//! Integration test for dirigate bridge connecting to Dirigent ACP Server.
//!
//! This test validates the end-to-end flow:
//! 1. Start Dirigent ACP Server on a test port (or assume one is running)
//! 2. Use dirigate bridge to connect via stdio
//! 3. Verify connection and communication works
//!
//! ## Running the tests
//!
//! ### Quick tests (no server required)
//!
//! These tests verify the bridge binary can be spawned and shows help:
//!
//! ```bash
//! # Run all non-ignored tests
//! cargo test --package dirigate --test dirigent_bridge_test
//!
//! # Or run specific tests
//! cargo test --package dirigate --test dirigent_bridge_test test_conductor_bridge_spawns
//! cargo test --package dirigate --test dirigent_bridge_test test_conductor_bridge_protocol
//! ```
//!
//! ### Full integration test (requires running server)
//!
//! The main integration test requires a Dirigent ACP Server running on http://localhost:3001/acp.
//!
//! **Step 1:** Start the Dirigent server
//! ```bash
//! # Option A: Via web UI
//! cargo run --package web
//! # Then enable ACP Server in the UI at Configuration > ACP Server
//!
//! # Option B: Via dirigent_core directly (if implemented)
//! # cargo run --package dirigent_core -- acp-server --port 3001
//! ```
//!
//! **Step 2:** Run the integration test
//! ```bash
//! cargo test --package dirigate --test dirigent_bridge_test test_conductor_bridge_to_dirigent -- --ignored --nocapture
//! ```
//!
//! ### Programmatic server test (future)
//!
//! This test demonstrates starting a minimal ACP server programmatically for testing.
//! It's currently marked as ignored until the full implementation is complete.
//!
//! ```bash
//! cargo test --package dirigate --test dirigent_bridge_test test_bridge_with_programmatic_server -- --ignored --nocapture
//! ```
//!
//! ## Test overview
//!
//! - `test_conductor_bridge_spawns` - Verifies the bridge binary exists and can show help (always runs)
//! - `test_conductor_bridge_protocol` - Basic protocol verification (always runs)
//! - `test_conductor_bridge_to_dirigent` - Full end-to-end test with real server (ignored by default)
//! - `test_bridge_with_programmatic_server` - Test with programmatically started server (ignored, future)

use anyhow::Result;
use serde_json::{json, Value};
use std::process::Stdio;
use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
use tokio::process::Command;

/// Path to the dirigate binary (debug build).
fn conductor_binary() -> std::path::PathBuf {
    let manifest_dir = env!("CARGO_MANIFEST_DIR");
    std::path::Path::new(manifest_dir)
        .parent()
        .unwrap()
        .parent()
        .unwrap()
        .join("target")
        .join("debug")
        .join(if cfg!(windows) {
            "dirigate.exe"
        } else {
            "dirigate"
        })
}

/// Helper to send a JSON-RPC request to the bridge and read the response.
///
/// This function writes a JSON-RPC request to stdin and reads responses from stdout.
/// It skips notifications (messages with "method" but no "id") and returns only
/// the response matching the request ID.
async fn send_bridge_request(
    stdin: &mut tokio::process::ChildStdin,
    stdout: &mut BufReader<tokio::process::ChildStdout>,
    request: Value,
    timeout_secs: u64,
) -> Result<Value> {
    // Send request
    let request_json = serde_json::to_string(&request)?;
    let request_id = request.get("id").cloned();

    stdin.write_all(request_json.as_bytes()).await?;
    stdin.write_all(b"\n").await?;
    stdin.flush().await?;

    // Read response, skipping notifications
    let start = std::time::Instant::now();
    loop {
        if start.elapsed() > std::time::Duration::from_secs(timeout_secs) {
            anyhow::bail!("Timeout waiting for response to request {:?}", request_id);
        }

        let mut line = String::new();
        match tokio::time::timeout(
            std::time::Duration::from_secs(2),
            stdout.read_line(&mut line),
        )
        .await
        {
            Ok(Ok(0)) => {
                anyhow::bail!("EOF reached before receiving response");
            }
            Ok(Ok(_)) => {
                let msg: Value = match serde_json::from_str(line.trim()) {
                    Ok(v) => v,
                    Err(e) => {
                        eprintln!("Failed to parse line: {}", line.trim());
                        eprintln!("Error: {}", e);
                        return Err(e.into());
                    }
                };

