import type { Observable } from "rxjs"
import { first, mergeMap, startWith } from "rxjs/operators"
import type { default as Torus } from "@toruslabs/torus-embed"
import type { TorusParams } from "@toruslabs/torus-embed/dist/types/interfaces"
import type {
	ConnectionState,
	EthereumProviderConnectionResult, Maybe,
} from "@rarible/connector"
import {
	AbstractConnectionProvider,
	cache, connectToWeb3, getStateConnecting,
} from "@rarible/connector"

export type TorusConfig = TorusParams

const PROVIDER_ID = "torus" as const

export class TorusConnectionProvider extends
	AbstractConnectionProvider<typeof PROVIDER_ID, EthereumProviderConnectionResult> {
	private readonly instance: Observable<Torus>
	private readonly connection: Observable<ConnectionState<EthereumProviderConnectionResult>>

	constructor(
		private readonly config: TorusConfig
	) {
		super()
		this.instance = cache(() => this._connect())
		this.connection = this.instance.pipe(
			mergeMap(instance => {
				const disconnect = () => instance.cleanUp()
				return connectToWeb3(instance.provider, { disconnect })
			}),
			startWith(getStateConnecting({ providerId: PROVIDER_ID })),
		)
	}

	private async _connect(): Promise<Torus> {
		const { default: Torus } = await import("@toruslabs/torus-embed")
		const torus = new Torus()
		await torus.init(this.config)
		await torus.login()
		return torus
	}

	getId(): string {
		return PROVIDER_ID
	}

	getConnection() {
		return this.connection
	}

	getOption(): Promise<Maybe<typeof PROVIDER_ID>> {
		return Promise.resolve(PROVIDER_ID)
	}

	async isAutoConnected(): Promise<boolean> {
		return false
	}

	async isConnected(): Promise<boolean> {
		const sdk = await this.instance.pipe(first()).toPromise()
		return !!(sdk?.isInitialized && sdk?.isLoggedIn)
	}
}