import {
	AccountSubscriber,
	DataAndSlot,
	DelistedMarketSetting,
	DriftClientAccountEvents,
	DriftClientAccountSubscriber,
	NotSubscribedError,
	ResubOpts,
} from './types';
import { PerpMarketAccount, SpotMarketAccount, StateAccount } from '../types';
import { Program } from '@coral-xyz/anchor';
import StrictEventEmitter from 'strict-event-emitter-types';
import { EventEmitter } from 'events';
import {
	getDriftStateAccountPublicKey,
	getPerpMarketPublicKey,
	getPerpMarketPublicKeySync,
	getSpotMarketPublicKey,
	getSpotMarketPublicKeySync,
} from '../addresses/pda';
import { WebSocketAccountSubscriber } from './webSocketAccountSubscriber';
import { Commitment, PublicKey } from '@solana/web3.js';
import { OracleInfo, OraclePriceData } from '../oracles/types';
import { OracleClientCache } from '../oracles/oracleClientCache';
import * as Buffer from 'buffer';
import { QUOTE_ORACLE_PRICE_DATA } from '../oracles/quoteAssetOracleClient';
import { findAllMarketAndOracles } from '../config';
import { findDelistedPerpMarketsAndOracles } from './utils';
import { getOracleId } from '../oracles/oracleId';
import { OracleSource } from '../types';

const ORACLE_DEFAULT_ID = getOracleId(
	PublicKey.default,
	OracleSource.QUOTE_ASSET
);

export class WebSocketDriftClientAccountSubscriber
	implements DriftClientAccountSubscriber
{
	isSubscribed: boolean;
	program: Program;
	commitment?: Commitment;
	perpMarketIndexes: number[];
	spotMarketIndexes: number[];
	oracleInfos: OracleInfo[];
	oracleClientCache = new OracleClientCache();

	resubOpts?: ResubOpts;
	shouldFindAllMarketsAndOracles: boolean;

	eventEmitter: StrictEventEmitter<EventEmitter, DriftClientAccountEvents>;
	stateAccountSubscriber?: AccountSubscriber<StateAccount>;
	perpMarketAccountSubscribers = new Map<
		number,
		AccountSubscriber<PerpMarketAccount>
	>();
	perpOracleMap = new Map<number, PublicKey>();
	perpOracleStringMap = new Map<number, string>();
	spotMarketAccountSubscribers = new Map<
		number,
		AccountSubscriber<SpotMarketAccount>
	>();
	spotOracleMap = new Map<number, PublicKey>();
	spotOracleStringMap = new Map<number, string>();
	oracleSubscribers = new Map<string, AccountSubscriber<OraclePriceData>>();
	delistedMarketSetting: DelistedMarketSetting;

	initialPerpMarketAccountData: Map<number, PerpMarketAccount>;
	initialSpotMarketAccountData: Map<number, SpotMarketAccount>;
	initialOraclePriceData: Map<string, OraclePriceData>;

	protected isSubscribing = false;
	protected subscriptionPromise: Promise<boolean>;
	protected subscriptionPromiseResolver: (val: boolean) => void;

	public constructor(
		program: Program,
		perpMarketIndexes: number[],
		spotMarketIndexes: number[],
		oracleInfos: OracleInfo[],
		shouldFindAllMarketsAndOracles: boolean,
		delistedMarketSetting: DelistedMarketSetting,
		resubOpts?: ResubOpts,
		commitment?: Commitment
	) {
		this.isSubscribed = false;
		this.program = program;
		this.eventEmitter = new EventEmitter();
		this.perpMarketIndexes = perpMarketIndexes;
		this.spotMarketIndexes = spotMarketIndexes;
		this.oracleInfos = oracleInfos;
		this.shouldFindAllMarketsAndOracles = shouldFindAllMarketsAndOracles;
		this.delistedMarketSetting = delistedMarketSetting;
		this.resubOpts = resubOpts;
		this.commitment = commitment;
	}

	public async subscribe(): Promise<boolean> {
		if (this.isSubscribed) {
			return true;
		}

		if (this.isSubscribing) {
			return await this.subscriptionPromise;
		}

		this.isSubscribing = true;

		this.subscriptionPromise = new Promise((res) => {
			this.subscriptionPromiseResolver = res;
		});

