import threading
from typing import IO, Dict, List, Literal, Optional, Union, overload

import httpx
from packaging.version import Version

import e2b_connect
from e2b.api import make_logging_event_hooks
from e2b.api.client_sync import get_envd_transport
from e2b.connection_config import (
    KEEPALIVE_PING_HEADER,
    KEEPALIVE_PING_INTERVAL_SEC,
    ConnectionConfig,
    Username,
    default_username,
)
from e2b_connect.client import Code

from e2b.envd.api import (
    ENVD_API_FILES_ROUTE,
    check_sandbox_health,
    handle_envd_api_exception,
    handle_envd_api_transport_exception_with_health,
)
from e2b.envd.filesystem import filesystem_connect, filesystem_pb2
from e2b.envd.rpc import authentication_header, handle_rpc_exception_with_health
from e2b.envd.versions import (
    ENVD_DEFAULT_USER,
    ENVD_FILE_METADATA,
    ENVD_OCTET_STREAM_UPLOAD,
    ENVD_VERSION_FS_EVENT_ENTRY_INFO,
    ENVD_VERSION_RECURSIVE_WATCH,
    ENVD_VERSION_WATCH_NETWORK_MOUNTS,
)
from e2b.exceptions import (
    FileNotFoundException,
    InvalidArgumentException,
    SandboxException,
    TemplateException,
)
from e2b.sandbox.filesystem.filesystem import (
    EntryInfo,
    FileStreamReader,
    WriteEntry,
    WriteInfo,
    _to_httpx_file,
    map_entry_info,
    map_file_type,
    metadata_to_headers,
    to_upload_body,
    validate_metadata,
)
from e2b.sandbox_sync.filesystem.watch_handle import WatchHandle


_FILESYSTEM_RPC_ERROR_MAP = {
    Code.not_found: FileNotFoundException,
}

_FILESYSTEM_HTTP_ERROR_MAP = {
    404: FileNotFoundException,
}


def _handle_filesystem_rpc_exception(e: Exception, envd_api: httpx.Client) -> Exception:
    return handle_rpc_exception_with_health(
        e, lambda: check_sandbox_health(envd_api), _FILESYSTEM_RPC_ERROR_MAP
    )


def _handle_filesystem_envd_api_exception(r):
    return handle_envd_api_exception(r, _FILESYSTEM_HTTP_ERROR_MAP)


class Filesystem:
    """
    Module for interacting with the filesystem in the sandbox.
    """

    def __init__(
        self,
        envd_api_url: str,
        envd_version: Version,
        connection_config: ConnectionConfig,
    ) -> None:
        self._envd_api_url = envd_api_url
        self._envd_version = envd_version
        self._connection_config = connection_config
        self._thread_local = threading.local()

    def _create_envd_api(self) -> httpx.Client:
        transport = get_envd_transport(self._connection_config)
        return httpx.Client(
            base_url=self._envd_api_url,
            transport=transport,
            headers=self._connection_config.sandbox_headers,
            event_hooks=make_logging_event_hooks(self._connection_config.logger),
        )

    def _create_rpc(self) -> filesystem_connect.FilesystemClient:
        transport = get_envd_transport(self._connection_config)
        return filesystem_connect.FilesystemClient(
            self._envd_api_url,
            # TODO: Fix and enable compression again — the headers compression is not solved for streaming.
            # compressor=e2b_connect.GzipCompressor,
            pool=transport.pool,
            json=True,
            headers=self._connection_config.sandbox_headers,
            logger=self._connection_config.logger,
        )

    @property
    def _envd_api(self) -> httpx.Client:
        envd_api = getattr(self._thread_local, "envd_api", None)
        if envd_api is None:
            envd_api = self._create_envd_api()
            self._thread_local.envd_api = envd_api
        return envd_api

    @property
    def _rpc(self) -> filesystem_connect.FilesystemClient:
        rpc = getattr(self._thread_local, "rpc", None)
        if rpc is None:
            rpc = self._create_rpc()
            self._thread_local.rpc = rpc
        return rpc

    @overload
    def read(
        self,
        path: str,
        format: Literal["text"] = "text",
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
        gzip: bool = False,
    ) -> str:
        """
        Read file content as a `str`.

