import { NextRequest, NextResponse } from 'next/server';
import { db } from '@/lib/db';

export async function POST(req: NextRequest) {
    try {
        const { name, webhook_url, payment_provider, provider_config, fee_percent } = await req.json();

        if (!name) {
            return NextResponse.json(
                { error: 'Firma adı zorunludur.' },
                { status: 400 }
            );
        }

        // Generate a 8-character short ID (e.g., P2C-A1B2C3)
        const generateShortId = () => {
            const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
            let result = '';
            for (let i = 0; i < 8; i++) {
                result += chars.charAt(Math.floor(Math.random() * chars.length));
            }
            return result;
        };

        const shortId = generateShortId();
        const provider = payment_provider || 'stripe';
        const configStr = provider_config ? JSON.stringify(provider_config) : '{}';

        const result = await db.query(
            `INSERT INTO merchants (name, webhook_url, short_id, payment_provider, provider_config, fee_percent) 
             VALUES ($1, $2, $3, $4, $5, $6) RETURNING *`,
            [name, webhook_url, shortId, provider, configStr, fee_percent || 1.0]
        );

        if (result.rows.length === 0) {
           throw new Error('Could not insert merchant');
        }

        return NextResponse.json(result.rows[0]);
    } catch (err: any) {
        console.error('Internal Error:', err);
        return NextResponse.json(
            { error: `Internal Server Error: ${err.message}` },
            { status: 500 }
        );
    }
}

export async function GET() {
    try {
        const merchantsResult = await db.query('SELECT * FROM merchants ORDER BY created_at DESC');
        const merchants = merchantsResult.rows;

        // Fetch breakdown per merchant
        const breakdownResult = await db.query(`
            SELECT 
                merchant_id, 
                COALESCE(paid_network, 'SİSTEM') as network, 
                COALESCE(paid_token, 'TRY') as token, 
                SUM(CAST(COALESCE(paid_amount_crypto, '0') AS numeric)) as amount
            FROM transactions 
            WHERE status = 'succeeded' AND paid_network IS NOT NULL
            GROUP BY merchant_id, paid_network, paid_token
        `);

        const breakdowns = breakdownResult.rows.reduce((acc: any, row: any) => {
            if (!acc[row.merchant_id]) acc[row.merchant_id] = [];
            acc[row.merchant_id].push({
                network: row.network,
                token: row.token,
                amount: row.amount
            });
            return acc;
        }, {});

        const merchantsWithBreakdown = merchants.map(m => ({
            ...m,
            balance_breakdown: breakdowns[m.id] || []
        }));

        return NextResponse.json(merchantsWithBreakdown);
    } catch (err: any) {
        return NextResponse.json(
            { error: `Internal Server Error: ${err.message}` },
            { status: 500 }
        );
    }
}