import { map } from "rxjs/operators";
import { Observable } from "rxjs";

import {
    ICoreNode,
    IFillNode,
    IGPano,
    ILatLon,
} from "../API";
import { IEdge } from "../Edge";
import {
    IEdgeStatus,
    NodeCache,
} from "../Graph";
import { ImageSize } from "../Viewer";
import IMesh from "../api/interfaces/IMesh";

/**
 * @class Node
 *
 * @classdesc Represents a node in the navigation graph.
 *
 * Explanation of position and bearing properties:
 *
 * When images are uploaded they will have GPS information in the EXIF, this is what
 * is called `originalLatLon` {@link Node.originalLatLon}.
 *
 * When Structure from Motions has been run for a node a `computedLatLon` that
 * differs from the `originalLatLon` will be created. It is different because
 * GPS positions are not very exact and SfM aligns the camera positions according
 * to the 3D reconstruction {@link Node.computedLatLon}.
 *
 * At last there exist a `latLon` property which evaluates to
 * the `computedLatLon` from SfM if it exists but falls back
 * to the `originalLatLon` from the EXIF GPS otherwise {@link Node.latLon}.
 *
 * Everything that is done in in the Viewer is based on the SfM positions,
 * i.e. `computedLatLon`. That is why the smooth transitions go in the right
 * direction (nd not in strange directions because of bad GPS).
 *
 * E.g. when placing a marker in the Viewer it is relative to the SfM
 * position i.e. the `computedLatLon`.
 *
 * The same concept as above also applies to the compass angle (or bearing) properties
 * `originalCa`, `computedCa` and `ca`.
 */
export class Node {
    private _cache: NodeCache;
    private _core: ICoreNode;
    private _fill: IFillNode;

    /**
     * Create a new node instance.
     *
     * @description Nodes are always created internally by the library.
     * Nodes can not be added to the library through any API method.
     *
     * @param {ICoreNode} coreNode - Raw core node data.
     * @ignore
     */
    constructor(core: ICoreNode) {
        this._cache = null;
        this._core = core;
        this._fill = null;
    }

    /**
     * Get assets cached.
     *
     * @description The assets that need to be cached for this property
     * to report true are the following: fill properties, image and mesh.
     * The library ensures that the current node will always have the
     * assets cached.
     *
     * @returns {boolean} Value indicating whether all assets have been
     * cached.
     *
     * @ignore
     */
    public get assetsCached(): boolean {
        return this._core != null &&
            this._fill != null &&
            this._cache != null &&
            this._cache.image != null &&
            this._cache.mesh != null;
    }

    /**
     * Get alt.
     *
     * @description If SfM has not been run the computed altitude is
     * set to a default value of two meters.
     *
     * @returns {number} Altitude, in meters.
     */
    public get alt(): number {
        return this._fill.calt;
    }

    /**
     * Get ca.
     *
     * @description If the SfM computed compass angle exists it will
     * be returned, otherwise the original EXIF compass angle.
     *
     * @returns {number} Compass angle, measured in degrees
     * clockwise with respect to north.
     */
    public get ca(): number {
        return this._fill.cca != null ? this._fill.cca : this._fill.ca;
    }

    /**
     * Get cameraProjection.
     *
     * @description Will be undefined if SfM has not been run.
     *
     * @returns {number} The camera projection of the image.
     */
    public get cameraProjectionType(): "perspective" | "fisheye" | "equirectangular" {
        return this._fill.camera_projection_type;
    }

    /**
     * Get capturedAt.
     *
     * @returns {number} Timestamp when the image was captured.
     */
    public get capturedAt(): number {
        return this._fill.captured_at;
    }

    /**
     * Get camera uuid.
     *
     * @description Will be undefined if the camera uuid was not
     * recorded in the image exif information.
     *
     * @returns {string} Universally unique id for camera used
     * when capturing image.
     */
    public get cameraUuid(): string {
        return this._fill.captured_with_camera_uuid;
    }

    /**
     * Get clusterKey.
     *
     * @returns {string} Unique key of the SfM cluster to which
     * the node belongs.
     */
    public get clusterKey(): string {
        return this._fill.cluster_key;
    }

    /**
     * Get clusterUrl.
     *
     * @returns {string} Url to the cluster reconstruction file.
     *
     * @ignore
     */
    public get clusterUrl(): string {
        return this._fill.cluster_url;
    }