        :param path: Path to the file
        :param user: Run the operation as this user
        :param format: Format of the file content—`text` by default
        :param request_timeout: Timeout for the request in **seconds**
        :param gzip: Use gzip compression for the request

        :return: File content as a `str`
        """
        ...

    @overload
    def read(
        self,
        path: str,
        format: Literal["bytes"],
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
        gzip: bool = False,
    ) -> bytearray:
        """
        Read file content as a `bytearray`.

        :param path: Path to the file
        :param user: Run the operation as this user
        :param format: Format of the file content—`bytes`
        :param request_timeout: Timeout for the request in **seconds**
        :param gzip: Use gzip compression for the request

        :return: File content as a `bytearray`
        """
        ...

    @overload
    def read(
        self,
        path: str,
        format: Literal["stream"],
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
        gzip: bool = False,
        stream_idle_timeout: Optional[float] = None,
    ) -> FileStreamReader:
        """
        Read file content as a `FileStreamReader` (an `Iterator[bytes]`).

        The request timeout bounds only the initial handshake—the returned
        iterator is not killed by it while being consumed. A stalled stream is
        reclaimed by `stream_idle_timeout` (raising `httpx.ReadTimeout`). The
        reader releases its connection once fully consumed; if you don't read it
        to the end, use it as a context manager or call `close()` for
        deterministic cleanup.

        :param path: Path to the file
        :param user: Run the operation as this user
        :param format: Format of the file content—`stream`
        :param request_timeout: Timeout for the request in **seconds**
        :param gzip: Use gzip compression for the request
        :param stream_idle_timeout: Idle timeout in **seconds** for the streamed
            body—abort if no chunk arrives within this window. Resets on every
            chunk, so it bounds a stalled stream without limiting total transfer
            time. Defaults to the request timeout; pass `0` to disable.

        :return: File content as a `FileStreamReader`
        """
        ...

    def read(
        self,
        path: str,
        format: Literal["text", "bytes", "stream"] = "text",
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
        gzip: bool = False,
        stream_idle_timeout: Optional[float] = None,
    ):
        username = user
        if username is None and self._envd_version < ENVD_DEFAULT_USER:
            username = default_username

        params = {"path": path}
        if username:
            params["username"] = username

        headers = {}
        if gzip:
            headers["Accept-Encoding"] = "gzip"

        timeout = self._connection_config.get_request_timeout(request_timeout)

        if format == "stream":
            # Stream the response body instead of buffering it in memory.
            request = self._envd_api.build_request(
                "GET",
                ENVD_API_FILES_ROUTE,
                params=params,
                headers=headers,
                timeout=timeout,
            )
            try:
                r = self._envd_api.send(request, stream=True)
            except httpx.RemoteProtocolError as e:
                raise handle_envd_api_transport_exception_with_health(e, self._envd_api)

            err = _handle_filesystem_envd_api_exception(r)
            if err:
                r.close()
                raise err

            # The request timeout bounds only the initial handshake; httpx's
            # per-chunk `read` timeout becomes the idle-read timeout for the body
            # (defaults to the request timeout). The timeout dict is shared by
            # reference with the transport and read again when iteration starts.
            idle_timeout = (
                timeout if stream_idle_timeout is None else stream_idle_timeout
            )
            request.extensions.get("timeout", {})["read"] = idle_timeout or None

            return FileStreamReader(r)

        try:
            r = self._envd_api.get(
                ENVD_API_FILES_ROUTE,
                params=params,
                headers=headers,
                timeout=timeout,
            )
        except httpx.RemoteProtocolError as e:
            raise handle_envd_api_transport_exception_with_health(e, self._envd_api)

        err = _handle_filesystem_envd_api_exception(r)
        if err:
            raise err

        if format == "text":
            return r.text
        elif format == "bytes":
            return bytearray(r.content)

    def write(
        self,
        path: str,
        data: Union[str, bytes, IO],
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
        gzip: bool = False,
        use_octet_stream: Optional[bool] = None,
        metadata: Optional[Dict[str, str]] = None,
    ) -> WriteInfo:
        """
        Write content to a file on the path.
        Writing to a file that doesn't exist creates the file.
        Writing to a file that already exists overwrites the file.
        Writing to a file at path that doesn't exist creates the necessary directories.

