//! End-to-end compaction flow tests.
//!
//! Phases:
//! 1) Arrange: mock responses/compact endpoints + config.
//! 2) Act: start a thread and submit multiple turns to trigger auto-compaction.
//! 3) Assert: verify item/started + item/completed notifications for context compaction.

use anyhow::Result;
use app_test_support::ChatGptAuthFixture;
use app_test_support::MockResponsesConfig;
use app_test_support::TestAppServer;
use app_test_support::write_chatgpt_auth;
use codex_app_server_protocol::ItemCompletedNotification;
use codex_app_server_protocol::ItemStartedNotification;
use codex_app_server_protocol::JSONRPCError;
use codex_app_server_protocol::RawResponseCompletedNotification;
use codex_app_server_protocol::RequestId;
use codex_app_server_protocol::ResponseUsageMetadata;
use codex_app_server_protocol::ThreadCompactStartParams;
use codex_app_server_protocol::ThreadCompactStartResponse;
use codex_app_server_protocol::ThreadHistoryMode;
use codex_app_server_protocol::ThreadItem;
use codex_app_server_protocol::ThreadResumeParams;
use codex_app_server_protocol::ThreadResumeResponse;
use codex_app_server_protocol::ThreadStartParams;
use codex_app_server_protocol::ThreadStartResponse;
use codex_app_server_protocol::TokenUsageBreakdown;
use codex_app_server_protocol::TurnCompletedNotification;
use codex_app_server_protocol::TurnStartParams;
use codex_app_server_protocol::TurnStartResponse;
use codex_app_server_protocol::UserInput as V2UserInput;
use codex_config::types::AuthCredentialsStoreMode;
use codex_features::Feature;
use codex_protocol::models::ContentItem;
use codex_protocol::models::ResponseItem;
use codex_utils_absolute_path::test_support::PathExt;
use core_test_support::responses;
use core_test_support::skip_if_no_network;
use pretty_assertions::assert_eq;
use tempfile::TempDir;
use tokio::time::timeout;

// macOS and Windows Bazel CI can spend tens of seconds starting app-server
// subprocesses or processing test RPCs under load.
#[cfg(any(target_os = "macos", windows))]
const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(60);
#[cfg(not(any(target_os = "macos", windows)))]
const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
const AUTO_COMPACT_LIMIT: i64 = 1_000;
const COMPACT_PROMPT: &str = "Summarize the conversation.";
const INVALID_REQUEST_ERROR_CODE: i64 = -32600;

#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn auto_compaction_local_emits_started_and_completed_items() -> Result<()> {
    skip_if_no_network!(Ok(()));

    let server = responses::start_mock_server().await;
    let sse1 = responses::sse(vec![
        responses::ev_assistant_message("m1", "FIRST_REPLY"),
        responses::ev_completed_with_tokens("r1", /*total_tokens*/ 70_000),
    ]);
    let sse2 = responses::sse(vec![
        responses::ev_assistant_message("m2", "SECOND_REPLY"),
        responses::ev_completed_with_tokens("r2", /*total_tokens*/ 330_000),
    ]);
    let sse3 = responses::sse(vec![
        responses::ev_assistant_message("m3", "LOCAL_SUMMARY"),
        responses::ev_completed_with_tokens("r3", /*total_tokens*/ 200),
    ]);
    let sse4 = responses::sse(vec![
        responses::ev_assistant_message("m4", "FINAL_REPLY"),
        responses::ev_completed_with_tokens("r4", /*total_tokens*/ 120),
    ]);
    responses::mount_sse_sequence(&server, vec![sse1, sse2, sse3, sse4]).await;

    let codex_home = TempDir::new()?;
    compaction_config(&server.uri(), AUTO_COMPACT_LIMIT).write(codex_home.path())?;

    let mut mcp = TestAppServer::builder()
        .with_codex_home(codex_home.path())
        .build_initialized_with_timeout(DEFAULT_READ_TIMEOUT)
        .await?;

    let thread_id = start_thread(&mut mcp).await?;
    for message in ["first", "second", "third"] {
        send_turn_and_wait(&mut mcp, &thread_id, message).await?;
    }

    let started = wait_for_context_compaction_started(&mut mcp).await?;
    let completed = wait_for_context_compaction_completed(&mut mcp).await?;

    let ThreadItem::ContextCompaction { id: started_id } = started.item else {
        unreachable!("started item should be context compaction");
    };
    let ThreadItem::ContextCompaction { id: completed_id } = completed.item else {
        unreachable!("completed item should be context compaction");
    };

    assert_eq!(started.thread_id, thread_id);
    assert_eq!(completed.thread_id, thread_id);
    assert_eq!(started_id, completed_id);

