import { ethers } from 'ethers';
import { Connection, PublicKey, Keypair, Transaction, SystemProgram, clusterApiUrl, LAMPORTS_PER_SOL } from '@solana/web3.js';
import { getAssociatedTokenAddress, getAccount } from '@solana/spl-token';
import bs58 from 'bs58';
import cryptoConfig from './crypto-config.json';
const { TronWeb } = require('tronweb');

// ERC20 ABI for checking USDT/USDC balances
const ERC20_ABI = [
    "function balanceOf(address owner) view returns (uint256)",
    "function decimals() view returns (uint8)",
    "function symbol() view returns (string)",
    "function transfer(address to, uint256 value) public returns (bool)"
];

export class CryptoEngine {
    private provider!: ethers.JsonRpcProvider;
    private solConnection!: Connection;
    private tronWeb: any;
    private network: string;
    private config: any;

    constructor(networkId: string = 'POLYGON') {
        this.network = networkId;
        this.config = cryptoConfig.networks.find(n => n.id === networkId);
        
        if (!this.config) throw new Error(`Network ${networkId} not found in config.`);

        if (this.network === 'SOLANA') {
            this.solConnection = new Connection(this.config.rpc, 'confirmed');
        } else if (this.network === 'TRON') {
            this.tronWeb = new TronWeb({
                fullHost: this.config.rpc,
                headers: { "TRON-PRO-API-KEY": process.env.TRON_GRID_API_KEY || "" }
            });
        } else if (this.network === 'BITCOIN') {
            // Bitcoin usually handled via Electrum OR simple Public API
        } else {
            this.provider = new ethers.JsonRpcProvider(this.config.rpc);
        }
    }

    /**
     * Helper to get token config from JSON
     */
    private getTokenConfig(symbol: string) {
        return this.config.tokens.find((t: any) => t.symbol === symbol);
    }

    /**
     * Generates a temporary wallet for a transaction.
     */
    static async createTemporaryWallet(network: string = 'POLYGON'): Promise<{ address: string, privateKey: string }> {
        if (network === 'SOLANA') {
            const keypair = Keypair.generate();
            return {
                address: keypair.publicKey.toBase58(),
                privateKey: bs58.encode(keypair.secretKey)
            };
        } else if (network === 'TRON') {
            const tempTronWeb = new TronWeb({ fullHost: 'https://api.trongrid.io' });
            const account = await tempTronWeb.createAccount();
            return {
                address: account.address.base58,
                privateKey: account.privateKey
            };
        } else if (network === 'BITCOIN') {
             // Mock SegWit address for logic
             return {
                 address: `bc1q${Math.random().toString(36).substring(2, 12)}...MOCK`,
                 privateKey: 'MOCK_BTC_PRIVATE_KEY'
             };
        } else {
            const wallet = ethers.Wallet.createRandom();
            return {
                address: wallet.address,
                privateKey: wallet.privateKey
            };
        }
    }

    /**
     * Sweeps funds from temporary wallet to Platform and Merchant
     */
    async sweepFunds(
        tempWalletPrivateKey: string,
        merchantAddress: string,
        platformAddress: string,
        tokenSymbol: string = 'USDT',
        feePercent: number = 1.0
    ) {
        if (this.network === 'SOLANA') {
            return this.sweepSolana(tempWalletPrivateKey, merchantAddress, platformAddress, tokenSymbol, feePercent);
        } else if (this.network === 'TRON') {
            return this.sweepTron(tempWalletPrivateKey, merchantAddress, platformAddress, tokenSymbol, feePercent);
        } else if (this.network === 'BITCOIN') {
            return this.sweepBitcoin(tempWalletPrivateKey, merchantAddress, platformAddress, tokenSymbol, feePercent);
        } else {
            return this.sweepEVM(tempWalletPrivateKey, merchantAddress, platformAddress, tokenSymbol, feePercent);
        }
    }

    private async sweepEVM(
        tempWalletPrivateKey: string,
        merchantAddress: string,
        platformAddress: string,
        tokenSymbol: string,
        feePercent: number
    ) {
        const tempWallet = new ethers.Wallet(tempWalletPrivateKey, this.provider);
        const tokenConfig = this.getTokenConfig(tokenSymbol);
        if (!tokenConfig) throw new Error(`Unsupported token ${tokenSymbol} on ${this.network}`);

        console.log(`[Sweep EVM] Split: ${feePercent}% to Platform, ${100 - feePercent}% to Merchant`);

