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 customerId = searchParams.get("customerId");
    const status = searchParams.get("status");
    const search = searchParams.get("search") || "";

    let query = `
      SELECT po.*,
        c.name AS customer_name,
        c.code AS customer_code,
        COUNT(poi.id) AS item_count,
        COALESCE(SUM(poi.quantity * poi.unit_price), 0) AS total_value,
        COALESCE(SUM(poi.quantity), 0) AS total_ordered,
        COALESCE(SUM(poi.shipped_quantity), 0) AS total_shipped
      FROM purchase_orders po
      JOIN customers c ON c.id = po.customer_id
      LEFT JOIN purchase_order_items poi ON poi.purchase_order_id = po.id
    `;

    const conditions: string[] = [];
    const params: (string | number)[] = [];
    let idx = 1;

    if (customerId) {
      conditions.push(`po.customer_id = $${idx++}`);
      params.push(Number(customerId));
    }
    if (status) {
      const statuses = status.split(",").map((s) => s.trim());
      const placeholders = statuses.map(() => `$${idx++}`).join(", ");
      conditions.push(`po.status IN (${placeholders})`);
      params.push(...statuses);
    }
    if (search) {
      conditions.push(
        `(po.po_number ILIKE $${idx} OR c.name ILIKE $${idx} OR po.customer_ref ILIKE $${idx})`
      );
      params.push(`%${search}%`);
      idx++;
    }

    if (conditions.length > 0) {
      query += ` WHERE ${conditions.join(" AND ")}`;
    }

    query += ` GROUP BY po.id, c.name, c.code ORDER BY po.created_at DESC`;

    const rows = await sql(query, params);
    return NextResponse.json(rows);
  } catch (error) {
    console.error("[v0] Orders GET error:", error);
    return NextResponse.json(
      { error: error instanceof Error ? error.message : "Failed to fetch orders" },
      { status: 500 }
    );
  }
}

export async function POST(request: NextRequest) {
  try {
    const sql = getDb();
    const body = await request.json();
    const {
      customer_id,
      po_number,
      customer_ref,
      status,
      order_date,
      due_date,
      notes,
      items,
    } = body;

    if (!customer_id || !po_number) {
      return NextResponse.json(
        { error: "Customer and PO number are required" },
        { status: 400 }
      );
    }

    // Create the order
    const orderRows = await sql(
      `INSERT INTO purchase_orders (customer_id, po_number, customer_ref, status, order_date, due_date, notes)
       VALUES ($1, $2, $3, $4, $5, $6, $7)
       RETURNING *`,
      [
        customer_id,
        po_number,
        customer_ref || null,
        status || "draft",
        order_date || new Date().toISOString().slice(0, 10),
        due_date || null,
        notes || null,
      ]
    );

    const order = orderRows[0];

    // Create items if provided
    if (items && Array.isArray(items) && items.length > 0) {
      for (const item of items) {
        await sql(
          `INSERT INTO purchase_order_items (purchase_order_id, product_id, quantity, unit_price, notes)
           VALUES ($1, $2, $3, $4, $5)`,
          [
            order.id,
            item.product_id,
            item.quantity,
            item.unit_price || 0,
            item.notes || null,
          ]
        );
      }
    }

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