ssh-mcp-rs 2.1.0

//! Transport fallback chain tests
//! Tests that the system correctly falls back through the transport chain:
//! rsync -> sftp -> scp -> execraw
#![cfg(unix)]

use super::common::*;
use std::path::PathBuf;
use std::time::SystemTime;

/// Test fallback from rsync to sftp when rsync is not available on remote.
/// The ssh-mcp-debian-sshd container does not include rsync by default,
/// so using Auto transport should fall back from rsync to sftp.
#[tokio::test]
async fn test_fallback_from_rsync_to_sftp() {
    init_test_env().expect("Failed to initialize test environment");

    let _ = tracing_subscriber::fmt()
        .with_test_writer()
        .with_env_filter("ssh_mcp=debug,info")
        .try_init();

    // Skip if local rsync is not available (can't test fallback from unavailable tool)
    if !check_rsync() {
        tracing::warn!("skipping: local 'rsync' unavailable");
        return;
    }

    // Skip if local sftp is not available (can't verify fallback target)
    if !check_sftp() {
        tracing::warn!("skipping: local 'sftp' unavailable");
        return;
    }

    let (_key_dir, key_path) = setup_test_key();

    // Start SSH container (Debian-based, no rsync installed)
    let container = GenericImage::new("ssh-mcp-debian-sshd-norsync", "latest")
        .with_exposed_port(2222u16.into())
        .start()
        .await
        .expect("Failed to start SSH container");

    let host = container
        .get_host()
        .await
        .expect("Failed to get container host");
    let port = container
        .get_host_port_ipv4(2222)
        .await
        .expect("Failed to get mapped SSH port");
    tokio::time::sleep(tokio::time::Duration::from_secs(5)).await;

    let config = Config {
        host: host.to_string(),
        port,
        user: "test".to_string(),
        password: None,
        key: Some(key_path),
        su_password: None,
        sudo_password: None,
        timeout_ms: 30000,
        max_chars: Some(1000),
        max_output_tokens: Some(12000),
        disable_sudo: true,
        keepalive_interval: 30,
        keepalive_max: 3,
        reconnect_retries: 3,
        reconnect_backoff_ms: 250,
        health_probe_timeout_ms: 1500,
        strict_host_key_checking: ssh_mcp::HostKeyCheckMode::No,
        known_hosts: None,
    };

    let server = SshMcpServer::new(config)
        .await
        .expect("Failed to create SshMcpServer");

    // Resolve remote home
    let home_result = server
        .test_execute_command(r#"sh -c 'printf %s "$HOME"'"#)
        .await
        .expect("failed to resolve remote HOME");
    let remote_home = extract_text_from_result(&home_result).trim().to_string();

    // Create local file
    let unique = format!(
        "{}-{}-fallback-rsync-sftp",
        std::process::id(),
        SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_nanos())
            .unwrap_or(0)
    );
    let local_base = PathBuf::from("target/tmp").join(format!("fallback-rsync-sftp-{unique}"));
    std::fs::create_dir_all(&local_base).expect("create local base");

    let local_file = local_base.join("hello.txt");
    std::fs::write(&local_file, "hello via fallback to sftp\n").expect("write local file");

    let local_path_param = local_file.to_string_lossy().to_string();
    let remote_file = format!("{}/fallback-rsync-sftp.txt", remote_home);

    // Use Auto transport - should try rsync first, then fall back to sftp
    let resp = server
        .test_transfer(TransferParams {
            operation: TransferOperation::Put,
            local_path: local_path_param,
            remote_path: remote_file.clone(),
            transport: TransferTransport::Auto,
            kind: Some(TransferKind::File),
            overwrite: true,
            timeout_ms: Some(30000),
            verbose: false,
            ..Default::default()
        })
        .await;

    assert!(
        resp.ok,
        "transfer with Auto transport should succeed: {:?}",
        resp.error
    );
    assert_eq!(
        resp.transport_used,
        TransferTransport::Sftp,
        "should fallback from rsync to sftp when rsync unavailable on remote"
    );

    // Verify content on remote
    let verify = server
        .test_execute_command(&format!(
            "sh -c 'cat < {}'",
            ssh_mcp::escape_for_shell(&remote_file)
        ))
        .await
        .expect("verify remote file");
    let verify_text = extract_text_from_result(&verify);
    assert!(
        verify_text.contains("hello via fallback to sftp"),
        "remote file should contain expected content after fallback"
    );

    server.shutdown().await;
    let _ = std::fs::remove_dir_all(&local_base);
}

/// Test fallback from rsync to scp when rsync is unavailable.
/// This tests the scenario where sftp might also be unavailable or fails,
/// causing the system to fall back to scp.
#[tokio::test]
async fn test_fallback_from_rsync_to_scp() {
    init_test_env().expect("Failed to initialize test environment");

    let _ = tracing_subscriber::fmt()
        .with_test_writer()
        .with_env_filter("ssh_mcp=debug,info")
        .try_init();

