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

export async function GET(
  _request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const sql = getDb();
    const { id } = await params;
    const rows = await sql(`SELECT * FROM customers WHERE id = $1`, [Number(id)]);

    if (rows.length === 0) {
      return NextResponse.json({ error: "Customer not found" }, { status: 404 });
    }

    return NextResponse.json(rows[0]);
  } catch (error) {
    console.error("[v0] Customer GET error:", error);
    return NextResponse.json(
      { error: error instanceof Error ? error.message : "Failed to fetch customer" },
      { status: 500 }
    );
  }
}

export async function PUT(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const sql = getDb();
    const { id } = await params;
    const body = await request.json();
    const { name, code, email, phone, address, contact_person, notes } = body;

    const rows = await sql(
      `UPDATE customers SET
        name = $1, code = $2, email = $3, phone = $4,
        address = $5, contact_person = $6, notes = $7, updated_at = NOW()
       WHERE id = $8
       RETURNING *`,
      [name, code, email || null, phone || null, address || null, contact_person || null, notes || null, Number(id)]
    );

    if (rows.length === 0) {
      return NextResponse.json({ error: "Customer not found" }, { status: 404 });
    }

    return NextResponse.json(rows[0]);
  } catch (error) {
    console.error("[v0] Customer PUT error:", error);
    return NextResponse.json(
      { error: error instanceof Error ? error.message : "Failed to update customer" },
      { status: 500 }
    );
  }
}

export async function DELETE(
  _request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const sql = getDb();
    const { id } = await params;

    const orderCheck = await sql(
      `SELECT COUNT(*) as count FROM purchase_orders WHERE customer_id = $1`,
      [Number(id)]
    );

    if (Number(orderCheck[0].count) > 0) {
      return NextResponse.json(
        { error: "Cannot delete customer with existing orders. Delete orders first." },
        { status: 400 }
      );
    }

    await sql(`DELETE FROM customers WHERE id = $1`, [Number(id)]);
    return NextResponse.json({ success: true });
  } catch (error) {
    console.error("[v0] Customer DELETE error:", error);
    return NextResponse.json(
      { error: error instanceof Error ? error.message : "Failed to delete customer" },
      { status: 500 }
    );
  }
}