@extends('layouts.app')
@section('title', 'Product POS')
@section('actions')
    <a href="{{ route('product-sales.index') }}" class="btn btn-outline-secondary"><i class="bi bi-receipt"></i> Sales</a>
@endsection

@section('content')
@php
    $posProducts = $products->map(fn ($p) => [
        'id' => $p->id,
        'name' => $p->name,
        'price' => (float) $p->sale_price,
        'stock' => (int) $p->quantity_stock,
        'category_id' => $p->product_category_id,
        'image' => $p->image_path ? Storage::url($p->image_path) : null,
    ])->values();
@endphp

@if($errors->any())
    <div class="alert alert-danger">{{ $errors->first() }}</div>
@endif

<div class="row g-3">
    {{-- Product grid --}}
    <div class="col-12 col-lg-8">
        <div class="card p-3 mb-3">
            <div class="row g-2">
                <div class="col-8">
                    <input type="text" id="posSearch" class="form-control form-control-sm" placeholder="Search product...">
                </div>
                <div class="col-4">
                    <select id="posCategory" class="form-select form-select-sm">
                        <option value="">All categories</option>
                        @foreach($categories as $c)<option value="{{ $c->id }}">{{ $c->name }}</option>@endforeach
                    </select>
                </div>
            </div>
        </div>
        <div class="row g-2" id="posGrid">
            @forelse($products as $p)
                <div class="col-6 col-md-4 col-xl-3 pos-card-col" data-name="{{ strtolower($p->name) }}" data-category="{{ $p->product_category_id }}">
                    <div class="card h-100 pos-card {{ $p->quantity_stock <= 0 ? 'opacity-50' : '' }}" role="button" data-id="{{ $p->id }}">
                        <div class="text-center p-2" style="height:90px;">
                            @if($p->image_path)
                                <img src="{{ Storage::url($p->image_path) }}" alt="{{ $p->name }}" style="max-height:80px;max-width:100%;object-fit:contain;">
                            @else
                                <div class="text-muted d-flex align-items-center justify-content-center h-100"><i class="bi bi-box" style="font-size:2rem;"></i></div>
                            @endif
                        </div>
                        <div class="p-2 border-top">
                            <div class="small fw-bold text-truncate">{{ $p->name }}</div>
                            <div class="d-flex justify-content-between small">
                                <span class="text-success">{{ number_format($p->sale_price, 2) }}</span>
                                <span class="{{ $p->quantity_stock <= 0 ? 'text-danger' : 'text-muted' }}">{{ $p->quantity_stock <= 0 ? 'Out' : 'Stock: '.$p->quantity_stock }}</span>
                            </div>
                        </div>
                    </div>
                </div>
            @empty
                <div class="col-12"><div class="card p-4 text-center text-muted">No active products. <a href="{{ route('products.create') }}">Add one</a>.</div></div>
            @endforelse
        </div>
    </div>

    {{-- Cart --}}
    <div class="col-12 col-lg-4">
        <div class="card p-3" style="position:sticky;top:1rem;">
            <h6 class="border-bottom pb-2"><i class="bi bi-cart3"></i> Cart</h6>
            <form method="POST" action="{{ route('pos.store') }}" id="posForm">
                @csrf
                <div id="cartItems" class="mb-2"><p class="text-muted small mb-0">Cart is empty. Click products to add.</p></div>
                <div id="cartHidden"></div>

                <div class="border-top pt-2">
                    <div class="d-flex justify-content-between"><span>Subtotal</span><strong id="subtotal">0.00</strong></div>
                    <div class="d-flex justify-content-between align-items-center mt-1">
                        <span>Discount</span>
                        <input type="number" step="0.01" min="0" name="discount_amount" id="discount" value="0" class="form-control form-control-sm text-end" style="width:110px;">
                    </div>
                    <div class="d-flex justify-content-between mt-1"><span class="fw-bold">Grand Total</span><strong id="grandTotal" class="text-primary">0.00</strong></div>
                    <div class="d-flex justify-content-between align-items-center mt-1">
                        <span>Amount Received</span>
                        <input type="number" step="0.01" min="0" name="amount_received" id="received" class="form-control form-control-sm text-end" style="width:110px;">
                    </div>
                    <div class="d-flex justify-content-between mt-1"><span>Balance / Change</span><strong id="balance">0.00</strong></div>
                    <input type="text" name="notes" class="form-control form-control-sm mt-2" placeholder="Notes (optional)">
                    <button type="submit" id="completeBtn" class="btn btn-success w-100 mt-2" disabled><i class="bi bi-check2-circle"></i> Complete Sale</button>
                </div>
            </form>
        </div>
    </div>
</div>