    /**
     * Get ck1.
     *
     * @description Will not be set if SfM has not been run.
     *
     * @returns {number} SfM computed radial distortion parameter
     * k1.
     */
    public get ck1(): number {
        return this._fill.ck1;
    }

    /**
     * Get ck2.
     *
     * @description Will not be set if SfM has not been run.
     *
     * @returns {number} SfM computed radial distortion parameter
     * k2.
     */
    public get ck2(): number {
        return this._fill.ck2;
    }

    /**
     * Get computedCA.
     *
     * @description Will not be set if SfM has not been run.
     *
     * @returns {number} SfM computed compass angle, measured
     * in degrees clockwise with respect to north.
     */
    public get computedCA(): number {
        return this._fill.cca;
    }

    /**
     * Get computedLatLon.
     *
     * @description Will not be set if SfM has not been run.
     *
     * @returns {ILatLon} SfM computed latitude longitude in WGS84 datum,
     * measured in degrees.
     */
    public get computedLatLon(): ILatLon {
        return this._core.cl;
    }

    /**
     * Get focal.
     *
     * @description Will not be set if SfM has not been run.
     *
     * @returns {number} SfM computed focal length.
     */
    public get focal(): number {
        return this._fill.cfocal;
    }

    /**
     * Get full.
     *
     * @description The library ensures that the current node will
     * always be full.
     *
     * @returns {boolean} Value indicating whether the node has all
     * properties filled.
     *
     * @ignore
     */
    public get full(): boolean {
        return this._fill != null;
    }

    /**
     * Get fullPano.
     *
     * @returns {boolean} Value indicating whether the node is a complete
     * 360 panorama.
     */
    public get fullPano(): boolean {
        return this._fill.gpano != null &&
            this._fill.gpano.CroppedAreaLeftPixels === 0 &&
            this._fill.gpano.CroppedAreaTopPixels === 0 &&
            this._fill.gpano.CroppedAreaImageWidthPixels === this._fill.gpano.FullPanoWidthPixels &&
            this._fill.gpano.CroppedAreaImageHeightPixels === this._fill.gpano.FullPanoHeightPixels;
    }

    /**
     * Get gpano.
     *
     * @description Will not be set for non panoramic images.
     *
     * @returns {IGPano} Panorama information for panorama images.
     */
    public get gpano(): IGPano {
        return this._fill.gpano;
    }

    /**
     * Get height.
     *
     * @returns {number} Height of original image, not adjusted
     * for orientation.
     */
    public get height(): number {
        return this._fill.height;
    }

    /**
     * Get image.
     *
     * @description The image will always be set on the current node.
     *
     * @returns {HTMLImageElement} Cached image element of the node.
     */
    public get image(): HTMLImageElement {
        return this._cache.image;
    }

    /**
     * Get image$.
     *
     * @returns {Observable<HTMLImageElement>} Observable emitting
     * the cached image when it is updated.
     *
     * @ignore
     */
    public get image$(): Observable<HTMLImageElement> {
        return this._cache.image$;
    }

    /**
     * Get key.
     *
     * @returns {string} Unique key of the node.
     */
    public get key(): string {
        return this._core.key;
    }

    /**
     * Get latLon.
     *
     * @description If the SfM computed latitude longitude exist
     * it will be returned, otherwise the original EXIF latitude
     * longitude.
     *
     * @returns {ILatLon} Latitude longitude in WGS84 datum,
     * measured in degrees.
     */
    public get latLon(): ILatLon {
        return this._core.cl != null ? this._core.cl : this._core.l;
    }

    /**
     * Get merged.
     *
     * @returns {boolean} Value indicating whether SfM has been
     * run on the node and the node has been merged into a
     * connected component.
     */
    public get merged(): boolean {
        return this._fill != null &&
            this._fill.merge_version != null &&
            this._fill.merge_version > 0;
    }

    /**
     * Get mergeCC.
     *
     * @description Will not be set if SfM has not yet been run on
     * node.
     *
     * @returns {number} SfM connected component key to which
     * image belongs.
     */
    public get mergeCC(): number {
        return this._fill.merge_cc;
    }