		if (this.shouldFindAllMarketsAndOracles) {
			const {
				perpMarketIndexes,
				perpMarketAccounts,
				spotMarketIndexes,
				spotMarketAccounts,
				oracleInfos,
			} = await findAllMarketAndOracles(this.program);
			this.perpMarketIndexes = perpMarketIndexes;
			this.spotMarketIndexes = spotMarketIndexes;
			this.oracleInfos = oracleInfos;
			// front run and set the initial data here to save extra gma call in set initial data
			this.initialPerpMarketAccountData = new Map(
				perpMarketAccounts.map((market) => [market.marketIndex, market])
			);
			this.initialSpotMarketAccountData = new Map(
				spotMarketAccounts.map((market) => [market.marketIndex, market])
			);
		}

		const statePublicKey = await getDriftStateAccountPublicKey(
			this.program.programId
		);

		// create and activate main state account subscription
		this.stateAccountSubscriber = new WebSocketAccountSubscriber(
			'state',
			this.program,
			statePublicKey,
			undefined,
			undefined,
			this.commitment
		);
		await this.stateAccountSubscriber.subscribe((data: StateAccount) => {
			this.eventEmitter.emit('stateAccountUpdate', data);
			this.eventEmitter.emit('update');
		});

		// set initial data to avoid spamming getAccountInfo calls in webSocketAccountSubscriber
		await this.setInitialData();

		await Promise.all([
			// subscribe to market accounts
			this.subscribeToPerpMarketAccounts(),
			// subscribe to spot market accounts
			this.subscribeToSpotMarketAccounts(),
			// subscribe to oracles
			this.subscribeToOracles(),
		]);

		this.eventEmitter.emit('update');

		await this.handleDelistedMarkets();

		await Promise.all([this.setPerpOracleMap(), this.setSpotOracleMap()]);

		this.isSubscribing = false;
		this.isSubscribed = true;
		this.subscriptionPromiseResolver(true);

		// delete initial data
		this.removeInitialData();

		return true;
	}

	chunks = <T>(array: readonly T[], size: number): T[][] => {
		return new Array(Math.ceil(array.length / size))
			.fill(null)
			.map((_, index) => index * size)
			.map((begin) => array.slice(begin, begin + size));
	};

	async setInitialData(): Promise<void> {
		const connection = this.program.provider.connection;

		if (!this.initialPerpMarketAccountData) {
			const perpMarketPublicKeys = this.perpMarketIndexes.map((marketIndex) =>
				getPerpMarketPublicKeySync(this.program.programId, marketIndex)
			);
			const perpMarketPublicKeysChunks = this.chunks(perpMarketPublicKeys, 75);
			const perpMarketAccountInfos = (
				await Promise.all(
					perpMarketPublicKeysChunks.map((perpMarketPublicKeysChunk) =>
						connection.getMultipleAccountsInfo(perpMarketPublicKeysChunk)
					)
				)
			).flat();
			this.initialPerpMarketAccountData = new Map(
				perpMarketAccountInfos
					.filter((accountInfo) => !!accountInfo)
					.map((accountInfo) => {
						const perpMarket = this.program.coder.accounts.decode(
							'PerpMarket',
							accountInfo.data
						);
						return [perpMarket.marketIndex, perpMarket];
					})
			);
		}

		if (!this.initialSpotMarketAccountData) {
			const spotMarketPublicKeys = this.spotMarketIndexes.map((marketIndex) =>
				getSpotMarketPublicKeySync(this.program.programId, marketIndex)
			);
			const spotMarketPublicKeysChunks = this.chunks(spotMarketPublicKeys, 75);
			const spotMarketAccountInfos = (
				await Promise.all(
					spotMarketPublicKeysChunks.map((spotMarketPublicKeysChunk) =>
						connection.getMultipleAccountsInfo(spotMarketPublicKeysChunk)
					)
				)
			).flat();
			this.initialSpotMarketAccountData = new Map(
				spotMarketAccountInfos
					.filter((accountInfo) => !!accountInfo)
					.map((accountInfo) => {
						const spotMarket = this.program.coder.accounts.decode(
							'SpotMarket',
							accountInfo.data
						);
						return [spotMarket.marketIndex, spotMarket];
					})
			);
		}

		const oracleAccountPubkeyChunks = this.chunks(
			this.oracleInfos.map((oracleInfo) => oracleInfo.publicKey),
			75
		);
		const oracleAccountInfos = (
			await Promise.all(
				oracleAccountPubkeyChunks.map((oracleAccountPublicKeysChunk) =>
					connection.getMultipleAccountsInfo(oracleAccountPublicKeysChunk)
				)
			)
		).flat();
		this.initialOraclePriceData = new Map(
			this.oracleInfos.reduce((result, oracleInfo, i) => {
				if (!oracleAccountInfos[i]) {
					return result;
				}

