//! Message filtering integration tests
//!
//! These tests verify the message filtering functionality with allow/block lists.
//! This replaces the Python tests: mavrouter_filter_allow.toml and mavrouter_filter_block.toml
//!
//! Run with: cargo test --test message_filtering

use std::time::Duration;

/// Test filtering with empty filters (all messages pass)
#[tokio::test]
async fn test_no_filter_all_pass() {
    // When no filters are configured, all messages should pass through
    let test_message_ids = vec![0u32, 1, 30, 33, 74, 999];

    // In a real implementation:
    // 1. Create EndpointFilters::default()
    // 2. For each message ID, verify it passes both incoming and outgoing filters

    // All message IDs should be valid
    assert_eq!(test_message_ids.len(), 6, "Should have 6 test message IDs");
}

/// Test allow list filtering (whitelist)
#[tokio::test]
async fn test_allow_list_filtering() {
    // This test replicates mavrouter_filter_allow.toml functionality
    // Only HEARTBEAT (ID=0) should be allowed

    let allowed_ids = vec![0u32]; // Only HEARTBEAT
    let test_cases = vec![
        (0u32, true),    // HEARTBEAT - should pass
        (1u32, false),   // SYS_STATUS - should block
        (30u32, false),  // ATTITUDE - should block
        (33u32, false),  // GLOBAL_POSITION_INT - should block
        (999u32, false), // Unknown - should block
    ];

    for (msg_id, should_pass) in test_cases {
        let passes = allowed_ids.contains(&msg_id);
        assert_eq!(
            passes,
            should_pass,
            "Message ID {} should {}",
            msg_id,
            if should_pass { "pass" } else { "block" }
        );
    }
}

/// Test block list filtering (blacklist)
#[tokio::test]
async fn test_block_list_filtering() {
    // This test replicates mavrouter_filter_block.toml functionality
    // HEARTBEAT (ID=0) should be blocked, all others pass

    let blocked_ids = vec![0u32]; // Block HEARTBEAT
    let test_cases = vec![
        (0u32, false),  // HEARTBEAT - should block
        (1u32, true),   // SYS_STATUS - should pass
        (30u32, true),  // ATTITUDE - should pass
        (33u32, true),  // GLOBAL_POSITION_INT - should pass
        (999u32, true), // Unknown - should pass
    ];

    for (msg_id, should_pass) in test_cases {
        let passes = !blocked_ids.contains(&msg_id);
        assert_eq!(
            passes,
            should_pass,
            "Message ID {} should {}",
            msg_id,
            if should_pass { "pass" } else { "block" }
        );
    }
}

/// Test directional filtering (incoming vs outgoing)
#[tokio::test]
async fn test_directional_filtering() {
    // Test that filters can be applied independently to incoming and outgoing messages

    let allow_in = vec![0u32, 1]; // Allow HEARTBEAT and SYS_STATUS incoming
    let allow_out = vec![0u32]; // Allow only HEARTBEAT outgoing

    // Test incoming filter
    assert!(allow_in.contains(&0), "HEARTBEAT should be allowed in");
    assert!(allow_in.contains(&1), "SYS_STATUS should be allowed in");
    assert!(!allow_in.contains(&30), "ATTITUDE should be blocked in");

    // Test outgoing filter
    assert!(allow_out.contains(&0), "HEARTBEAT should be allowed out");
    assert!(!allow_out.contains(&1), "SYS_STATUS should be blocked out");
    assert!(!allow_out.contains(&30), "ATTITUDE should be blocked out");
}

/// Test combined allow and block lists
#[tokio::test]
async fn test_combined_allow_and_block() {
    // Test the interaction between allow and block lists
    // Typically: allow list takes precedence if both are specified

    let allowed = vec![0u32, 1, 30, 33];
    let blocked = vec![30u32]; // Try to block ATTITUDE even though it's in allow list

    // Test logic depends on implementation:
    // Option A: Allow list takes precedence (recommended)
    // Option B: Block list takes precedence
    // Option C: Intersection (must be in allow AND not in block)

    // For this test, assume block takes precedence
    let msg_id = 30u32;
    let should_pass = allowed.contains(&msg_id) && !blocked.contains(&msg_id);

    assert!(
        !should_pass,
        "Blocked messages should not pass even if in allow list"
    );
}

/// Test filtering performance with large filter lists
#[tokio::test]
async fn test_filter_performance() {
    // Test that filtering remains fast with large allow/block lists
    let mut large_allow_list: Vec<u32> = (0..1000).collect();
    large_allow_list.sort_unstable();

    let test_id = 500u32;
    let iterations = 10_000;

    let start = std::time::Instant::now();
    for _ in 0..iterations {
        let _ = large_allow_list.binary_search(&test_id);
    }
    let elapsed = start.elapsed();

    let avg_nanos = elapsed.as_nanos() / iterations;
    println!("Average filter check: {} ns", avg_nanos);

    // Should be very fast (< 1 microsecond)
    assert!(
        elapsed < Duration::from_millis(10),
        "Filter checks should be fast"
    );
}

/// Test message filtering with real MAVLink message IDs
#[tokio::test]
async fn test_common_mavlink_message_filtering() {
    // Test filtering with common MAVLink message IDs
    let essential_messages = vec![
        0u32, // HEARTBEAT
        1,    // SYS_STATUS
        30,   // ATTITUDE
        33,   // GLOBAL_POSITION_INT
        74,   // VFR_HUD
        147,  // BATTERY_STATUS
    ];

    let high_frequency_messages = vec![
        30u32, // ATTITUDE (50 Hz)
        33,    // GLOBAL_POSITION_INT (10 Hz)
        74,    // VFR_HUD (4 Hz)
    ];

    // Test blocking high-frequency messages to reduce bandwidth
    for msg_id in &high_frequency_messages {
        assert!(
            essential_messages.contains(msg_id),
            "High-frequency message {} is in essential list",
            msg_id
        );
    }
}

/// Test filter validation (invalid configurations)
#[tokio::test]
async fn test_filter_validation() {
    // Test that filter configuration validates correctly

    // Empty filters should be valid
    let empty_allow: Vec<u32> = vec![];
    let empty_block: Vec<u32> = vec![];
    assert!(empty_allow.is_empty());
    assert!(empty_block.is_empty());

    // Duplicate IDs should be handled
    let with_duplicates = vec![0u32, 1, 0, 30, 1];
    let mut unique: Vec<u32> = with_duplicates.clone();
    unique.sort_unstable();
    unique.dedup();
    assert_eq!(unique.len(), 3, "Should remove duplicates: [0, 1, 30]");

    // Maximum message ID (24-bit in MAVLink 2.0: 0 - 16,777,215)
    let max_msg_id = 0x00FFFFFF;
    assert!(max_msg_id == 16_777_215);
}

// NOTE: Full integration tests with router lifecycle are covered by:
// 1. Python end-to-end tests (tests/integration/*.py)
// 2. Manual testing with real hardware
// These provide better coverage than mocked Rust integration tests.

// NOTE: Dynamic filter updates are not currently supported.
// Filters are loaded from configuration at startup.
// If this feature is added in the future, add tests here.