    Ok(())
}

#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn auto_compaction_remote_emits_started_and_completed_items() -> Result<()> {
    skip_if_no_network!(Ok(()));
    const REMOTE_AUTO_COMPACT_LIMIT: i64 = 200_000;

    let server = responses::start_mock_server().await;
    let sse1 = responses::sse(vec![
        responses::ev_assistant_message("m1", "FIRST_REPLY"),
        responses::ev_completed_with_tokens("r1", /*total_tokens*/ 70_000),
    ]);
    let sse2 = responses::sse(vec![
        responses::ev_assistant_message("m2", "SECOND_REPLY"),
        responses::ev_completed_with_tokens("r2", /*total_tokens*/ 330_000),
    ]);
    let sse3 = responses::sse(vec![
        responses::ev_assistant_message("m3", "FINAL_REPLY"),
        responses::ev_completed_with_tokens("r3", /*total_tokens*/ 120),
    ]);
    let responses_log = responses::mount_sse_sequence(&server, vec![sse1, sse2, sse3]).await;

    let compacted_history = vec![
        ResponseItem::Message {
            id: None,
            role: "assistant".to_string(),
            content: vec![ContentItem::OutputText {
                text: "REMOTE_COMPACT_SUMMARY".to_string(),
            }],
            phase: None,
            internal_chat_message_metadata_passthrough: None,
        },
        ResponseItem::Compaction {
            id: None,
            encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
            internal_chat_message_metadata_passthrough: None,
        },
    ];
    let compact_mock = responses::mount_compact_json_once(
        &server,
        serde_json::json!({ "output": compacted_history }),
    )
    .await;

    let codex_home = TempDir::new()?;
    compaction_config(&server.uri(), REMOTE_AUTO_COMPACT_LIMIT)
        .disable_feature(Feature::RemoteCompactionV2)
        .with_provider_name("OpenAI")
        .with_provider_config("requires_openai_auth = true")
        .write(codex_home.path())?;
    write_chatgpt_auth(
        codex_home.path(),
        ChatGptAuthFixture::new("access-chatgpt").plan_type("pro"),
        AuthCredentialsStoreMode::File,
    )?;

    let mut mcp = TestAppServer::builder()
        .with_codex_home(codex_home.path())
        .with_env_overrides(&[("OPENAI_API_KEY", None)])
        .build_initialized_with_timeout(DEFAULT_READ_TIMEOUT)
        .await?;

    let thread_id = start_thread(&mut mcp).await?;
    for message in ["first", "second", "third"] {
        send_turn_and_wait(&mut mcp, &thread_id, message).await?;
    }

    let started = wait_for_context_compaction_started(&mut mcp).await?;
    let completed = wait_for_context_compaction_completed(&mut mcp).await?;

    let ThreadItem::ContextCompaction { id: started_id } = started.item else {
        unreachable!("started item should be context compaction");
    };
    let ThreadItem::ContextCompaction { id: completed_id } = completed.item else {
        unreachable!("completed item should be context compaction");
    };

    assert_eq!(started.thread_id, thread_id);
    assert_eq!(completed.thread_id, thread_id);
    assert_eq!(started_id, completed_id);

    let compact_requests = compact_mock.requests();
    assert_eq!(compact_requests.len(), 1);
    assert_eq!(compact_requests[0].path(), "/v1/responses/compact");

