//! Integration tests for Trueno-DB storage backend (Sprint 40)
//!
//! These tests validate the trueno-db integration for golden thread trace storage.
//!
//! # Test Coverage
//!
//! - ✅ Database initialization
//! - ✅ Batch insert operations
//! - ✅ Query by trace ID
//! - ✅ Query by time range
//! - ✅ Query by process ID
//! - ✅ Error span queries
//! - ✅ Storage statistics
//! - ⏳ Performance validation: <20ms p95 (requires trueno-db integration)
//!
//! # Note
//!
//! Currently, these tests use a placeholder implementation since the full
//! trueno-db API integration is pending. The tests validate the API surface
//! and ensure the code compiles correctly.
//!
//! TODO Sprint 40: Replace placeholder with actual trueno-db integration

use renacer::span_record::{SpanKind, SpanRecord, StatusCode};
use renacer::trueno_db_storage::TruenoDbStorage;
use std::collections::HashMap;
use tempfile::TempDir;

/// Create a test span with specified parameters
fn create_span(
    trace_id: [u8; 16],
    span_id: [u8; 8],
    parent_id: Option<[u8; 8]>,
    name: &str,
    logical_clock: u64,
    status: StatusCode,
) -> SpanRecord {
    SpanRecord::new(
        trace_id,
        span_id,
        parent_id,
        name.to_string(),
        SpanKind::Internal,
        logical_clock * 1000,
        logical_clock * 2000,
        logical_clock,
        status,
        String::new(),
        HashMap::new(),
        HashMap::new(),
        1234,
        5678,
    )
}

#[test]
fn test_trueno_db_creation() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();
    assert_eq!(storage.path(), path);
}

#[test]
fn test_trueno_db_insert_single_span() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    let span = create_span([1; 16], [1; 8], None, "test_span", 1, StatusCode::Ok);

    storage.insert_batch(&[span]).unwrap();
}

#[test]
fn test_trueno_db_insert_batch() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    // Create batch of 100 spans
    let trace_id = [0x4b; 16];
    let mut batch = vec![];

    for i in 0..100 {
        let span = create_span(
            trace_id,
            [(i as u8); 8],
            None,
            &format!("span_{}", i),
            i,
            StatusCode::Ok,
        );
        batch.push(span);
    }

    storage.insert_batch(&batch).unwrap();
}

#[test]
fn test_trueno_db_query_by_trace_id() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    let trace_id = [
        0x4b, 0xf9, 0x2f, 0x3c, 0x7b, 0x64, 0x4b, 0xf9, 0x2f, 0x3c, 0x7b, 0x64, 0x4b, 0xf9, 0x2f,
        0x3c,
    ];

    // Insert spans
    let mut batch = vec![];
    for i in 0..10 {
        let span = create_span(
            trace_id,
            [(i as u8); 8],
            None,
            &format!("span_{}", i),
            i,
            StatusCode::Ok,
        );
        batch.push(span);
    }
    storage.insert_batch(&batch).unwrap();

    // Query by trace ID
    let results = storage.query_by_trace_id(&trace_id).unwrap();

    // TODO Sprint 40: Once integrated with trueno-db, verify:
    // assert_eq!(results.len(), 10);
    // for (i, span) in results.iter().enumerate() {
    //     assert_eq!(span.logical_clock, i as u64);
    // }

    // For now, placeholder returns empty
    assert_eq!(results.len(), 0);
}

#[test]
fn test_trueno_db_query_by_time_range() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    let trace_id = [0x4b; 16];

    // Insert spans with different timestamps
    let mut batch = vec![];
    for i in 0..100 {
        let span = create_span(
            trace_id,
            [(i as u8); 8],
            None,
            &format!("span_{}", i),
            i,
            StatusCode::Ok,
        );
        batch.push(span);
    }
    storage.insert_batch(&batch).unwrap();

    // Query time range: [20, 30)
    let start = 20 * 1000;
    let end = 30 * 1000;

    let results = storage
        .query_by_trace_id_and_time(&trace_id, start, end)
        .unwrap();

    // TODO Sprint 40: Verify results
    // assert_eq!(results.len(), 10);

    // Placeholder returns empty
    assert_eq!(results.len(), 0);
}

#[test]
fn test_trueno_db_query_by_process_id() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    // Insert spans from different processes
    let mut batch = vec![];
    for i in 0..100 {
        let mut span = create_span(
            [1; 16],
            [(i as u8); 8],
            None,
            &format!("span_{}", i),
            i,
            StatusCode::Ok,
        );
        span.process_id = (i % 3) as u32; // 3 different processes
        batch.push(span);
    }
    storage.insert_batch(&batch).unwrap();

    // Query process 1
    let results = storage.query_by_process_id(1).unwrap();

    // TODO Sprint 40: Verify results
    // assert_eq!(results.len(), 33 or 34); // ~100/3

    // Placeholder returns empty
    assert_eq!(results.len(), 0);
}

#[test]
fn test_trueno_db_query_errors() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    // Insert mix of OK and ERROR spans
    let mut batch = vec![];
    for i in 0..100 {
        let status = if i % 10 == 0 {
            StatusCode::Error
        } else {
            StatusCode::Ok
        };
        let span = create_span(
            [1; 16],
            [(i as u8); 8],
            None,
            &format!("span_{}", i),
            i,
            status,
        );
        batch.push(span);
    }
    storage.insert_batch(&batch).unwrap();

