"""Comprehensive FTP test suite for BambuFTPClient.

Tests against a real mock implicit FTPS server, covering:
- Connection (auth, SSL modes, timeout, caching)
- File listing
- Download (bytes, to_file, 0-byte regression)
- Upload (chunked transfer, progress, error codes)
- Delete
- File size
- Storage info (AVBL, directory scan, diagnose_storage)
- Model-specific behavior (X1C prot_p, A1 prot_c fallback)
- Async wrappers
- Failure injection scenarios (regressions for 0.1.8 bugs)
"""

import time
from pathlib import Path

import pytest

from backend.app.services.bambu_ftp import (
    BambuFTPClient,
    FileNotOnPrinterError,
    cache_3mf_download,
    clear_3mf_cache,
    delete_file_async,
    download_file_async,
    download_file_try_paths_async,
    get_cached_3mf,
    list_files_async,
    normalize_3mf_name,
    upload_file_async,
    with_ftp_retry,
)

# Brief delay to allow pyftpdlib to flush uploaded files to disk.
# Needed because upload_file() skips voidresp() for all models,
# so the server may still be processing the data channel close event.
_UPLOAD_FLUSH_DELAY = 0.3


# ---------------------------------------------------------------------------
# TestConnection
# ---------------------------------------------------------------------------
class TestConnection:
    """Tests for FTP connect/disconnect behavior."""

    def test_connect_success(self, ftp_client_factory):
        """Successful implicit FTPS connection and login."""
        client = ftp_client_factory()
        assert client.connect() is True
        client.disconnect()

    def test_connect_wrong_access_code(self, ftp_client_factory):
        """Wrong access code returns False."""
        client = ftp_client_factory(access_code="wrongcode")
        assert client.connect() is False

    def test_connect_unreachable_host(self, ftp_server):
        """Unreachable host returns False."""
        client = BambuFTPClient(
            ip_address="192.0.2.1",  # TEST-NET, guaranteed unreachable
            access_code="12345678",
            timeout=1.0,
            printer_model="X1C",
        )
        client.FTP_PORT = ftp_server.port
        assert client.connect() is False

    def test_connect_timeout(self, ftp_server):
        """Very short timeout triggers timeout error."""
        client = BambuFTPClient(
            ip_address="192.0.2.1",
            access_code="12345678",
            timeout=0.001,  # Extremely short
            printer_model="X1C",
        )
        client.FTP_PORT = ftp_server.port
        assert client.connect() is False

    def test_disconnect_clean(self, ftp_client_factory):
        """Clean disconnect after successful connect."""
        client = ftp_client_factory()
        client.connect()
        client.disconnect()
        assert client._ftp is None

    def test_disconnect_without_connect(self, ftp_client_factory):
        """Disconnect without connect does not raise."""
        client = ftp_client_factory()
        client.disconnect()  # Should not raise
        assert client._ftp is None

    def test_x1c_uses_prot_p(self, ftp_client_factory):
        """X1C model connects with prot_p (protected data channel)."""
        client = ftp_client_factory(printer_model="X1C")
        assert client.connect() is True
        assert client._should_use_prot_c() is False
        client.disconnect()

    def test_a1_defaults_prot_p(self, ftp_client_factory):
        """A1 model defaults to prot_p when no cache exists."""
        client = ftp_client_factory(printer_model="A1")
        assert client._should_use_prot_c() is False
        assert client.connect() is True
        client.disconnect()

    def test_a1_force_prot_c(self, ftp_client_factory):
        """A1 model with force_prot_c uses clear data channel."""
        client = ftp_client_factory(printer_model="A1", force_prot_c=True)
        assert client._should_use_prot_c() is True
        assert client.connect() is True
        client.disconnect()

    def test_cached_mode_respected(self, ftp_client_factory):
        """Cached mode is used on subsequent connections."""
        BambuFTPClient.cache_mode("127.0.0.1", "prot_c")
        client = ftp_client_factory(printer_model="A1")
        assert client._should_use_prot_c() is True
        assert client.connect() is True
        client.disconnect()


# ---------------------------------------------------------------------------
# TestDisconnectServerGone — isolated class because server.stop() calls
# close_all() which nukes all asyncore sockets globally.
# ---------------------------------------------------------------------------
class TestDisconnectServerGone:
    """Test disconnect behavior when the server has stopped."""

    def test_disconnect_after_server_gone(self, ftp_certs, tmp_path):
        """Disconnect after server has stopped does not raise.

        disconnect() catches OSError, ftplib.Error, and EOFError so that
        best-effort cleanup never propagates exceptions to the caller.
        """
        from backend.tests.unit.services.mock_ftp_server import (
            MockBambuFTPServer,
        )

        from .conftest import _find_free_port

        cert_path, key_path = ftp_certs
        port = _find_free_port()
        server = MockBambuFTPServer("127.0.0.1", port, str(tmp_path), cert_path, key_path)
        server.start()

        client = BambuFTPClient("127.0.0.1", "12345678", timeout=5.0)
        client.FTP_PORT = port
        client.connect()

        server.stop()
        # Should not raise — disconnect() catches all connection errors
        client.disconnect()
        assert client._ftp is None


# ---------------------------------------------------------------------------
# TestListFiles
# ---------------------------------------------------------------------------
class TestListFiles:
    """Tests for directory listing."""

