//! Presence & FOAF Discovery Integration Tests
//!
//! These tests verify presence beacons and FOAF (Friend-of-a-Friend) discovery
//! work correctly across the VPS mesh. Currently stubbed - will be implemented
//! after Phase 1.3 (Gossip Overlay Integration) completes.
//!
//! **Status**: Awaiting Phase 1.3 completion (saorsa-gossip-presence integration)

use std::time::Duration;
use tempfile::TempDir;
use tokio::time::sleep;
use x0x::{network::NetworkConfig, Agent};

/// VPS bootstrap nodes (from Phase 3.1)
const VPS_NODES: &[&str] = &[
    "142.93.199.50:12000",   // saorsa-2 (NYC)
    "147.182.234.192:12000", // saorsa-3 (SFO)
    "65.21.157.229:12000",   // saorsa-6 (Helsinki)
    "116.203.101.172:12000", // saorsa-7 (Nuremberg)
    "149.28.156.231:12000",  // saorsa-8 (Singapore)
    "45.77.176.184:12000",   // saorsa-9 (Tokyo)
];

/// Helper to create agent with VPS bootstrap
async fn create_agent_with_vps() -> Result<Agent, Box<dyn std::error::Error>> {
    let temp_dir = TempDir::new()?;
    let bootstrap_addrs = VPS_NODES.iter().filter_map(|s| s.parse().ok()).collect();

    let agent = Agent::builder()
        .with_machine_key(temp_dir.path().join("machine.key"))
        .with_network_config(NetworkConfig {
            bind_addr: Some("0.0.0.0:0".parse()?),
            bootstrap_nodes: bootstrap_addrs,
            ..Default::default()
        })
        .build()
        .await?;

    Ok(agent)
}

/// Test 1: Presence beacon propagation across VPS mesh
///
/// Verifies that when an agent comes online, presence beacons propagate
/// to all VPS nodes within 5 seconds (beacon_ttl/2 interval).
#[tokio::test]
#[ignore = "requires Phase 1.3 (saorsa-gossip-presence) and VPS testnet"]
async fn test_presence_beacon_propagation() {
    let agent = create_agent_with_vps()
        .await
        .expect("Failed to create agent");

    agent.join_network().await.expect("Failed to join network");

    // Wait for presence beacon propagation
    sleep(Duration::from_secs(5)).await;

    // TODO: Query VPS nodes for presence of this agent
    // Expected: All 6 VPS nodes should have this agent's presence beacon

    // For now, verify agent is connected
    assert!(
        agent.network().is_some(),
        "Agent should be connected to network"
    );
}

/// Test 2: Presence beacon expiration
///
/// Verifies that presence beacons expire after beacon_ttl (15 minutes)
/// when not refreshed.
#[tokio::test]
#[ignore = "requires Phase 1.3 and long test duration (15+ minutes)"]
async fn test_presence_beacon_expiration() {
    let agent = create_agent_with_vps()
        .await
        .expect("Failed to create agent");

    agent.join_network().await.expect("Failed to join network");

    // Agent should be visible initially
    sleep(Duration::from_secs(5)).await;
    // TODO: Verify agent presence is visible

    // Simulate agent going offline (drop agent, stop beacons)
    drop(agent);

    // Wait for beacon TTL to expire (15 minutes + grace period)
    sleep(Duration::from_secs(16 * 60)).await;

    // TODO: Verify agent is no longer visible on VPS nodes
    // Expected: Agent marked as offline after beacon expiration
}

/// Test 3: FOAF query with TTL=1 (immediate neighbors only)
///
/// Verifies that FOAF queries with TTL=1 only discover immediate neighbors,
/// not multi-hop peers.
#[tokio::test]
#[ignore = "requires Phase 1.3 (FOAF discovery) and VPS testnet"]
async fn test_foaf_ttl_1_immediate_neighbors() {
    let agent = create_agent_with_vps()
        .await
        .expect("Failed to create agent");

    agent.join_network().await.expect("Failed to join network");

    // Wait for mesh formation
    sleep(Duration::from_secs(10)).await;

    // TODO: Perform FOAF query with TTL=1
    // let neighbors = agent.discover_agents_foaf(TTL=1).await?;

    // Expected: Only immediate neighbors (VPS nodes) returned
    // Expected: No multi-hop peers included
}

/// Test 4: FOAF query with TTL=3 (up to 3 hops)
///
/// Verifies that FOAF queries with TTL=3 discover agents up to 3 hops away.
#[tokio::test]
#[ignore = "requires Phase 1.3 (FOAF discovery) and VPS testnet with multiple agents"]
async fn test_foaf_ttl_3_multi_hop() {
    let agent = create_agent_with_vps()
        .await
        .expect("Failed to create agent");

    agent.join_network().await.expect("Failed to join network");

    // Wait for mesh formation
    sleep(Duration::from_secs(10)).await;

    // TODO: Perform FOAF query with TTL=3
    // let discovered = agent.discover_agents_foaf(TTL=3).await?;

