use std::sync::Arc;
use std::time::Duration;

use surrealdb::{
    engine::remote::ws::{Client, Ws},
    opt::auth::Root,
    Surreal,
};
use tokio::time::{sleep, timeout};
use vapora_a2a::{
    bridge::CoordinatorBridge,
    protocol::{A2aMessage, A2aMessagePart, A2aTask, TaskState},
    task_manager::TaskManager,
};
use vapora_agents::{
    config::AgentConfig,
    coordinator::AgentCoordinator,
    nats_bridge::{NatsBridge, NatsBrokerConfig, TaskResult},
    registry::AgentRegistry,
};

async fn setup_test_db() -> Surreal<Client> {
    let db = Surreal::new::<Ws>("127.0.0.1:8000")
        .await
        .expect("Failed to connect to SurrealDB");

    db.signin(Root {
        username: "root",
        password: "root",
    })
    .await
    .expect("Failed to sign in");

    db.use_ns("test")
        .use_db("vapora_a2a_integration_test")
        .await
        .expect("Failed to use namespace");

    db
}

async fn setup_test_nats_bridge(registry: Arc<AgentRegistry>) -> Arc<NatsBridge> {
    let config = NatsBrokerConfig {
        url: "nats://127.0.0.1:4222".to_string(),
        stream_name: "VAPORA_TASKS_TEST".to_string(),
        consumer_name: "vapora-a2a-integration-test".to_string(),
        ..NatsBrokerConfig::default()
    };
    Arc::new(
        NatsBridge::connect(config, registry)
            .await
            .expect("Failed to connect NatsBridge"),
    )
}

/// Test 1: Task persistence — tasks survive TaskManager restart
#[tokio::test]
#[ignore] // Requires SurrealDB running
async fn test_task_persistence_after_restart() {
    let db = setup_test_db().await;
    let task_manager = Arc::new(TaskManager::new(db.clone()));

    let task = A2aTask {
        id: "persistence-test-123".to_string(),
        message: A2aMessage {
            role: "user".to_string(),
            parts: vec![A2aMessagePart::Text("Test persistence task".to_string())],
        },
        metadata: Default::default(),
    };

    task_manager
        .create(task)
        .await
        .expect("Failed to create task");

    // Simulate restart with a new TaskManager instance pointing to same DB
    let task_manager2 = Arc::new(TaskManager::new(db.clone()));

    let status = task_manager2
        .get("persistence-test-123")
        .await
        .expect("Task not found after restart");

    assert_eq!(status.id, "persistence-test-123");
    assert_eq!(status.state, TaskState::Waiting.as_str());

    let _ = db
        .query("DELETE FROM a2a_tasks WHERE task_id = $task_id")
        .bind(("task_id", "persistence-test-123"))
        .await;
}

/// Test 2: JetStream result updates DB — NatsBridge receives TaskResult and
/// persists completion to SurrealDB
#[tokio::test]
#[ignore] // Requires SurrealDB + NATS running
async fn test_jetstream_task_completion_updates_db() {
    let db = setup_test_db().await;
    let registry = Arc::new(AgentRegistry::new(10));
    let nats_bridge = setup_test_nats_bridge(registry.clone()).await;

    let task_manager = Arc::new(TaskManager::new(db.clone()));
    let config = AgentConfig::default();
    let coordinator = Arc::new(
        AgentCoordinator::new(config, registry)
            .await
            .expect("Failed to create coordinator"),
    );

    let bridge = Arc::new(CoordinatorBridge::new(
        coordinator,
        task_manager.clone(),
        Some(nats_bridge.clone()),
    ));

    bridge
        .start_result_listener()
        .await
        .expect("Failed to start result listener");

    let task_id = "jetstream-completion-test-456".to_string();

    let task = A2aTask {
        id: task_id.clone(),
        message: A2aMessage {
            role: "user".to_string(),
            parts: vec![A2aMessagePart::Text(
                "Test JetStream completion".to_string(),
            )],
        },
        metadata: Default::default(),
    };

    task_manager
        .create(task)
        .await
        .expect("Failed to create task");

    // Publish TaskResult to JetStream via a separate raw client — simulates
    // agent completing a task and publishing to vapora.tasks.completed.
    let raw_client = async_nats::connect("127.0.0.1:4222")
        .await
        .expect("Failed to connect raw NATS client");
    let js = async_nats::jetstream::new(raw_client);

    let result = TaskResult {
        task_id: task_id.clone(),
        agent_id: "test-agent".to_string(),
        result: "Test output from agent".to_string(),
        success: true,
        duration_ms: 500,
    };

    js.publish(
        "vapora.tasks.completed".to_string(),
        serde_json::to_vec(&result).unwrap().into(),
    )
    .await
    .expect("Failed to publish to JetStream")
    .await
    .expect("Failed to receive JetStream ack");

    // Allow the pull consumer to fetch and process the message
    sleep(Duration::from_millis(1500)).await;

    let status = task_manager
        .get(&task_id)
        .await
        .expect("Failed to get task status");

    assert_eq!(status.state, TaskState::Completed.as_str());
    assert!(status.result.is_some());

    let result_msg = status.result.unwrap();
    assert_eq!(result_msg.message.parts.len(), 1);

    if let A2aMessagePart::Text(text) = &result_msg.message.parts[0] {
        assert_eq!(text, "Test output from agent");
    } else {
        panic!("Expected text message part");
    }

    let _ = db
        .query("DELETE FROM a2a_tasks WHERE task_id = $task_id")
        .bind(("task_id", task_id))
        .await;
}

