let activeViewer = null;

/**
 * Initializes and shows the Pannellum 360° panorama viewer with security overlays.
 * @param {string} imageUrl - Authorized URL to fetch the secure image stream
 */
function initPanoramaViewer(imageUrl) {
    const container = document.getElementById('viewer-container');
    container.style.display = 'block';

    if (activeViewer) {
        try {
            activeViewer.destroy();
        } catch (e) {}
    }

    // Initialize Pannellum Equirectangular viewer
    activeViewer = pannellum.viewer('panorama-viewer', {
        "type": "equirectangular",
        "panorama": imageUrl,
        "autoLoad": true,
        "showControls": true,
        "compass": false,
        "mouseZoom": true,
        "keyboardZoom": true
    });

    // Security constraints inside the viewer
    applyViewerSecurity();
}

/**
 * Closes and destroys the active panorama viewer.
 */
function closeViewer() {
    document.getElementById('viewer-container').style.display = 'none';
    if (activeViewer) {
        try {
            activeViewer.destroy();
        } catch (e) {}
        activeViewer = null;
    }
}

/**
 * Appends event listeners to block right-clicks and common image saving shortcuts.
 */
function applyViewerSecurity() {
    const viewer = document.getElementById('viewer-container');

    // Block right-clicks inside the 3D Viewer Container
    viewer.addEventListener('contextmenu', (e) => {
        e.preventDefault();
        alert('Security Alert: Direct image downloading or copying is disabled on this asset.');
    });

    // Block drag and drop
    viewer.addEventListener('dragstart', (e) => {
        e.preventDefault();
    });
}

// Global safety shortcut listeners (F12, Ctrl+S, Ctrl+U, Ctrl+Shift+I)
document.addEventListener('keydown', (e) => {
    // Only enforce when viewer is active
    if (document.getElementById('viewer-container').style.display === 'block') {
        const isCtrlS = e.ctrlKey && (e.key === 's' || e.key === 'S');
        const isCtrlU = e.ctrlKey && (e.key === 'u' || e.key === 'U');
        const isF12 = e.key === 'F12';
        const isCtrlShiftI = e.ctrlKey && e.shiftKey && (e.key === 'i' || e.key === 'I');

        if (isCtrlS || isCtrlU || isF12 || isCtrlShiftI) {
            e.preventDefault();
            alert('Security Alert: Inspection and saving functions are restricted on this viewer.');
            return false;
        }
    }
});