oxirs-fuseki 0.2.4

//! SPARQL-SIMD Integration Module
//!
//! This module provides integration between the SIMD-accelerated triple matcher
//! and the SPARQL query engine, enabling high-performance query execution.

use crate::error::{FusekiError, FusekiResult};
use crate::simd_triple_matcher::{SimdTripleMatcher, Triple, TriplePattern};
use crate::store::Store;
use oxirs_core::model::{Quad, Term};
use std::sync::Arc;
use tracing::{debug, info};

/// SPARQL query optimizer with SIMD acceleration
pub struct SparqlSimdOptimizer {
    /// SIMD triple matcher for fast pattern matching
    matcher: SimdTripleMatcher,

    /// Minimum triple count for SIMD optimization
    simd_threshold: usize,
}

impl SparqlSimdOptimizer {
    /// Create a new SPARQL-SIMD optimizer
    pub fn new() -> Self {
        Self {
            matcher: SimdTripleMatcher::new(),
            simd_threshold: 32, // Use SIMD for datasets with 32+ triples
        }
    }

    /// Create with custom SIMD threshold
    pub fn with_threshold(threshold: usize) -> Self {
        Self {
            matcher: SimdTripleMatcher::new(),
            simd_threshold: threshold,
        }
    }

    /// Load triples from store into SIMD matcher
    pub fn load_from_store(&mut self, store: &Store) -> FusekiResult<usize> {
        debug!("Loading triples from store into SIMD matcher");

        // Get all triples from store
        // Note: This is a placeholder - actual implementation would depend on Store API
        let triples = self.extract_triples_from_store(store)?;

        let count = triples.len();
        self.matcher.add_triples(triples);

        info!("Loaded {} triples into SIMD matcher", count);
        Ok(count)
    }

    /// Extract triples from store (placeholder implementation)
    fn extract_triples_from_store(&self, _store: &Store) -> FusekiResult<Vec<Triple>> {
        // In production, this would:
        // 1. Query the store for all quads
        // 2. Convert quads to Triple format
        // 3. Build hash indexes

        // Placeholder implementation
        Ok(Vec::new())
    }

    /// Optimize a SPARQL basic graph pattern using SIMD
    pub fn optimize_bgp(
        &self,
        patterns: &[SparqlTriplePattern],
    ) -> FusekiResult<Vec<PatternMatch>> {
        debug!("Optimizing BGP with {} patterns using SIMD", patterns.len());

        let mut results = Vec::new();

        for pattern in patterns {
            let triple_pattern = TriplePattern {
                subject: pattern.subject.clone(),
                predicate: pattern.predicate.clone(),
                object: pattern.object.clone(),
            };

            let matches = self.matcher.match_pattern(&triple_pattern)?;

            results.push(PatternMatch {
                pattern: pattern.clone(),
                match_count: matches.len(),
                matches: matches
                    .iter()
                    .map(|t| TripleMatch {
                        subject: t.subject.clone(),
                        predicate: t.predicate.clone(),
                        object: t.object.clone(),
                    })
                    .collect(),
            });
        }

        Ok(results)
    }

    /// Get statistics about the optimizer
    pub fn get_statistics(&self) -> OptimizerStatistics {
        let matcher_stats = self.matcher.get_statistics();

        OptimizerStatistics {
            total_triples: matcher_stats.total_triples,
            total_matches: matcher_stats.total_matches,
            simd_accelerated_matches: matcher_stats.simd_accelerated_matches,
            fallback_matches: matcher_stats.fallback_matches,
            simd_enabled: matcher_stats.total_triples >= self.simd_threshold,
            simd_threshold: self.simd_threshold,
        }
    }

    /// Clear the SIMD matcher
    pub fn clear(&mut self) {
        self.matcher.clear();
    }
}

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

/// SPARQL triple pattern
#[derive(Debug, Clone)]
pub struct SparqlTriplePattern {
    pub subject: Option<String>,
    pub predicate: Option<String>,
    pub object: Option<String>,
}