    def test_list_empty_directory(self, ftp_client_factory):
        """Listing an empty directory returns empty list."""
        client = ftp_client_factory()
        client.connect()
        files = client.list_files("/cache")
        assert files == []
        client.disconnect()

    def test_list_directory_with_files(self, ftp_client_factory, ftp_server):
        """Files in directory are listed correctly."""
        ftp_server.add_file("cache/test.3mf", b"x" * 1024)
        ftp_server.add_file("cache/test2.gcode", b"y" * 512)
        client = ftp_client_factory()
        client.connect()
        files = client.list_files("/cache")
        names = {f["name"] for f in files}
        assert "test.3mf" in names
        assert "test2.gcode" in names
        client.disconnect()

    def test_directories_marked(self, ftp_client_factory, ftp_server):
        """Subdirectories are identified with is_directory=True."""
        ftp_server.add_directory("model/subdir")
        client = ftp_client_factory()
        client.connect()
        files = client.list_files("/model")
        dirs = [f for f in files if f["is_directory"]]
        assert len(dirs) >= 1
        assert dirs[0]["name"] == "subdir"
        client.disconnect()

    def test_nonexistent_path_returns_empty(self, ftp_client_factory):
        """Listing a nonexistent path returns empty list."""
        client = ftp_client_factory()
        client.connect()
        files = client.list_files("/nonexistent/path")
        assert files == []
        client.disconnect()

    def test_file_sizes_and_paths(self, ftp_client_factory, ftp_server):
        """File sizes and full paths are parsed correctly."""
        ftp_server.add_file("cache/sized.bin", b"a" * 2048)
        client = ftp_client_factory()
        client.connect()
        files = client.list_files("/cache")
        sized = [f for f in files if f["name"] == "sized.bin"]
        assert len(sized) == 1
        assert sized[0]["size"] == 2048
        assert sized[0]["path"] == "/cache/sized.bin"
        client.disconnect()


# ---------------------------------------------------------------------------
# TestDownload
# ---------------------------------------------------------------------------
class TestDownload:
    """Tests for file download operations."""

    def test_download_file_returns_bytes(self, ftp_client_factory, ftp_server):
        """download_file() returns file content as bytes."""
        content = b"Hello FTP World!"
        ftp_server.add_file("cache/hello.txt", content)
        client = ftp_client_factory()
        client.connect()
        result = client.download_file("/cache/hello.txt")
        assert result == content
        client.disconnect()

    def test_download_file_missing(self, ftp_client_factory):
        """download_file() returns None for missing file."""
        client = ftp_client_factory()
        client.connect()
        result = client.download_file("/cache/does_not_exist.txt")
        assert result is None
        client.disconnect()

    def test_download_to_file_writes_to_disk(self, ftp_client_factory, ftp_server, tmp_path):
        """download_to_file() writes content to local filesystem."""
        content = b"Downloaded content"
        ftp_server.add_file("cache/dl.bin", content)
        local = tmp_path / "output" / "dl.bin"
        client = ftp_client_factory()
        client.connect()
        result = client.download_to_file("/cache/dl.bin", local)
        assert result is True
        assert local.read_bytes() == content
        client.disconnect()

    def test_download_to_file_creates_parent_dirs(self, ftp_client_factory, ftp_server, tmp_path):
        """download_to_file() creates parent directories automatically."""
        ftp_server.add_file("cache/nested.txt", b"nested content")
        local = tmp_path / "deep" / "nested" / "path" / "nested.txt"
        client = ftp_client_factory()
        client.connect()
        result = client.download_to_file("/cache/nested.txt", local)
        assert result is True
        assert local.exists()
        client.disconnect()

    def test_zero_byte_download_returns_false(self, ftp_client_factory, ftp_server, tmp_path):
        """0-byte download returns False and cleans up (regression test)."""
        ftp_server.add_file("cache/empty.bin", b"")
        local = tmp_path / "empty.bin"
        client = ftp_client_factory()
        client.connect()
        result = client.download_to_file("/cache/empty.bin", local)
        assert result is False
        assert not local.exists()
        client.disconnect()

    def test_download_to_file_missing_raises_not_on_printer(self, ftp_client_factory, tmp_path):
        """Missing file raises FileNotOnPrinterError so callers can short-circuit
        the retry loop — 550 means the file isn't there and retrying won't help."""
        from backend.app.services.bambu_ftp import FileNotOnPrinterError

        local = tmp_path / "missing.bin"
        client = ftp_client_factory()
        client.connect()
        try:
            with pytest.raises(FileNotOnPrinterError):
                client.download_to_file("/cache/no_such_file.bin", local)
        finally:
            client.disconnect()

    def test_download_large_file(self, ftp_client_factory, ftp_server):
        """Large file download (>1MB) works correctly."""
        large_content = b"X" * (1024 * 1024 + 500)  # ~1MB + 500 bytes
        ftp_server.add_file("cache/large.bin", large_content)
        client = ftp_client_factory()
        client.connect()
        result = client.download_file("/cache/large.bin")
        assert result == large_content
        client.disconnect()

    def test_download_not_connected(self):
        """download_file() returns None when not connected."""
        client = BambuFTPClient("127.0.0.1", "12345678")
        assert client.download_file("/cache/test.bin") is None


# ---------------------------------------------------------------------------
# TestUpload
# ---------------------------------------------------------------------------
class TestUpload:
    """Tests for file upload operations."""

    def test_upload_success(self, ftp_client_factory, ftp_server, tmp_path):
        """Successful upload via transfercmd (not storbinary)."""
        content = b"Upload test content"
        local = tmp_path / "upload.3mf"
        local.write_bytes(content)
        client = ftp_client_factory()
        client.connect()
        result = client.upload_file(local, "/cache/upload.3mf")
        assert result is True
        client.disconnect()
        # Verify via fresh connection (upload_file skips voidresp() for all
        # models, so the original session can't be reused for download)
        time.sleep(_UPLOAD_FLUSH_DELAY)
        client2 = ftp_client_factory()
        client2.connect()
        downloaded = client2.download_file("/cache/upload.3mf")
        assert downloaded == content
        client2.disconnect()

    def test_upload_progress_callback(self, ftp_client_factory, ftp_server, tmp_path):
        """Progress callback receives updates during upload."""
        content = b"P" * 2048
        local = tmp_path / "progress.bin"
        local.write_bytes(content)

        progress_calls = []

        def on_progress(uploaded, total):
            progress_calls.append((uploaded, total))

        client = ftp_client_factory()
        client.connect()
        client.upload_file(local, "/cache/progress.bin", on_progress)
        assert len(progress_calls) >= 1
        # Last call should report full file uploaded
        assert progress_calls[-1][0] == len(content)
        assert progress_calls[-1][1] == len(content)
        client.disconnect()

    def test_upload_not_connected(self, tmp_path):
        """Upload when not connected returns False."""
        local = tmp_path / "test.bin"
        local.write_bytes(b"data")
        client = BambuFTPClient("127.0.0.1", "12345678")
        assert client.upload_file(local, "/cache/test.bin") is False

