//! Regression coverage for SQLite initialization, cached filesystem detection, and competing locks.

use super::SqliteConfig;
use codex_utils_absolute_path::test_support::PathExt;
use pretty_assertions::assert_eq;
use sqlx::sqlite::SqliteAutoVacuum;
use sqlx::sqlite::SqliteConnectOptions;
use sqlx::sqlite::SqliteJournalMode;
use sqlx::sqlite::SqlitePoolOptions;

#[tokio::test]
async fn configured_log_directory_is_initialized_on_use_and_retries_after_failure()
-> anyhow::Result<()> {
    let sqlite_home = crate::runtime::test_support::unique_temp_dir();
    tokio::fs::create_dir_all(&sqlite_home).await?;
    let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
        let _ = std::fs::remove_dir_all(sqlite_home);
    });
    let logs_home = sqlite_home.join("logs");
    tokio::fs::write(&logs_home, "not a directory").await?;
    let sqlite = SqliteConfig::new_for_testing(sqlite_home.as_path().abs());
    sqlite.is_nfs.set(/*value*/ true)?;
    let fallback_logs_path = sqlite.logs_db_path();
    let sqlite = sqlite.with_local_logs_home(logs_home.clone());
    sqlite.logs_is_nfs.set(/*value*/ false)?;

    // Opening unrelated state must not require the configured logs directory.
    let pool = sqlite.open_read_write_pool(&sqlite.state_db_path()).await?;
    pool.close().await;
    assert!(
        crate::StateRuntime::init(sqlite.clone(), "openai".to_string())
            .await
            .is_err()
    );
    assert!(!fallback_logs_path.exists());

    // A failed initialization must remain retryable without replacing the config.
    tokio::fs::remove_file(&logs_home).await?;
    let runtime = crate::StateRuntime::init(sqlite.clone(), "openai".to_string()).await?;
    assert!(sqlite.logs_db_path().is_file());
    assert!(!fallback_logs_path.exists());
    runtime.close().await;
    // The configured logs directory has its own filesystem, independent of the NFS state home.
    let mut modes = Vec::new();
    for path in [sqlite.state_db_path(), sqlite.logs_db_path()] {
        let pool = sqlite
            .open_read_only_pool(&path, /*busy_timeout*/ None)
            .await?;
        modes.push(
            sqlx::query_scalar::<_, String>("PRAGMA journal_mode")
                .fetch_one(&pool)
                .await?,
        );
        pool.close().await;
    }
    assert_eq!(modes, vec!["delete".to_string(), "wal".to_string()]);
    Ok(())
}

#[cfg(unix)]
#[tokio::test]
async fn configured_log_directory_lock_is_shared_by_reader_and_writer_config_clones()
-> anyhow::Result<()> {
    let sqlite_home = crate::runtime::test_support::unique_temp_dir();
    let logs_home = sqlite_home.join("logs");
    tokio::fs::create_dir_all(&logs_home).await?;
    let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
        let _ = std::fs::remove_dir_all(sqlite_home);
    });
    let initial = SqliteConfig::new_for_testing(logs_home.as_path().abs());
    let logs_path = initial.logs_db_path();
    initial
        .open_read_write_pool(&logs_path)
        .await?
        .close()
        .await;

    for read_only in [false, true] {
        let sqlite = SqliteConfig::new_for_testing(sqlite_home.as_path().abs())
            .with_local_logs_home(logs_home.clone());
        let clone = sqlite.clone();
        let cleanup_lock = std::fs::File::open(&logs_home)?;
        cleanup_lock.try_lock()?;
        cleanup_lock.unlock()?;

        let pool = if read_only {
            sqlite
                .open_read_only_pool(&logs_path, /*busy_timeout*/ None)
                .await?
        } else {
            sqlite.open_read_write_pool(&logs_path).await?
        };
        assert!(matches!(
            cleanup_lock.try_lock(),
            Err(std::fs::TryLockError::WouldBlock)
        ));
        drop(sqlite);
        assert!(matches!(
            cleanup_lock.try_lock(),
            Err(std::fs::TryLockError::WouldBlock)
        ));

        pool.close().await;
        drop(clone);
        cleanup_lock.try_lock()?;
    }
    Ok(())
}