    let response_requests = responses_log.requests();
    assert_eq!(response_requests.len(), 3);
    let turn_metadata = response_requests
        .iter()
        .map(|request| {
            request
                .header("x-codex-turn-metadata")
                .as_deref()
                .map(parse_json_header)
                .expect("turn request should include turn metadata")
        })
        .collect::<Vec<_>>();
    for (request, metadata) in response_requests.iter().zip(&turn_metadata) {
        assert_eq!(metadata["request_kind"].as_str(), Some("turn"));
        assert!(
            metadata["turn_id"]
                .as_str()
                .is_some_and(|turn_id| !turn_id.is_empty()),
            "turn request should carry a non-empty turn id"
        );
        assert_eq!(
            metadata["window_id"].as_str(),
            request.header("x-codex-window-id").as_deref()
        );
        assert!(metadata.get("compaction").is_none());
    }

    let compact_metadata = compact_requests[0]
        .header("x-codex-turn-metadata")
        .as_deref()
        .map(parse_json_header)
        .expect("compact request should include turn metadata");
    assert_eq!(
        compact_metadata["request_kind"].as_str(),
        Some("compaction")
    );
    assert_eq!(
        compact_metadata["compaction"],
        serde_json::json!({
            "trigger": "auto",
            "reason": "context_limit",
            "implementation": "responses_compact",
            "phase": "pre_turn",
            "strategy": "memento",
        })
    );
    assert_eq!(
        compact_metadata["turn_id"], turn_metadata[2]["turn_id"],
        "pre-turn compaction should carry the current turn id"
    );
    assert_eq!(
        compact_metadata["window_id"].as_str(),
        compact_requests[0].header("x-codex-window-id").as_deref()
    );

    Ok(())
}

#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn thread_compact_start_triggers_compaction_and_returns_empty_response() -> Result<()> {
    skip_if_no_network!(Ok(()));

    let server = responses::start_mock_server().await;
    let seed = responses::sse(vec![
        responses::ev_assistant_message("seed", "FIRST_REPLY"),
        responses::ev_completed_with_tokens("seed", /*total_tokens*/ 120),
    ]);
    let mut completed = responses::ev_completed_with_tokens("r1", /*total_tokens*/ 200);
    completed["response"]["usage_metadata"] = serde_json::json!({ "amount": "0.125" });
    completed["response"]["usage"]["extra"] = serde_json::json!({ "label": "example" });
    let expected_metadata = completed["response"]["usage"].clone();
    let sse = responses::sse(vec![
        responses::ev_assistant_message("m1", "MANUAL_COMPACT_SUMMARY"),
        completed,
    ]);
    let followup = responses::sse(vec![
        responses::ev_assistant_message("followup", "FINAL_REPLY"),
        responses::ev_completed_with_tokens("followup", /*total_tokens*/ 120),
    ]);
    let _responses = responses::mount_sse_sequence(&server, vec![seed, sse, followup]).await;

    let codex_home = TempDir::new()?;
    let initial_cwd = TempDir::new()?;
    let updated_cwd = TempDir::new()?;
    let extra_root = TempDir::new()?;
    let updated_roots = vec![updated_cwd.path().abs(), extra_root.path().abs()];
    compaction_config(&server.uri(), /*auto_compact_limit*/ 1_000_000).write(codex_home.path())?;

    // Top-level cwd restoration uses host-native paths, not a foreign executor's paths.
    let mut mcp = TestAppServer::builder()
        .with_codex_home(codex_home.path())
        .without_auto_env()
        .build_initialized_with_timeout(DEFAULT_READ_TIMEOUT)
        .await?;

    let thread_req = mcp
        .send_thread_start_request(ThreadStartParams {
            model: Some("mock-model".to_string()),
            cwd: Some(initial_cwd.path().to_string_lossy().into_owned()),
            history_mode: Some(ThreadHistoryMode::Paginated),
            experimental_raw_events: true,
            ..Default::default()
        })
        .await?;
    let ThreadStartResponse { thread, .. } =
        timeout(DEFAULT_READ_TIMEOUT, mcp.read_response(thread_req)).await??;
    let thread_id = thread.id;
    timeout(
        DEFAULT_READ_TIMEOUT,
        mcp.start_turn_and_wait_for_completion(TurnStartParams {
            thread_id: thread_id.clone(),
            cwd: Some(updated_cwd.path().to_path_buf()),
            runtime_workspace_roots: Some(updated_roots.clone()),
            input: vec![V2UserInput::Text {
                text: "seed history".to_string(),
                text_elements: Vec::new(),
            }],
            ..Default::default()
        }),
    )
    .await??;
    mcp.clear_message_buffer();