                // Skip notifications (they have "method" but no "id")
                if msg.get("method").is_some() && msg.get("id").is_none() {
                    eprintln!("Skipping notification: {:?}", msg.get("method"));
                    continue;
                }

                // Check if this is the response we're looking for
                if let Some(id) = request_id.as_ref() {
                    if msg.get("id") == Some(id) {
                        return Ok(msg);
                    } else {
                        eprintln!(
                            "Got response with id {:?}, expected {:?}",
                            msg.get("id"),
                            id
                        );
                        continue;
                    }
                } else {
                    // No ID means we're looking for any response
                    return Ok(msg);
                }
            }
            Ok(Err(e)) => {
                anyhow::bail!("IO error reading from stdout: {}", e);
            }
            Err(_) => {
                // Timeout on this read, loop and try again
                continue;
            }
        }
    }
}

/// Test that dirigate bridge can be spawned and shows help.
#[tokio::test]
async fn test_conductor_bridge_spawns() -> Result<()> {
    let binary = conductor_binary();
    if !binary.exists() {
        eprintln!(
            "Conductor binary not found at {:?}. Run 'cargo build --package dirigate' first.",
            binary
        );
        return Ok(()); // Skip test if binary doesn't exist
    }

    // Test that --help works
    let output = Command::new(&binary)
        .args(&["bridge", "--help"])
        .output()
        .await?;

    assert!(
        output.status.success(),
        "conductor bridge --help should succeed"
    );

    let stdout = String::from_utf8(output.stdout)?;
    assert!(
        stdout.contains("bridge") || stdout.contains("Bridge"),
        "Help output should mention bridge. Got: {}",
        stdout
    );
    assert!(
        stdout.contains("server") || stdout.contains("ACP"),
        "Help output should mention server or ACP"
    );

    println!("✓ Conductor bridge binary spawns successfully");

    Ok(())
}

/// Test that dirigate bridge can connect to Dirigent ACP Server.
///
/// **Prerequisites:**
/// - A Dirigent ACP Server must be running on http://localhost:8080/acp
/// - Start the live server with ACP enabled (Configuration > ACP Server)
///
/// **Note:** By default, ACP is nested at /acp on the main Dioxus server (port 8080).
/// If you configured ACP to run on a separate port, adjust the server_url below.
///
/// **To run this test:**
/// ```bash
/// # Start server first (enable ACP Server in Configuration UI)
/// dx serve --package web
///
/// # Then run test
/// cargo test --package dirigate --test dirigent_bridge_test test_conductor_bridge_to_dirigent -- --ignored --nocapture
/// ```
#[tokio::test]
#[ignore = "Requires running Dirigent ACP Server on localhost:8080"]
async fn test_conductor_bridge_to_dirigent() -> Result<()> {
    let binary = conductor_binary();
    if !binary.exists() {
        eprintln!(
            "Conductor binary not found at {:?}. Run 'cargo build --package dirigate' first.",
            binary
        );
        return Ok(()); // Skip test if binary doesn't exist
    }

    let server_url = "http://localhost:8080/acp";

    println!("Starting dirigate bridge to {}", server_url);

    // Start dirigate bridge process
    let mut dirigate = Command::new(&binary)
        .args(&["bridge", "--server-url", server_url, "--verbose"])
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped()) // Capture stderr for debugging
        .spawn()?;

    // Get handles for stdin/stdout
    let mut stdin = dirigate.stdin.take().expect("Failed to get stdin");
    let stdout = dirigate.stdout.take().expect("Failed to get stdout");
    let mut reader = BufReader::new(stdout);

    println!("Bridge process started, sending initialize request");

    // Send initialize request
    let initialize_request = json!({
        "jsonrpc": "2.0",
        "id": 1,
        "method": "initialize",
        "params": {
            "protocolVersion": 1,
            "clientCapabilities": {
                "tools": {
                    "supported": true
                }
            }
        }
    });

    let response = send_bridge_request(&mut stdin, &mut reader, initialize_request, 10).await?;

    // Verify we got a valid JSON-RPC response
    assert_eq!(response["jsonrpc"], "2.0");
    assert_eq!(response["id"], 1);

    // Check for result or error
    if response.get("result").is_some() {
        println!("✓ Successfully connected to Dirigent server via dirigate bridge");
        println!(
            "Initialize response: {}",
            serde_json::to_string_pretty(&response)?
        );