#[cfg(target_os = "linux")]
#[tokio::test]
async fn sqlite_home_filesystem_probe_is_shared_by_clones_until_config_replacement()
-> anyhow::Result<()> {
    let sqlite_home = crate::runtime::test_support::unique_temp_dir();
    tokio::fs::create_dir_all(&sqlite_home).await?;
    let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
        let _ = std::fs::remove_dir_all(sqlite_home);
    });
    let sqlite = SqliteConfig::new_for_testing(sqlite_home.as_path().abs());
    let clone = sqlite.clone();
    let is_nfs = sqlite.is_nfs().await?;
    tokio::fs::remove_dir(&sqlite_home).await?;
    // This clone has never queried the home. It must reuse the original's probe,
    // because a fresh filesystem lookup would fail now that the home is absent.
    assert_eq!(clone.is_nfs().await?, is_nfs);

    let fresh = SqliteConfig::new_for_testing(sqlite_home.as_path().abs());
    assert_eq!(
        fresh
            .is_nfs()
            .await
            .unwrap_err()
            .downcast_ref::<std::io::Error>()
            .unwrap()
            .kind(),
        std::io::ErrorKind::NotFound
    );
    Ok(())
}

#[cfg(target_os = "linux")]
#[tokio::test]
async fn failed_sqlite_home_filesystem_probe_recovers_after_home_creation() -> anyhow::Result<()> {
    let sqlite_home = crate::runtime::test_support::unique_temp_dir();
    let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
        let _ = std::fs::remove_dir_all(sqlite_home);
    });
    let sqlite = SqliteConfig::new_for_testing(sqlite_home.as_path().abs());
    assert_eq!(
        sqlite
            .is_nfs()
            .await
            .unwrap_err()
            .downcast_ref::<std::io::Error>()
            .unwrap()
            .kind(),
        std::io::ErrorKind::NotFound
    );
    tokio::fs::create_dir_all(&sqlite_home).await?;
    sqlite.is_nfs().await?;
    Ok(())
}

#[tokio::test]
async fn open_read_write_pool_initializes_fresh_database_settings() -> anyhow::Result<()> {
    for (enforced, nfs, partial_journal) in [
        (false, false, None),
        (false, false, Some(SqliteJournalMode::Delete)),
        (false, true, None),
        (false, true, Some(SqliteJournalMode::Delete)),
        (false, true, Some(SqliteJournalMode::Wal)),
        (true, false, None),
        (true, false, Some(SqliteJournalMode::Delete)),
        (true, cfg!(unix), None),
        (true, cfg!(unix), Some(SqliteJournalMode::Delete)),
    ] {
        let sqlite_home = crate::runtime::test_support::unique_temp_dir();
        tokio::fs::create_dir_all(&sqlite_home).await?;
        let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
            let _ = std::fs::remove_dir_all(sqlite_home);
        });
        let sqlite = SqliteConfig::from_sqlite_home_with_nfs_enforcement(
            sqlite_home.as_path().abs(),
            enforced,
        );
        sqlite.is_nfs.set(nfs)?;
        let path = sqlite.logs_db_path();
        if let Some(journal_mode) = partial_journal {
            // Startup must finish initialization when settings were written before the schema.
            let partial = SqlitePoolOptions::new()
                .max_connections(/*max*/ 1)
                .connect_with(
                    SqliteConnectOptions::new()
                        .filename(&path)
                        .create_if_missing(/*create*/ true)
                        .auto_vacuum(SqliteAutoVacuum::Incremental)
                        .journal_mode(journal_mode),
                )
                .await?;
            partial.close().await;
            assert!(tokio::fs::metadata(&path).await?.len() > 0);
        }
        let pool = sqlite.open_read_write_pool(&path).await?;
        // Hold connections open so the assertions cover lazy pool connections too.
        let mut connections = Vec::new();
        let mut settings = Vec::new();
        for _ in 0..5 {
            let mut connection = pool.acquire().await?;
            let current: (String, i64, i64) = sqlx::query_as(
                "SELECT journal_mode, auto_vacuum, synchronous
                 FROM pragma_journal_mode, pragma_auto_vacuum, pragma_synchronous",
            )
            .fetch_one(&mut *connection)
            .await?;
            settings.push(current);
            connections.push(connection);
        }
        assert_eq!(
            settings,
            vec![
                (
                    if nfs { "delete" } else { "wal" }.to_string(),
                    SqliteAutoVacuum::Incremental as i64,
                    if nfs { 3 } else { 1 },
                );
                5
            ]
        );
        drop(connections);
        pool.close().await;
    }
    Ok(())
}