    // Query errors
    let results = storage.query_errors().unwrap();

    // TODO Sprint 40: Verify results
    // assert_eq!(results.len(), 10); // 10% error rate

    // Placeholder returns empty
    assert_eq!(results.len(), 0);
}

#[test]
fn test_trueno_db_stats() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    // Insert spans
    let mut batch = vec![];
    for i in 0..1000 {
        let span = create_span(
            [1; 16],
            [(i as u8); 8],
            None,
            &format!("span_{}", i),
            i,
            StatusCode::Ok,
        );
        batch.push(span);
    }
    storage.insert_batch(&batch).unwrap();

    // Get stats
    let stats = storage.stats().unwrap();

    // TODO Sprint 40: Verify actual stats
    // assert_eq!(stats.total_spans, 1000);
    // assert!(stats.file_size_bytes > 0);
    // assert!(stats.compression_ratio > 1.0);

    // Placeholder returns zero stats
    assert_eq!(stats.total_spans, 0);
    assert_eq!(stats.file_size_bytes, 0);
}

#[test]
fn test_trueno_db_flush() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    // Insert spans
    let span = create_span([1; 16], [1; 8], None, "test", 1, StatusCode::Ok);
    storage.insert_batch(&[span]).unwrap();

    // Flush to disk
    storage.flush().unwrap();

    // No panic = success
}

#[test]
fn test_trueno_db_empty_batch_insert() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    // Insert empty batch (should be no-op)
    storage.insert_batch(&[]).unwrap();
}

#[test]
fn test_trueno_db_large_batch_insert() {
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    // Large batch: 10,000 spans
    let mut batch = vec![];
    for i in 0..10_000 {
        let span = create_span(
            [1; 16],
            [(i % 256) as u8; 8],
            None,
            &format!("span_{}", i),
            i,
            StatusCode::Ok,
        );
        batch.push(span);
    }

    storage.insert_batch(&batch).unwrap();
}

#[test]
fn test_trueno_db_trace_with_hierarchy() {
    // Test inserting a trace with parent-child relationships
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    let trace_id = [0x4b; 16];
    let mut batch = vec![];

    // Root span
    let root = create_span(trace_id, [0; 8], None, "root", 0, StatusCode::Ok);
    batch.push(root);

    // Child spans
    for i in 1..10 {
        let child = create_span(
            trace_id,
            [(i as u8); 8],
            Some([0; 8]), // parent is root
            &format!("child_{}", i),
            i,
            StatusCode::Ok,
        );
        batch.push(child);
    }

    storage.insert_batch(&batch).unwrap();

    // Query should return all spans in order
    let results = storage.query_by_trace_id(&trace_id).unwrap();

    // TODO Sprint 40: Verify hierarchy
    // assert_eq!(results.len(), 10);
    // assert!(results[0].is_root());
    // for span in &results[1..] {
    //     assert!(!span.is_root());
    // }

    // Placeholder returns empty
    assert_eq!(results.len(), 0);
}

#[test]
fn test_trueno_db_concurrent_inserts() {
    // Test thread-safe concurrent inserts
    use std::sync::Arc;
    use std::thread;

    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = Arc::new(TruenoDbStorage::new(&path).unwrap());
    let mut handles = vec![];

    // Spawn 5 threads, each inserting 100 spans
    for thread_id in 0..5 {
        let storage_clone = storage.clone();
        let handle = thread::spawn(move || {
            let mut batch = vec![];
            for i in 0..100 {
                let span = create_span(
                    [(thread_id as u8); 16],
                    [(i as u8); 8],
                    None,
                    &format!("thread_{}_span_{}", thread_id, i),
                    i,
                    StatusCode::Ok,
                );
                batch.push(span);
            }
            storage_clone.insert_batch(&batch).unwrap();
        });
        handles.push(handle);
    }

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

    // TODO Sprint 40: Verify all 500 spans inserted
    // let stats = storage.stats().unwrap();
    // assert_eq!(stats.total_spans, 500);
}

#[test]
fn test_span_record_with_attributes() {
    // Test that span attributes are properly stored
    let tmp_dir = TempDir::new().unwrap();
    let path = tmp_dir.path().join("traces.parquet");

    let storage = TruenoDbStorage::new(&path).unwrap();

    let mut attributes = HashMap::new();
    attributes.insert("syscall.name".to_string(), "read".to_string());
    attributes.insert("syscall.fd".to_string(), "3".to_string());
    attributes.insert("file.path".to_string(), "/etc/passwd".to_string());

    let mut resource = HashMap::new();
    resource.insert("service.name".to_string(), "renacer".to_string());
    resource.insert("host.name".to_string(), "test-server".to_string());

    let span = SpanRecord::new(
        [1; 16],
        [1; 8],
        None,
        "read".to_string(),
        SpanKind::Internal,
        1000,
        2000,
        1,
        StatusCode::Ok,
        String::new(),
        attributes,
        resource,
        1234,
        5678,
    );

    storage.insert_batch(&[span]).unwrap();

    // TODO Sprint 40: Query and verify attributes
}
