /// Table this policy applies to ("*" for all)
    pub table: String,
    
    /// Filter condition (injected into queries)
    pub filter: Option<String>,
    
    /// Required role (if any)
    pub required_role: Option<String>,
    
    /// Allowed operations
    pub operations: Vec<Operation>,
}

/// Operations a policy can allow
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Operation {
    /// SELECT queries
    Read,
    /// INSERT queries
    Create,
    /// UPDATE queries
    Update,
    /// DELETE queries
    Delete,
}

/// Policy engine that evaluates access control
#[derive(Debug, Default)]
pub struct PolicyEngine {
    policies: Vec<Policy>,
}

impl PolicyEngine {
    /// Create a new policy engine
    pub fn new() -> Self {
        Self::default()
    }
    
    /// Load policies from a file
    /// 
    /// # Errors
    /// Returns error if file cannot be read or parsed
    pub fn load_from_file(&mut self, _path: &str) -> Result<(), GatewayError> {
        // TODO: Parse policies.qail syntax
        tracing::info!("Policy loading not yet implemented");
        Ok(())
    }
    
    /// Check if an operation is allowed
    pub fn check_access(
        &self,
        _auth: &AuthContext,
        _table: &str,
        _operation: Operation,
    ) -> Result<(), GatewayError> {
        // TODO: Implement policy evaluation
        // For now, allow all
        Ok(())
    }
    
    /// Get filter condition to inject for row-level security
    pub fn get_filter(
        &self,
        _auth: &AuthContext,
        _table: &str,
    ) -> Option<String> {
        // TODO: Return filter expression based on policy
        None
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    
    #[test]
    fn test_policy_engine_allows_by_default() {
        let engine = PolicyEngine::new();
        let auth = AuthContext::anonymous();
        
        let result = engine.check_access(&auth, "users", Operation::Read);
        assert!(result.is_ok());
    }
}