        // Mocking the real transfer for demo
        return {
            success: true,
            platformTx: '0x' + Math.random().toString(16).slice(2, 66),
            merchantTx: '0x' + Math.random().toString(16).slice(2, 66)
        };
    }

    async fuelWallet(targetAddress: string, amount: string) {
        const gasTankKey = process.env.CRYPTO_GAS_TANK_KEY;
        if (!gasTankKey) {
            console.warn("[CryptoEngine] No CRYPTO_GAS_TANK_KEY provided. Fueling skipped (Demo mode).");
            return;
        }

        try {
            const gasTank = new ethers.Wallet(gasTankKey, this.provider);
            const tx = await gasTank.sendTransaction({
                to: targetAddress,
                value: ethers.parseEther(amount)
            });
            await tx.wait();
            console.log(`[CryptoEngine] Fueled ${targetAddress} with ${amount} native currency. Hash: ${tx.hash}`);
        } catch (error) {
            console.error("[CryptoEngine] Fueling failed:", error);
        }
    }

    private async sweepSolana(
        tempWalletPrivateKey: string,
        merchantAddress: string,
        platformAddress: string,
        tokenSymbol: string,
        feePercent: number
    ) {
        // ... Solana logic ...
        return {
            success: true,
            platformTx: 'sol_mock_tx_' + Math.random().toString(36).substring(7),
            merchantTx: 'sol_mock_tx_' + Math.random().toString(36).substring(7)
        };
    }

    private async sweepTron(
        tempWalletPrivateKey: string,
        merchantAddress: string,
        platformAddress: string,
        tokenSymbol: string,
        feePercent: number
    ) {
        console.log(`[Sweep TRON] Split: ${feePercent}% to Platform, ${100 - feePercent}% to Merchant`);
        return {
            success: true,
            platformTx: 'tron_mock_tx_' + Math.random().toString(36).substring(7),
            merchantTx: 'tron_mock_tx_' + Math.random().toString(36).substring(7)
        };
    }

    private async sweepBitcoin(
        tempWalletPrivateKey: string,
        merchantAddress: string,
        platformAddress: string,
        tokenSymbol: string,
        feePercent: number
    ) {
        console.log(`[Sweep BTC] Split: ${feePercent}% to Platform, ${100 - feePercent}% to Merchant`);
        return {
            success: true,
            platformTx: 'btc_mock_tx_' + Math.random().toString(36).substring(7),
            merchantTx: 'btc_mock_tx_' + Math.random().toString(36).substring(7)
        };
    }

    /**
     * Verifies if a specific amount has arrived at the address.
     */
    async verifyPayment(address: string, expectedAmount: string, tokenSymbol?: string): Promise<{
        success: boolean;
        txHash?: string;
        error?: string;
    }> {
        try {
            const tokenConfig = this.getTokenConfig(tokenSymbol || 'USDT');
            if (!tokenConfig) return { success: false, error: "Token not supported in config" };

            if (this.network === 'SOLANA') {
                const pubKey = new PublicKey(address);
                if (tokenConfig.address === 'NATIVE') {
                    const balance = await this.solConnection.getBalance(pubKey);
                    const balanceInSol = balance / LAMPORTS_PER_SOL;
                    if (balanceInSol >= parseFloat(expectedAmount)) return { success: true };
                } else {
                    const tokenMint = new PublicKey(tokenConfig.address);
                    const ata = await getAssociatedTokenAddress(tokenMint, pubKey);
                    try {
                        const accountInfo = await getAccount(this.solConnection, ata);
                        const balance = Number(accountInfo.amount) / Math.pow(10, tokenConfig.decimals);
                        if (balance >= parseFloat(expectedAmount)) return { success: true };
                    } catch (e) {}
                }
            } else if (this.network === 'TRON') {
                if (tokenConfig.address === 'NATIVE') {
                    const balance = await this.tronWeb.trx.getBalance(address);
                    const balanceInTrx = balance / 1000000;
                    if (balanceInTrx >= parseFloat(expectedAmount)) return { success: true };
                } else {
                    const contract = await this.tronWeb.contract().at(tokenConfig.address);
                    const balance = await contract.balanceOf(address).call();
                    const formattedBalance = balance / Math.pow(10, tokenConfig.decimals);
                    if (formattedBalance >= parseFloat(expectedAmount)) return { success: true };
                }
            } else if (this.network === 'BITCOIN') {
                // Check balance via public API (blockchain.info)
                const res = await fetch(`https://blockchain.info/rawaddr/${address}`);
                if (res.ok) {
                    const data = await res.json();
                    const balanceInBtc = data.final_balance / 100000000;
                    if (balanceInBtc >= parseFloat(expectedAmount)) return { success: true };
                }
            } else {
                if (tokenConfig.address === 'NATIVE') {
                    const balance = await this.provider.getBalance(address);
                    const balanceInEth = ethers.formatEther(balance);
                    if (parseFloat(balanceInEth) >= parseFloat(expectedAmount)) return { success: true };
                } else {
                    const contract = new ethers.Contract(tokenConfig.address, ERC20_ABI, this.provider);
                    const balance = await contract.balanceOf(address);
                    const formattedBalance = ethers.formatUnits(balance, tokenConfig.decimals);
                    if (parseFloat(formattedBalance) >= parseFloat(expectedAmount)) return { success: true };
                }
            }
            return { success: false };
        } catch (error: any) {
            return { success: false, error: error.message };
        }
    }
}