// Global ATON

import AppState from "./state.js";
import { config } from "../config.js";
import UI from "./ui.js";

const Scene = {};

Scene.UI = UI;

/**
 * @todo Experimental...
 * @param {THREE.Object3D} object - A THREE Object3D instance
 */
Scene.showEdges = function(object) {
    const edgeMaterial = new THREE.LineBasicMaterial( { color: 0x000000 } );

    object.traverse(function(child) {
    
        if (child.isMesh) {
            let edges = new THREE.EdgesGeometry(child.geometry, 45);
            let line = new THREE.LineSegments(edges, edgeMaterial);
            child.add(line);
        
            console.log(child);
        }
    });
}

/**
 * Calculate bounding box for the scene root object
 * and return it along with its center and size (bad?).
 * It only uses meshes to prevent "empty" nodes in the scene
 * from being included in the calculation.
 * @todo Use ATON.Node.getBound()? [bounding sphere]
 */
Scene.getRootBoundingBox = function() {
    const meshes = [];
    AppState.root.traverse(obj => {
        if (obj.isMesh) meshes.push(obj);
    });

    if (meshes.length === 0) return null;

    const bbox = new THREE.Box3().setFromObject(meshes[0]);
    for (let i = 1; i < meshes.length; i++) {
        bbox.union(new THREE.Box3().setFromObject(meshes[i]));
    }

    const center = bbox.getCenter(new THREE.Vector3());
    const size = bbox.getSize(new THREE.Vector3());

    return { bbox, center, size };
}

/**
 * 
 * @param {THREE.Sphere} boundingSphere - The bounding sphere for the main node
 * @returns {THREE.Mesh}
 */
Scene.createClippingPlaneMesh = function (boundingSphere) {
    const planeSize = boundingSphere.radius * 1.5;
    const mesh = new THREE.Mesh(
        new THREE.PlaneGeometry(planeSize, planeSize),
        new THREE.MeshBasicMaterial({ color: 0xffff00, opacity: 0.1, side: THREE.DoubleSide, transparent: true })
    );

    return mesh;
}

/**
 * 
 * @param {THREE.Mesh} planeMesh 
 * @param {THREE.ArrowHelper} arrowHelper 
 * @param {String} axis 
 */
Scene.dragClipper = function(planeMesh, axis) {
    const controls = new THREE.DragControls(
        [planeMesh],
        ATON.Nav._camera,
        ATON._renderer.domElement,
    ); 

    const startPosition = new THREE.Vector3();
    // Only move along the selected axis (exlude the others)
    const excludedAxes = ['x', 'y', 'z'].filter(a => a != axis);

    if (AppState.clipping.enabled && AppState.clipping.vector) {
        controls.addEventListener('dragstart', function (event) {
            startPosition.copy(event.object.position);
            ATON.Nav.setUserControl(false);
        });

        controls.addEventListener('drag', function(event) {
            const point = event.object.position;
            Scene.updateClipper(AppState.clipping.vector, point);
            for (const a of excludedAxes) {
                event.object.position[a] = startPosition[a];
            }
        });

        controls.addEventListener('dragend', function (event) {
            ATON.Nav.setUserControl(true);
        });

        AppState.clipping.controls = controls;
    }
}

/**
 * @param {String} axis - The axis along which the plane's normal should be directed,
 *                        one of 'x', 'y', 'z'
 * @param {Number} orientation - Positive (1) or negative (-1) orientation on the axis
 */
Scene.addClippingPlane = function(axis, orientation = -1) {
    axis = axis.toLowerCase();
    const bound = AppState.clipping.boundingSphere;

    if (!bound) return;

    const vector = [
        axis === 'x' ? orientation : 0,
        axis === 'y' ? orientation : 0,
        axis === 'z' ? orientation : 0,
    ];

    AppState.clipping.vector = vector;

    // First, add a default clipping plane
    // at a default point (calculated...)
    const defaultPoint = bound.center.clone();
    Scene.activateClipper(vector, axis, defaultPoint);
}

/**
 * @todo WIP!
 * Activate clipping plane
 * @param {Number[]} vector - The vector array to direct the plane
 * @param {String} axis - The x,y,z axis
 * @param {?THREE.Vector3} point - The queried scene point
 */
Scene.activateClipper = function(vector, axis, point = null) {
    ATON.enableClipPlanes();
    Scene.updateClipper(vector, point);
    Scene.dragClipper(AppState.clipping.helper, axis);
}

