import { NextRequest, NextResponse } from 'next/server';
import { db } from '@/lib/db';
import { CryptoEngine } from '@/lib/crypto-engine';

export async function POST(req: NextRequest) {
    try {
        const { merchantId, amount, network, currency } = await req.json();

        if (!merchantId || !amount || !network) {
            return NextResponse.json({ error: 'Missing required fields' }, { status: 400 });
        }

        // 1. Fetch Merchant details
        const merchantRes = await db.query('SELECT * FROM merchants WHERE id = $1', [merchantId]);
        const merchant = merchantRes.rows[0];

        if (!merchant) {
            return NextResponse.json({ error: 'Merchant not found' }, { status: 404 });
        }

        // Resolve per-network payout address
        const netKey = ['POLYGON', 'BSC', 'ETH'].includes(network) ? 'EVM' : network;
        const payoutAddresses = merchant.payout_addresses || {};
        const destinationAddress = payoutAddresses[netKey] || merchant.payout_address;

        if (!destinationAddress) {
            return NextResponse.json({ error: `Merchant payout address for ${netKey} is not set. Please configure it in merchant settings.` }, { status: 400 });
        }

        const availableBalance = parseFloat(merchant.available_balance || '0');
        const payoutAmount = parseFloat(amount);

        if (availableBalance < payoutAmount) {
            return NextResponse.json({ error: 'Insufficient balance' }, { status: 400 });
        }

        // 2. Get Treasury Private Key based on network
        const treasuryKeys: Record<string, string | undefined> = {
            'POLYGON': process.env.TREASURY_EVM_KEY,
            'BSC': process.env.TREASURY_EVM_KEY,
            'ETH': process.env.TREASURY_EVM_KEY,
            'SOLANA': process.env.TREASURY_SOL_KEY,
            'TRON': process.env.TREASURY_TRON_KEY,
            'BITCOIN': process.env.TREASURY_BTC_KEY
        };

        const privateKey = treasuryKeys[network];
        if (!privateKey) {
            return NextResponse.json({ error: `Treasury private key for ${network} is not configured in .env` }, { status: 500 });
        }

        // 3. Check merchant's crypto balance for this network/token
        const selectedCurrency = currency || 'SOL';

        const balRes = await db.query(
            'SELECT balance, withdrawn FROM merchant_balances WHERE merchant_id = $1 AND network = $2 AND token = $3',
            [merchantId, network, selectedCurrency]
        );

        const cryptoBalance = balRes.rows[0] ? parseFloat(balRes.rows[0].balance) : 0;
        const cryptoWithdrawn = balRes.rows[0] ? parseFloat(balRes.rows[0].withdrawn) : 0;
        const cryptoAvailable = cryptoBalance - cryptoWithdrawn;

        if (cryptoAvailable < payoutAmount) {
            return NextResponse.json({ 
                error: `Yetersiz ${selectedCurrency} bakiyesi. Çekilebilir: ${cryptoAvailable.toFixed(6)} ${selectedCurrency}, talep edilen: ${payoutAmount} ${selectedCurrency}` 
            }, { status: 400 });
        }

        // 4. Execute Transfer
        const engine = new CryptoEngine(network);
        const transfer = await engine.sendPayout(
            privateKey,
            destinationAddress,
            amount.toString(),
            selectedCurrency
        );

        if (!transfer.success) {
            return NextResponse.json({ error: transfer.error || 'Blockchain transfer failed' }, { status: 500 });
        }

        // 5. Update Database
        await db.query('BEGIN');
        try {
            // Deduct from merchant's crypto balance
            await db.query(`
                UPDATE merchant_balances 
                SET withdrawn = withdrawn + $1
                WHERE merchant_id = $2 AND network = $3 AND token = $4
            `, [payoutAmount, merchantId, network, selectedCurrency]);

            // Also update legacy TRY balance (best effort price conversion)
            try {
                const coinIdMap: Record<string, string> = {
                    'SOL': 'solana', 'USDC': 'usd-coin', 'USDT': 'tether', 
                    'TRX': 'tron', 'BTC': 'bitcoin', 'ETH': 'ethereum',
                    'MATIC': 'matic-network', 'BNB': 'binancecoin'
                };
                const coinId = coinIdMap[selectedCurrency] || 'solana';
                const priceRes = await fetch(`https://api.coingecko.com/api/v3/simple/price?ids=${coinId}&vs_currencies=try`);
                const priceData = await priceRes.json();
                const tryEquivalent = payoutAmount * (priceData[coinId]?.try || 0);
                
                if (tryEquivalent > 0) {
                    await db.query(`
                        UPDATE merchants 
                        SET available_balance = GREATEST(0, available_balance - $1),
                            withdrawn_balance = withdrawn_balance + $1
                        WHERE id = $2
                    `, [tryEquivalent, merchantId]);
                }
            } catch (e) {
                console.warn('[Payout] TRY balance update skipped (price fetch failed)');
            }

            // Log the payout
            await db.query(`
                INSERT INTO payouts (merchant_id, amount, currency, network, destination_address, tx_hash, status)
                VALUES ($1, $2, $3, $4, $5, $6, $7)
            `, [
                merchantId, 
                payoutAmount,
                selectedCurrency, 
                network, 
                destinationAddress, 
                transfer.txHash, 
                'succeeded'
            ]);

            await db.query('COMMIT');
            console.log(`[Payout] ✅ Sent ${payoutAmount} ${selectedCurrency} on ${network} to ${destinationAddress}`);
        } catch (dbErr) {
            await db.query('ROLLBACK');
            throw dbErr;
        }

        return NextResponse.json({ 
            success: true, 
            txHash: transfer.txHash,
            message: 'Payout processed successfully'
        });

    } catch (err: any) {
        console.error('Payout Error:', err);
        return NextResponse.json({ error: err.message }, { status: 500 });
    }
}

export async function GET(req: NextRequest) {
    try {
        const { searchParams } = new URL(req.url);
        const merchantId = searchParams.get('merchantId');

        let query = 'SELECT * FROM payouts ORDER BY created_at DESC';
        let params: any[] = [];

        if (merchantId) {
            query = 'SELECT * FROM payouts WHERE merchant_id = $1 ORDER BY created_at DESC';
            params = [merchantId];
        }

        const result = await db.query(query, params);
        return NextResponse.json(result.rows);
    } catch (err: any) {
        return NextResponse.json({ error: err.message }, { status: 500 });
    }
}