    /**
     * Get mergeVersion.
     *
     * @returns {number} Version for which SfM was run and image was merged.
     */
    public get mergeVersion(): number {
        return this._fill.merge_version;
    }

    /**
     * Get mesh.
     *
     * @description The mesh will always be set on the current node.
     *
     * @returns {IMesh} SfM triangulated mesh of reconstructed
     * atomic 3D points.
     */
    public get mesh(): IMesh {
        return this._cache.mesh;
    }

    /**
     * Get organizationKey.
     *
     * @returns {string} Unique key of the organization to which
     * the node belongs. If the node does not belong to an
     * organization the organization key will be undefined.
     */
    public get organizationKey(): string {
        return this._fill.organization_key;
    }

    /**
     * Get orientation.
     *
     * @returns {number} EXIF orientation of original image.
     */
    public get orientation(): number {
        return this._fill.orientation;
    }

    /**
     * Get originalAlt.
     *
     * @returns {number} EXIF altitude, in meters, if available.
     */
    public get originalAlt(): number {
        return this._fill.altitude;
    }

    /**
     * Get originalCA.
     *
     * @returns {number} Original EXIF compass angle, measured in
     * degrees.
     */
    public get originalCA(): number {
        return this._fill.ca;
    }

    /**
     * Get originalLatLon.
     *
     * @returns {ILatLon} Original EXIF latitude longitude in
     * WGS84 datum, measured in degrees.
     */
    public get originalLatLon(): ILatLon {
        return this._core.l;
    }

    /**
     * Get pano.
     *
     * @returns {boolean} Value indicating whether the node is a panorama.
     * It could be a cropped or full panorama.
     */
    public get pano(): boolean {
        return this._fill.gpano != null &&
            this._fill.gpano.FullPanoWidthPixels != null;
    }

    /**
     * Get private.
     *
     * @returns {boolean} Value specifying if image is accessible to
     * organization members only or to everyone.
     */
    public get private(): boolean {
        return this._fill.private;
    }

    /**
     * Get projectKey.
     *
     * @returns {string} Unique key of the project to which
     * the node belongs. If the node does not belong to a
     * project the project key will be undefined.
     *
     * @deprecated This property will be deprecated in favor
     * of the organization key and private properties.
     *
     * @ignore
     */
    public get projectKey(): string {
        return this._fill.project != null ?
            this._fill.project.key :
            null;
    }

    /**
     * Get quality score.
     *
     * @returns {number} A number between zero and one
     * determining the quality of the image. Blurriness
     * (motion blur / out-of-focus), occlusion (camera
     * mount, ego vehicle, water-drops), windshield
     * reflections, bad illumination (exposure, glare),
     * and bad weather condition (fog, rain, snow)
     * affect the quality score.
     */
    public get qualityScore(): number {
        return this._fill.quality_score;
    }

    /**
     * Get rotation.
     *
     * @description Will not be set if SfM has not been run.
     *
     * @returns {Array<number>} Rotation vector in angle axis representation.
     */
    public get rotation(): number[] {
        return this._fill.c_rotation;
    }

    /**
     * Get scale.
     *
     * @description Will not be set if SfM has not been run.
     *
     * @returns {number} Scale of atomic reconstruction.
     */
    public get scale(): number {
        return this._fill.atomic_scale;
    }

    /**
     * Get sequenceKey.
     *
     * @returns {string} Unique key of the sequence to which
     * the node belongs.
     */
    public get sequenceKey(): string {
        return this._core.sequence_key;
    }

    /**
     * Get sequenceEdges.
     *
     * @returns {IEdgeStatus} Value describing the status of the
     * sequence edges.
     *
     * @ignore
     */
    public get sequenceEdges(): IEdgeStatus {
        return this._cache.sequenceEdges;
    }

    /**
     * Get sequenceEdges$.
     *
     * @description Internal observable, should not be used as an API.
     *
     * @returns {Observable<IEdgeStatus>} Observable emitting
     * values describing the status of the sequence edges.
     *
     * @ignore
     */
    public get sequenceEdges$(): Observable<IEdgeStatus> {
        return this._cache.sequenceEdges$;
    }

    /**
     * Get spatialEdges.
     *
     * @returns {IEdgeStatus} Value describing the status of the
     * spatial edges.
     *
     * @ignore
     */
    public get spatialEdges(): IEdgeStatus {
        return this._cache.spatialEdges;
    }