/// Test 3: Task state transitions work correctly (SurrealDB only)
#[tokio::test]
#[ignore] // Requires SurrealDB running
async fn test_task_state_transitions() {
    let db = setup_test_db().await;
    let task_manager = Arc::new(TaskManager::new(db.clone()));

    let task_id = "state-transition-test-789".to_string();

    let task = A2aTask {
        id: task_id.clone(),
        message: A2aMessage {
            role: "user".to_string(),
            parts: vec![A2aMessagePart::Text("Test state transitions".to_string())],
        },
        metadata: Default::default(),
    };

    task_manager
        .create(task)
        .await
        .expect("Failed to create task");

    let status = task_manager.get(&task_id).await.unwrap();
    assert_eq!(status.state, TaskState::Waiting.as_str());

    task_manager
        .update_state(&task_id, TaskState::Working)
        .await
        .expect("Failed to update to working");

    let status = task_manager.get(&task_id).await.unwrap();
    assert_eq!(status.state, TaskState::Working.as_str());

    let result = vapora_a2a::protocol::A2aTaskResult {
        message: A2aMessage {
            role: "assistant".to_string(),
            parts: vec![A2aMessagePart::Text("Task completed".to_string())],
        },
        artifacts: None,
    };

    task_manager
        .complete(&task_id, result)
        .await
        .expect("Failed to complete task");

    let status = task_manager.get(&task_id).await.unwrap();
    assert_eq!(status.state, TaskState::Completed.as_str());
    assert!(status.result.is_some());

    let _ = db
        .query("DELETE FROM a2a_tasks WHERE task_id = $task_id")
        .bind(("task_id", task_id))
        .await;
}

/// Test 4: Task failure handling (SurrealDB only)
#[tokio::test]
#[ignore] // Requires SurrealDB running
async fn test_task_failure_handling() {
    let db = setup_test_db().await;
    let task_manager = Arc::new(TaskManager::new(db.clone()));

    let task_id = "failure-test-999".to_string();

    let task = A2aTask {
        id: task_id.clone(),
        message: A2aMessage {
            role: "user".to_string(),
            parts: vec![A2aMessagePart::Text("Test failure handling".to_string())],
        },
        metadata: Default::default(),
    };

    task_manager
        .create(task)
        .await
        .expect("Failed to create task");

    let error = vapora_a2a::protocol::A2aErrorObj {
        code: -1,
        message: "Test error message".to_string(),
    };

    task_manager
        .fail(&task_id, error)
        .await
        .expect("Failed to fail task");

    let status = task_manager.get(&task_id).await.unwrap();
    assert_eq!(status.state, TaskState::Failed.as_str());
    assert!(status.error.is_some());
    assert_eq!(status.error.unwrap().message, "Test error message");

    let _ = db
        .query("DELETE FROM a2a_tasks WHERE task_id = $task_id")
        .bind(("task_id", task_id))
        .await;
}

/// Test 5: End-to-end task dispatch with timeout
#[tokio::test]
#[ignore] // Requires SurrealDB + NATS + Agent running
async fn test_end_to_end_task_dispatch() {
    let db = setup_test_db().await;
    let registry = Arc::new(AgentRegistry::new(10));
    let nats_bridge = setup_test_nats_bridge(registry.clone()).await;

    let task_manager = Arc::new(TaskManager::new(db.clone()));
    let config = AgentConfig::default();
    let coordinator = Arc::new(
        AgentCoordinator::new(config, registry)
            .await
            .expect("Failed to create coordinator"),
    );

    let bridge = Arc::new(CoordinatorBridge::new(
        coordinator,
        task_manager.clone(),
        Some(nats_bridge),
    ));

    bridge
        .start_result_listener()
        .await
        .expect("Failed to start result listener");

    let task = A2aTask {
        id: "e2e-test-task-001".to_string(),
        message: A2aMessage {
            role: "user".to_string(),
            parts: vec![A2aMessagePart::Text(
                "Create hello world function".to_string(),
            )],
        },
        metadata: Default::default(),
    };

    let task_id = bridge
        .dispatch(task)
        .await
        .expect("Failed to dispatch task");

    assert!(!task_id.is_empty());

    let status_result = timeout(Duration::from_secs(30), async {
        loop {
            let status = task_manager.get(&task_id).await.unwrap();
            if status.state == TaskState::Completed.as_str()
                || status.state == TaskState::Failed.as_str()
            {
                return status;
            }
            sleep(Duration::from_millis(500)).await;
        }
    })
    .await;

    assert!(
        status_result.is_ok(),
        "Task did not complete within 30 seconds"
    );

    let final_status = status_result.unwrap();
    assert_eq!(final_status.state, TaskState::Completed.as_str());

    let _ = db
        .query("DELETE FROM a2a_tasks WHERE task_id = $task_id")
        .bind(("task_id", task_id))
        .await;
}