    def test_upload_553_no_sd_card(self, ftp_client_factory, ftp_server, tmp_path):
        """553 error (no SD card) returns False."""
        ftp_server.inject_failure("STOR", 553, "Could not create file.")
        local = tmp_path / "test.bin"
        local.write_bytes(b"data")
        client = ftp_client_factory()
        client.connect()
        result = client.upload_file(local, "/cache/test.bin")
        assert result is False
        client.disconnect()

    def test_upload_550_permission_denied(self, ftp_client_factory, ftp_server, tmp_path):
        """550 error (permission denied) returns False."""
        ftp_server.inject_failure("STOR", 550, "Permission denied.")
        local = tmp_path / "test.bin"
        local.write_bytes(b"data")
        client = ftp_client_factory()
        client.connect()
        result = client.upload_file(local, "/cache/test.bin")
        assert result is False
        client.disconnect()

    def test_upload_552_storage_full(self, ftp_client_factory, ftp_server, tmp_path):
        """552 error (storage full) returns False."""
        ftp_server.inject_failure("STOR", 552, "Storage quota exceeded.")
        local = tmp_path / "test.bin"
        local.write_bytes(b"data")
        client = ftp_client_factory()
        client.connect()
        result = client.upload_file(local, "/cache/test.bin")
        assert result is False
        client.disconnect()

    def test_upload_426_data_stream_failure_returns_false(self, ftp_client_factory, ftp_server, tmp_path):
        """426 'Failure reading network stream' from voidresp() must fail.

        Regression for #1401: P2S firmware 01.02.00.00 (and possibly other
        Bambu firmware revisions) returns 426 after the data channel closes,
        indicating the printer received only a partial file. Previously the
        client logged a warning and returned True, so the dispatcher sent a
        print command for a truncated 3MF and the printer surfaced a
        confusing 'unable to parse 3mf file' error. The 426 must instead
        cause the upload to return False.
        """
        import ftplib

        local = tmp_path / "test.bin"
        local.write_bytes(b"data" * 256)
        client = ftp_client_factory()
        client.connect()

        def raise_426():
            raise ftplib.error_temp("426 Failure reading network stream.")

        client._ftp.voidresp = raise_426

        result = client.upload_file(local, "/cache/test.bin")
        assert result is False, "Upload must fail on 426 to prevent dispatching a truncated file"
        client.disconnect()

    def test_upload_bytes_426_data_stream_failure_returns_false(self, ftp_client_factory, ftp_server):
        """upload_bytes() also fails on 426 (same root cause as upload_file)."""
        import ftplib

        client = ftp_client_factory()
        client.connect()

        def raise_426():
            raise ftplib.error_temp("426 Failure reading network stream.")

        client._ftp.voidresp = raise_426

        result = client.upload_bytes(b"x" * 1024, "/cache/bytes.bin")
        assert result is False
        client.disconnect()

    def test_upload_bytes_success(self, ftp_client_factory, ftp_server):
        """upload_bytes() writes data to server."""
        data = b"Bytes upload content"
        client = ftp_client_factory()
        client.connect()
        result = client.upload_bytes(data, "/cache/bytes.bin")
        assert result is True
        client.disconnect()
        # Verify via fresh connection
        time.sleep(_UPLOAD_FLUSH_DELAY)
        client2 = ftp_client_factory()
        client2.connect()
        downloaded = client2.download_file("/cache/bytes.bin")
        assert downloaded == data
        client2.disconnect()

    def test_upload_bytes_failure(self, ftp_client_factory, ftp_server):
        """upload_bytes() returns False on STOR failure."""
        ftp_server.inject_failure("STOR", 553, "No space.")
        client = ftp_client_factory()
        client.connect()
        result = client.upload_bytes(b"data", "/cache/fail.bin")
        assert result is False
        client.disconnect()

    def test_upload_large_chunked(self, ftp_client_factory, ftp_server, tmp_path):
        """Large file upload in chunks completes without error.

        Uses 2.5MB to trigger multiple chunks with 64KB CHUNK_SIZE.
        Content verification skipped because upload_file() skips
        voidresp() for all models, so the server may still be flushing
        when we check. The upload result=True confirms the client sent
        all chunks without error.
        """
        content = b"C" * (1024 * 1024 * 2 + 512 * 1024)
        local = tmp_path / "large.bin"
        local.write_bytes(content)

        progress_calls = []

        def on_progress(uploaded, total):
            progress_calls.append((uploaded, total))

        client = ftp_client_factory()
        client.connect()
        result = client.upload_file(local, "/cache/large.bin", on_progress)
        assert result is True
        # Verify many chunks were sent (2.5MB / 64KB = 40 chunks)
        assert len(progress_calls) >= 38
        assert progress_calls[-1][0] == len(content)
        client.disconnect()


# ---------------------------------------------------------------------------
# TestDelete
# ---------------------------------------------------------------------------
class TestDelete:
    """Tests for file deletion."""

    def test_delete_success(self, ftp_client_factory, ftp_server):
        """Successful file deletion."""
        ftp_server.add_file("cache/to_delete.bin", b"delete me")
        client = ftp_client_factory()
        client.connect()
        result = client.delete_file("/cache/to_delete.bin")
        assert result is True
        assert not ftp_server.file_exists("cache/to_delete.bin")
        client.disconnect()

    def test_delete_not_found(self, ftp_client_factory):
        """Deleting a nonexistent file returns False."""
        client = ftp_client_factory()
        client.connect()
        result = client.delete_file("/cache/no_such_file.bin")
        assert result is False
        client.disconnect()

    def test_delete_not_connected(self):
        """Delete when not connected returns False."""
        client = BambuFTPClient("127.0.0.1", "12345678")
        assert client.delete_file("/cache/test.bin") is False


# ---------------------------------------------------------------------------
# TestFileSize
# ---------------------------------------------------------------------------
class TestFileSize:
    """Tests for get_file_size."""

