import assert from 'assert';

import { Connection, PublicKey, Transaction } from '@solana/web3.js'
import {
  TOKEN_PROGRAM_ID,
  createTransferInstruction,
  createAssociatedTokenAccountInstruction,
  ASSOCIATED_TOKEN_PROGRAM_ID
} from '@solana/spl-token'

import { WalletType } from './types'

assert(process.env.NEXT_PUBLIC_SOLANA_RPC_URL, 'SOLANA_RPC_URL is required');
assert(process.env.NEXT_PUBLIC_MTM_TOKEN_MINT, 'MTM_TOKEN_MINT is required');
assert(process.env.NEXT_PUBLIC_PAYMENT_RECEIVER_ADDRESS, 'PAYMENT_RECEIVER_ADDRESS is required');

const MTM_TOKEN_MINT = process.env.NEXT_PUBLIC_MTM_TOKEN_MINT;
const PAYMENT_RECEIVER_ADDRESS = process.env.NEXT_PUBLIC_PAYMENT_RECEIVER_ADDRESS;
const SOLANA_RPC_URL = process.env.NEXT_PUBLIC_SOLANA_RPC_URL;
const SOLANA_WEBSOCKET_URL = process.env.NEXT_PUBLIC_SOLANA_WEBSOCKET_URL;

const USDC_MINT = 'EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v'; // USDC mint address

const connection = new Connection(
  SOLANA_RPC_URL,
  {
    commitment: 'confirmed',
    wsEndpoint: SOLANA_WEBSOCKET_URL,
    confirmTransactionInitialTimeout: 60000,
  }
)

export interface PaymentResult {
  success: boolean
  transactionSignature?: string
  error?: string
}

async function findAssociatedTokenAddress(
  walletAddress: PublicKey,
  tokenMintAddress: PublicKey
): Promise<PublicKey> {
  return PublicKey.findProgramAddressSync(
    [
      walletAddress.toBuffer(),
      TOKEN_PROGRAM_ID.toBuffer(),
      tokenMintAddress.toBuffer(),
    ],
    ASSOCIATED_TOKEN_PROGRAM_ID
  )[0]
}

export async function getUSDCToMTMQuote() {
  const url = `https://api.jup.ag/price/v2?ids=${USDC_MINT}&vsToken=${MTM_TOKEN_MINT}`;

  const response = await fetch(url);

  if (!response.ok) {
    throw new Error(`Failed to fetch quote: ${response.statusText}`);
  }

  const quoteResponse = await response.json();
  const price = quoteResponse['data'][USDC_MINT]['price']

  return price;
}

interface WalletAdapter {
  signAndSendTransaction(transaction: Transaction): Promise<{ signature: string }>
}

export async function processMTMPayment(
  walletPublicKey: string,
  tokenAmount: number,
  walletType: WalletType
): Promise<PaymentResult> {
  try {
    let wallet: WalletAdapter | null = null;

    if (walletType === 'phantom') {
      wallet = window.phantom?.solana || null;
    } else if (walletType === 'solflare') {
      wallet = window.solflare || null;
    }

    if (!wallet) {
      throw new Error(`${walletType} wallet not found`)
    }

    const senderPublicKey = new PublicKey(walletPublicKey)
    const mintPublicKey = new PublicKey(MTM_TOKEN_MINT)
    const receiverPublicKey = new PublicKey(PAYMENT_RECEIVER_ADDRESS)

    console.log('Processing payment with keys:', {
      sender: senderPublicKey.toBase58(),
      mint: mintPublicKey.toBase58(),
      receiver: receiverPublicKey.toBase58(),
    })

    const senderATA = await findAssociatedTokenAddress(
      senderPublicKey,
      mintPublicKey
    )

    const receiverATA = await findAssociatedTokenAddress(
      receiverPublicKey,
      mintPublicKey
    )

    console.log('Token accounts:', {
      senderATA: senderATA.toBase58(),
      receiverATA: receiverATA.toBase58(),
    })

    const transaction = new Transaction()

    const [senderATAInfo, receiverATAInfo] = await Promise.all([
      connection.getAccountInfo(senderATA),
      connection.getAccountInfo(receiverATA),
    ])

    if (!receiverATAInfo) {
      console.log('Creating receiver token account')
      transaction.add(
        createAssociatedTokenAccountInstruction(
          senderPublicKey,
          receiverATA,
          receiverPublicKey,
          mintPublicKey
        )
      )
    }

    if (!senderATAInfo) {
      console.log('Creating sender token account')
      transaction.add(
        createAssociatedTokenAccountInstruction(
          senderPublicKey,
          senderATA,
          senderPublicKey,
          mintPublicKey
        )
      )
    }

    transaction.add(
      createTransferInstruction(
        senderATA,
        receiverATA,
        senderPublicKey,
        BigInt(tokenAmount * (10 ** 6))
      )
    )

    const latestBlockhash = await connection.getLatestBlockhash('confirmed')
    transaction.recentBlockhash = latestBlockhash.blockhash
    transaction.feePayer = senderPublicKey

    console.log('Sending transaction...')
    const { signature } = await wallet.signAndSendTransaction(transaction)
    console.log('Transaction sent:', signature)

    const confirmation = await connection.confirmTransaction({
      signature,
      blockhash: latestBlockhash.blockhash,
      lastValidBlockHeight: latestBlockhash.lastValidBlockHeight,
    }, 'confirmed')

    if (confirmation.value.err) {
      console.error('Transaction error:', confirmation.value.err)
      throw new Error(`Transaction failed: ${JSON.stringify(confirmation.value.err)}`)
    }

    return { success: true, transactionSignature: signature };
  } catch (error) {
    console.error('Payment error:', error)
    return {
      success: false,
      error: error instanceof Error ? error.message : 'Payment failed'
    }
  }
}