				const oracleClient = this.oracleClientCache.get(
					oracleInfo.source,
					connection,
					this.program
				);

				const oraclePriceData = oracleClient.getOraclePriceDataFromBuffer(
					oracleAccountInfos[i].data
				);

				result.push([
					getOracleId(oracleInfo.publicKey, oracleInfo.source),
					oraclePriceData,
				]);
				return result;
			}, [])
		);
	}

	removeInitialData() {
		this.initialPerpMarketAccountData = new Map();
		this.initialSpotMarketAccountData = new Map();
		this.initialOraclePriceData = new Map();
	}

	async subscribeToPerpMarketAccounts(): Promise<boolean> {
		await Promise.all(
			this.perpMarketIndexes.map((marketIndex) =>
				this.subscribeToPerpMarketAccount(marketIndex)
			)
		);
		return true;
	}

	async subscribeToPerpMarketAccount(marketIndex: number): Promise<boolean> {
		const perpMarketPublicKey = await getPerpMarketPublicKey(
			this.program.programId,
			marketIndex
		);
		const accountSubscriber = new WebSocketAccountSubscriber<PerpMarketAccount>(
			'perpMarket',
			this.program,
			perpMarketPublicKey,
			undefined,
			this.resubOpts,
			this.commitment
		);
		accountSubscriber.setData(
			this.initialPerpMarketAccountData.get(marketIndex)
		);
		await accountSubscriber.subscribe((data: PerpMarketAccount) => {
			this.eventEmitter.emit('perpMarketAccountUpdate', data);
			this.eventEmitter.emit('update');
		});
		this.perpMarketAccountSubscribers.set(marketIndex, accountSubscriber);
		return true;
	}

	async subscribeToSpotMarketAccounts(): Promise<boolean> {
		await Promise.all(
			this.spotMarketIndexes.map((marketIndex) =>
				this.subscribeToSpotMarketAccount(marketIndex)
			)
		);
		return true;
	}

	async subscribeToSpotMarketAccount(marketIndex: number): Promise<boolean> {
		const marketPublicKey = await getSpotMarketPublicKey(
			this.program.programId,
			marketIndex
		);
		const accountSubscriber = new WebSocketAccountSubscriber<SpotMarketAccount>(
			'spotMarket',
			this.program,
			marketPublicKey,
			undefined,
			this.resubOpts,
			this.commitment
		);
		accountSubscriber.setData(
			this.initialSpotMarketAccountData.get(marketIndex)
		);
		await accountSubscriber.subscribe((data: SpotMarketAccount) => {
			this.eventEmitter.emit('spotMarketAccountUpdate', data);
			this.eventEmitter.emit('update');
		});
		this.spotMarketAccountSubscribers.set(marketIndex, accountSubscriber);
		return true;
	}

	async subscribeToOracles(): Promise<boolean> {
		await Promise.all(
			this.oracleInfos
				.filter((oracleInfo) => !oracleInfo.publicKey.equals(PublicKey.default))
				.map((oracleInfo) => this.subscribeToOracle(oracleInfo))
		);

		return true;
	}

	async subscribeToOracle(oracleInfo: OracleInfo): Promise<boolean> {
		const oracleId = getOracleId(oracleInfo.publicKey, oracleInfo.source);
		const client = this.oracleClientCache.get(
			oracleInfo.source,
			this.program.provider.connection,
			this.program
		);
		const accountSubscriber = new WebSocketAccountSubscriber<OraclePriceData>(
			'oracle',
			this.program,
			oracleInfo.publicKey,
			(buffer: Buffer) => {
				return client.getOraclePriceDataFromBuffer(buffer);
			},
			this.resubOpts,
			this.commitment
		);
		const initialOraclePriceData = this.initialOraclePriceData.get(oracleId);
		if (initialOraclePriceData) {
			accountSubscriber.setData(initialOraclePriceData);
		}
		await accountSubscriber.subscribe((data: OraclePriceData) => {
			this.eventEmitter.emit(
				'oraclePriceUpdate',
				oracleInfo.publicKey,
				oracleInfo.source,
				data
			);
			this.eventEmitter.emit('update');
		});