    def test_file_size_correct(self, ftp_client_factory, ftp_server):
        """Returns correct file size."""
        ftp_server.add_file("cache/sized.bin", b"a" * 4096)
        client = ftp_client_factory()
        client.connect()
        size = client.get_file_size("/cache/sized.bin")
        assert size == 4096
        client.disconnect()

    def test_file_size_missing(self, ftp_client_factory):
        """Returns None for missing file."""
        client = ftp_client_factory()
        client.connect()
        size = client.get_file_size("/cache/no_file.bin")
        assert size is None
        client.disconnect()

    def test_file_size_not_connected(self):
        """Returns None when not connected."""
        client = BambuFTPClient("127.0.0.1", "12345678")
        assert client.get_file_size("/cache/test.bin") is None


# ---------------------------------------------------------------------------
# TestStorageInfo
# ---------------------------------------------------------------------------
class TestStorageInfo:
    """Tests for storage info and diagnostics."""

    def test_avbl_parsed(self, ftp_client_factory, ftp_server):
        """AVBL response is parsed for free_bytes."""
        ftp_server.set_avbl_bytes(5000000000)
        client = ftp_client_factory()
        client.connect()
        info = client.get_storage_info()
        assert info is not None
        assert info["free_bytes"] == 5000000000
        client.disconnect()

    def test_used_bytes_from_scan(self, ftp_client_factory, ftp_server):
        """used_bytes calculated from directory scan."""
        ftp_server.add_file("cache/file1.bin", b"a" * 1000)
        ftp_server.add_file("cache/file2.bin", b"b" * 2000)
        client = ftp_client_factory()
        client.connect()
        info = client.get_storage_info()
        assert info is not None
        assert info["used_bytes"] >= 3000  # At least these two files
        client.disconnect()

    def test_storage_info_not_connected(self):
        """Returns None when not connected."""
        client = BambuFTPClient("127.0.0.1", "12345678")
        assert client.get_storage_info() is None

    def test_diagnose_storage_success(self, ftp_client_factory, ftp_server):
        """diagnose_storage() returns connected=True with working diagnostics."""
        client = ftp_client_factory()
        client.connect()
        diag = client.diagnose_storage()
        assert diag["connected"] is True
        assert diag["can_list_root"] is True
        assert diag["can_list_cache"] is True
        assert diag["pwd"] is not None
        assert diag["storage_info"] is not None
        client.disconnect()

    def test_diagnose_storage_not_connected(self):
        """diagnose_storage() reports not connected."""
        client = BambuFTPClient("127.0.0.1", "12345678")
        diag = client.diagnose_storage()
        assert diag["connected"] is False
        assert "FTP not connected" in diag["errors"]


# ---------------------------------------------------------------------------
# TestModelSpecificBehavior
# ---------------------------------------------------------------------------
class TestModelSpecificBehavior:
    """Tests for printer model-specific FTP behavior."""

    def test_x1c_upload(self, ftp_client_factory, ftp_server, tmp_path):
        """X1C upload with session reuse succeeds."""
        content = b"X1C upload data"
        local = tmp_path / "x1c.3mf"
        local.write_bytes(content)
        client = ftp_client_factory(printer_model="X1C")
        client.connect()
        result = client.upload_file(local, "/cache/x1c.3mf")
        assert result is True
        client.disconnect()
        # Verify via fresh connection
        time.sleep(_UPLOAD_FLUSH_DELAY)
        client2 = ftp_client_factory(printer_model="X1C")
        client2.connect()
        downloaded = client2.download_file("/cache/x1c.3mf")
        assert downloaded == content
        client2.disconnect()

    def test_a1_upload_prot_c(self, ftp_client_factory, ftp_server, tmp_path):
        """A1 model upload with prot_c succeeds."""
        content = b"A1 upload data"
        local = tmp_path / "a1.3mf"
        local.write_bytes(content)
        client = ftp_client_factory(printer_model="A1", force_prot_c=True)
        client.connect()
        result = client.upload_file(local, "/cache/a1.3mf")
        assert result is True
        client.disconnect()
        # Verify via fresh connection
        time.sleep(_UPLOAD_FLUSH_DELAY)
        client2 = ftp_client_factory(printer_model="A1", force_prot_c=True)
        client2.connect()
        downloaded = client2.download_file("/cache/a1.3mf")
        assert downloaded == content
        client2.disconnect()

    def test_a1_mini_upload(self, ftp_client_factory, ftp_server, tmp_path):
        """A1 Mini model upload succeeds."""
        content = b"A1 Mini data"
        local = tmp_path / "a1mini.3mf"
        local.write_bytes(content)
        client = ftp_client_factory(printer_model="A1 Mini", force_prot_c=True)
        client.connect()
        result = client.upload_file(local, "/cache/a1mini.3mf")
        assert result is True
        client.disconnect()

    def test_p1s_upload(self, ftp_client_factory, ftp_server, tmp_path):
        """P1S model upload with session reuse succeeds."""
        content = b"P1S upload data"
        local = tmp_path / "p1s.3mf"
        local.write_bytes(content)
        client = ftp_client_factory(printer_model="P1S")
        client.connect()
        result = client.upload_file(local, "/cache/p1s.3mf")
        assert result is True
        client.disconnect()

    def test_unknown_model_defaults_prot_p(self, ftp_client_factory):
        """Unknown model defaults to prot_p."""
        client = ftp_client_factory(printer_model="FuturePrinter3000")
        assert client._is_a1_model() is False
        assert client._should_use_prot_c() is False
        assert client.connect() is True
        client.disconnect()

    def test_mode_cache_persists_and_clears(self, ftp_client_factory):
        """Mode cache works within a test and clears between tests."""
        # Cache should be empty at start (autouse fixture clears it)
        assert BambuFTPClient._mode_cache == {}

        # Connect and cache a mode
        BambuFTPClient.cache_mode("127.0.0.1", "prot_p")
        assert BambuFTPClient._mode_cache["127.0.0.1"] == "prot_p"

        # New client for same IP uses cached mode
        client = ftp_client_factory(printer_model="A1")
        assert client._get_cached_mode() == "prot_p"
        assert client._should_use_prot_c() is False
        client.disconnect()


# ---------------------------------------------------------------------------
# TestAsyncWrappers
# ---------------------------------------------------------------------------
class TestAsyncWrappers:
    """Tests for async wrapper functions using patch_ftp_port fixture."""