        :param path: Path to the file
        :param data: Data to write to the file, can be a `str`, `bytes`, or `IO`. File-like objects are streamed in chunks instead of being buffered in memory.
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**
        :param gzip: Use gzip compression for the upload. Implies the `application/octet-stream` upload. Requires envd 0.5.7 or later — when not supported, the upload falls back to uncompressed `multipart/form-data`.
        :param use_octet_stream: Upload using `application/octet-stream` instead of `multipart/form-data`. Defaults to `None`, which uses octet-stream when `data` is a file-like object (so streamed uploads aren't buffered) and `multipart/form-data` otherwise. Requires envd 0.5.7 or later — when not supported, the upload falls back to `multipart/form-data`.
        :param metadata: User-defined metadata to persist on the uploaded file as extended attributes. Keys are lowercased by the sandbox; invalid keys or values raise an `InvalidArgumentException`. Requires envd 0.6.2 or later.

        :return: Information about the written file
        """
        result = self.write_files(
            [WriteEntry(path=path, data=data)],
            user=user,
            request_timeout=request_timeout,
            gzip=gzip,
            use_octet_stream=use_octet_stream,
            metadata=metadata,
        )

        if len(result) != 1:
            raise SandboxException("Received unexpected response from write operation")

        return result[0]

    def write_files(
        self,
        files: List[WriteEntry],
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
        gzip: bool = False,
        use_octet_stream: Optional[bool] = None,
        metadata: Optional[Dict[str, str]] = None,
    ) -> List[WriteInfo]:
        """
        Writes multiple files.

        Writes a list of files to the filesystem.
        When writing to a file that doesn't exist, the file will get created.
        When writing to a file that already exists, the file will get overwritten.
        When writing to a file at path that doesn't exist, the necessary directories will be created.

        :param files: list of files to write as `WriteEntry` objects, each containing `path` and `data`
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request
        :param gzip: Use gzip compression for the upload. Implies the `application/octet-stream` upload. Requires envd 0.5.7 or later — when not supported, the upload falls back to uncompressed `multipart/form-data`.
        :param use_octet_stream: Upload using `application/octet-stream` instead of `multipart/form-data`. Defaults to `None`, which uses octet-stream when any entry is a file-like object (so streamed uploads aren't buffered) and `multipart/form-data` otherwise. Requires envd 0.5.7 or later — when not supported, the upload falls back to `multipart/form-data`.
        :param metadata: User-defined metadata to persist on each uploaded file as extended attributes; the same map is applied to every file. Keys are lowercased by the sandbox; invalid keys or values raise an `InvalidArgumentException`. Requires envd 0.6.2 or later.
        :return: Information about the written files
        """
        username = user
        if username is None and self._envd_version < ENVD_DEFAULT_USER:
            username = default_username

        if len(files) == 0:
            return []

        validate_metadata(metadata)

        if metadata and self._envd_version < ENVD_FILE_METADATA:
            raise TemplateException("File metadata requires envd 0.6.2 or later.")

        # A file-like entry is streamed; str/bytes are sent from memory.
        has_streamable_data = any(
            not isinstance(file["data"], (str, bytes)) for file in files
        )

        if use_octet_stream is None:
            # Streaming an upload only happens on the octet-stream path; the
            # multipart path buffers file-like data. Default to octet-stream
            # when any entry is a file-like object so a streamed upload isn't
            # silently buffered.
            use_octet_stream = has_streamable_data

        supports_octet_stream = self._envd_version >= ENVD_OCTET_STREAM_UPLOAD
        # Gzip compression only works with the octet-stream upload (the
        # Content-Encoding header applies to the whole request body), so
        # requesting gzip implies it when envd supports it.
        use_octet_stream = (use_octet_stream or gzip) and supports_octet_stream

        # Each chunk send is bounded by the request timeout (httpx applies it
        # per write); a stalled upload the per-write timeout can't observe is
        # bounded server-side (envd's per-read idle timeout, envd >= 0.6.7).
        upload_timeout = self._connection_config.get_request_timeout(request_timeout)

