from datetime import datetime
from pathlib import Path
from uuid import UUID

from docker import DockerClient
from docker.errors import DockerException, NotFound
from docker.types import Mount

from adapter.config.model import SandboxConfig
from domain.error import SandboxError, SandboxStartError
from domain.sandbox import SandboxSession, SandboxStatus
from usecase.interface import SandboxRuntime

SANDBOX_LABELS = ('session_id', 'chat_id', 'expires_at')


class DockerSandboxRuntime(SandboxRuntime):
    def __init__(
        self,
        config: SandboxConfig,
        client: DockerClient,
    ) -> None:
        self._config = config
        self._client = client

    def create(
        self,
        *,
        session_id: UUID,
        chat_id: UUID,
        created_at: datetime,
        expires_at: datetime,
    ) -> SandboxSession:
        try:
            chat_path = self._chat_path(chat_id)
            dependencies_path = self._readonly_host_path(
                self._config.dependencies_host_path
            )
            lambda_tools_path = self._readonly_host_path(
                self._config.lambda_tools_host_path
            )
            chat_path.mkdir(parents=True, exist_ok=True)
            container = self._client.containers.run(
                self._config.image,
                detach=True,
                labels=self._labels(session_id, chat_id, expires_at),
                mounts=self._mounts(chat_path, dependencies_path, lambda_tools_path),
            )
        except (DockerException, OSError, ValueError) as exc:
            raise SandboxStartError(str(chat_id)) from exc

        container_id = str(getattr(container, 'id', '')).strip()
        if not container_id:
            raise SandboxStartError(str(chat_id))

        return SandboxSession(
            session_id=session_id,
            chat_id=chat_id,
            container_id=container_id,
            status=SandboxStatus.RUNNING,
            created_at=created_at,
            expires_at=expires_at,
        )

    def stop(self, container_id: str) -> None:
        try:
            container = self._client.containers.get(container_id)
            container.stop()
        except NotFound:
            return
        except DockerException as exc:
            raise SandboxError('sandbox_stop_failed') from exc

    def list_active_sessions(self) -> list[SandboxSession]:
        try:
            containers = self._client.containers.list(
                filters={'label': list(SANDBOX_LABELS)}
            )
        except DockerException as exc:
            raise SandboxError('sandbox_list_failed') from exc

        sessions: list[SandboxSession] = []
        for container in containers:
            session = self._session_from_container(container)
            if session is None:
                continue
            sessions.append(session)

        return sessions

    def _labels(
        self,
        session_id: UUID,
        chat_id: UUID,
        expires_at: datetime,
    ) -> dict[str, str]:
        return {
            'session_id': str(session_id),
            'chat_id': str(chat_id),
            'expires_at': expires_at.isoformat(),
        }

    def _mounts(
        self,
        chat_path: Path,
        dependencies_path: Path,
        lambda_tools_path: Path,
    ) -> list[Mount]:
        return [
            Mount(
                target=self._config.chat_mount_path,
                source=str(chat_path),
                type='bind',
            ),
            Mount(
                target=self._config.dependencies_mount_path,
                source=str(dependencies_path),
                type='bind',
                read_only=True,
            ),
            Mount(
                target=self._config.lambda_tools_mount_path,
                source=str(lambda_tools_path),
                type='bind',
                read_only=True,
            ),
        ]

    def _chat_path(self, chat_id: UUID) -> Path:
        chats_root = self._host_path(self._config.chats_root)
        chat_path = (chats_root / str(chat_id)).resolve(strict=False)
        if not chat_path.is_relative_to(chats_root):
            raise ValueError('invalid chat path')
        return chat_path

    def _readonly_host_path(self, path_value: str) -> Path:
        host_path = self._host_path(path_value)
        if not host_path.exists():
            raise ValueError('invalid host path')
        return host_path

    def _session_from_container(self, container: object) -> SandboxSession | None:
        container_id = str(getattr(container, 'id', '')).strip()
        labels = getattr(container, 'labels', None)
        if not container_id or not isinstance(labels, dict):
            return None

        try:
            session_id = UUID(labels['session_id'])
            chat_id = UUID(labels['chat_id'])
            created_at = self._container_created_at(container)
            expires_at = _parse_datetime(labels['expires_at'])
        except (KeyError, TypeError, ValueError):
            return None

        return SandboxSession(
            session_id=session_id,
            chat_id=chat_id,
            container_id=container_id,
            status=SandboxStatus.RUNNING,
            created_at=created_at,
            expires_at=expires_at,
        )

    def _container_created_at(self, container: object) -> datetime:
        attrs = getattr(container, 'attrs', None)
        if not isinstance(attrs, dict):
            reload_container = getattr(container, 'reload', None)
            if callable(reload_container):
                reload_container()
                attrs = getattr(container, 'attrs', None)

        if not isinstance(attrs, dict):
            raise ValueError('invalid container attrs')

        raw_created_at = attrs.get('Created')
        if not isinstance(raw_created_at, str):
            raise ValueError('invalid created_at')

        return _parse_datetime(raw_created_at)

    def _host_path(self, path_value: str) -> Path:
        return Path(path_value).expanduser().resolve(strict=False)


def _parse_datetime(value: str) -> datetime:
    normalized = f'{value[:-1]}+00:00' if value.endswith('Z') else value
    return datetime.fromisoformat(normalized)