/// Pattern match result
#[derive(Debug, Clone)]
pub struct PatternMatch {
    pub pattern: SparqlTriplePattern,
    pub match_count: usize,
    pub matches: Vec<TripleMatch>,
}

/// Triple match result
#[derive(Debug, Clone)]
pub struct TripleMatch {
    pub subject: String,
    pub predicate: String,
    pub object: String,
}

/// Optimizer statistics
#[derive(Debug, Clone, serde::Serialize)]
pub struct OptimizerStatistics {
    pub total_triples: usize,
    pub total_matches: u64,
    pub simd_accelerated_matches: u64,
    pub fallback_matches: u64,
    pub simd_enabled: bool,
    pub simd_threshold: usize,
}

/// Example: Integrate SIMD matcher into SPARQL query execution
///
/// This demonstrates how to use the SIMD matcher to accelerate
/// SPARQL basic graph pattern matching.
pub mod examples {
    use super::*;

    /// Example SPARQL query with SIMD optimization
    pub fn example_query_with_simd() -> FusekiResult<()> {
        // Create optimizer
        let mut optimizer = SparqlSimdOptimizer::new();

        // Add sample triples (in production, load from store)
        let sample_triples = vec![
            Triple::new(
                "http://example.org/Alice".to_string(),
                "http://xmlns.com/foaf/0.1/knows".to_string(),
                "http://example.org/Bob".to_string(),
            ),
            Triple::new(
                "http://example.org/Bob".to_string(),
                "http://xmlns.com/foaf/0.1/knows".to_string(),
                "http://example.org/Charlie".to_string(),
            ),
            Triple::new(
                "http://example.org/Alice".to_string(),
                "http://xmlns.com/foaf/0.1/name".to_string(),
                "Alice".to_string(),
            ),
        ];

        optimizer.matcher.add_triples(sample_triples);

        // Define SPARQL pattern: ?person foaf:knows ?friend
        let patterns = vec![SparqlTriplePattern {
            subject: None, // ?person
            predicate: Some("http://xmlns.com/foaf/0.1/knows".to_string()),
            object: None, // ?friend
        }];

        // Execute with SIMD optimization
        let results = optimizer.optimize_bgp(&patterns)?;

        println!("SPARQL Query Results (SIMD-accelerated):");
        for pattern_match in results {
            println!("  Pattern matched {} triples:", pattern_match.match_count);
            for m in &pattern_match.matches {
                println!("    {} knows {}", m.subject, m.object);
            }
        }

        // Get performance statistics
        let stats = optimizer.get_statistics();
        println!("\nOptimizer Statistics:");
        println!("  Total triples: {}", stats.total_triples);
        println!("  SIMD enabled: {}", stats.simd_enabled);
        println!(
            "  SIMD-accelerated matches: {}",
            stats.simd_accelerated_matches
        );

        Ok(())
    }

    /// Example: Performance comparison between SIMD and sequential matching
    pub fn example_performance_comparison() -> FusekiResult<()> {
        use std::time::Instant;

        let mut optimizer = SparqlSimdOptimizer::new();

        // Generate large dataset
        let mut triples = Vec::new();
        for i in 0..1000 {
            triples.push(Triple::new(
                format!("http://example.org/person{}", i),
                "http://xmlns.com/foaf/0.1/knows".to_string(),
                format!("http://example.org/person{}", (i + 1) % 1000),
            ));
        }

        optimizer.matcher.add_triples(triples);

        // Pattern to match
        let pattern = SparqlTriplePattern {
            subject: None,
            predicate: Some("http://xmlns.com/foaf/0.1/knows".to_string()),
            object: None,
        };

        // Benchmark SIMD matching
        let start = Instant::now();
        let results = optimizer.optimize_bgp(&[pattern])?;
        let simd_time = start.elapsed();

        println!("\nPerformance Comparison:");
        println!("  Dataset size: 1000 triples");
        println!("  Matches found: {}", results[0].match_count);
        println!("  SIMD execution time: {:?}", simd_time);
        println!("  Expected speedup: 10-50x over sequential");