        // Verify the response has expected fields
        let result = &response["result"];
        assert!(
            result.get("protocolVersion").is_some()
                || result.get("agentCapabilities").is_some()
                || result.get("client_id").is_some(),
            "Initialize result should have protocol version, capabilities, or client_id"
        );
    } else if response.get("error").is_some() {
        eprintln!("✗ Got error response from server:");
        eprintln!("{}", serde_json::to_string_pretty(&response)?);
        anyhow::bail!("Server returned error: {:?}", response["error"]);
    } else {
        anyhow::bail!("Response has neither result nor error: {:?}", response);
    }

    // Optional: Test creating a session
    println!("\nTesting session creation...");
    let session_request = json!({
        "jsonrpc": "2.0",
        "method": "session/new",
        "id": 2,
        "params": {
            "cwd": ".",
            "mcpServers": []
        }
    });

    let session_response = send_bridge_request(&mut stdin, &mut reader, session_request, 10).await?;

    assert_eq!(session_response["jsonrpc"], "2.0");
    assert_eq!(session_response["id"], 2);

    if session_response.get("result").is_some() {
        let session_id = session_response["result"]["sessionId"]
            .as_str()
            .expect("sessionId should be a string");
        println!("✓ Created session: {}", session_id);
        println!(
            "Session response: {}",
            serde_json::to_string_pretty(&session_response)?
        );
    } else if session_response.get("error").is_some() {
        eprintln!("Got error creating session:");
        eprintln!("{}", serde_json::to_string_pretty(&session_response)?);
        // Don't fail the test - session creation might not be implemented yet
        println!("⚠ Session creation returned error (may not be implemented yet)");
    }

    // Clean up
    dirigate.kill().await?;

    Ok(())
}

/// Test dirigate bridge with a simulated server response (unit test style).
///
/// This test doesn't require a real server - it just verifies the bridge
/// can be spawned and interacts correctly at the protocol level.
#[tokio::test]
async fn test_conductor_bridge_protocol() -> Result<()> {
    let binary = conductor_binary();
    if !binary.exists() {
        return Ok(()); // Skip if binary not built
    }

    // This test would ideally mock the HTTP server, but that's complex.
    // For now, we just verify the binary exists and can be invoked.
    // A full mock server test could be added later.

    let output = Command::new(&binary)
        .args(&["bridge", "--help"])
        .output()
        .await?;

    assert!(output.status.success());

    println!("✓ Bridge protocol test passed (basic verification)");

    Ok(())
}

/// Test that demonstrates how to start a minimal Dirigent ACP Server programmatically.
///
/// **NOTE:** This test is currently a placeholder showing the structure.
/// It requires the full dirigent_acp_api to be implemented with a way to
/// start the server programmatically.
#[tokio::test]
#[ignore = "Requires full dirigent_acp_api implementation"]
async fn test_bridge_with_programmatic_server() -> Result<()> {
    use dirigent_acp_api::{create_acp_server_router, AcpServerConfig, AcpServerState, NoOpConnectorOperations};

    // Create server configuration
    let config = AcpServerConfig::enabled().set_port(0); // Use random port

    // Create server state
    let state = AcpServerState::new(config.clone());

    // Create the router with no-op connector operations
    let router = create_acp_server_router(state, NoOpConnectorOperations);

    // Start server in background
    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await?;
    let server_addr = listener.local_addr()?;
    let server_url = format!("http://{}/acp", server_addr);

    println!("Started test server at {}", server_url);

    tokio::spawn(async move {
        axum::serve(listener, router).await.unwrap();
    });

    // Give server time to start
    tokio::time::sleep(tokio::time::Duration::from_millis(500)).await;

    // Now test the bridge
    let binary = conductor_binary();
    if !binary.exists() {
        return Ok(());
    }

    let mut dirigate = Command::new(&binary)
        .args(&["bridge", "--server-url", &server_url])
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .spawn()?;

    let mut stdin = dirigate.stdin.take().unwrap();
    let stdout = dirigate.stdout.take().unwrap();
    let mut reader = BufReader::new(stdout);

    // Send initialize
    let init_request = json!({
        "jsonrpc": "2.0",
        "id": 1,
        "method": "initialize",
        "params": {
            "protocolVersion": 1,
            "clientCapabilities": {}
        }
    });

    let response = send_bridge_request(&mut stdin, &mut reader, init_request, 5).await?;

    assert_eq!(response["jsonrpc"], "2.0");
    assert!(
        response.get("result").is_some() || response.get("error").is_some(),
        "Should get a valid response"
    );

    println!("✓ Bridge successfully connected to programmatic server");

    dirigate.kill().await?;

    Ok(())
}