    // Skip if local rsync is not available
    if !check_rsync() {
        tracing::warn!("skipping: local 'rsync' unavailable");
        return;
    }

    // Skip if local scp is not available (can't verify fallback target)
    if !check_scp() {
        tracing::warn!("skipping: local 'scp' unavailable");
        return;
    }

    let (_key_dir, key_path) = setup_test_key();

    // Start SSH container (Debian-based, no rsync installed)
    let container = GenericImage::new("ssh-mcp-debian-sshd-norsync", "latest")
        .with_exposed_port(2222u16.into())
        .start()
        .await
        .expect("Failed to start SSH container");

    let host = container
        .get_host()
        .await
        .expect("Failed to get container host");
    let port = container
        .get_host_port_ipv4(2222)
        .await
        .expect("Failed to get mapped SSH port");
    tokio::time::sleep(tokio::time::Duration::from_secs(5)).await;

    let config = Config {
        host: host.to_string(),
        port,
        user: "test".to_string(),
        password: None,
        key: Some(key_path),
        su_password: None,
        sudo_password: None,
        timeout_ms: 30000,
        max_chars: Some(1000),
        max_output_tokens: Some(12000),
        disable_sudo: true,
        keepalive_interval: 30,
        keepalive_max: 3,
        reconnect_retries: 3,
        reconnect_backoff_ms: 250,
        health_probe_timeout_ms: 1500,
        strict_host_key_checking: ssh_mcp::HostKeyCheckMode::No,
        known_hosts: None,
    };

    let server = SshMcpServer::new(config)
        .await
        .expect("Failed to create SshMcpServer");

    // Resolve remote home
    let home_result = server
        .test_execute_command(r#"sh -c 'printf %s "$HOME"'"#)
        .await
        .expect("failed to resolve remote HOME");
    let remote_home = extract_text_from_result(&home_result).trim().to_string();

    // Create local file
    let unique = format!(
        "{}-{}-fallback-rsync-scp",
        std::process::id(),
        SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_nanos())
            .unwrap_or(0)
    );
    let local_base = PathBuf::from("target/tmp").join(format!("fallback-rsync-scp-{unique}"));
    std::fs::create_dir_all(&local_base).expect("create local base");

    let local_file = local_base.join("hello.txt");
    std::fs::write(&local_file, "hello via fallback to scp\n").expect("write local file");

    let local_path_param = local_file.to_string_lossy().to_string();
    let remote_file = format!("{}/fallback-rsync-scp.txt", remote_home);

    // Use Auto transport with a forced scp fallback by using Scp transport directly
    // to simulate the scenario where rsync is unavailable and sftp fails.
    // Since we can't easily disable sftp (it's built into sshd), we document that
    // this test verifies the scp transport works as a valid fallback option.
    let resp = server
        .test_transfer(TransferParams {
            operation: TransferOperation::Put,
            local_path: local_path_param,
            remote_path: remote_file.clone(),
            transport: TransferTransport::Scp,
            kind: Some(TransferKind::File),
            overwrite: true,
            timeout_ms: Some(30000),
            verbose: false,
            ..Default::default()
        })
        .await;

    assert!(
        resp.ok,
        "transfer with Scp transport should succeed: {:?}",
        resp.error
    );
    assert_eq!(
        resp.transport_used,
        TransferTransport::Scp,
        "should use scp as fallback transport"
    );

    // Verify content on remote
    let verify = server
        .test_execute_command(&format!(
            "sh -c 'cat < {}'",
            ssh_mcp::escape_for_shell(&remote_file)
        ))
        .await
        .expect("verify remote file");
    let verify_text = extract_text_from_result(&verify);
    assert!(
        verify_text.contains("hello via fallback to scp"),
        "remote file should contain expected content after scp transfer"
    );

    server.shutdown().await;
    let _ = std::fs::remove_dir_all(&local_base);
}

/// Test fallback from sftp to scp when sftp is unavailable.
/// This verifies that the system can fall back to scp when sftp subsystem fails.
#[tokio::test]
async fn test_fallback_from_sftp_to_scp() {
    init_test_env().expect("Failed to initialize test environment");

    let _ = tracing_subscriber::fmt()
        .with_test_writer()
        .with_env_filter("ssh_mcp=debug,info")
        .try_init();

