{% extends "base.html" %}

{% block content %}
<div class="container d-flex flex-column justify-content-start align-items-center py-4" style="min-height: 100vh;">
    <div class="card shadow-sm w-100">
        <div class="card-body d-flex flex-column">
            <h5 class="card-title text-center mb-4">Item Scanner</h5>
            <video id="camera" autoplay class="w-100 mb-3" muted></video>

            <div class="mb-3">
                <label for="manualSearch" class="form-label">Or search manually</label>
                <input type="text" class="form-control" id="manualSearch" placeholder="Enter item name">
            </div>

            <ul class="list-group mb-3" id="searchResults"></ul>

            <button class="btn btn-primary w-100" id="createItemBtn">Create New Item</button>
        </div>
    </div>
</div>
{% endblock%}

{% block scripts %}
<script>
    const baseURL = "{{url_for('add_meal.select_item', input='!')}}";
    const baseURL2 = "{{url_for('add_meal.add_new_item', input='!')}}";
</script>
<script type="module">
    // Import barcode scanner
    import { BrowserMultiFormatReader } from 'https://cdn.jsdelivr.net/npm/@zxing/library@0.21.3/+esm';

    // constants
    const codeReader = new BrowserMultiFormatReader();
    const videoElement = document.getElementById('camera');

    // Start async camera thingymibob
    document.addEventListener('DOMContentLoaded', async () => {
        console.log('[DEBUG] Page loaded, starting barcode scan');

        try {
            await navigator.mediaDevices.getUserMedia({ video: true });
        } catch (err) {
            alert("No camera found or no camera permission");
            console.error("Could not access the camera:", err);
            return;
        }

        console.log('[DEBUG] Permission given and at least one device present');
        const devices = await codeReader.listVideoInputDevices();
        console.log('[DEBUG] Cameras found:', devices);

        const rearCamera = devices.find(device => device.label.toLowerCase().includes('back'))
            || devices.find(device => device.label.toLowerCase().includes('rear'))
            || devices[0]; // fallback

        const selectedDeviceId = rearCamera?.deviceId;
        await codeReader.decodeFromVideoDevice(selectedDeviceId, videoElement, async (result, err) => {
            if (result) {
                // Result found, redirect to the URL
                console.log(result)
                const codeText = result.getText();
                window.location.href = baseURL.replace("!", encodeURIComponent(codeText));
            }
        });
    });
</script>

<script>
    const searchInput = document.getElementById('manualSearch');
    const resultsList = document.getElementById('searchResults');
    const createBtn = document.getElementById('createItemBtn');

    let controller; // keeps track of the current fetch

    // TODO: Debounce input, wait for user to stop typing (f.e. 300ms) 
    searchInput.addEventListener('input', () => {
        const query = searchInput.value.toLowerCase();

        // Check if there is enough input to fetch
        if (query.length < 2) {
            resultsList.innerHTML = '';
            return;
        }

        if (controller) controller.abort(); // Abort previous fetch if still running
        controller = new AbortController(); // new controller for this fetch
        const signal = controller.signal;   // Signal to fetch to listen for aborts

        fetch(`{{url_for("add_meal.query")}}?q=${encodeURIComponent(query)}`, { signal })
            .then(response => response.json())
            .then(data => {
                resultsList.innerHTML = ''; // clear before appending
                data.forEach(item => {
                    // Create list item with button inside that changes the hidden form and submits it
                    const li = document.createElement('li');
                    li.className = 'list-group-item p-0';
                    const btn = document.createElement('button');
                    btn.className = 'list-group-item list-group-item-action m-0 border-0';
                    btn.style.width = '100%'; // make it fill the li
                    btn.textContent = item;

                    btn.addEventListener('click', () => {
                        window.location.href = baseURL.replace("!", encodeURIComponent(item));
                    });

                    li.appendChild(btn);
                    resultsList.appendChild(li);
                });
            }).catch(err => {
                if (err.name == 'AbortError') {
                    console.log("Fetch aborted");
                }
                if (err.name !== 'AbortError') {
                    console.error('Fetch error:', err);
                }
            });
    });
</script>
<script>
    createBtn.addEventListener('click', () => {
        const newItem = searchInput.value.trim()
        window.location.href = newItem ? baseURL2.replace("!", encodeURIComponent(newItem)) : baseURL2;
    });
</script>

{% endblock %}