#[tokio::test]
async fn open_read_write_pool_uses_database_directory_for_filesystem_probe() -> anyhow::Result<()> {
    let directory = crate::runtime::test_support::unique_temp_dir();
    tokio::fs::create_dir_all(&directory).await?;
    let _cleanup = scopeguard::guard(directory.clone(), |directory| {
        let _ = std::fs::remove_dir_all(directory);
    });
    let nfs = codex_file_system::is_nfs(&directory)?;
    let missing_home = directory.join("absent");
    for (index, cached_home_nfs) in [None, Some(!nfs)].into_iter().enumerate() {
        let sqlite = SqliteConfig::new_for_testing(missing_home.as_path().abs());
        if let Some(nfs) = cached_home_nfs {
            sqlite.is_nfs.set(nfs)?;
        }
        // An unrelated missing home or its cached filesystem must not affect this database.
        let path = directory.join(format!("database-{index}.sqlite"));
        let pool = sqlite.open_read_write_pool(&path).await?;
        let settings: (String, i64) = sqlx::query_as(
            "SELECT journal_mode, synchronous FROM pragma_journal_mode, pragma_synchronous",
        )
        .fetch_one(&pool)
        .await?;
        assert_eq!(
            settings,
            (
                if nfs { "delete" } else { "wal" }.to_string(),
                if nfs { 3 } else { 1 },
            )
        );
        pool.close().await;
    }
    Ok(())
}

#[tokio::test]
async fn open_read_write_pool_preserves_existing_settings_under_write_lock() -> anyhow::Result<()> {
    let sqlite_home = crate::runtime::test_support::unique_temp_dir();
    tokio::fs::create_dir_all(&sqlite_home).await?;
    let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
        let _ = std::fs::remove_dir_all(sqlite_home);
    });
    let sqlite = SqliteConfig::new_for_testing(sqlite_home.as_path().abs());
    sqlite.is_nfs.set(/*value*/ true)?;
    let database_path = sqlite.logs_db_path();
    let existing_pool = SqlitePoolOptions::new()
        .max_connections(1)
        .connect_with(
            SqliteConnectOptions::new()
                .filename(&database_path)
                .create_if_missing(true)
                .auto_vacuum(SqliteAutoVacuum::Full)
                .journal_mode(SqliteJournalMode::Wal),
        )
        .await?;
    sqlx::query("CREATE TABLE existing (id INTEGER PRIMARY KEY)")
        .execute(&existing_pool)
        .await?;

    let mut lock_holder = existing_pool.acquire().await?;
    sqlx::query("BEGIN IMMEDIATE")
        .execute(&mut *lock_holder)
        .await?;

    let pool = sqlite.open_read_write_pool(&database_path).await?;
    let settings: (String, i64, i64) = sqlx::query_as(
        "SELECT journal_mode, auto_vacuum, synchronous
         FROM pragma_journal_mode, pragma_auto_vacuum, pragma_synchronous",
    )
    .fetch_one(&pool)
    .await?;

    assert_eq!(settings, ("wal".into(), SqliteAutoVacuum::Full as i64, 1));
    sqlx::query("ROLLBACK").execute(&mut *lock_holder).await?;
    drop(lock_holder);
    pool.close().await;
    existing_pool.close().await;
    Ok(())
}