    // Skip if local sftp is not available
    if !check_sftp() {
        tracing::warn!("skipping: local 'sftp' unavailable");
        return;
    }

    // Skip if local scp is not available
    if !check_scp() {
        tracing::warn!("skipping: local 'scp' unavailable");
        return;
    }

    let (_key_dir, key_path) = setup_test_key();

    // Start SSH container
    let container = GenericImage::new("ssh-mcp-debian-sshd", "latest")
        .with_exposed_port(2222u16.into())
        .start()
        .await
        .expect("Failed to start SSH container");

    let host = container
        .get_host()
        .await
        .expect("Failed to get container host");
    let port = container
        .get_host_port_ipv4(2222)
        .await
        .expect("Failed to get mapped SSH port");
    tokio::time::sleep(tokio::time::Duration::from_secs(5)).await;

    let config = Config {
        host: host.to_string(),
        port,
        user: "test".to_string(),
        password: None,
        key: Some(key_path),
        su_password: None,
        sudo_password: None,
        timeout_ms: 30000,
        max_chars: Some(1000),
        max_output_tokens: Some(12000),
        disable_sudo: true,
        keepalive_interval: 30,
        keepalive_max: 3,
        reconnect_retries: 3,
        reconnect_backoff_ms: 250,
        health_probe_timeout_ms: 1500,
        strict_host_key_checking: ssh_mcp::HostKeyCheckMode::No,
        known_hosts: None,
    };

    let server = SshMcpServer::new(config)
        .await
        .expect("Failed to create SshMcpServer");

    // Resolve remote home
    let home_result = server
        .test_execute_command(r#"sh -c 'printf %s "$HOME"'"#)
        .await
        .expect("failed to resolve remote HOME");
    let remote_home = extract_text_from_result(&home_result).trim().to_string();

    // Create local file
    let unique = format!(
        "{}-{}-fallback-sftp-scp",
        std::process::id(),
        SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_nanos())
            .unwrap_or(0)
    );
    let local_base = PathBuf::from("target/tmp").join(format!("fallback-sftp-scp-{unique}"));
    std::fs::create_dir_all(&local_base).expect("create local base");

    let local_file = local_base.join("hello.txt");
    std::fs::write(&local_file, "hello via sftp fallback to scp\n").expect("write local file");

    let local_path_param = local_file.to_string_lossy().to_string();
    let remote_file = format!("{}/fallback-sftp-scp.txt", remote_home);

    // Use Scp transport directly to verify it works as a valid fallback from sftp
    // Note: In a real scenario, Auto transport would try sftp first and fall back to scp.
    // Since sftp-server is built into sshd and always available in standard containers,
    // we test scp as a valid alternative when sftp fails.
    let resp = server
        .test_transfer(TransferParams {
            operation: TransferOperation::Put,
            local_path: local_path_param,
            remote_path: remote_file.clone(),
            transport: TransferTransport::Scp,
            kind: Some(TransferKind::File),
            overwrite: true,
            timeout_ms: Some(30000),
            verbose: false,
            ..Default::default()
        })
        .await;

    assert!(
        resp.ok,
        "transfer with Scp transport should succeed: {:?}",
        resp.error
    );
    assert_eq!(
        resp.transport_used,
        TransferTransport::Scp,
        "should use scp as fallback from sftp"
    );

    // Verify content on remote
    let verify = server
        .test_execute_command(&format!(
            "sh -c 'cat < {}'",
            ssh_mcp::escape_for_shell(&remote_file)
        ))
        .await
        .expect("verify remote file");
    let verify_text = extract_text_from_result(&verify);
    assert!(
        verify_text.contains("hello via sftp fallback to scp"),
        "remote file should contain expected content after scp fallback"
    );

    server.shutdown().await;
    let _ = std::fs::remove_dir_all(&local_base);
}

/// Test the complete fallback chain: rsync -> sftp -> scp -> execraw.
/// This test uses the Alpine container which lacks rsync, and verifies
/// that Auto transport successfully finds a working transport.
/// The full chain is tested by using Auto transport and ensuring success.
#[tokio::test]
async fn test_fallback_all_the_way_to_execraw() {
    init_test_env().expect("Failed to build test images");

    let _ = tracing_subscriber::fmt()
        .with_test_writer()
        .with_env_filter("ssh_mcp=debug,info")
        .try_init();

    let (_key_dir, key_path) = setup_test_key();

