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

export async function GET(request: NextRequest) {
  try {
    const sql = getDb();
    const { searchParams } = new URL(request.url);
    const search = searchParams.get("search") || "";

    let rows;
    if (search) {
      rows = await sql(
        `SELECT c.*,
          COUNT(po.id) AS order_count,
          COALESCE(SUM(
            CASE WHEN po.status != 'cancelled' THEN
              (SELECT COALESCE(SUM(poi.quantity * poi.unit_price), 0) FROM purchase_order_items poi WHERE poi.purchase_order_id = po.id)
            ELSE 0 END
          ), 0) AS total_revenue
         FROM customers c
         LEFT JOIN purchase_orders po ON po.customer_id = c.id
         WHERE c.name ILIKE $1 OR c.code ILIKE $1 OR c.email ILIKE $1 OR c.contact_person ILIKE $1
         GROUP BY c.id
         ORDER BY c.name ASC`,
        [`%${search}%`]
      );
    } else {
      rows = await sql(
        `SELECT c.*,
          COUNT(po.id) AS order_count,
          COALESCE(SUM(
            CASE WHEN po.status != 'cancelled' THEN
              (SELECT COALESCE(SUM(poi.quantity * poi.unit_price), 0) FROM purchase_order_items poi WHERE poi.purchase_order_id = po.id)
            ELSE 0 END
          ), 0) AS total_revenue
         FROM customers c
         LEFT JOIN purchase_orders po ON po.customer_id = c.id
         GROUP BY c.id
         ORDER BY c.name ASC`
      );
    }

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

export async function POST(request: NextRequest) {
  try {
    const sql = getDb();
    const body = await request.json();
    const { name, code, email, phone, address, contact_person, notes } = body;

    if (!name || !code) {
      return NextResponse.json({ error: "Name and code are required" }, { status: 400 });
    }

    const rows = await sql(
      `INSERT INTO customers (name, code, email, phone, address, contact_person, notes)
       VALUES ($1, $2, $3, $4, $5, $6, $7)
       RETURNING *`,
      [name, code, email || null, phone || null, address || null, contact_person || null, notes || null]
    );

    return NextResponse.json(rows[0], { status: 201 });
  } catch (error) {
    console.error("[v0] Customers POST error:", error);
    return NextResponse.json(
      { error: error instanceof Error ? error.message : "Failed to create customer" },
      { status: 500 }
    );
  }
}