ruvector-graph 0.1.2

//! Transaction tests for ACID guarantees
//!
//! Tests to verify atomicity, consistency, isolation, and durability properties.

use ruvector_graph::transaction::{IsolationLevel, Transaction};
use ruvector_graph::{GraphDB, Label, Node, Properties, PropertyValue};
use std::sync::Arc;
use std::thread;

// ============================================================================
// Atomicity Tests
// ============================================================================

#[test]
fn test_transaction_commit() {
    let _db = GraphDB::new();

    let tx = Transaction::begin(IsolationLevel::ReadCommitted).unwrap();

    // TODO: Implement transaction operations
    // tx.create_node(...)?;
    // tx.create_edge(...)?;

    let result = tx.commit();
    assert!(result.is_ok());
}

#[test]
fn test_transaction_rollback() {
    let _db = GraphDB::new();

    let tx = Transaction::begin(IsolationLevel::ReadCommitted).unwrap();

    // TODO: Implement transaction operations
    // tx.create_node(...)?;

    let result = tx.rollback();
    assert!(result.is_ok());

    // TODO: Verify that changes were not applied
}

#[test]
fn test_transaction_atomic_batch_insert() {
    let db = GraphDB::new();

    // TODO: Implement transactional batch insert
    // Either all nodes are created or none
    /*
    let tx = db.begin_transaction(IsolationLevel::Serializable)?;

    for i in 0..100 {
        tx.create_node(Node::new(
            format!("node_{}", i),
            vec![],
            Properties::new(),
        ))?;

        if i == 50 {
            // Simulate error
            tx.rollback()?;
            break;
        }
    }

    // Verify no nodes were created
    assert!(db.get_node("node_0").is_none());
    */

    // For now, just create without transaction
    for i in 0..10 {
        db.create_node(Node::new(format!("node_{}", i), vec![], Properties::new()))
            .unwrap();
    }

    assert!(db.get_node("node_0").is_some());
}

#[test]
fn test_transaction_rollback_on_constraint_violation() {
    // TODO: Implement
    // When a constraint is violated, the entire transaction should roll back
}

// ============================================================================
// Isolation Level Tests
// ============================================================================

#[test]
fn test_isolation_read_uncommitted() {
    let tx = Transaction::begin(IsolationLevel::ReadUncommitted).unwrap();
    assert_eq!(tx.isolation_level, IsolationLevel::ReadUncommitted);
    tx.commit().unwrap();
}

#[test]
fn test_isolation_read_committed() {
    let tx = Transaction::begin(IsolationLevel::ReadCommitted).unwrap();
    assert_eq!(tx.isolation_level, IsolationLevel::ReadCommitted);
    tx.commit().unwrap();
}

#[test]
fn test_isolation_repeatable_read() {
    let tx = Transaction::begin(IsolationLevel::RepeatableRead).unwrap();
    assert_eq!(tx.isolation_level, IsolationLevel::RepeatableRead);
    tx.commit().unwrap();
}

#[test]
fn test_isolation_serializable() {
    let tx = Transaction::begin(IsolationLevel::Serializable).unwrap();
    assert_eq!(tx.isolation_level, IsolationLevel::Serializable);
    tx.commit().unwrap();
}

// ============================================================================
// Concurrency and Isolation Tests
// ============================================================================

#[test]
fn test_concurrent_transactions_read_committed() {
    let db = Arc::new(GraphDB::new());

    // Create initial node
    let mut props = Properties::new();
    props.insert("counter".to_string(), PropertyValue::Integer(0));
    db.create_node(Node::new(
        "counter".to_string(),
        vec![Label {
            name: "Counter".to_string(),
        }],
        props,
    ))
    .unwrap();

