coop/backend/src/services/solana.ts

import {
	ASSOCIATED_TOKEN_PROGRAM_ID,
	createBurnInstruction,
	createMintToInstruction,
	getAccount,
	getOrCreateAssociatedTokenAccount,
	TOKEN_PROGRAM_ID,
} from "@solana/spl-token";
import {
	Connection,
	Keypair,
	PublicKey,
	SystemProgram,
	sendAndConfirmTransaction,
	Transaction,
} from "@solana/web3.js";
import bs58 from "bs58";
import { prisma } from "../utils/prisma";

const RPC_URL = process.env.SOLANA_RPC_URL || "https://api.devnet.solana.com";
const PROGRAM_ID = new PublicKey(
	process.env.SOLANA_PROGRAM_ID ||
		"CoopCredits111111111111111111111111111111111",
);
const DECIMALS = parseInt(process.env.SOLANA_TOKEN_DECIMALS || "6");

// Backend mint authority keypair (stored securely)
let mintAuthority: Keypair | null = null;

try {
	if (process.env.SOLANA_MINT_AUTHORITY_KEYPAIR) {
		const raw = process.env.SOLANA_MINT_AUTHORITY_KEYPAIR.trim();
		let secretKey: Uint8Array;
		if (raw.startsWith("[")) {
			secretKey = new Uint8Array(JSON.parse(raw));
		} else {
			secretKey = bs58.decode(raw);
		}
		mintAuthority = Keypair.fromSecretKey(secretKey);
	}
} catch (error) {
	console.warn("Mint authority not configured");
}

export const connection = new Connection(RPC_URL, "confirmed");

// Get token mint address from program state
export async function getTokenMint(): Promise<PublicKey | null> {
	try {
		// In a real implementation, you'd derive this from the program state
		// For now, return from environment or stored config
		const config = await prisma.systemSettings.findFirst();
		if (config) {
			// Store/retrieve mint address from config
			return null; // Placeholder
		}
		return null;
	} catch (error) {
		console.error("Failed to get token mint:", error);
		return null;
	}
}

// Create a new Solana wallet for a user
export function createWallet(): { publicKey: string; secretKey: string } {
	const keypair = Keypair.generate();

	return {
		publicKey: keypair.publicKey.toBase58(),
		secretKey: bs58.encode(keypair.secretKey),
	};
}

// Get or create token account for user
export async function getOrCreateTokenAccount(
	userPublicKey: PublicKey,
	mint: PublicKey,
): Promise<PublicKey> {
	const tokenAccount = await getOrCreateAssociatedTokenAccount(
		connection,
		mintAuthority!, // payer
		mint,
		userPublicKey,
	);

	return tokenAccount.address;
}

// Mint tokens to user (called by backend after watch event)
export async function mintTokens(
	userWalletAddress: string,
	amount: number,
	metadata: {
		sessionId: string;
		contentTitle: string;
		watchDurationMinutes: number;
	},
): Promise<string | null> {
	if (!mintAuthority) {
		throw new Error("Mint authority not configured");
	}

	try {
		const userPublicKey = new PublicKey(userWalletAddress);
		const mint = await getTokenMint();

		if (!mint) {
			throw new Error("Token mint not found");
		}

		// Get or create user's token account
		const tokenAccount = await getOrCreateTokenAccount(userPublicKey, mint);

		// Calculate amount with decimals
		const amountWithDecimals = amount * 10 ** DECIMALS;

		// Create mint instruction
		const mintInstruction = createMintToInstruction(
			mint,
			tokenAccount,
			mintAuthority.publicKey,
			BigInt(Math.floor(amountWithDecimals)),
		);

		// Create and send transaction
		const transaction = new Transaction().add(mintInstruction);
		const signature = await sendAndConfirmTransaction(connection, transaction, [
			mintAuthority,
		]);

		console.log(`Minted ${amount} COOP to ${userWalletAddress}: ${signature}`);

		return signature;
	} catch (error) {
		console.error("Failed to mint tokens:", error);
		return null;
	}
}

// Burn tokens from user (called when content request is approved)
export async function burnTokens(
	userWalletAddress: string,
	userSecretKey: string,
	amount: number,
): Promise<string | null> {
	try {
		const userKeypair = Keypair.fromSecretKey(bs58.decode(userSecretKey));
		const mint = await getTokenMint();

		if (!mint) {
			throw new Error("Token mint not found");
		}

		const userPublicKey = new PublicKey(userWalletAddress);
		const tokenAccount = await getOrCreateTokenAccount(userPublicKey, mint);

		// Check balance
		const accountInfo = await getAccount(connection, tokenAccount);
		const amountWithDecimals = BigInt(Math.floor(amount * 10 ** DECIMALS));

		if (accountInfo.amount < amountWithDecimals) {
			throw new Error("Insufficient balance");
		}

		// Create burn instruction
		const burnInstruction = createBurnInstruction(
			tokenAccount,
			mint,
			userKeypair.publicKey,
			amountWithDecimals,
		);

		const transaction = new Transaction().add(burnInstruction);
		const signature = await sendAndConfirmTransaction(connection, transaction, [
			userKeypair,
		]);

		console.log(
			`Burned ${amount} COOP from ${userWalletAddress}: ${signature}`,
		);

		return signature;
	} catch (error) {
		console.error("Failed to burn tokens:", error);
		return null;
	}
}

// Get token balance for user
export async function getTokenBalance(walletAddress: string): Promise<number> {
	try {
		const mint = await getTokenMint();
		if (!mint) return 0;

		const userPublicKey = new PublicKey(walletAddress);

		try {
			const tokenAccount = await getOrCreateAssociatedTokenAccount(
				connection,
				mintAuthority!,
				mint,
				userPublicKey,
			);

			const accountInfo = await getAccount(connection, tokenAccount.address);
			return Number(accountInfo.amount) / 10 ** DECIMALS;
		} catch {
			return 0;
		}
	} catch (error) {
		console.error("Failed to get token balance:", error);
		return 0;
	}
}

// Request airdrop for testing (devnet only)
export async function requestAirdrop(
	walletAddress: string,
): Promise<string | null> {
	try {
		const publicKey = new PublicKey(walletAddress);
		const signature = await connection.requestAirdrop(
			publicKey,
			2 * 1000000000,
		); // 2 SOL
		await connection.confirmTransaction(signature);
		return signature;
	} catch (error) {
		console.error("Airdrop failed:", error);
		return null;
	}
}