logos-blockchain-block-explorer-template/src/core/app.py

from asyncio import Task, gather
from typing import Literal, Optional

from fastapi import FastAPI
from pydantic_settings import BaseSettings, SettingsConfigDict
from starlette.datastructures import State

from db.blocks import BlockRepository
from db.clients import DbClient
from db.transaction import TransactionRepository
from node.api.base import NodeApi
from node.manager.base import NodeManager
from src import DIR_REPO

ENV_FILEPATH = DIR_REPO.joinpath(".env")


class NBESettings(BaseSettings):
    model_config = SettingsConfigDict(env_file=ENV_FILEPATH, extra="ignore")

    node_compose_filepath: str

    node_api: Literal["http", "fake"]
    node_manager: Literal["docker", "noop"]

    node_api_host: str = "127.0.0.1"
    node_api_port: int = 8000
    node_api_timeout: int = 60
    node_api_protocol: str = "http"


class NBEState(State):
    signal_exit: bool = False  # TODO: asyncio.Event
    node_manager: Optional[NodeManager]
    node_api: Optional[NodeApi]
    db_client: DbClient
    block_repository: BlockRepository
    transaction_repository: TransactionRepository
    subscription_to_updates_handle: Task
    backfill_handle: Task

    @property
    def is_running(self) -> bool:
        return not self.signal_exit

    async def stop(self):
        self.signal_exit = True
        await self._wait_tasks_finished()

    async def _wait_tasks_finished(self):
        await gather(
            self.subscription_to_updates_handle,
            self.backfill_handle,
            return_exceptions=True,
        )


class NBE(FastAPI):
    state: NBEState
    settings: NBESettings

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.state = NBEState()
        self.settings = NBESettings()  # type: ignore[call-arg] # The missing parameter is filled from the env file