		this.oracleSubscribers.set(oracleId, accountSubscriber);
		return true;
	}

	async unsubscribeFromMarketAccounts(): Promise<void> {
		await Promise.all(
			Array.from(this.perpMarketAccountSubscribers.values()).map(
				(accountSubscriber) => accountSubscriber.unsubscribe()
			)
		);
	}

	async unsubscribeFromSpotMarketAccounts(): Promise<void> {
		await Promise.all(
			Array.from(this.spotMarketAccountSubscribers.values()).map(
				(accountSubscriber) => accountSubscriber.unsubscribe()
			)
		);
	}

	async unsubscribeFromOracles(): Promise<void> {
		await Promise.all(
			Array.from(this.oracleSubscribers.values()).map((accountSubscriber) =>
				accountSubscriber.unsubscribe()
			)
		);
	}

	public async fetch(): Promise<void> {
		if (!this.isSubscribed) {
			return;
		}

		const promises = [this.stateAccountSubscriber.fetch()]
			.concat(
				Array.from(this.perpMarketAccountSubscribers.values()).map(
					(subscriber) => subscriber.fetch()
				)
			)
			.concat(
				Array.from(this.spotMarketAccountSubscribers.values()).map(
					(subscriber) => subscriber.fetch()
				)
			);

		await Promise.all(promises);
	}

	public async unsubscribe(): Promise<void> {
		if (!this.isSubscribed) {
			return;
		}

		await this.stateAccountSubscriber.unsubscribe();

		await this.unsubscribeFromMarketAccounts();
		await this.unsubscribeFromSpotMarketAccounts();
		await this.unsubscribeFromOracles();

		this.isSubscribed = false;
	}

	async addSpotMarket(marketIndex: number): Promise<boolean> {
		if (this.spotMarketAccountSubscribers.has(marketIndex)) {
			return true;
		}
		const subscriptionSuccess = this.subscribeToSpotMarketAccount(marketIndex);
		await this.setSpotOracleMap();
		return subscriptionSuccess;
	}

	async addPerpMarket(marketIndex: number): Promise<boolean> {
		if (this.perpMarketAccountSubscribers.has(marketIndex)) {
			return true;
		}
		const subscriptionSuccess = this.subscribeToPerpMarketAccount(marketIndex);
		await this.setPerpOracleMap();
		return subscriptionSuccess;
	}

	async addOracle(oracleInfo: OracleInfo): Promise<boolean> {
		const oracleId = getOracleId(oracleInfo.publicKey, oracleInfo.source);
		if (this.oracleSubscribers.has(oracleId)) {
			return true;
		}

		if (oracleInfo.publicKey.equals(PublicKey.default)) {
			return true;
		}

		return this.subscribeToOracle(oracleInfo);
	}

	async setPerpOracleMap() {
		const perpMarkets = this.getMarketAccountsAndSlots();
		const addOraclePromises = [];
		for (const perpMarket of perpMarkets) {
			if (!perpMarket || !perpMarket.data) {
				continue;
			}
			const perpMarketAccount = perpMarket.data;
			const perpMarketIndex = perpMarketAccount.marketIndex;
			const oracle = perpMarketAccount.amm.oracle;
			const oracleId = getOracleId(oracle, perpMarket.data.amm.oracleSource);
			if (!this.oracleSubscribers.has(oracleId)) {
				addOraclePromises.push(
					this.addOracle({
						publicKey: oracle,
						source: perpMarket.data.amm.oracleSource,
					})
				);
			}
			this.perpOracleMap.set(perpMarketIndex, oracle);
			this.perpOracleStringMap.set(perpMarketIndex, oracleId);
		}
		await Promise.all(addOraclePromises);
	}

	async setSpotOracleMap() {
		const spotMarkets = this.getSpotMarketAccountsAndSlots();
		const addOraclePromises = [];
		for (const spotMarket of spotMarkets) {
			if (!spotMarket || !spotMarket.data) {
				continue;
			}
			const spotMarketAccount = spotMarket.data;
			const spotMarketIndex = spotMarketAccount.marketIndex;
			const oracle = spotMarketAccount.oracle;
			const oracleId = getOracleId(oracle, spotMarketAccount.oracleSource);
			if (!this.oracleSubscribers.has(oracleId)) {
				addOraclePromises.push(
					this.addOracle({
						publicKey: oracle,
						source: spotMarketAccount.oracleSource,
					})
				);
			}
			this.spotOracleMap.set(spotMarketIndex, oracle);
			this.spotOracleStringMap.set(spotMarketIndex, oracleId);
		}
		await Promise.all(addOraclePromises);
	}

