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

export async function GET(
    req: NextRequest,
    context: { params: Promise<{ id: string }> }
) {
    try {
        const { id } = await context.params;
        const result = await db.query('SELECT * FROM merchants WHERE id = $1 LIMIT 1', [id]);
        const data = result.rows[0];

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

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

export async function PATCH(
    req: NextRequest,
    context: { params: Promise<{ id: string }> }
) {
    try {
        const { id } = await context.params;
        const body = await req.json();

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

        // Build dynamic update
        const fields: string[] = [];
        const values: any[] = [];
        let idx = 1;

        const addField = (col: string, val: any) => {
            if (val !== undefined) {
                fields.push(`${col} = $${idx++}`);
                values.push(val);
            }
        };

        addField('name', body.name);
        addField('webhook_url', body.webhook_url);
        addField('fee_percent', body.fee_percent || 1.0);
        addField('payout_address', body.payout_address);
        
        if (body.payout_addresses !== undefined) {
            fields.push(`payout_addresses = $${idx++}`);
            values.push(JSON.stringify(body.payout_addresses));
        }
        if (body.payment_provider !== undefined) {
            addField('payment_provider', body.payment_provider);
        }
        if (body.provider_config !== undefined) {
            fields.push(`provider_config = $${idx++}`);
            values.push(JSON.stringify(body.provider_config));
        }

        values.push(id);
        const query = `UPDATE merchants SET ${fields.join(', ')} WHERE id = $${idx} RETURNING *`;
        
        const result = await db.query(query, values);
        const data = result.rows[0];

        if (!data) {
            return NextResponse.json({ error: 'Update failed or merchant not found' }, { status: 500 });
        }

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

export async function DELETE(
    req: NextRequest,
    context: { params: Promise<{ id: string }> }
) {
    try {
        const { id } = await context.params;
        await db.query('DELETE FROM merchants WHERE id = $1', [id]);

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