http.py

import json
import logging
import os.path
import ssl
from io import BytesIO
from pathlib import Path
from typing import (
    Any,
    AsyncIterable,
    Dict,
    Iterable,
    List,
    Optional,
    Tuple,
    Type,
    Union,
    overload,
)

import aiohttp
from aiohttp.web import HTTPNotFound
from aleph_message import parse_message
from aleph_message.models import AlephMessage, ItemHash, ItemType
from aleph_message.status import MessageStatus
from pydantic import ValidationError

from ..conf import settings
from ..exceptions import (
    FileTooLarge,
    ForgottenMessageError,
    InvalidHashError,
    MessageNotFoundError,
)
from ..query.filters import MessageFilter, PostFilter
from ..query.responses import MessagesResponse, Post, PostsResponse, PriceResponse
from ..types import GenericMessage
from ..utils import (
    Writable,
    check_unix_socket_valid,
    copy_async_readable_to_buffer,
    extended_json_encoder,
    get_message_type_value,
)
from .abstract import AlephClient

logger = logging.getLogger(__name__)


class AlephHttpClient(AlephClient):
    api_server: str
    _http_session: Optional[aiohttp.ClientSession]

    def __init__(
        self,
        api_server: Optional[str] = None,
        api_unix_socket: Optional[str] = None,
        allow_unix_sockets: bool = True,
        timeout: Optional[aiohttp.ClientTimeout] = None,
        ssl_context: Optional[ssl.SSLContext] = None,
    ):
        """AlephClient can use HTTP(S) or HTTP over Unix sockets.
        Unix sockets are used when running inside a virtual machine,
        and can be shared across containers in a more secure way than TCP ports.
        """
        self.api_server = api_server or settings.API_HOST
        if not self.api_server:
            raise ValueError("Missing API host")

        self.connector: Union[aiohttp.BaseConnector, None]
        unix_socket_path = api_unix_socket or settings.API_UNIX_SOCKET

        if ssl_context:
            self.connector = aiohttp.TCPConnector(ssl=ssl_context)
        elif unix_socket_path and allow_unix_sockets:
            check_unix_socket_valid(unix_socket_path)
            self.connector = aiohttp.UnixConnector(path=unix_socket_path)
        else:
            self.connector = None

        self.timeout = timeout
        self._http_session = None

    @property
    def http_session(self) -> aiohttp.ClientSession:
        if self._http_session is None:
            raise Exception(
                f"{self.__class__.__name__} can only be using within an async context manager.\n\n"
                "Please use it this way:\n\n"
                f"    async with {self.__class__.__name__}(...) as client:"
            )

        return self._http_session

    async def __aenter__(self):
        if self._http_session is None:
            self._http_session = (
                aiohttp.ClientSession(
                    base_url=self.api_server,
                    connector=self.connector,
                    timeout=self.timeout,
                    json_serialize=extended_json_encoder,
                )
                if self.timeout
                else aiohttp.ClientSession(
                    base_url=self.api_server,
                    connector=self.connector,
                    json_serialize=lambda obj: json.dumps(
                        obj, default=extended_json_encoder
                    ),
                )
            )

        return self

    async def __aexit__(self, exc_type, exc_val, exc_tb):
        # Avoid cascade in error handling
        if self._http_session is not None:
            await self._http_session.close()

    async def fetch_aggregate(self, address: str, key: str) -> Dict[str, Dict]:
        params: Dict[str, Any] = {"keys": key}

        async with self.http_session.get(
            f"/api/v0/aggregates/{address}.json", params=params
        ) as resp:
            resp.raise_for_status()
            result = await resp.json()
            data = result.get("data", dict())
            return data.get(key)

    async def fetch_aggregates(
        self, address: str, keys: Optional[Iterable[str]] = None
    ) -> Dict[str, Dict]:
        keys_str = ",".join(keys) if keys else ""
        params: Dict[str, Any] = {}
        if keys_str:
            params["keys"] = keys_str

        async with self.http_session.get(
            f"/api/v0/aggregates/{address}.json",
            params=params,
        ) as resp:
            resp.raise_for_status()
            result = await resp.json()
            data = result.get("data", dict())
            return data

    async def get_posts(
        self,
        page_size: int = 200,
        page: int = 1,
        post_filter: Optional[PostFilter] = None,
        ignore_invalid_messages: Optional[bool] = True,
        invalid_messages_log_level: Optional[int] = logging.NOTSET,
    ) -> PostsResponse:
        ignore_invalid_messages = (
            True if ignore_invalid_messages is None else ignore_invalid_messages
        )
        invalid_messages_log_level = (
            logging.NOTSET
            if invalid_messages_log_level is None
            else invalid_messages_log_level
        )

