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 query = `
      SELECT spl.*,
        s.name AS supplier_name,
        s.code AS supplier_code,
        s.email AS supplier_email,
        s.phone AS supplier_phone,
        s.address AS supplier_address,
        s.contact_person AS supplier_contact,
        (SELECT COUNT(*) FROM supplier_packing_list_items spli WHERE spli.supplier_packing_list_id = spl.id) AS item_count,
        (SELECT COALESCE(SUM(spli.quantity), 0) FROM supplier_packing_list_items spli WHERE spli.supplier_packing_list_id = spl.id) AS total_quantity
      FROM supplier_packing_lists spl
      JOIN suppliers s ON s.id = spl.supplier_id
    `;
    const conditions: string[] = [];
    const params: (string | number)[] = [];

    if (search) {
      params.push(`%${search}%`);
      const i = params.length;
      conditions.push(
        `(spl.packing_number ILIKE $${i} OR s.name ILIKE $${i})`
      );
    }

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

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

export async function POST(request: NextRequest) {
  try {
    const sql = getDb();
    const body = await request.json();
    const { supplier_id, items, notes } = body;

    if (!supplier_id || !items?.length) {
      return NextResponse.json(
        { error: "supplier_id and items are required" },
        { status: 400 }
      );
    }

    // Validate items have component_id and quantity
    for (const item of items) {
      if (!item.component_id || !item.quantity || item.quantity <= 0) {
        return NextResponse.json(
          { error: "Each item must have a component_id and a positive quantity" },
          { status: 400 }
        );
      }
    }

    // Fetch supplier name for packing number generation
    const supplierRows = await sql(
      `SELECT name FROM suppliers WHERE id = $1`,
      [supplier_id]
    );
    if (supplierRows.length === 0) {
      return NextResponse.json({ error: "Supplier not found" }, { status: 404 });
    }
    const supplierName = String(supplierRows[0].name).replace(/[^a-zA-Z0-9]/g, "").toUpperCase();

    // Generate packing number: PL-EACH-YYYY_MM_DD-RR-SUPPLIERNAME
    const now = new Date();
    const yyyy = now.getFullYear();
    const mm = String(now.getMonth() + 1).padStart(2, "0");
    const dd = String(now.getDate()).padStart(2, "0");
    const datePrefix = `PL-EACH-${yyyy}_${mm}_${dd}`;
    const dateSuffix = `-${supplierName}`;

    // Count existing supplier packing lists with same date + supplier to determine revision
    const existingRows = await sql(
      `SELECT COUNT(*) AS cnt FROM supplier_packing_lists WHERE packing_number LIKE $1`,
      [`${datePrefix}-%${dateSuffix}`]
    );
    const revision = Number(existingRows[0].cnt) + 1;
    const packing_number = `${datePrefix}-${String(revision).padStart(2, "0")}${dateSuffix}`;

    // Create supplier packing list
    const plRows = await sql(
      `INSERT INTO supplier_packing_lists (supplier_id, packing_number, notes)
       VALUES ($1, $2, $3)
       RETURNING *`,
      [supplier_id, packing_number, notes || null]
    );
    const packingList = plRows[0];

    // Insert items
    for (const item of items) {
      await sql(
        `INSERT INTO supplier_packing_list_items (supplier_packing_list_id, component_id, quantity)
         VALUES ($1, $2, $3)`,
        [packingList.id, item.component_id, item.quantity]
      );
    }

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