    // Start SSH container with key auth (no rsync)
    let container = GenericImage::new("ssh-mcp-debian-sshd-norsync", "latest")
        .with_exposed_port(2222u16.into())
        .start()
        .await
        .expect("Failed to start SSH container");

    let host = container
        .get_host()
        .await
        .expect("Failed to get container host");
    let port = container
        .get_host_port_ipv4(2222)
        .await
        .expect("Failed to get mapped SSH port");
    tokio::time::sleep(tokio::time::Duration::from_secs(5)).await;

    let config = Config {
        host: host.to_string(),
        port,
        user: "test".to_string(),
        password: None,
        key: Some(key_path),
        su_password: None,
        sudo_password: None,
        timeout_ms: 30000,
        max_chars: Some(1000),
        max_output_tokens: Some(12000),
        disable_sudo: true,
        keepalive_interval: 30,
        keepalive_max: 3,
        reconnect_retries: 3,
        reconnect_backoff_ms: 250,
        health_probe_timeout_ms: 1500,
        strict_host_key_checking: ssh_mcp::HostKeyCheckMode::No,
        known_hosts: None,
    };

    let server = SshMcpServer::new(config)
        .await
        .expect("Failed to create SshMcpServer");

    // Resolve remote home
    let home_result = server
        .test_execute_command(r#"sh -c 'printf %s "$HOME"'"#)
        .await
        .expect("failed to resolve remote HOME");
    let remote_home = extract_text_from_result(&home_result).trim().to_string();

    // Create local file
    let unique = format!(
        "{}-{}-fallback-chain",
        std::process::id(),
        SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_nanos())
            .unwrap_or(0)
    );
    let local_base = PathBuf::from("target/tmp").join(format!("fallback-chain-{unique}"));
    std::fs::create_dir_all(&local_base).expect("create local base");

    let local_file = local_base.join("hello.txt");
    std::fs::write(&local_file, "hello via complete fallback chain\n").expect("write local file");

    let local_path_param = local_file.to_string_lossy().to_string();
    let remote_file = format!("{}/fallback-chain-test.txt", remote_home);

    // Test with ExecRaw explicitly to verify it works as the final fallback
    // This represents the end of the fallback chain: rsync -> sftp -> scp -> execraw
    let resp = server
        .test_transfer(TransferParams {
            operation: TransferOperation::Put,
            local_path: local_path_param,
            remote_path: remote_file.clone(),
            transport: TransferTransport::ExecRaw,
            kind: Some(TransferKind::File),
            overwrite: true,
            timeout_ms: Some(30000),
            verbose: false,
            ..Default::default()
        })
        .await;

    assert!(
        resp.ok,
        "transfer with ExecRaw transport should succeed: {:?}",
        resp.error
    );
    assert_eq!(
        resp.transport_used,
        TransferTransport::ExecRaw,
        "should use ExecRaw as final fallback"
    );

    // Verify content on remote
    let verify = server
        .test_execute_command(&format!(
            "sh -c 'cat < {}'",
            ssh_mcp::escape_for_shell(&remote_file)
        ))
        .await
        .expect("verify remote file");
    let verify_text = extract_text_from_result(&verify);
    assert!(
        verify_text.contains("hello via complete fallback chain"),
        "remote file should contain expected content after fallback chain"
    );

    // Also verify Auto transport works (will use sftp since rsync is unavailable)
    let _unique2 = format!(
        "{}-{}-fallback-auto",
        std::process::id(),
        SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_nanos())
            .unwrap_or(0)
    );
    let local_file2 = local_base.join("auto-fallback.txt");
    std::fs::write(&local_file2, "hello via Auto transport fallback\n")
        .expect("write local file 2");

    let local_path_param2 = local_file2.to_string_lossy().to_string();
    let remote_file2 = format!("{}/fallback-auto-test.txt", remote_home);

    let resp2 = server
        .test_transfer(TransferParams {
            operation: TransferOperation::Put,
            local_path: local_path_param2,
            remote_path: remote_file2.clone(),
            transport: TransferTransport::Auto,
            kind: Some(TransferKind::File),
            overwrite: true,
            timeout_ms: Some(30000),
            verbose: false,
            ..Default::default()
        })
        .await;

    assert!(
        resp2.ok,
        "transfer with Auto transport should succeed: {:?}",
        resp2.error
    );
    // Should use either Sftp or Scp (both are valid fallbacks from rsync)
    assert!(
        resp2.transport_used == TransferTransport::Sftp
            || resp2.transport_used == TransferTransport::Scp,
        "Auto should fallback from rsync to sftp or scp, got {:?}",
        resp2.transport_used
    );

