import { LIQUIDITY_STATE_LAYOUT_V4, MAINNET_PROGRAM_ID, MARKET_STATE_LAYOUT_V3, Token } from "@raydium-io/raydium-sdk";
import bs58 from "bs58";
import { Connection, PublicKey } from "@solana/web3.js";
import { TOKEN_PROGRAM_ID } from "@solana/spl-token";
import { EventEmitter } from "events";

export class Listeners extends EventEmitter {
	private subscriptions: number[] = [];

	constructor(private readonly connection: Connection) {
		super();
	}

	public async start(config: {
		walletPublicKey: PublicKey;
		quoteToken: Token;
		autoSell: boolean;
		cacheNewMarkets: boolean;
	}) {
		if (config.cacheNewMarkets) {
			const openBookSubscription = await this.subscribeToOpenBookMarkets(config);
			this.subscriptions.push(openBookSubscription);
		}

		const raydiumSubscription = await this.subscribeToRaydiumPools(config);
		this.subscriptions.push(raydiumSubscription);

		if (config.autoSell) {
			const walletSubscription = await this.subscribeToWalletChanges(config);
			this.subscriptions.push(walletSubscription);
		}
	}

	private async subscribeToOpenBookMarkets(config: { quoteToken: Token }) {
		return this.connection.onProgramAccountChange(
			MAINNET_PROGRAM_ID.OPENBOOK_MARKET,
			async (updatedAccountInfo) => {
				this.emit("market", updatedAccountInfo);
			},
			this.connection.commitment,
			[
				{ dataSize: MARKET_STATE_LAYOUT_V3.span },
				{
					memcmp: {
						offset: MARKET_STATE_LAYOUT_V3.offsetOf("quoteMint"),
						bytes: config.quoteToken.mint.toBase58(),
					},
				},
			],
		);
	}

	private async subscribeToRaydiumPools(config: { quoteToken: Token }) {
		return this.connection.onProgramAccountChange(
			MAINNET_PROGRAM_ID.AmmV4,
			async (updatedAccountInfo) => {
				this.emit("pool", updatedAccountInfo);
			},
			this.connection.commitment,
			[
				{ dataSize: LIQUIDITY_STATE_LAYOUT_V4.span },
				{
					memcmp: {
						offset: LIQUIDITY_STATE_LAYOUT_V4.offsetOf("quoteMint"),
						bytes: config.quoteToken.mint.toBase58(),
					},
				},
				{
					memcmp: {
						offset: LIQUIDITY_STATE_LAYOUT_V4.offsetOf("marketProgramId"),
						bytes: MAINNET_PROGRAM_ID.OPENBOOK_MARKET.toBase58(),
					},
				},
				{
					memcmp: {
						offset: LIQUIDITY_STATE_LAYOUT_V4.offsetOf("status"),
						bytes: bs58.encode([6, 0, 0, 0, 0, 0, 0, 0]),
					},
				},
			],
		);
	}

	private async subscribeToWalletChanges(config: { walletPublicKey: PublicKey }) {
		return this.connection.onProgramAccountChange(
			TOKEN_PROGRAM_ID,
			async (updatedAccountInfo) => {
				this.emit("wallet", updatedAccountInfo);
			},
			this.connection.commitment,
			[
				{
					dataSize: 165,
				},
				{
					memcmp: {
						offset: 32,
						bytes: config.walletPublicKey.toBase58(),
					},
				},
			],
		);
	}

	public async stop() {
		for (let i = this.subscriptions.length; i >= 0; --i) {
			const subscription = this.subscriptions[i];
			await this.connection.removeAccountChangeListener(subscription);
			this.subscriptions.splice(i, 1);
		}
	}
}