//! SPARQL query optimizer

/// SPARQL query optimizer
///
/// TODO: Implement optimization rules
/// - Join reordering
/// - Filter pushdown
/// - Index selection
/// - Cardinality estimation

pub struct SparqlOptimizer;

impl SparqlOptimizer {
    /// Create a new optimizer
    pub fn new() -> Self {
        Self
    }

    /// Optimize a query
    pub fn optimize(&self) {
        // TODO: Implement optimization
    }
}

impl Default for SparqlOptimizer {
    fn default() -> Self {
        Self::new()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_optimizer_creation() {
        let opt = SparqlOptimizer::new();
        opt.optimize(); // should not panic
    }

    #[test]
    fn test_optimizer_default() {
        let opt = SparqlOptimizer::default();
        opt.optimize();
    }
}