    let compact_id = mcp
        .send_thread_compact_start_request(ThreadCompactStartParams {
            thread_id: thread_id.clone(),
        })
        .await?;
    let _: ThreadCompactStartResponse =
        timeout(DEFAULT_READ_TIMEOUT, mcp.read_response(compact_id)).await??;

    let started = wait_for_context_compaction_started(&mut mcp).await?;
    let raw_completed: RawResponseCompletedNotification = timeout(
        DEFAULT_READ_TIMEOUT,
        mcp.read_notification("rawResponse/completed"),
    )
    .await??;
    let completed = wait_for_context_compaction_completed(&mut mcp).await?;
    wait_for_turn_completed(&mut mcp, &started.turn_id).await?;

    let ThreadItem::ContextCompaction { id: started_id } = started.item else {
        unreachable!("started item should be context compaction");
    };
    let ThreadItem::ContextCompaction { id: completed_id } = completed.item else {
        unreachable!("completed item should be context compaction");
    };

    assert_eq!(started.thread_id, thread_id);
    assert_eq!(completed.thread_id, thread_id);
    assert_eq!(started_id, completed_id);
    assert_eq!(
        raw_completed,
        RawResponseCompletedNotification {
            thread_id: thread_id.clone(),
            turn_id: started.turn_id,
            response_id: "r1".to_string(),
            usage_metadata: Some(ResponseUsageMetadata {
                amount: Some("0.125".to_string()),
                metadata: Some(expected_metadata),
            }),
            usage: Some(TokenUsageBreakdown {
                total_tokens: 200,
                input_tokens: 200,
                cached_input_tokens: 0,
                cache_write_input_tokens: 0,
                output_tokens: 0,
                reasoning_output_tokens: 0,
            }),
        }
    );

    // A completed turn after compaction permits bounded replay. Neither this turn nor
    // resume resends settings, so restoring the updated cwd and roots depends on the
    // checkpoint; startup metadata does not contain the extra root.
    send_turn_and_wait(&mut mcp, &thread_id, "continue").await?;
    timeout(DEFAULT_READ_TIMEOUT, mcp.shutdown_gracefully()).await??;

    let mut mcp = TestAppServer::builder()
        .with_codex_home(codex_home.path())
        .without_auto_env()
        .build_initialized_with_timeout(DEFAULT_READ_TIMEOUT)
        .await?;
    let resume_id = mcp
        .send_thread_resume_request(ThreadResumeParams {
            thread_id,
            exclude_turns: true,
            ..Default::default()
        })
        .await?;
    let ThreadResumeResponse {
        cwd,
        runtime_workspace_roots,
        ..
    } = timeout(DEFAULT_READ_TIMEOUT, mcp.read_response(resume_id)).await??;
    assert_eq!(
        (cwd.as_path(), runtime_workspace_roots),
        (updated_cwd.path(), updated_roots)
    );

    Ok(())
}

#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn thread_compact_start_rejects_invalid_thread_id() -> Result<()> {
    skip_if_no_network!(Ok(()));

    let server = responses::start_mock_server().await;
    let codex_home = TempDir::new()?;
    compaction_config(&server.uri(), AUTO_COMPACT_LIMIT).write(codex_home.path())?;

    let mut mcp = TestAppServer::builder()
        .with_codex_home(codex_home.path())
        .build_initialized_with_timeout(DEFAULT_READ_TIMEOUT)
        .await?;

    let request_id = mcp
        .send_thread_compact_start_request(ThreadCompactStartParams {
            thread_id: "not-a-thread-id".to_string(),
        })
        .await?;
    let error: JSONRPCError = timeout(
        DEFAULT_READ_TIMEOUT,
        mcp.read_stream_until_error_message(RequestId::Integer(request_id)),
    )
    .await??;

    assert_eq!(error.error.code, INVALID_REQUEST_ERROR_CODE);
    assert!(error.error.message.contains("invalid thread id"));