/**
 * 
 * @param {THREE.Vector3} vector 
 * @param {THREE.Vector3} point 
 */
Scene.updateClipper = function(vector, point) {
    // Useless guard...
    if (vector) {
        // Normal of the clipping plane along the axis facing down
        const normal = new THREE.Vector3(...vector).normalize();
        const plane = AppState.clipping.plane ?? ATON.addClipPlane(normal, point);
        // Add a visible plane helper for the clipping plane
        const visiblePlane = AppState.clipping.helper ?? Scene.createClippingPlaneMesh(AppState.clipping.boundingSphere);

        if (!AppState.clipping.helper) {
            AppState.root.add(visiblePlane);
            AppState.clipping.helper = visiblePlane;
        } 

        visiblePlane.position.copy(point);
        visiblePlane.lookAt(point.clone().add(normal));

        plane.setFromNormalAndCoplanarPoint(normal, point);
        AppState.clipping.plane = plane;
    }
}

/**
 * 
 * @param {THREE.Vector3} vector - An object with x,y,z coordinates
 */
Scene.changeLightDirection = function(vector) {
    ATON.setMainLightDirection(vector);
}

/**
 * 
 * @param {Boolean} isEnabled 
 */
Scene.toggleAmbientOcclusion = function(isEnabled) {
    ATON.FX.togglePass(ATON.FX.PASS_AO, isEnabled);
    console.log('Ambient occlusion', isEnabled ? 'ON' : 'OFF');
}

Scene.init = function() {
    ATON.realize();
    ATON.UI.addBasicEvents();
    ATON.UI.init();
    // All assets for this app are stored here
    ATON.setPathCollection('/a/scaenae/assets/');
    // Initial light direction
    ATON.setMainLightDirection(new THREE.Vector3(0.2,-0.3,-0.7));
    ATON.toggleShadows(true);
    ATON.setExposure(config.scene.initialExposure);
    // Open settings side panel when clicking on settings btn
    Scene.UI.toggleSettingsPanel('settings');
    Scene.UI.toggleContentMenu('menu');

    AppState.camera = ATON.Nav._camera;
    AppState.renderer = ATON._renderer;

    ATON.Nav.setUserControl(true);
}
/**
 * Reset clipping state after disabling from UI
 * @todo DragControls errors!!
 */
Scene.resetClipping = function () {
    AppState.clipping.enabled = false;
    ATON.disableClipPlanes();
    AppState.clipping.controls.deactivate();
    // Manually remove event listeners from DragControls!!
    AppState.renderer.domElement.removeEventListener( 'pointermove', AppState.clipping.controls.onPointerMove );
    AppState.renderer.domElement.removeEventListener( 'pointerdown', AppState.clipping.controls.onPointerDown );
    AppState.renderer.domElement.removeEventListener( 'pointerup', AppState.clipping.controls.onPointerCancel );
    AppState.renderer.domElement.removeEventListener( 'pointerleave', AppState.clipping.controls.onPointerCancel )
    AppState.clipping.controls = null;
    AppState.clipping.helper.removeFromParent();
    AppState.root.remove(AppState.clipping.helper);
    AppState.clipping.helper = null;
    AppState.clipping.plane = null;
    AppState.clipping.vector = null;
    // Ensure nav controls are reactivated!
    ATON.Nav.setUserControl(true);
}
/**
 * @param {Object} marker - The marker object from config
 */
Scene.openScene = function(marker) {
    Scene.init();
    Scene.UI.toggleClipperBar('#clipper', '#clipper-bar');

    // Load 3D models and create nodes
    Scene.loadNodes(marker.nodes);

    ATON.setMainPanorama(marker.pano);
    // TODO: hardcoded...
    AppState.initialRotation = new THREE.Vector3(0, 1.5, 0);
    //Scene.showEdges(mainNode);

    ATON.setAutoLP(config.scene.autoLP);
    AppState.lightProbe = config.scene.autoLP;
    Scene.toggleAmbientOcclusion(true);
    AppState.ambientOcclusion = true;
    AppState.root = ATON.getRootScene();
}

/**
 * 
 * @param {Array} nodes 
 */
Scene.loadNodes = function (nodes) {
    nodes.forEach(n => {
        let node = ATON.createSceneNode(n.label);
        node.load(n.model);
        node.setRotation(0, 1.5, 0);
        node.attachToRoot();

        if (n.isMain) {
            AppState.mainNodeId = n.label;
            // ATON.Node.getBound() returns a THREE.Sphere object
            AppState.clipping.boundingSphere = node.getBound();
        }

        AppState.nodes.push({id: n.label, active: true});
    });
}

export default Scene;