#[tokio::test]
async fn open_read_write_pool_preserves_delete_under_write_lock() -> anyhow::Result<()> {
    let sqlite_home = crate::runtime::test_support::unique_temp_dir();
    tokio::fs::create_dir_all(&sqlite_home).await?;
    let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
        let _ = std::fs::remove_dir_all(sqlite_home);
    });
    let sqlite = SqliteConfig::new_for_testing(sqlite_home.as_path().abs())
        .enable_delete_mode_on_nfs(/*enabled*/ true);
    sqlite.is_nfs.set(cfg!(unix))?;
    let database_path = sqlite.logs_db_path();
    let existing_pool = SqlitePoolOptions::new()
        .max_connections(1)
        .connect_with(
            SqliteConnectOptions::new()
                .filename(&database_path)
                .create_if_missing(true)
                .journal_mode(SqliteJournalMode::Delete),
        )
        .await?;
    sqlx::query("CREATE TABLE existing (id INTEGER PRIMARY KEY)")
        .execute(&existing_pool)
        .await?;
    let mut lock_holder = existing_pool.acquire().await?;
    sqlx::query("BEGIN IMMEDIATE")
        .execute(&mut *lock_holder)
        .await?;

    let pool = sqlite.open_read_write_pool(&database_path).await?;
    // Keep each acquired connection open to test connections that the pool initializes later.
    let mut connections = Vec::new();
    let mut settings = Vec::new();
    for _ in 0..5 {
        let mut connection = pool.acquire().await?;
        let journal: String = sqlx::query_scalar("PRAGMA journal_mode")
            .fetch_one(&mut *connection)
            .await?;
        let synchronous: i64 = sqlx::query_scalar("PRAGMA synchronous")
            .fetch_one(&mut *connection)
            .await?;
        settings.push((journal, synchronous));
        connections.push(connection);
    }
    assert_eq!(settings, vec![("delete".to_string(), 3); 5]);
    drop(connections);
    sqlx::query("ROLLBACK").execute(&mut *lock_holder).await?;
    drop(lock_holder);
    existing_pool.close().await;

    sqlx::query("INSERT INTO existing VALUES(42)")
        .execute(&pool)
        .await?;
    pool.close().await;
    let reopened = sqlite.open_read_write_pool(&database_path).await?;
    let journal: String = sqlx::query_scalar("PRAGMA journal_mode")
        .fetch_one(&reopened)
        .await?;
    let rows: Vec<i64> = sqlx::query_scalar("SELECT id FROM existing")
        .fetch_all(&reopened)
        .await?;
    assert_eq!((journal, rows), ("delete".into(), vec![42]));
    reopened.close().await;
    Ok(())
}

#[tokio::test]
async fn open_read_write_pool_preserves_empty_database_lock_error() -> anyhow::Result<()> {
    let sqlite_home = crate::runtime::test_support::unique_temp_dir();
    tokio::fs::create_dir_all(&sqlite_home).await?;
    let _cleanup = scopeguard::guard(sqlite_home.clone(), |sqlite_home| {
        let _ = std::fs::remove_dir_all(sqlite_home);
    });
    let sqlite = SqliteConfig::new_for_testing(sqlite_home.as_path().abs());
    let database_path = sqlite.logs_db_path();
    let existing_pool = SqlitePoolOptions::new()
        .max_connections(/*max*/ 1)
        .connect_with(
            SqliteConnectOptions::new()
                .filename(&database_path)
                .create_if_missing(/*create*/ true)
                .auto_vacuum(SqliteAutoVacuum::Incremental)
                .journal_mode(SqliteJournalMode::Delete),
        )
        .await?;
    // Leave the schema empty so startup must initialize WAL.
    let mut lock_holder = existing_pool.acquire().await?;
    sqlx::query("BEGIN IMMEDIATE")
        .execute(&mut *lock_holder)
        .await?;

    let error = sqlite
        .open_read_write_pool(&database_path)
        .await
        .expect_err("WAL setup must fail while another connection holds the writer lock");
    assert_eq!(
        error
            .downcast_ref::<sqlx::Error>()
            .and_then(sqlx::Error::as_database_error)
            .and_then(sqlx::error::DatabaseError::code),
        Some("5".into())
    );
    assert!(crate::sqlite_error_detail_is_lock(&error.to_string()));