        if not post_filter:
            params = {
                "page": str(page),
                "pagination": str(page_size),
            }
        else:
            params = post_filter.as_http_params()
            params["page"] = str(page)
            params["pagination"] = str(page_size)

        async with self.http_session.get("/api/v0/posts.json", params=params) as resp:
            resp.raise_for_status()
            response_json = await resp.json()
            posts_raw = response_json["posts"]

            posts: List[Post] = []
            for post_raw in posts_raw:
                try:
                    posts.append(Post.model_validate(post_raw))
                except ValidationError as e:
                    if not ignore_invalid_messages:
                        raise e
                    if invalid_messages_log_level:
                        logger.log(level=invalid_messages_log_level, msg=e)
            return PostsResponse(
                posts=posts,
                pagination_page=response_json["pagination_page"],
                pagination_total=response_json["pagination_total"],
                pagination_per_page=response_json["pagination_per_page"],
                pagination_item=response_json["pagination_item"],
            )

    async def download_file_to_buffer(
        self,
        file_hash: str,
        output_buffer: Writable[bytes],
    ) -> None:
        """
        Download a file from the storage engine and write it to the specified output buffer.
        :param file_hash: The hash of the file to retrieve.
        :param output_buffer: Writable binary buffer. The file will be written to this buffer.
        """

        async with self.http_session.get(
            f"/api/v0/storage/raw/{file_hash}"
        ) as response:
            if response.status == 200:
                await copy_async_readable_to_buffer(
                    response.content, output_buffer, chunk_size=16 * 1024
                )
            if response.status == 413:
                ipfs_hash = ItemHash(file_hash)
                if ipfs_hash.item_type == ItemType.ipfs:
                    return await self.download_file_ipfs_to_buffer(
                        file_hash, output_buffer
                    )
                else:
                    raise FileTooLarge(f"The file from {file_hash} is too large")

    async def download_file_ipfs_to_buffer(
        self,
        file_hash: str,
        output_buffer: Writable[bytes],
    ) -> None:
        """
        Download a file from the storage engine and write it to the specified output buffer.

        :param file_hash: The hash of the file to retrieve.
        :param output_buffer: The binary output buffer to write the file data to.
        """
        async with aiohttp.ClientSession() as session:
            async with session.get(
                f"https://ipfs.aleph.im/ipfs/{file_hash}"
            ) as response:
                if response.status == 200:
                    await copy_async_readable_to_buffer(
                        response.content, output_buffer, chunk_size=16 * 1024
                    )
                else:
                    response.raise_for_status()

    async def download_file(self, file_hash: str) -> bytes:
        """
        Get a file from the storage engine as raw bytes.

        Warning: Downloading large files can be slow and memory intensive. Use `download_file_to()` to download them directly to disk instead.

        :param file_hash: The hash of the file to retrieve.
        """
        buffer = BytesIO()
        await self.download_file_to_buffer(file_hash, output_buffer=buffer)
        return buffer.getvalue()

    async def download_file_to_path(
        self,
        file_hash: str,
        path: Union[Path, str],
    ) -> Path:
        """
        Download a file from the storage engine to given path.

        :param file_hash: The hash of the file to retrieve.
        :param path: The path to which the file should be saved.
        """
        if not isinstance(path, Path):
            path = Path(path)

        if not os.path.exists(path):
            dir_path = os.path.dirname(path)
            if dir_path:
                os.makedirs(dir_path, exist_ok=True)

        with open(path, "wb") as file_buffer:
            await self.download_file_to_buffer(file_hash, output_buffer=file_buffer)

        return path

    async def download_file_ipfs(
        self,
        file_hash: str,
    ) -> bytes:
        """
        Get a file from the ipfs storage engine as raw bytes.

        Warning: Downloading large files can be slow.

        :param file_hash: The hash of the file to retrieve.
        """
        buffer = BytesIO()
        await self.download_file_ipfs_to_buffer(file_hash, output_buffer=buffer)
        return buffer.getvalue()

    async def get_messages(
        self,
        page_size: int = 200,
        page: int = 1,
        message_filter: Optional[MessageFilter] = None,
        ignore_invalid_messages: Optional[bool] = True,
        invalid_messages_log_level: Optional[int] = logging.NOTSET,
    ) -> MessagesResponse:
        ignore_invalid_messages = (
            True if ignore_invalid_messages is None else ignore_invalid_messages
        )
        invalid_messages_log_level = (
            logging.NOTSET
            if invalid_messages_log_level is None
            else invalid_messages_log_level
        )

        if not message_filter:
            params = {
                "page": str(page),
                "pagination": str(page_size),
            }
        else:
            params = message_filter.as_http_params()
            params["page"] = str(page)
            params["pagination"] = str(page_size)

        async with self.http_session.get(
            "/api/v0/messages.json", params=params
        ) as resp:
            resp.raise_for_status()
            response_json = await resp.json()
            messages_raw = response_json["messages"]