    // Expected: Agents up to 3 hops away discovered
    // Expected: Query latency < 2 seconds
    // Expected: Privacy preserved (no full path visibility)
}

/// Test 5: FOAF discovery by specific AgentId
///
/// Verifies that FOAF can find a specific agent within TTL hops.
#[tokio::test]
#[ignore = "requires Phase 1.3 (FOAF discovery) and VPS testnet with target agent"]
async fn test_foaf_find_specific_agent() {
    let agent_a = create_agent_with_vps()
        .await
        .expect("Failed to create agent A");
    let agent_b = create_agent_with_vps()
        .await
        .expect("Failed to create agent B");

    agent_a
        .join_network()
        .await
        .expect("Failed to join network");
    agent_b
        .join_network()
        .await
        .expect("Failed to join network");

    // Wait for both agents to be visible
    sleep(Duration::from_secs(10)).await;

    let target_agent_id = agent_b.agent_id();

    // TODO: Agent A searches for Agent B via FOAF
    // let result = agent_a.discover_agent_by_id(target_agent_id, TTL=3).await?;

    // Expected: Agent A finds Agent B within 3 hops
    // Expected: Discovery latency < 2 seconds
    // Expected: Returns network address for Agent B

    assert_ne!(
        agent_a.agent_id(),
        target_agent_id,
        "Agents should have different IDs"
    );
}

/// Test 6: Presence event subscription
///
/// Verifies that agents can subscribe to presence events (online/offline)
/// and receive notifications when other agents join/leave.
#[tokio::test]
#[ignore = "requires Phase 1.3 (presence events) and VPS testnet"]
async fn test_presence_event_subscription() {
    let agent = create_agent_with_vps()
        .await
        .expect("Failed to create agent");

    agent.join_network().await.expect("Failed to join network");

    // TODO: Subscribe to presence events
    // let mut presence_rx = agent.subscribe_presence().await?;

    // Wait for initial presence beacons
    sleep(Duration::from_secs(5)).await;

    // TODO: Verify presence events for VPS nodes
    // while let Some(event) = presence_rx.recv().await {
    //     match event {
    //         PresenceEvent::AgentOnline(agent_id) => {
    //             // Verify VPS node AgentIds
    //         }
    //         PresenceEvent::AgentOffline(_) => {
    //             // Should not see offline events initially
    //         }
    //     }
    // }

    // Expected: Receive AgentOnline events for VPS nodes
    // Expected: No AgentOffline events (all nodes healthy)
}

/// Test 7: FOAF privacy verification
///
/// Verifies that FOAF queries preserve privacy by not revealing full paths.
#[tokio::test]
#[ignore = "requires Phase 1.3 (FOAF privacy) and VPS testnet"]
async fn test_foaf_privacy() {
    let agent = create_agent_with_vps()
        .await
        .expect("Failed to create agent");

    agent.join_network().await.expect("Failed to join network");

    sleep(Duration::from_secs(10)).await;

    // TODO: Perform FOAF query and inspect response
    // let (discovered_agents, query_metadata) = agent.discover_agents_foaf_detailed(TTL=3).await?;

    // Expected: Response does NOT include full path from source to target
    // Expected: Response does NOT reveal intermediate nodes
    // Expected: Only TTL hop count and target agent info returned
}

/// Test 8: Concurrent presence beacons from multiple agents
///
/// Verifies that the VPS mesh can handle concurrent presence beacons
/// from many agents without message loss.
#[tokio::test]
#[ignore = "requires Phase 1.3 and VPS testnet"]
async fn test_concurrent_presence_beacons() {
    let num_agents = 10;
    let mut handles = Vec::new();

    for i in 0..num_agents {
        let handle = tokio::spawn(async move {
            let temp_dir = TempDir::new().expect("Failed to create temp dir");
            let bootstrap_addrs = VPS_NODES.iter().filter_map(|s| s.parse().ok()).collect();

            let agent = Agent::builder()
                .with_machine_key(temp_dir.path().join(format!("machine-{}.key", i)))
                .with_network_config(NetworkConfig {
                    bind_addr: Some("0.0.0.0:0".parse().unwrap()),
                    bootstrap_nodes: bootstrap_addrs,
                    ..Default::default()
                })
                .build()
                .await
                .expect("Failed to create agent");

            agent.join_network().await.expect("Failed to join network");

            // Keep agent alive for presence beacon propagation
            sleep(Duration::from_secs(10)).await;

            agent.agent_id()
        });
        handles.push(handle);
    }

    let agent_ids: Vec<_> = futures::future::join_all(handles)
        .await
        .into_iter()
        .map(|r| r.expect("Task failed"))
        .collect();

    // TODO: Query VPS nodes for all agent presences
    // Expected: All 10 agents visible on VPS nodes
    // Expected: No beacon message loss

    assert_eq!(
        agent_ids.len(),
        num_agents,
        "All agents should complete successfully"
    );
}