    // TODO: Implement transactional updates
    // Spawn multiple threads that increment the counter
    let handles: Vec<_> = (0..10)
        .map(|_| {
            let db_clone = Arc::clone(&db);
            thread::spawn(move || {
                // TODO: Begin transaction, read counter, increment, commit
                // For now, just read
                let _node = db_clone.get_node("counter");
            })
        })
        .collect();

    for handle in handles {
        handle.join().unwrap();
    }

    // TODO: Verify final counter value
}

#[test]
fn test_dirty_read_prevention() {
    // TODO: Implement
    // Verify that a transaction doesn't see uncommitted changes from another transaction
    // when using appropriate isolation level
}

#[test]
fn test_non_repeatable_read_prevention() {
    // TODO: Implement
    // Verify that repeatable read isolation prevents non-repeatable reads
}

#[test]
fn test_phantom_read_prevention() {
    // TODO: Implement
    // Verify that serializable isolation prevents phantom reads
}

// ============================================================================
// Deadlock Detection and Prevention
// ============================================================================

#[test]
fn test_deadlock_detection() {
    // TODO: Implement
    // Create a scenario that would cause deadlock and verify it's detected
}

#[test]
fn test_deadlock_timeout() {
    // TODO: Implement
    // Verify that transactions timeout if they can't acquire locks
}

// ============================================================================
// Multi-Version Concurrency Control (MVCC) Tests
// ============================================================================

#[test]
fn test_mvcc_snapshot_isolation() {
    // TODO: Implement
    // Verify that each transaction sees a consistent snapshot of the database
}

#[test]
fn test_mvcc_concurrent_reads_and_writes() {
    // TODO: Implement
    // Verify that readers don't block writers and vice versa
}

// ============================================================================
// Write Skew Tests
// ============================================================================

#[test]
fn test_write_skew_detection() {
    // TODO: Implement
    // Classic write skew scenario: two transactions read overlapping data
    // and make decisions based on what they read, leading to inconsistency
}

// ============================================================================
// Long-Running Transaction Tests
// ============================================================================

#[test]
fn test_long_running_transaction_timeout() {
    // TODO: Implement
    // Verify that long-running transactions can be configured to timeout
}

#[test]
fn test_transaction_progress_tracking() {
    // TODO: Implement
    // Verify that we can track progress of long-running transactions
}

// ============================================================================
// Savepoint Tests
// ============================================================================

#[test]
fn test_transaction_savepoint() {
    // TODO: Implement
    // Create savepoint, make changes, rollback to savepoint
}

#[test]
fn test_nested_savepoints() {
    // TODO: Implement
    // Create nested savepoints and rollback to different levels
}

// ============================================================================
// Consistency Tests
// ============================================================================

#[test]
fn test_referential_integrity() {
    // TODO: Implement
    // Verify that edges cannot reference non-existent nodes
}

#[test]
fn test_unique_constraint_enforcement() {
    // TODO: Implement
    // Verify that unique constraints are enforced within transactions
}

#[test]
fn test_index_consistency() {
    // TODO: Implement
    // Verify that indexes remain consistent after transaction commit/rollback
}

// ============================================================================
// Durability Tests
// ============================================================================

#[test]
fn test_write_ahead_log() {
    // TODO: Implement
    // Verify that changes are logged before being applied
}

#[test]
fn test_crash_recovery() {
    // TODO: Implement
    // Simulate crash and verify that committed transactions are preserved
}

#[test]
fn test_checkpoint_mechanism() {
    // TODO: Implement
    // Verify that checkpoints work correctly for durability
}

// ============================================================================
// Transaction Isolation Anomaly Tests
// ============================================================================

#[test]
fn test_lost_update_prevention() {
    // TODO: Implement
    // T1 and T2 both read same value, modify it, and write back
    // Verify that one update isn't lost
}

#[test]
fn test_read_skew_prevention() {
    // TODO: Implement
    // Transaction reads two related values at different times
    // Verify consistency based on isolation level
}

// ============================================================================
// Performance Tests
// ============================================================================

#[test]
fn test_transaction_throughput() {
    // TODO: Implement
    // Measure throughput of small transactions
}

#[test]
fn test_lock_contention_handling() {
    // TODO: Implement
    // Verify graceful handling of high lock contention
}