"""Docker container sandbox backend.
execute() is synchronous. server.py calls it via loop.run_in_executor().
"""
from __future__ import annotations

import logging
import os

import docker
from deepagents.backends.protocol import ExecuteResponse, FileDownloadResponse, FileUploadResponse
from deepagents.backends.sandbox import BaseSandbox

logger = logging.getLogger(__name__)


class DockerSandbox(BaseSandbox):
    """Docker container-based sandbox implementation.

    Extends BaseSandbox, which auto-implements file I/O (read/write/ls/grep)
    by delegating to execute(). Only need to implement: id property, execute(),
    upload_files(), download_files(), and container lifecycle.
    """

    def __init__(
        self,
        container_id: str | None = None,
        *,
        image: str | None = None,
        network: str = "galaxis-net",
        mem_limit: str = "4g",
        cpu_count: int = 2,
        pids_limit: int = 256,
        environment: dict | None = None,
        default_timeout: int = 300,
    ):
        self._docker = docker.DockerClient(
            base_url=os.environ.get("DOCKER_HOST", "unix:///var/run/docker.sock")
        )
        self._default_timeout = default_timeout

        if container_id:
            # Connect to existing container
            self._container = self._docker.containers.get(container_id)
        else:
            # Create new container
            resolved_image = image or os.environ.get("SANDBOX_IMAGE", "galaxis-sandbox:latest")
            self._container = self._docker.containers.run(
                image=resolved_image,
                detach=True,
                network=network,
                mem_limit=mem_limit,
                cpu_count=cpu_count,
                pids_limit=pids_limit,
                environment=environment or {},
                labels={"galaxis-agent-sandbox": "true"},
                working_dir="/workspace",
            )
        self._id = self._container.id

    @property
    def id(self) -> str:
        return self._id

    def execute(
        self,
        command: str,
        *,
        timeout: int | None = None,
    ) -> ExecuteResponse:
        """Execute a shell command in the container.

        Synchronous method - server.py calls via loop.run_in_executor().
        """
        effective_timeout = timeout if timeout is not None else self._default_timeout

        # Wrap command with timeout if specified
        if effective_timeout and effective_timeout > 0:
            cmd = ["timeout", str(effective_timeout), "sh", "-c", command]
        else:
            cmd = ["sh", "-c", command]

        # Execute command in container with demux=True to separate stdout/stderr
        result = self._container.exec_run(cmd=cmd, demux=True, workdir="/workspace")

        # Decode output
        stdout = (result.output[0] or b"").decode("utf-8", errors="replace")
        stderr = (result.output[1] or b"").decode("utf-8", errors="replace")
        output = stdout + stderr

        exit_code = result.exit_code

        # Handle timeout exit code
        if exit_code == 124:
            output += f"\n[TIMEOUT] Command timed out after {effective_timeout}s"

        return ExecuteResponse(output=output, exit_code=exit_code, truncated=False)

    def upload_files(self, files: list[tuple[str, bytes]]) -> list[FileUploadResponse]:
        """Upload multiple files to the sandbox.

        Supports partial success - returns errors per-file rather than raising.
        """
        responses = []
        for path, content in files:
            try:
                # Use tar to upload file to container
                import io
                import tarfile

                # Create tar archive in memory
                tar_stream = io.BytesIO()
                tar = tarfile.open(fileobj=tar_stream, mode="w")

                # Add file to archive
                tarinfo = tarfile.TarInfo(name=os.path.basename(path))
                tarinfo.size = len(content)
                tar.addfile(tarinfo, io.BytesIO(content))
                tar.close()

                # Upload to container
                tar_stream.seek(0)
                self._container.put_archive(os.path.dirname(path) or "/workspace", tar_stream)

                responses.append(FileUploadResponse(path=path, error=None))
            except Exception as e:
                logger.exception("Failed to upload file: %s", path)
                responses.append(FileUploadResponse(path=path, error=str(e)))

        return responses

    def download_files(self, paths: list[str]) -> list[FileDownloadResponse]:
        """Download multiple files from the sandbox.

        Supports partial success - returns errors per-file rather than raising.
        """
        responses = []
        for path in paths:
            try:
                # Get file from container as tar archive
                bits, stat = self._container.get_archive(path)

                # Extract content from tar
                import io
                import tarfile

                tar_stream = io.BytesIO(b"".join(bits))
                tar = tarfile.open(fileobj=tar_stream)

                # Get first file from archive
                member = tar.next()
                if member:
                    f = tar.extractfile(member)
                    if f:
                        content = f.read()
                        responses.append(FileDownloadResponse(path=path, content=content, error=None))
                    else:
                        responses.append(FileDownloadResponse(path=path, content=None, error="Not a file"))
                else:
                    responses.append(FileDownloadResponse(path=path, content=None, error="Empty archive"))

                tar.close()
            except Exception as e:
                logger.exception("Failed to download file: %s", path)
                responses.append(FileDownloadResponse(path=path, content=None, error=str(e)))

        return responses

    def close(self):
        """Stop and remove the container."""
        try:
            self._container.stop(timeout=10)
            self._container.remove(force=True)
        except docker.errors.NotFound:
            pass
        except Exception:
            logger.exception("Failed to remove container: %s", self._id)