    sqlx::query("ROLLBACK").execute(&mut *lock_holder).await?;
    // A failed opener must release its locks before another writer can proceed.
    sqlx::query("BEGIN EXCLUSIVE")
        .execute(&mut *lock_holder)
        .await?;
    sqlx::query("ROLLBACK").execute(&mut *lock_holder).await?;
    drop(lock_holder);
    existing_pool.close().await;

    let pool = sqlite.open_read_write_pool(&database_path).await?;
    sqlx::query("CREATE TABLE initialized (id INTEGER PRIMARY KEY)")
        .execute(&pool)
        .await?;
    let journal: String = sqlx::query_scalar("PRAGMA journal_mode")
        .fetch_one(&pool)
        .await?;
    assert_eq!(journal, "wal");
    pool.close().await;
    Ok(())
}

#[cfg(unix)]
#[tokio::test]
async fn required_nfs_migration_preserves_runtime_data_and_backups_after_restart()
-> anyhow::Result<()> {
    use std::os::unix::fs::PermissionsExt;

    let home = tempfile::tempdir()?;
    let original = SqliteConfig::new_for_testing(home.path().abs());
    let runtime = crate::StateRuntime::init(original.clone(), "test-provider".into()).await?;
    runtime.checkpoint_backfill("before-migration").await?;
    let before = runtime.get_backfill_state().await?;
    runtime.close().await;
    original.open_memories_v2_db().await?.close().await;
    crate::open_thread_history_db(&original)
        .await?
        .close()
        .await;
    let state_path = original.state_db_path();
    assert!(crate::NfsDbMigration::needs_migration(&state_path).await?);
    let bytes = std::fs::read(&state_path)?;
    std::fs::set_permissions(&state_path, std::fs::Permissions::from_mode(/*mode*/ 0o060))?;
    let staging = tempfile::tempdir()?;
    let result = crate::NfsDbMigration::lock(home.path())?
        .migrate(&state_path, staging.path())
        .await;
    std::fs::set_permissions(&state_path, std::fs::Permissions::from_mode(/*mode*/ 0o600))?;
    assert!(result.is_err());
    assert_eq!(std::fs::read(&state_path)?, bytes);
    let mut backups = Vec::new();
    for db in original
        .runtime_db_paths()
        .into_iter()
        .filter(|db| db.path.exists())
    {
        std::fs::set_permissions(&db.path, std::fs::Permissions::from_mode(/*mode*/ 0o644))?;
        let name = db.path.file_name().unwrap().to_str().unwrap();
        backups.push((
            home.path()
                .join(format!("{name}_wal_migration_backup"))
                .join(name),
            std::fs::read(&db.path)?,
        ));
    }
    let sqlite = SqliteConfig::from_sqlite_home_with_nfs_enforcement(
        home.path().abs(),
        /*enforce_delete_on_nfs*/ true,
    );
    sqlite.is_nfs.set(/*value*/ true)?;
    assert!(crate::NfsDbMigration::needs_permission_confirmation(
        &sqlite.state_db_path()
    )?);
    let migrated = crate::StateRuntime::init(sqlite.clone(), "test-provider".into()).await?;
    assert_eq!(migrated.get_backfill_state().await?, before);
    migrated.checkpoint_backfill("after-migration").await?;
    let after = migrated.get_backfill_state().await?;
    migrated.close().await;
    assert!(!crate::NfsDbMigration::needs_migration(&state_path).await?);