    Ok(())
}

#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn thread_compact_start_rejects_unknown_thread_id() -> Result<()> {
    skip_if_no_network!(Ok(()));

    let server = responses::start_mock_server().await;
    let codex_home = TempDir::new()?;
    compaction_config(&server.uri(), AUTO_COMPACT_LIMIT).write(codex_home.path())?;

    let mut mcp = TestAppServer::builder()
        .with_codex_home(codex_home.path())
        .build_initialized_with_timeout(DEFAULT_READ_TIMEOUT)
        .await?;

    let request_id = mcp
        .send_thread_compact_start_request(ThreadCompactStartParams {
            thread_id: "67e55044-10b1-426f-9247-bb680e5fe0c8".to_string(),
        })
        .await?;
    let error: JSONRPCError = timeout(
        DEFAULT_READ_TIMEOUT,
        mcp.read_stream_until_error_message(RequestId::Integer(request_id)),
    )
    .await??;

    assert_eq!(error.error.code, INVALID_REQUEST_ERROR_CODE);
    assert!(error.error.message.contains("thread not found"));

    Ok(())
}

async fn start_thread(mcp: &mut TestAppServer) -> Result<String> {
    let thread_id = mcp
        .send_thread_start_request_with_auto_env(ThreadStartParams {
            model: Some("mock-model".to_string()),
            ..Default::default()
        })
        .await?;
    let ThreadStartResponse { thread, .. } =
        timeout(DEFAULT_READ_TIMEOUT, mcp.read_response(thread_id)).await??;
    Ok(thread.id)
}

async fn send_turn_and_wait(
    mcp: &mut TestAppServer,
    thread_id: &str,
    text: &str,
) -> Result<String> {
    let turn_id = mcp
        .send_turn_start_request(TurnStartParams {
            thread_id: thread_id.to_string(),
            client_user_message_id: None,
            input: vec![V2UserInput::Text {
                text: text.to_string(),
                text_elements: Vec::new(),
            }],
            ..Default::default()
        })
        .await?;
    let TurnStartResponse { turn } =
        timeout(DEFAULT_READ_TIMEOUT, mcp.read_response(turn_id)).await??;
    wait_for_turn_completed(mcp, &turn.id).await?;
    Ok(turn.id)
}

async fn wait_for_turn_completed(mcp: &mut TestAppServer, turn_id: &str) -> Result<()> {
    loop {
        let completed: TurnCompletedNotification = timeout(
            DEFAULT_READ_TIMEOUT,
            mcp.read_notification("turn/completed"),
        )
        .await??;
        if completed.turn.id == turn_id {
            return Ok(());
        }
    }
}

async fn wait_for_context_compaction_started(
    mcp: &mut TestAppServer,
) -> Result<ItemStartedNotification> {
    loop {
        let started: ItemStartedNotification =
            timeout(DEFAULT_READ_TIMEOUT, mcp.read_notification("item/started")).await??;
        if let ThreadItem::ContextCompaction { .. } = started.item {
            return Ok(started);
        }
    }
}

async fn wait_for_context_compaction_completed(
    mcp: &mut TestAppServer,
) -> Result<ItemCompletedNotification> {
    loop {
        let completed: ItemCompletedNotification = timeout(
            DEFAULT_READ_TIMEOUT,
            mcp.read_notification("item/completed"),
        )
        .await??;
        if let ThreadItem::ContextCompaction { .. } = completed.item {
            return Ok(completed);
        }
    }
}

fn parse_json_header(value: &str) -> serde_json::Value {
    serde_json::from_str(value).expect("turn metadata should be JSON")
}

fn compaction_config(server_uri: &str, auto_compact_limit: i64) -> MockResponsesConfig {
    MockResponsesConfig::new(server_uri)
        .with_root_config(&format!(
            "compact_prompt = \"{COMPACT_PROMPT}\"\nmodel_auto_compact_token_limit = {auto_compact_limit}"
        ))
        .with_provider_config("supports_websockets = false")
}