    /**
     * Get spatialEdges$.
     *
     * @description Internal observable, should not be used as an API.
     *
     * @returns {Observable<IEdgeStatus>} Observable emitting
     * values describing the status of the spatial edges.
     *
     * @ignore
     */
    public get spatialEdges$(): Observable<IEdgeStatus> {
        return this._cache.spatialEdges$;
    }

    /**
     * Get userKey.
     *
     * @returns {string} Unique key of the user who uploaded
     * the image.
     */
    public get userKey(): string {
        return this._fill.user.key;
    }

    /**
     * Get username.
     *
     * @returns {string} Username of the user who uploaded
     * the image.
     */
    public get username(): string {
        return this._fill.user.username;
    }

    /**
     * Get width.
     *
     * @returns {number} Width of original image, not
     * adjusted for orientation.
     */
    public get width(): number {
        return this._fill.width;
    }

    /**
     * Cache the image and mesh assets.
     *
     * @description The assets are always cached internally by the
     * library prior to setting a node as the current node.
     *
     * @returns {Observable<Node>} Observable emitting this node whenever the
     * load status has changed and when the mesh or image has been fully loaded.
     *
     * @ignore
     */
    public cacheAssets$(): Observable<Node> {
        return this._cache
            .cacheAssets$(
                this._fill,
                this.pano,
                this.merged)
            .pipe(
                map(
                    (): Node => {
                        return this;
                    }));
    }

    /**
     * Cache the image asset.
     *
     * @description Use for caching a differently sized image than
     * the one currently held by the node.
     *
     * @returns {Observable<Node>} Observable emitting this node whenever the
     * load status has changed and when the mesh or image has been fully loaded.
     *
     * @ignore
     */
    public cacheImage$(imageSize: ImageSize): Observable<Node> {
        return this._cache.cacheImage$(this._fill, imageSize).pipe(
            map(
                (): Node => {
                    return this;
                }));
    }

    /**
     * Cache the sequence edges.
     *
     * @description The sequence edges are cached asynchronously
     * internally by the library.
     *
     * @param {Array<IEdge>} edges - Sequence edges to cache.
     * @ignore
     */
    public cacheSequenceEdges(edges: IEdge[]): void {
        this._cache.cacheSequenceEdges(edges);
    }

    /**
     * Cache the spatial edges.
     *
     * @description The spatial edges are cached asynchronously
     * internally by the library.
     *
     * @param {Array<IEdge>} edges - Spatial edges to cache.
     * @ignore
     */
    public cacheSpatialEdges(edges: IEdge[]): void {
        this._cache.cacheSpatialEdges(edges);
    }

    /**
     * Dispose the node.
     *
     * @description Disposes all cached assets.
     * @ignore
     */
    public dispose(): void {
        if (this._cache != null) {
            this._cache.dispose();
            this._cache = null;
        }

        this._core = null;
        this._fill = null;
    }

    /**
     * Initialize the node cache.
     *
     * @description The node cache is initialized internally by
     * the library.
     *
     * @param {NodeCache} cache - The node cache to set as cache.
     * @ignore
     */
    public initializeCache(cache: NodeCache): void {
        if (this._cache != null) {
            throw new Error(`Node cache already initialized (${this.key}).`);
        }

        this._cache = cache;
    }

    /**
     * Fill the node with all properties.
     *
     * @description The node is filled internally by
     * the library.
     *
     * @param {IFillNode} fill - The fill node struct.
     * @ignore
     */
    public makeFull(fill: IFillNode): void {
        if (fill == null) {
            throw new Error("Fill can not be null.");
        }

        this._fill = fill;
    }

    /**
     * Reset the sequence edges.
     *
     * @ignore
     */
    public resetSequenceEdges(): void {
        this._cache.resetSequenceEdges();
    }

    /**
     * Reset the spatial edges.
     *
     * @ignore
     */
    public resetSpatialEdges(): void {
        this._cache.resetSpatialEdges();
    }

    /**
     * Clears the image and mesh assets, aborts
     * any outstanding requests and resets edges.
     *
     * @ignore
     */
    public uncache(): void {
        if (this._cache == null) {
            return;
        }

        this._cache.dispose();
        this._cache = null;
    }
}

export default Node;