    @pytest.mark.asyncio
    async def test_upload_file_async_success(self, patch_ftp_port, tmp_path):
        """upload_file_async succeeds for X1C."""
        content = b"async upload"
        local = tmp_path / "async_up.3mf"
        local.write_bytes(content)
        result = await upload_file_async(
            "127.0.0.1",
            "12345678",
            local,
            "/cache/async_up.3mf",
            timeout=30.0,
            printer_model="X1C",
        )
        assert result is True

    @pytest.mark.asyncio
    async def test_upload_file_async_a1_fallback(self, patch_ftp_port, tmp_path):
        """upload_file_async tries prot_p then falls back to prot_c for A1."""
        content = b"a1 async upload"
        local = tmp_path / "a1_async.3mf"
        local.write_bytes(content)
        # For A1 models, if prot_p succeeds we get True.
        # If prot_p fails, it tries prot_c. Either way should succeed
        # against our mock server which accepts both.
        result = await upload_file_async(
            "127.0.0.1",
            "12345678",
            local,
            "/cache/a1_async.3mf",
            timeout=30.0,
            printer_model="A1",
        )
        assert result is True

    @pytest.mark.asyncio
    async def test_download_file_async_success(self, patch_ftp_port, tmp_path):
        """download_file_async succeeds."""
        server = patch_ftp_port
        content = b"async download content"
        server.add_file("cache/async_dl.bin", content)
        local = tmp_path / "async_dl.bin"
        result = await download_file_async(
            "127.0.0.1",
            "12345678",
            "/cache/async_dl.bin",
            local,
            timeout=30.0,
            printer_model="X1C",
        )
        assert result is True
        assert local.read_bytes() == content

    @pytest.mark.asyncio
    async def test_download_file_async_a1_fallback(self, patch_ftp_port, tmp_path):
        """download_file_async falls back for A1 models."""
        server = patch_ftp_port
        server.add_file("cache/a1_dl.bin", b"a1 data")
        local = tmp_path / "a1_dl.bin"
        result = await download_file_async(
            "127.0.0.1",
            "12345678",
            "/cache/a1_dl.bin",
            local,
            timeout=30.0,
            printer_model="A1",
        )
        assert result is True

    @pytest.mark.asyncio
    async def test_download_file_async_timeout_salvages_completed_zombie(self, tmp_path, monkeypatch):
        """Executor thread that completes after wait_for timeout is salvaged.

        asyncio.wait_for cannot cancel run_in_executor threads, so the FTP
        download may still complete after we give up waiting. If the thread
        genuinely finished (signalled via completion["success"] and the file
        is on disk), download_file_async should return True rather than False.

        Regression for #972: A1 user with 14 MB 3MF hit the hardcoded 60s
        timeout, but the download thread finished ~45s later. The successful
        file was written to disk but the async wrapper returned False, so the
        archive was created as a fallback with no 3MF data.
        """
        from backend.app.services import bambu_ftp

        # Clear mode cache so prot_p path is exercised.
        bambu_ftp.BambuFTPClient._mode_cache.pop("127.0.0.1", None)

        local = tmp_path / "zombie.bin"
        expected_content = b"late arrival but complete"

        class FakeClient:
            """Connects instantly, download_to_file sleeps past wait_for's
            timeout then writes the file and returns True."""

            def __init__(self, *args, **kwargs):
                pass

            def connect(self):
                return True

            def download_to_file(self, remote_path, local_path):
                time.sleep(0.4)  # longer than wait_for timeout=0.1
                local_path.write_bytes(expected_content)
                return True

            def disconnect(self):
                pass

        monkeypatch.setattr(bambu_ftp, "BambuFTPClient", FakeClient)
        monkeypatch.setattr(FakeClient, "_mode_cache", {}, raising=False)
        monkeypatch.setattr(FakeClient, "A1_MODELS", {"A1"}, raising=False)

        def _noop_cache(ip, mode):
            pass

        monkeypatch.setattr(FakeClient, "cache_mode", staticmethod(_noop_cache), raising=False)

        result = await download_file_async(
            "127.0.0.1",
            "12345678",
            "/cache/zombie.bin",
            local,
            timeout=0.1,
            printer_model="X1C",
        )
        assert result is True
        assert local.read_bytes() == expected_content

    @pytest.mark.asyncio
    async def test_download_file_async_timeout_no_salvage_when_incomplete(self, tmp_path, monkeypatch):
        """Timeout returns False when thread has not signalled success.

        A partial file on disk (mid-retrbinary) must NOT be mistaken for a
        completed download — only the thread's explicit success flag permits
        salvage.
        """
        from backend.app.services import bambu_ftp

        bambu_ftp.BambuFTPClient._mode_cache.pop("127.0.0.1", None)

        local = tmp_path / "partial.bin"

        class FakeClient:
            def __init__(self, *args, **kwargs):
                pass

            def connect(self):
                return True

            def download_to_file(self, remote_path, local_path):
                # Simulate an in-progress partial write that never completes
                # within the salvage grace period.
                local_path.write_bytes(b"partial...")
                time.sleep(2.0)
                return True  # would complete eventually, but too late

            def disconnect(self):
                pass

        monkeypatch.setattr(bambu_ftp, "BambuFTPClient", FakeClient)
        monkeypatch.setattr(FakeClient, "_mode_cache", {}, raising=False)
        monkeypatch.setattr(FakeClient, "A1_MODELS", set(), raising=False)
        monkeypatch.setattr(FakeClient, "cache_mode", staticmethod(lambda ip, mode: None), raising=False)

        result = await download_file_async(
            "127.0.0.1",
            "12345678",
            "/cache/partial.bin",
            local,
            timeout=0.1,
            printer_model="X1C",
        )
        assert result is False

    @pytest.mark.asyncio
    async def test_download_file_async_timeout_waits_for_slow_zombie(self, tmp_path, monkeypatch):
        """A zombie that completes within the 30s grace window is salvaged.