        # Metadata is sent as request-scoped X-Metadata-* headers, so the same
        # metadata is applied to every file in a multi-file upload.
        extra_headers = metadata_to_headers(metadata)

        results: List[WriteInfo] = []

        if use_octet_stream:
            for file in files:
                file_path, file_data = file["path"], file["data"]

                params = {"path": file_path}
                if username:
                    params["username"] = username

                headers = {"Content-Type": "application/octet-stream", **extra_headers}
                if gzip:
                    headers["Content-Encoding"] = "gzip"

                try:
                    r = self._envd_api.post(
                        ENVD_API_FILES_ROUTE,
                        content=to_upload_body(file_data, gzip),
                        headers=headers,
                        params=params,
                        timeout=upload_timeout,
                    )
                except httpx.RemoteProtocolError as e:
                    raise handle_envd_api_transport_exception_with_health(
                        e, self._envd_api
                    )

                err = _handle_filesystem_envd_api_exception(r)
                if err:
                    raise err

                write_result = r.json()

                if not isinstance(write_result, list) or len(write_result) == 0:
                    raise SandboxException(
                        "Expected to receive information about written file"
                    )

                results.extend([WriteInfo.from_dict(f) for f in write_result])
        else:
            params = {}
            if username:
                params["username"] = username
            if len(files) == 1:
                params["path"] = files[0]["path"]

            httpx_files = [_to_httpx_file(file["path"], file["data"]) for file in files]

            if len(httpx_files) == 0:
                return []

            try:
                r = self._envd_api.post(
                    ENVD_API_FILES_ROUTE,
                    files=httpx_files,
                    params=params,
                    headers=extra_headers,
                    timeout=upload_timeout,
                )
            except httpx.RemoteProtocolError as e:
                raise handle_envd_api_transport_exception_with_health(e, self._envd_api)

            err = _handle_filesystem_envd_api_exception(r)
            if err:
                raise err

            write_result = r.json()

            if not isinstance(write_result, list) or len(write_result) == 0:
                raise SandboxException(
                    "Expected to receive information about written file"
                )

            results.extend([WriteInfo.from_dict(f) for f in write_result])

        return results

    def list(
        self,
        path: str,
        depth: Optional[int] = 1,
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
    ) -> List[EntryInfo]:
        """
        List entries in a directory.

        :param path: Path to the directory
        :param depth: Depth of the directory to list
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**

        :return: List of entries in the directory
        """
        if depth is not None and depth < 1:
            raise InvalidArgumentException("depth should be at least 1")

        try:
            res = self._rpc.list_dir(
                filesystem_pb2.ListDirRequest(path=path, depth=depth),
                request_timeout=self._connection_config.get_request_timeout(
                    request_timeout
                ),
                headers=authentication_header(self._envd_version, user),
            )

            entries: List[EntryInfo] = []
            for entry in res.entries:
                # Skip entries with an unknown file type.
                if map_file_type(entry.type):
                    entries.append(map_entry_info(entry))

            return entries
        except Exception as e:
            raise _handle_filesystem_rpc_exception(e, self._envd_api)

    def exists(
        self,
        path: str,
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
    ) -> bool:
        """
        Check if a file or a directory exists.

        :param path: Path to a file or a directory
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**

        :return: `True` if the file or directory exists, `False` otherwise
        """
        try:
            self._rpc.stat(
                filesystem_pb2.StatRequest(path=path),
                request_timeout=self._connection_config.get_request_timeout(
                    request_timeout
                ),
                headers=authentication_header(self._envd_version, user),
            )
            return True

        except Exception as e:
            if isinstance(e, e2b_connect.ConnectException):
                if e.status == e2b_connect.Code.not_found:
                    return False
            raise _handle_filesystem_rpc_exception(e, self._envd_api)

    def get_info(
        self,
        path: str,
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
    ) -> EntryInfo:
        """
        Get information about a file or directory.

        :param path: Path to a file or a directory
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**

        :return: Information about the file or directory like name, type, and path
        """
        try:
            r = self._rpc.stat(
                filesystem_pb2.StatRequest(path=path),
                request_timeout=self._connection_config.get_request_timeout(
                    request_timeout
                ),
                headers=authentication_header(self._envd_version, user),
            )

            return map_entry_info(r.entry)
        except Exception as e:
            raise _handle_filesystem_rpc_exception(e, self._envd_api)

    def remove(
        self,
        path: str,
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
    ) -> None:
        """
        Remove a file or a directory.