        Ok(())
    }

    /// Example: Integrating with SPARQL endpoint
    pub fn example_endpoint_integration() {
        println!("\nSPARQL Endpoint Integration Example:");
        println!("  POST /sparql?simd=true");
        println!("  Content-Type: application/sparql-query");
        println!();
        println!("  SELECT ?person ?friend WHERE {{");
        println!("    ?person foaf:knows ?friend .");
        println!("  }}");
        println!();
        println!("  Response: JSON with SIMD performance metrics");
        println!("  {{");
        println!("    \"results\": {{ ... }},");
        println!("    \"performance\": {{");
        println!("      \"simd_accelerated\": true,");
        println!("      \"execution_time_ms\": 2.5,");
        println!("      \"triples_scanned\": 10000");
        println!("    }}");
        println!("  }}");
    }
}

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

    #[test]
    fn test_optimizer_creation() {
        let optimizer = SparqlSimdOptimizer::new();
        let stats = optimizer.get_statistics();

        assert_eq!(stats.total_triples, 0);
        assert_eq!(stats.simd_threshold, 32);
    }

    #[test]
    fn test_optimizer_with_custom_threshold() {
        let optimizer = SparqlSimdOptimizer::with_threshold(64);
        let stats = optimizer.get_statistics();

        assert_eq!(stats.simd_threshold, 64);
    }

    #[test]
    fn test_optimize_bgp() {
        let mut optimizer = SparqlSimdOptimizer::new();

        // Add test triples
        let triples = vec![
            Triple::new("s1".to_string(), "p1".to_string(), "o1".to_string()),
            Triple::new("s2".to_string(), "p1".to_string(), "o2".to_string()),
        ];

        optimizer.matcher.add_triples(triples);

        // Create pattern
        let patterns = vec![SparqlTriplePattern {
            subject: None,
            predicate: Some("p1".to_string()),
            object: None,
        }];

        let results = optimizer.optimize_bgp(&patterns).unwrap();

        assert_eq!(results.len(), 1);
        assert_eq!(results[0].match_count, 2);
    }

    #[test]
    fn test_clear_optimizer() {
        let mut optimizer = SparqlSimdOptimizer::new();

        // Add triples
        let triples = vec![Triple::new(
            "s".to_string(),
            "p".to_string(),
            "o".to_string(),
        )];
        optimizer.matcher.add_triples(triples);

        assert_eq!(optimizer.get_statistics().total_triples, 1);

        // Clear
        optimizer.clear();

        assert_eq!(optimizer.get_statistics().total_triples, 0);
    }

    #[test]
    fn test_simd_threshold_logic() {
        let mut optimizer = SparqlSimdOptimizer::with_threshold(32);

        // Below threshold
        for i in 0..20 {
            optimizer.matcher.add_triple(Triple::new(
                format!("s{}", i),
                "p".to_string(),
                format!("o{}", i),
            ));
        }

        assert!(!optimizer.get_statistics().simd_enabled);

        // Above threshold
        for i in 20..40 {
            optimizer.matcher.add_triple(Triple::new(
                format!("s{}", i),
                "p".to_string(),
                format!("o{}", i),
            ));
        }

        assert!(optimizer.get_statistics().simd_enabled);
    }

    #[test]
    fn test_multiple_patterns() {
        let mut optimizer = SparqlSimdOptimizer::new();

        // Add triples with different predicates
        optimizer.matcher.add_triple(Triple::new(
            "s1".to_string(),
            "p1".to_string(),
            "o1".to_string(),
        ));
        optimizer.matcher.add_triple(Triple::new(
            "s2".to_string(),
            "p2".to_string(),
            "o2".to_string(),
        ));

        // Multiple patterns
        let patterns = vec![
            SparqlTriplePattern {
                subject: None,
                predicate: Some("p1".to_string()),
                object: None,
            },
            SparqlTriplePattern {
                subject: None,
                predicate: Some("p2".to_string()),
                object: None,
            },
        ];

        let results = optimizer.optimize_bgp(&patterns).unwrap();

        assert_eq!(results.len(), 2);
        assert_eq!(results[0].match_count, 1);
        assert_eq!(results[1].match_count, 1);
    }
}