        Regression for #1014: on slow WiFi, download_to_file can overshoot the
        user's ftp_timeout by 10–30 s without being stuck. The old fixed 0.5 s
        post-timeout sleep was too short — it gave up and started attempt 2
        while attempt 1's zombie thread kept running, and by the time the zombie
        wrote the file to disk with a success flag, attempt 2 had already
        reported failure (its own completion dict was still False). The async
        wrapper now waits up to min(timeout, 30 s) for the worker thread to
        finish before returning, so a slow-but-progressing download salvages.
        """
        from backend.app.services import bambu_ftp

        bambu_ftp.BambuFTPClient._mode_cache.pop("127.0.0.1", None)

        local = tmp_path / "slow_zombie.bin"
        expected_content = b"finished during grace window"

        class FakeClient:
            """Mimics a slow FTP: wait_for gives up at 1.0 s but RETR takes
            1.5 s total. Old 0.5 s fixed sleep would have bailed (0.5 < 0.5
            extra); new grace = max(min(1.0, 30), 0.5) = 1.0 s covers the
            remaining 0.5 s so salvage succeeds."""

            def __init__(self, *args, **kwargs):
                pass

            def connect(self):
                return True

            def download_to_file(self, remote_path, local_path):
                time.sleep(1.5)  # wait_for times out at 1.0 s; zombie finishes 0.5 s later
                local_path.write_bytes(expected_content)
                return True

            def disconnect(self):
                pass

        monkeypatch.setattr(bambu_ftp, "BambuFTPClient", FakeClient)
        monkeypatch.setattr(FakeClient, "_mode_cache", {}, raising=False)
        monkeypatch.setattr(FakeClient, "A1_MODELS", set(), raising=False)
        monkeypatch.setattr(FakeClient, "cache_mode", staticmethod(lambda ip, mode: None), raising=False)

        result = await download_file_async(
            "127.0.0.1",
            "12345678",
            "/cache/slow_zombie.bin",
            local,
            timeout=1.0,
            printer_model="X1C",
        )
        assert result is True
        assert local.read_bytes() == expected_content

    @pytest.mark.asyncio
    async def test_download_file_try_paths_first_succeeds(self, patch_ftp_port, tmp_path):
        """download_file_try_paths_async succeeds on first path."""
        server = patch_ftp_port
        server.add_file("cache/try1.bin", b"first path")
        local = tmp_path / "try.bin"
        result = await download_file_try_paths_async(
            "127.0.0.1",
            "12345678",
            ["/cache/try1.bin", "/cache/try2.bin"],
            local,
            printer_model="X1C",
        )
        assert result is True
        assert local.read_bytes() == b"first path"

    @pytest.mark.asyncio
    async def test_download_file_try_paths_fallback(self, patch_ftp_port, tmp_path):
        """download_file_try_paths_async falls back to second path."""
        server = patch_ftp_port
        server.add_file("cache/second.bin", b"second path")
        local = tmp_path / "fallback.bin"
        result = await download_file_try_paths_async(
            "127.0.0.1",
            "12345678",
            ["/cache/missing.bin", "/cache/second.bin"],
            local,
            printer_model="X1C",
        )
        assert result is True
        assert local.read_bytes() == b"second path"

    @pytest.mark.asyncio
    async def test_list_files_async_success(self, patch_ftp_port):
        """list_files_async returns file list."""
        server = patch_ftp_port
        server.add_file("cache/listed.bin", b"data")
        result = await list_files_async(
            "127.0.0.1",
            "12345678",
            "/cache",
            timeout=30.0,
            printer_model="X1C",
        )
        names = {f["name"] for f in result}
        assert "listed.bin" in names

    @pytest.mark.asyncio
    async def test_delete_file_async_success(self, patch_ftp_port):
        """delete_file_async deletes a file."""
        server = patch_ftp_port
        server.add_file("cache/to_async_del.bin", b"delete me")
        result = await delete_file_async(
            "127.0.0.1",
            "12345678",
            "/cache/to_async_del.bin",
            printer_model="X1C",
        )
        assert result is True
        assert not server.file_exists("cache/to_async_del.bin")


# ---------------------------------------------------------------------------
# TestFailureScenarios
# ---------------------------------------------------------------------------
class TestFailureScenarios:
    """Regression tests for known FTP failure modes."""

    def test_550_caught_by_broad_except(self, ftp_client_factory, ftp_server, tmp_path):
        """550 error_perm is caught by (OSError, ftplib.Error) handler.

        Regression: error_perm is a subclass of ftplib.Error, so the
        broad except clause in upload_file catches it correctly.
        """
        ftp_server.inject_failure("STOR", 550, "Permission denied.")
        local = tmp_path / "test.bin"
        local.write_bytes(b"data")
        client = ftp_client_factory()
        client.connect()
        result = client.upload_file(local, "/cache/test.bin")
        assert result is False
        client.disconnect()

    def test_zero_byte_download_detected(self, ftp_client_factory, ftp_server, tmp_path):
        """0-byte download is detected and file is cleaned up.

        Regression: Prior to fix, 0-byte downloads were reported as success.
        """
        ftp_server.add_file("cache/zero.bin", b"")
        local = tmp_path / "zero.bin"
        client = ftp_client_factory()
        client.connect()
        result = client.download_to_file("/cache/zero.bin", local)
        assert result is False
        assert not local.exists()
        client.disconnect()

    def test_connection_refused_handled(self):
        """Connection refused is handled gracefully."""
        client = BambuFTPClient("127.0.0.1", "12345678", timeout=2.0)
        client.FTP_PORT = 1  # Almost certainly not listening
        assert client.connect() is False

    def test_auth_failure_530(self, ftp_client_factory, ftp_server):
        """530 authentication failure returns False."""
        ftp_server.inject_failure("PASS", 530, "Login incorrect.")
        client = ftp_client_factory()
        result = client.connect()
        assert result is False

    def test_retr_550_handled(self, ftp_client_factory, ftp_server):
        """RETR 550 (file not found) returns None."""
        ftp_server.inject_failure("RETR", 550, "File not found.")
        ftp_server.add_file("cache/exists.bin", b"data")
        client = ftp_client_factory()
        client.connect()
        result = client.download_file("/cache/exists.bin")
        assert result is None
        client.disconnect()