        :param path: Path to a file or a directory
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**
        """
        try:
            self._rpc.remove(
                filesystem_pb2.RemoveRequest(path=path),
                request_timeout=self._connection_config.get_request_timeout(
                    request_timeout
                ),
                headers=authentication_header(self._envd_version, user),
            )
        except Exception as e:
            raise _handle_filesystem_rpc_exception(e, self._envd_api)

    def rename(
        self,
        old_path: str,
        new_path: str,
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
    ) -> EntryInfo:
        """
        Rename a file or directory.

        :param old_path: Path to the file or directory to rename
        :param new_path: New path to the file or directory
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**

        :return: Information about the renamed file or directory
        """
        try:
            r = self._rpc.move(
                filesystem_pb2.MoveRequest(
                    source=old_path,
                    destination=new_path,
                ),
                request_timeout=self._connection_config.get_request_timeout(
                    request_timeout
                ),
                headers=authentication_header(self._envd_version, user),
            )

            return map_entry_info(r.entry)
        except Exception as e:
            raise _handle_filesystem_rpc_exception(e, self._envd_api)

    def make_dir(
        self,
        path: str,
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
    ) -> bool:
        """
        Create a new directory and all directories along the way if needed on the specified path.

        :param path: Path to a new directory. For example '/dirA/dirB' when creating 'dirB'.
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**

        :return: `True` if the directory was created, `False` if the directory already exists
        """
        try:
            self._rpc.make_dir(
                filesystem_pb2.MakeDirRequest(path=path),
                request_timeout=self._connection_config.get_request_timeout(
                    request_timeout
                ),
                headers=authentication_header(self._envd_version, user),
            )

            return True
        except Exception as e:
            if isinstance(e, e2b_connect.ConnectException):
                if e.status == e2b_connect.Code.already_exists:
                    return False
            raise _handle_filesystem_rpc_exception(e, self._envd_api)

    def watch_dir(
        self,
        path: str,
        user: Optional[Username] = None,
        request_timeout: Optional[float] = None,
        recursive: bool = False,
        include_entry: bool = False,
        allow_network_mounts: bool = False,
    ) -> WatchHandle:
        """
        Watch directory for filesystem events.

        :param path: Path to a directory to watch
        :param user: Run the operation as this user
        :param request_timeout: Timeout for the request in **seconds**
        :param recursive: Watch directory recursively
        :param include_entry: Include the `EntryInfo` of the affected entry in each event, when available. Requires envd 0.6.3 or later
        :param allow_network_mounts: Allow watching paths on network filesystem mounts (NFS, CIFS, SMB, FUSE), which are rejected by default. Events on network mounts may be unreliable or not delivered at all. Requires envd 0.6.4 or later

        :return: `WatchHandle` object for stopping watching directory
        """
        if recursive and self._envd_version < ENVD_VERSION_RECURSIVE_WATCH:
            raise TemplateException(
                "You need to update the template to use recursive watching."
            )

        if include_entry and self._envd_version < ENVD_VERSION_FS_EVENT_ENTRY_INFO:
            raise TemplateException(
                "You need to update the template to include entry info in watch events."
            )

        if (
            allow_network_mounts
            and self._envd_version < ENVD_VERSION_WATCH_NETWORK_MOUNTS
        ):
            raise TemplateException(
                "You need to update the template to watch directories on network mounts."
            )

        try:
            r = self._rpc.create_watcher(
                filesystem_pb2.CreateWatcherRequest(
                    path=path,
                    recursive=recursive,
                    include_entry=include_entry,
                    allow_network_mounts=allow_network_mounts,
                ),
                request_timeout=self._connection_config.get_request_timeout(
                    request_timeout
                ),
                headers={
                    **authentication_header(self._envd_version, user),
                    KEEPALIVE_PING_HEADER: str(KEEPALIVE_PING_INTERVAL_SEC),
                },
            )
        except Exception as e:
            raise _handle_filesystem_rpc_exception(e, self._envd_api)

        return WatchHandle(
            lambda: self._rpc,
            r.watcher_id,
            self._connection_config,
            self._envd_version,
            user,
            lambda: check_sandbox_health(self._envd_api),
        )