    // Simulate a crash after moving the original but before reinstalling a lazy database.
    let lazy = sqlite.memories_v2_db_path();
    let name = lazy.file_name().unwrap().to_str().unwrap();
    std::fs::rename(
        &lazy,
        home.path()
            .join(format!("{name}_wal_migration_backup/delete.sqlite")),
    )?;
    assert!(crate::NfsDbMigration::needs_permission_confirmation(&lazy)?);
    assert!(crate::NfsDbMigration::needs_migration(&lazy).await?);
    let restarted = crate::StateRuntime::init(sqlite.clone(), "test-provider".into()).await?;
    assert_eq!(restarted.get_backfill_state().await?, after);
    restarted.close().await;
    // Include lazily created databases: they must also start in DELETE mode.
    for db in sqlite.runtime_db_paths() {
        let pool = sqlite.open_read_write_pool(&db.path).await?;
        let settings: (String, i64) = sqlx::query_as(
            "SELECT journal_mode, synchronous FROM pragma_journal_mode, pragma_synchronous",
        )
        .fetch_one(&pool)
        .await?;
        assert_eq!(settings, ("delete".into(), 3));
        pool.close().await;
        if backups
            .iter()
            .any(|(backup, _)| backup.file_name() == db.path.file_name())
        {
            assert_eq!(
                std::fs::metadata(&db.path)?.permissions().mode() & 0o777,
                0o644
            );
        }
    }
    for (path, bytes) in backups {
        assert_eq!(std::fs::read(path)?, bytes);
    }
    Ok(())
}

#[cfg(unix)]
#[tokio::test]
async fn required_nfs_migration_refuses_active_wal_and_retries_after_close() -> anyhow::Result<()> {
    use std::future::Future;
    use std::os::unix::fs::PermissionsExt;
    use std::task::Poll;

    let home = tempfile::tempdir()?;
    let logs_home = home.path().join("local-logs");
    let sqlite =
        SqliteConfig::new_for_testing(home.path().abs()).with_local_logs_home(logs_home.clone());
    let logs = sqlite.open_read_write_pool(&sqlite.logs_db_path()).await?;
    sqlx::query("CREATE TABLE existing_logs (id INTEGER PRIMARY KEY)")
        .execute(&logs)
        .await?;
    let path = sqlite.state_db_path();
    let pool = sqlite.open_read_write_pool(&path).await?;
    sqlx::raw_sql("CREATE TABLE entries(id); INSERT INTO entries VALUES(42);")
        .execute(&pool)
        .await?;
    std::fs::set_permissions(&path, std::fs::Permissions::from_mode(/*mode*/ 0o600))?;
    let required = SqliteConfig::new_for_testing(home.path().abs())
        .with_local_logs_home(logs_home)
        .enable_delete_mode_on_nfs(/*enabled*/ true);
    required.is_nfs.set(/*value*/ true)?;
    required.logs_is_nfs.set(/*value*/ false)?;
    assert!(crate::NfsDbMigration::needs_migration(&path).await?);
    let error = required.open_read_write_pool(&path).await.unwrap_err();
    assert!(
        error
            .to_string()
            .contains("required NFS database migration failed"),
        "{error:#}"
    );
    assert!(!crate::is_sqlite_corruption_error(&error));
    pool.close().await;
    let migration_lock = crate::NfsDbMigration::lock(home.path())?;
    let mut opening = Box::pin(required.open_read_write_pool(&path));
    std::future::poll_fn(|cx| {
        assert!(opening.as_mut().poll(cx).is_pending());
        Poll::Ready(())
    })
    .await;
    drop(migration_lock);
    let migrated = opening.await?;
    let rows: Vec<i64> = sqlx::query_scalar("SELECT id FROM entries")
        .fetch_all(&migrated)
        .await?;
    assert_eq!(rows, vec![42]);
    migrated.close().await;
    // An active local logs database must remain in WAL while the NFS state database migrates.
    let journal: String = sqlx::query_scalar("PRAGMA journal_mode")
        .fetch_one(&logs)
        .await?;
    assert_eq!(journal, "wal");
    logs.close().await;
    // Old versions may create legacy WAL logs after startup. Managed cleanup must not write them.
    let legacy = sqlite
        .open_read_write_pool(&sqlite.legacy_logs_db_path().unwrap())
        .await?;
    assert!(required.open_legacy_logs_for_cleanup().await?.is_none());
    let journal: String = sqlx::query_scalar("PRAGMA journal_mode")
        .fetch_one(&legacy)
        .await?;
    assert_eq!(journal, "wal");
    legacy.close().await;
    Ok(())
}