    def test_cwd_550_handled(self, ftp_client_factory, ftp_server):
        """CWD 550 is handled in list_files."""
        ftp_server.inject_failure("CWD", 550, "Directory not found.")
        client = ftp_client_factory()
        client.connect()
        result = client.list_files("/nonexistent")
        assert result == []
        client.disconnect()

    def test_stor_553_handled(self, ftp_client_factory, ftp_server, tmp_path):
        """STOR 553 (no SD card) handled gracefully."""
        ftp_server.inject_failure("STOR", 553, "Could not create file.")
        local = tmp_path / "test.bin"
        local.write_bytes(b"test")
        client = ftp_client_factory()
        client.connect()
        result = client.upload_file(local, "/cache/test.bin")
        assert result is False
        client.disconnect()

    def test_diagnose_storage_cwd_failure_doesnt_propagate(self, ftp_client_factory, ftp_server):
        """diagnose_storage CWD failure doesn't crash the whole operation.

        Regression: diagnose_storage() was called in the upload path and
        a CWD failure would propagate and crash the upload.
        """
        ftp_server.inject_failure("CWD", 550, "No such directory.", count=2)
        client = ftp_client_factory()
        client.connect()
        diag = client.diagnose_storage()
        # Should still return results (with errors noted)
        assert diag["connected"] is True
        assert len(diag["errors"]) > 0
        client.disconnect()

    def test_failure_injection_count_decrements(self, ftp_client_factory, ftp_server):
        """Failure injection with count decrements and eventually succeeds."""
        ftp_server.add_file("cache/retry.bin", b"data after retry")
        ftp_server.inject_failure("RETR", 550, "Temporary error.", count=1)
        client = ftp_client_factory()
        client.connect()
        # First attempt fails
        result1 = client.download_file("/cache/retry.bin")
        assert result1 is None
        # Second attempt succeeds (failure count exhausted)
        result2 = client.download_file("/cache/retry.bin")
        assert result2 == b"data after retry"
        client.disconnect()

    def test_upload_skips_voidresp(self, ftp_client_factory, ftp_server, tmp_path):
        """Upload returns True without calling voidresp() for any model.

        voidresp() is skipped for all models: A1 printers hang on it,
        H2D printers delay the 226 response by 30+ seconds, and X1C/P1S
        gain nothing from waiting. The file is on the SD card once
        sendall() returns.
        """
        content = b"voidresp test data"
        local = tmp_path / "voidresp_test.3mf"
        local.write_bytes(content)
        for model in ("X1C", "A1", "H2D", None):
            client = ftp_client_factory(printer_model=model)
            client.connect()
            result = client.upload_file(local, "/cache/voidresp_test.3mf")
            assert result is True, f"Upload failed for model={model}"
            client.disconnect()
            # Verify the file is actually on the server
            time.sleep(_UPLOAD_FLUSH_DELAY)
            client2 = ftp_client_factory()
            client2.connect()
            downloaded = client2.download_file("/cache/voidresp_test.3mf")
            assert downloaded == content, f"Content mismatch for model={model}"
            client2.disconnect()


# ---------------------------------------------------------------------------
# Short-circuit retries on 550 (#972)
# ---------------------------------------------------------------------------
class TestFileNotOnPrinterShortCircuit:
    """FileNotOnPrinterError must bypass the retry budget.

    Before this fix, a 3MF path that wasn't on the printer (550) cost
    `ftp_retry_count + 1` attempts × `ftp_retry_delay` seconds per candidate
    path. With ftp_retry_count=10 and four candidate paths, that's ~22 min
    of dead retries before the real path is tried. #972 in the wild showed
    48 min of retrying paths that didn't exist.
    """

    async def test_with_ftp_retry_propagates_file_not_on_printer_without_retrying(self):
        """with_ftp_retry raises FileNotOnPrinterError on first attempt.

        Verifies non_retry_exceptions short-circuits before the retry loop
        has a chance to sleep and try again.
        """
        attempts = {"n": 0}

        async def always_missing(*_args, **_kwargs):
            attempts["n"] += 1
            raise FileNotOnPrinterError("/cache/absent.3mf: 550")

        with pytest.raises(FileNotOnPrinterError):
            await with_ftp_retry(
                always_missing,
                max_retries=10,
                retry_delay=0.01,
                operation_name="test 550 short-circuit",
                non_retry_exceptions=(FileNotOnPrinterError,),
            )

        assert attempts["n"] == 1, "550 must not trigger any retry"

    async def test_with_ftp_retry_still_retries_transient_errors(self):
        """Non-550 exceptions continue to retry up to max_retries + 1."""
        attempts = {"n": 0}

        async def flaky(*_args, **_kwargs):
            attempts["n"] += 1
            raise TimeoutError("transient")

        result = await with_ftp_retry(
            flaky,
            max_retries=2,
            retry_delay=0.01,
            operation_name="test transient retries",
            non_retry_exceptions=(FileNotOnPrinterError,),
        )

        assert result is None
        assert attempts["n"] == 3, "Transient errors should retry to exhaustion"

    def test_download_to_file_raises_on_missing_path(self, ftp_client_factory, tmp_path):
        """download_to_file surfaces 550 as FileNotOnPrinterError end-to-end
        against the real mock FTPS server, not just a hand-rolled mock."""
        local = tmp_path / "never_downloaded.3mf"
        client = ftp_client_factory()
        client.connect()
        try:
            with pytest.raises(FileNotOnPrinterError):
                client.download_to_file("/cache/does_not_exist.3mf", local)
        finally:
            client.disconnect()
        assert not local.exists(), "Partial file must be cleaned up on 550"


# ---------------------------------------------------------------------------
# 3MF download cache (#972)
# ---------------------------------------------------------------------------
class TestThreeMFCache:
    """Cover endpoint and archive flow share downloaded 3MF bytes via this
    cache. Tests isolate themselves with clear_3mf_cache(delete_files=False)
    so they don't clobber each other."""

