<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use App\Models\Shipment;
use App\Models\ShipmentItem;
use App\Models\Order;
use Carbon\Carbon;

class ShipmentController extends Controller
{
    /**
     * Show shipment page (Create Shipment + Shipment List)
     */
   public function index()
    {
        // 1) Get all used order IDs
        $usedOrderIds = ShipmentItem::pluck('order_id')->toArray();

        // 2) Load available orders (not used in any shipment)
        $availableOrders = Order::whereNotIn('id', $usedOrderIds)->get();

        // 3) Load all shipments for listing
        $shipments = Shipment::latest()->get();

        // Return your file: resources/views/admin/shipment.blade.php
        return view('admin.shipments', compact('availableOrders', 'shipments'));
    }


    /**
     * Store new shipment
     */
    public function store(Request $request)
    {
        $request->validate([
            'origin'        => 'required|string',
            'destination'   => 'required|string',
            'shipment_date' => 'required|date',
            'order_ids'     => 'required|array|min:1',
        ]);

        // -----------------------------
        // PREVENT DUPLICATE ORDERS
        // -----------------------------
        foreach ($request->order_ids as $id) {
            if (ShipmentItem::where('order_id', $id)->exists()) {
                return back()->with('error', "Order ID $id is already assigned to a shipment.");
            }
        }

        // -----------------------------
        // GENERATE UNIQUE SHIPMENT ID
        // -----------------------------
        $year    = date('y');
        $prefix  = "SHIP-$year-";

        $lastShipment = Shipment::latest('id')->first();
        $nextNumber   = $lastShipment ? intval(substr($lastShipment->shipment_id, -8)) + 1 : 1;

        $newShipmentId = $prefix . str_pad($nextNumber, 8, '0', STR_PAD_LEFT);

        // -----------------------------
        // CALCULATE TOTALS
        // -----------------------------
        $orders = Order::whereIn('id', $request->order_ids)->get();

        $total_ctn       = $orders->sum('ctn');
        $total_qty       = $orders->sum('qty');
        $total_ttl_qty   = $orders->sum('ttl_qty');
        $total_amount    = $orders->sum('ttl_amount');
        $total_cbm       = $orders->sum('cbm');
        $total_ttl_cbm   = $orders->sum('ttl_cbm');
        $total_kg        = $orders->sum('kg');
        $total_ttl_kg    = $orders->sum('ttl_kg');

        // -----------------------------
        // CREATE SHIPMENT
        //-------------------------------
        $shipment = Shipment::create([
            'shipment_id'    => $newShipmentId,
            'origin'         => $request->origin,
            'destination'    => $request->destination,
            'status'         => Shipment::STATUS_PENDING,
            'shipment_date'  => $request->shipment_date,

            'total_ctn'      => $total_ctn,
            'total_qty'      => $total_qty,
            'total_ttl_qty'  => $total_ttl_qty,
            'total_amount'   => $total_amount,
            'total_cbm'      => $total_cbm,
            'total_ttl_cbm'  => $total_ttl_cbm,
            'total_kg'       => $total_kg,
            'total_ttl_kg'   => $total_ttl_kg,
        ]);

        // -----------------------------
        // INSERT SHIPMENT ITEMS
        // -----------------------------
        foreach ($orders as $order) {
            ShipmentItem::create([
                'shipment_id'      => $shipment->id,
                'order_id'         => $order->id,
                'order_ctn'        => $order->ctn,
                'order_qty'        => $order->qty,
                'order_ttl_qty'    => $order->ttl_qty,
                'order_ttl_amount' => $order->ttl_amount,
                'order_ttl_kg'     => $order->ttl_kg,
            ]);
        }

        return redirect()->back()->with('success', "Shipment $newShipmentId created successfully!");
    }


    /**
     * Show shipment details (for modal popup)
     */
    public function show($id)
    {
        $shipment = Shipment::findOrFail($id);

        // Load full order data from orders table
        $orders = Order::whereIn('id', 
                    ShipmentItem::where('shipment_id', $id)->pluck('order_id')
                )->get();

        return response()->json([
            'shipment' => $shipment,
            'orders'   => $orders
        ]);
    }


    /**
     * Update Shipment status from action button
     */
    public function updateStatus(Request $request)
    {
        $request->validate([
            'shipment_id' => 'required|exists:shipments,id',
            'status'      => 'required|string'
        ]);

        // 1) Update shipment status
        $shipment = Shipment::findOrFail($request->shipment_id);
        $shipment->status = $request->status;
        $shipment->save();

        // 2) Update ALL related orders' status
        foreach ($shipment->orders as $order) {
            $order->status = $shipment->status;  // status is string: pending, in_transit, dispatched, delivered
            $order->save();
        }

        return redirect()->back()->with(
            'success',
            "Shipment status updated to {$shipment->statusLabel()} and related orders updated."
        );
    }


}