            # All messages may not be valid according to the latest specification in
            # aleph-message. This allows the user to specify how errors should be handled.
            messages: List[AlephMessage] = []
            for message_raw in messages_raw:
                try:
                    message = parse_message(message_raw)
                    messages.append(message)
                except KeyError as e:
                    if not ignore_invalid_messages:
                        raise e
                    logger.log(
                        level=invalid_messages_log_level,
                        msg=f"KeyError: Field '{e.args[0]}' not found",
                    )
                except ValidationError as e:
                    if not ignore_invalid_messages:
                        raise e
                    if invalid_messages_log_level:
                        logger.log(level=invalid_messages_log_level, msg=e)

            return MessagesResponse(
                messages=messages,
                pagination_page=response_json["pagination_page"],
                pagination_total=response_json["pagination_total"],
                pagination_per_page=response_json["pagination_per_page"],
                pagination_item=response_json["pagination_item"],
            )

    @overload
    async def get_message(
        self,
        item_hash: str,
        message_type: Optional[Type[GenericMessage]] = None,
    ) -> GenericMessage: ...

    @overload
    async def get_message(
        self,
        item_hash: str,
        message_type: Optional[Type[GenericMessage]] = None,
        with_status: bool = False,
    ) -> Tuple[GenericMessage, MessageStatus]: ...

    async def get_message(
        self,
        item_hash: str,
        message_type: Optional[Type[GenericMessage]] = None,
        with_status: bool = False,
    ) -> Union[GenericMessage, Tuple[GenericMessage, MessageStatus]]:
        async with self.http_session.get(f"/api/v0/messages/{item_hash}") as resp:
            try:
                resp.raise_for_status()
            except aiohttp.ClientResponseError as e:
                if e.status == 404:
                    raise MessageNotFoundError(f"No such hash {item_hash}")
                raise e
            message_raw = await resp.json()
        if message_raw["status"] == "forgotten":
            raise ForgottenMessageError(
                f"The requested message {message_raw['item_hash']} has been forgotten by {', '.join(message_raw['forgotten_by'])}"
            )
        message = parse_message(message_raw["message"])
        if message_type:
            expected_type = get_message_type_value(message_type)
            if message.type != expected_type:
                raise TypeError(
                    f"The message type '{message.type}' "
                    f"does not match the expected type '{expected_type}'"
                )
        if with_status:
            return message, message_raw["status"]
        else:
            return message

    async def get_message_error(
        self,
        item_hash: str,
    ) -> Optional[Dict[str, Any]]:
        async with self.http_session.get(f"/api/v0/messages/{item_hash}") as resp:
            try:
                resp.raise_for_status()
            except aiohttp.ClientResponseError as e:
                if e.status == 404:
                    raise MessageNotFoundError(f"No such hash {item_hash}")
                raise e
            message_raw = await resp.json()
        if message_raw["status"] == "forgotten":
            raise ForgottenMessageError(
                f"The requested message {message_raw['item_hash']} has been forgotten by {', '.join(message_raw['forgotten_by'])}"
            )
        if message_raw["status"] != "rejected":
            return None
        return {
            "error_code": message_raw["error_code"],
            "details": message_raw["details"],
        }

    async def watch_messages(
        self,
        message_filter: Optional[MessageFilter] = None,
    ) -> AsyncIterable[AlephMessage]:
        message_filter = message_filter or MessageFilter()
        params = message_filter.as_http_params()

        async with self.http_session.ws_connect(
            "/api/ws0/messages", params=params
        ) as ws:
            logger.debug("Websocket connected")
            async for msg in ws:
                if msg.type == aiohttp.WSMsgType.TEXT:
                    if msg.data == "close cmd":
                        await ws.close()
                        break
                    else:
                        data = json.loads(msg.data)
                        yield parse_message(data)
                elif msg.type == aiohttp.WSMsgType.ERROR:
                    break

    async def get_program_price(self, item_hash: str) -> PriceResponse:
        async with self.http_session.get(f"/api/v0/price/{item_hash}") as resp:
            try:
                resp.raise_for_status()
                response_json = await resp.json()
                return PriceResponse(
                    required_tokens=response_json["required_tokens"],
                    payment_type=response_json["payment_type"],
                )
            except aiohttp.ClientResponseError as e:
                if e.status == 400:
                    raise InvalidHashError(f"Bad request or no such hash {item_hash}")
                raise e

    async def get_message_status(self, item_hash: str) -> MessageStatus:
        """return Status of a message"""
        async with self.http_session.get(f"/api/v0/messages/{item_hash}") as resp:
            if resp.status == HTTPNotFound.status_code:
                raise MessageNotFoundError(f"No such hash {item_hash}")
            resp.raise_for_status()