    def setup_method(self):
        clear_3mf_cache(delete_files=False)

    def teardown_method(self):
        clear_3mf_cache(delete_files=False)

    def test_normalize_collapses_filename_variants(self):
        """Bambu names vary (.3mf, .gcode.3mf, with spaces) — they all map
        to the same cache slot so both flows agree on the key."""
        canonical = normalize_3mf_name("Broly_Legendary.gcode.3mf")
        assert normalize_3mf_name("Broly_Legendary.3mf") == canonical
        assert normalize_3mf_name("Broly_Legendary") == canonical
        # Bambu Studio rewrites spaces to underscores on upload — treat as equal
        assert normalize_3mf_name("Broly Legendary") == canonical
        # Case is also collapsed so keys match across capitalizations
        assert normalize_3mf_name("BROLY_LEGENDARY.3MF") == canonical

    def test_cache_hit_returns_stored_path(self, tmp_path):
        """get_cached_3mf returns the same Path that was put in."""
        f = tmp_path / "Broly.gcode.3mf"
        f.write_bytes(b"fake 3mf content")
        cache_3mf_download(1, "Broly.gcode.3mf", f)
        assert get_cached_3mf(1, "Broly.gcode.3mf") == f

    def test_cache_lookup_uses_normalized_name(self, tmp_path):
        """Caching under .gcode.3mf and querying with bare name still hits."""
        f = tmp_path / "Broly.gcode.3mf"
        f.write_bytes(b"x")
        cache_3mf_download(1, "Broly.gcode.3mf", f)
        assert get_cached_3mf(1, "Broly.3mf") == f
        assert get_cached_3mf(1, "Broly") == f

    def test_cache_miss_on_different_printer(self, tmp_path):
        """Printer id is part of the key — two printers never collide."""
        f = tmp_path / "A.3mf"
        f.write_bytes(b"x")
        cache_3mf_download(1, "A.3mf", f)
        assert get_cached_3mf(2, "A.3mf") is None

    def test_cache_evicts_when_file_deleted(self, tmp_path):
        """Stale entry (file gone) returns None and is dropped from the dict."""
        f = tmp_path / "A.3mf"
        f.write_bytes(b"x")
        cache_3mf_download(1, "A.3mf", f)
        f.unlink()
        assert get_cached_3mf(1, "A.3mf") is None
        # Re-populating after eviction works — no ghost entries remain.
        f.write_bytes(b"y")
        cache_3mf_download(1, "A.3mf", f)
        assert get_cached_3mf(1, "A.3mf") == f

    def test_clear_by_printer_scoped(self, tmp_path, monkeypatch):
        """Clearing one printer leaves the other untouched."""
        from backend.app.core import config as _config

        monkeypatch.setattr(_config.settings, "archive_dir", tmp_path)
        temp_dir = tmp_path / "temp"
        temp_dir.mkdir()
        f1 = temp_dir / "one.3mf"
        f1.write_bytes(b"1")
        f2 = temp_dir / "two.3mf"
        f2.write_bytes(b"2")
        cache_3mf_download(1, "one.3mf", f1)
        cache_3mf_download(2, "two.3mf", f2)
        clear_3mf_cache(1)
        assert get_cached_3mf(1, "one.3mf") is None
        assert get_cached_3mf(2, "two.3mf") == f2
        # clear_3mf_cache defaulted to delete_files=True, so the temp file is gone
        assert not f1.exists()
        assert f2.exists()

    def test_clear_without_deleting_files(self, tmp_path, monkeypatch):
        """delete_files=False leaves files on disk — used by tests."""
        from backend.app.core import config as _config

        monkeypatch.setattr(_config.settings, "archive_dir", tmp_path)
        temp_dir = tmp_path / "temp"
        temp_dir.mkdir()
        f = temp_dir / "keep.3mf"
        f.write_bytes(b"x")
        cache_3mf_download(1, "keep.3mf", f)
        clear_3mf_cache(1, delete_files=False)
        assert get_cached_3mf(1, "keep.3mf") is None
        assert f.exists()

    def test_clear_does_not_delete_persistent_files(self, tmp_path, monkeypatch):
        """Regression for #1212 / "file disappeared overnight" reports.

        Dispatch sites added in #1166 cache the live archive copy and library
        file bytes — paths outside ``archive_dir/temp`` — so /cover can skip
        FTP. Those files are user data; the cache cleanup must never unlink
        them. Pre-fix, ``clear_3mf_cache(printer_id, delete_files=True)`` ran
        on every ``on_print_complete`` and silently destroyed them, leaving a
        DB row whose ``file_path`` pointed at nothing — breaking Reprint and
        View G-code with a 404.
        """
        from backend.app.core import config as _config

        monkeypatch.setattr(_config.settings, "archive_dir", tmp_path / "archive")
        (tmp_path / "archive" / "temp").mkdir(parents=True)

        archive_file = tmp_path / "archive" / "1" / "20260504_wallhooks" / "wallhooks.gcode.3mf"
        archive_file.parent.mkdir(parents=True)
        archive_file.write_bytes(b"archive bytes")

        library_file = tmp_path / "library_files" / "abcd.3mf"
        library_file.parent.mkdir(parents=True)
        library_file.write_bytes(b"library bytes")

        temp_file = tmp_path / "archive" / "temp" / "cover_1_x.3mf"
        temp_file.write_bytes(b"temp bytes")

        cache_3mf_download(1, "wallhooks.gcode.3mf", archive_file)
        cache_3mf_download(1, "library.3mf", library_file)
        cache_3mf_download(1, "cover_1_x.3mf", temp_file)

        clear_3mf_cache(1)

        # All three cache entries are dropped from the dict.
        assert get_cached_3mf(1, "wallhooks.gcode.3mf") is None
        assert get_cached_3mf(1, "library.3mf") is None
        assert get_cached_3mf(1, "cover_1_x.3mf") is None
        # But only the temp file is unlinked — user data survives.
        assert archive_file.exists(), "archive 3mf must not be deleted by cache cleanup"
        assert library_file.exists(), "library 3mf must not be deleted by cache cleanup"
        assert not temp_file.exists(), "temp file should still be cleaned up"