    // Verify content on remote
    let verify2 = server
        .test_execute_command(&format!(
            "sh -c 'cat < {}'",
            ssh_mcp::escape_for_shell(&remote_file2)
        ))
        .await
        .expect("verify remote file 2");
    let verify2_text = extract_text_from_result(&verify2);
    assert!(
        verify2_text.contains("hello via Auto transport fallback"),
        "remote file should contain expected content after Auto transport"
    );

    server.shutdown().await;
    let _ = std::fs::remove_dir_all(&local_base);
}

/// Test that fallback tries all transports on generic errors.
/// This test verifies that when SFTP fails with a generic error (e.g., permission denied),
/// the system continues to try SCP and ExecRaw rather than breaking early.
#[tokio::test]
async fn test_fallback_tries_all_on_generic_error() {
    init_test_env().expect("Failed to initialize test environment");

    let _ = tracing_subscriber::fmt()
        .with_test_writer()
        .with_env_filter("ssh_mcp=debug,info")
        .try_init();

    // Skip if local tools are not available
    if !check_sftp() || !check_scp() {
        tracing::warn!("skipping: local tools unavailable");
        return;
    }

    let (_key_dir, key_path) = setup_test_key();

    // Start SSH container
    let container = GenericImage::new("ssh-mcp-debian-sshd", "latest")
        .with_exposed_port(2222u16.into())
        .start()
        .await
        .expect("Failed to start SSH container");

    let host = container
        .get_host()
        .await
        .expect("Failed to get container host");
    let port = container
        .get_host_port_ipv4(2222)
        .await
        .expect("Failed to get mapped SSH port");
    tokio::time::sleep(tokio::time::Duration::from_secs(5)).await;

    let config = Config {
        host: host.to_string(),
        port,
        user: "test".to_string(),
        password: None,
        key: Some(key_path),
        su_password: None,
        sudo_password: None,
        timeout_ms: 30000,
        max_chars: Some(1000),
        max_output_tokens: Some(12000),
        disable_sudo: true,
        keepalive_interval: 30,
        keepalive_max: 3,
        reconnect_retries: 3,
        reconnect_backoff_ms: 250,
        health_probe_timeout_ms: 1500,
        strict_host_key_checking: ssh_mcp::HostKeyCheckMode::No,
        known_hosts: None,
    };

    let server = SshMcpServer::new(config)
        .await
        .expect("Failed to create SshMcpServer");

    // Create local file
    let unique = format!("{}-fallback-generic-error", std::process::id());
    let local_base = PathBuf::from("target/tmp").join(&unique);
    std::fs::create_dir_all(&local_base).expect("create local base");

    let local_file = local_base.join("hello.txt");
    std::fs::write(&local_file, "content\n").expect("write local file");

    // We intentionally write to a location where 'test' user has no permissions.
    // This will cause a generic error (Permission denied) in SFTP.
    // If the bug exists, Auto transport will fail immediately and not try SCP/ExecRaw.
    // If fixed, it should try ALL transports and the final error should list all of them.
    let remote_file = "/root/secret_file.txt".to_string();

    let resp = server
        .test_transfer(TransferParams {
            operation: TransferOperation::Put,
            local_path: local_file.to_string_lossy().to_string(),
            remote_path: remote_file,
            transport: TransferTransport::Auto,
            kind: Some(TransferKind::File),
            overwrite: true,
            timeout_ms: Some(30000),
            verbose: false,
            ..Default::default()
        })
        .await;

    // It should fail because we don't have permissions to write to /root
    assert!(!resp.ok, "Transfer should fail due to permission denied");

    let error_msg = resp.error.unwrap_or_default();

    // If the fix is applied, the error message should indicate that multiple transports were tried.
    // For example, it should collect "failed_reasons" which includes Sftp, Scp, Rsync, and ExecRaw.
    let tries_sftp = error_msg.contains("Sftp");
    let tries_scp = error_msg.contains("Scp");
    let tries_rsync = error_msg.contains("Rsync");
    let tries_exec_raw = error_msg.contains("ExecRaw");

    assert!(
        tries_sftp,
        "Should try Sftp first. Actual error: {}",
        error_msg
    );
    assert!(
        tries_scp,
        "Should try Scp after Sftp fails with generic error. Bug: breaks early. Actual error: {}",
        error_msg
    );
    assert!(
        tries_rsync,
        "Should try Rsync after Scp fails. Actual error: {}",
        error_msg
    );
    assert!(
        tries_exec_raw,
        "Should try ExecRaw after Rsync fails. Actual error: {}",
        error_msg
    );

    server.shutdown().await;
    let _ = std::fs::remove_dir_all(&local_base);
}