<script>
(function () {
    const PRODUCTS = @json($posProducts);
    const byId = {};
    PRODUCTS.forEach(p => byId[p.id] = p);
    const cart = {}; // id -> qty

    const grid = document.getElementById('posGrid');
    const cartItems = document.getElementById('cartItems');
    const cartHidden = document.getElementById('cartHidden');
    const subtotalEl = document.getElementById('subtotal');
    const grandEl = document.getElementById('grandTotal');
    const balanceEl = document.getElementById('balance');
    const discountEl = document.getElementById('discount');
    const receivedEl = document.getElementById('received');
    const completeBtn = document.getElementById('completeBtn');

    function money(n) { return (Math.round(n * 100) / 100).toFixed(2); }

    function add(id) {
        const p = byId[id];
        if (!p || p.stock <= 0) return;
        const cur = cart[id] || 0;
        if (cur + 1 > p.stock) return;      // cannot exceed stock
        cart[id] = cur + 1;
        render();
    }
    function setQty(id, qty) {
        const p = byId[id];
        qty = parseInt(qty) || 0;
        if (qty <= 0) { delete cart[id]; }
        else { cart[id] = Math.min(qty, p.stock); }
        render();
    }

    function render() {
        const ids = Object.keys(cart);
        let subtotal = 0, hidden = '', rows = '', i = 0;
        ids.forEach(id => {
            const p = byId[id], qty = cart[id], line = p.price * qty;
            subtotal += line;
            hidden += `<input type="hidden" name="items[${i}][product_id]" value="${id}"><input type="hidden" name="items[${i}][quantity]" value="${qty}">`;
            rows += `<div class="d-flex align-items-center justify-content-between mb-1 small">
                <div class="me-1" style="min-width:0;"><div class="fw-bold text-truncate">${p.name}</div>
                    <div class="text-muted">${money(p.price)} × ${qty} = ${money(line)}</div></div>
                <div class="text-nowrap">
                    <button type="button" class="btn btn-sm btn-outline-secondary py-0 px-1" data-dec="${id}">−</button>
                    <span class="px-1">${qty}</span>
                    <button type="button" class="btn btn-sm btn-outline-secondary py-0 px-1" data-inc="${id}">+</button>
                    <button type="button" class="btn btn-sm btn-outline-danger py-0 px-1" data-rem="${id}">×</button>
                </div></div>`;
            i++;
        });
        cartItems.innerHTML = rows || '<p class="text-muted small mb-0">Cart is empty. Click products to add.</p>';
        cartHidden.innerHTML = hidden;
        const discount = Math.min(parseFloat(discountEl.value) || 0, subtotal);
        const grand = subtotal - discount;
        subtotalEl.textContent = money(subtotal);
        grandEl.textContent = money(grand);
        const received = parseFloat(receivedEl.value);
        balanceEl.textContent = money((isNaN(received) ? grand : received) - grand);
        completeBtn.disabled = ids.length === 0;
    }

    grid.addEventListener('click', e => {
        const card = e.target.closest('.pos-card');
        if (card) add(parseInt(card.dataset.id));
    });
    cartItems.addEventListener('click', e => {
        const t = e.target;
        if (t.dataset.inc) add(parseInt(t.dataset.inc));
        else if (t.dataset.dec) setQty(t.dataset.dec, (cart[t.dataset.dec] || 0) - 1);
        else if (t.dataset.rem) setQty(t.dataset.rem, 0);
    });
    discountEl.addEventListener('input', render);
    receivedEl.addEventListener('input', render);

    // Search + category filter.
    const search = document.getElementById('posSearch'), cat = document.getElementById('posCategory');
    function filter() {
        const q = (search.value || '').toLowerCase(), c = cat.value;
        document.querySelectorAll('.pos-card-col').forEach(col => {
            const okName = col.dataset.name.includes(q);
            const okCat = !c || col.dataset.category === c;
            col.style.display = (okName && okCat) ? '' : 'none';
        });
    }
    search.addEventListener('input', filter);
    cat.addEventListener('change', filter);

    render();
})();
</script>
@endsection