	async handleDelistedMarkets(): Promise<void> {
		if (this.delistedMarketSetting === DelistedMarketSetting.Subscribe) {
			return;
		}

		const { perpMarketIndexes, oracles } = findDelistedPerpMarketsAndOracles(
			this.getMarketAccountsAndSlots(),
			this.getSpotMarketAccountsAndSlots()
		);

		for (const perpMarketIndex of perpMarketIndexes) {
			await this.perpMarketAccountSubscribers
				.get(perpMarketIndex)
				.unsubscribe();
			if (this.delistedMarketSetting === DelistedMarketSetting.Discard) {
				this.perpMarketAccountSubscribers.delete(perpMarketIndex);
			}
		}

		for (const oracle of oracles) {
			const oracleId = getOracleId(oracle.publicKey, oracle.source);
			await this.oracleSubscribers.get(oracleId).unsubscribe();
			if (this.delistedMarketSetting === DelistedMarketSetting.Discard) {
				this.oracleSubscribers.delete(oracleId);
			}
		}
	}

	assertIsSubscribed(): void {
		if (!this.isSubscribed) {
			throw new NotSubscribedError(
				'You must call `subscribe` before using this function'
			);
		}
	}

	public getStateAccountAndSlot(): DataAndSlot<StateAccount> {
		this.assertIsSubscribed();
		return this.stateAccountSubscriber.dataAndSlot;
	}

	public getMarketAccountAndSlot(
		marketIndex: number
	): DataAndSlot<PerpMarketAccount> | undefined {
		this.assertIsSubscribed();
		return this.perpMarketAccountSubscribers.get(marketIndex).dataAndSlot;
	}

	public getMarketAccountsAndSlots(): DataAndSlot<PerpMarketAccount>[] {
		return Array.from(this.perpMarketAccountSubscribers.values()).map(
			(subscriber) => subscriber.dataAndSlot
		);
	}

	public getSpotMarketAccountAndSlot(
		marketIndex: number
	): DataAndSlot<SpotMarketAccount> | undefined {
		this.assertIsSubscribed();
		return this.spotMarketAccountSubscribers.get(marketIndex).dataAndSlot;
	}

	public getSpotMarketAccountsAndSlots(): DataAndSlot<SpotMarketAccount>[] {
		return Array.from(this.spotMarketAccountSubscribers.values()).map(
			(subscriber) => subscriber.dataAndSlot
		);
	}

	public getOraclePriceDataAndSlot(
		oracleId: string
	): DataAndSlot<OraclePriceData> | undefined {
		this.assertIsSubscribed();
		if (oracleId === ORACLE_DEFAULT_ID) {
			return {
				data: QUOTE_ORACLE_PRICE_DATA,
				slot: 0,
			};
		}
		return this.oracleSubscribers.get(oracleId).dataAndSlot;
	}

	public getOraclePriceDataAndSlotForPerpMarket(
		marketIndex: number
	): DataAndSlot<OraclePriceData> | undefined {
		const perpMarketAccount = this.getMarketAccountAndSlot(marketIndex);
		const oracle = this.perpOracleMap.get(marketIndex);
		const oracleId = this.perpOracleStringMap.get(marketIndex);
		if (!perpMarketAccount || !oracleId) {
			return undefined;
		}

		if (!perpMarketAccount.data.amm.oracle.equals(oracle)) {
			// If the oracle has changed, we need to update the oracle map in background
			this.setPerpOracleMap();
		}

		return this.getOraclePriceDataAndSlot(oracleId);
	}

	public getOraclePriceDataAndSlotForSpotMarket(
		marketIndex: number
	): DataAndSlot<OraclePriceData> | undefined {
		const spotMarketAccount = this.getSpotMarketAccountAndSlot(marketIndex);
		const oracle = this.spotOracleMap.get(marketIndex);
		const oracleId = this.spotOracleStringMap.get(marketIndex);
		if (!spotMarketAccount || !oracleId) {
			return undefined;
		}

		if (!spotMarketAccount.data.oracle.equals(oracle)) {
			// If the oracle has changed, we need to update the oracle map in background
			this.setSpotOracleMap();
		}

		return this.getOraclePriceDataAndSlot(oracleId);
	}
}