/*****************************************************************************
 * Open MCT, Copyright (c) 2014-2021, United States Government
 * as represented by the Administrator of the National Aeronautics and Space
 * Administration. All rights reserved.
 *
 * Open MCT is licensed under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 * Open MCT includes source code licensed under additional open source
 * licenses. See the Open Source Licenses file (LICENSES.md) included with
 * this source code distribution or the Licensing information page available
 * at runtime from the About dialog for additional information.
 *****************************************************************************/

const DEFAULT_IMAGE_SAMPLES = [
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18731.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18732.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18733.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18734.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18735.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18736.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18737.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18738.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18739.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18740.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18741.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18742.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18743.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18744.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18745.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18746.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18747.jpg",
    "https://www.hq.nasa.gov/alsj/a16/AS16-117-18748.jpg"
];
const DEFAULT_IMAGE_LOAD_DELAY_IN_MILISECONDS = 20000;
const MIN_IMAGE_LOAD_DELAY_IN_MILISECONDS = 5000;

let openmctInstance;

export default function () {
    return function install(openmct) {
        openmctInstance = openmct;
        openmct.types.addType('example.imagery', {
            key: 'example.imagery',
            name: 'Example Imagery',
            cssClass: 'icon-image',
            description: 'For development use. Creates example imagery '
                + 'data that mimics a live imagery stream.',
            creatable: true,
            initialize: (object) => {
                object.configuration = {
                    imageLocation: '',
                    imageLoadDelayInMilliSeconds: DEFAULT_IMAGE_LOAD_DELAY_IN_MILISECONDS,
                    imageSamples: []
                };

                object.telemetry = {
                    values: [
                        {
                            name: 'Name',
                            key: 'name'
                        },
                        {
                            name: 'Time',
                            key: 'utc',
                            format: 'utc',
                            hints: {
                                domain: 2
                            }
                        },
                        {
                            name: 'Local Time',
                            key: 'local',
                            format: 'local-format',
                            hints: {
                                domain: 1
                            }
                        },
                        {
                            name: 'Image',
                            key: 'url',
                            format: 'image',
                            hints: {
                                image: 1
                            }
                        },
                        {
                            name: 'Image Download Name',
                            key: 'imageDownloadName',
                            format: 'imageDownloadName',
                            hints: {
                                imageDownloadName: 1
                            }
                        }
                    ]
                };
            },
            form: [
                {
                    key: 'imageLocation',
                    name: 'Images url list (comma separated)',
                    control: 'textarea',
                    cssClass: 'l-inline',
                    property: [
                        "configuration",
                        "imageLocation"
                    ]
                },
                {
                    key: 'imageLoadDelayInMilliSeconds',
                    name: 'Image load delay (milliseconds)',
                    control: 'numberfield',
                    required: true,
                    cssClass: 'l-inline',
                    property: [
                        "configuration",
                        "imageLoadDelayInMilliSeconds"
                    ]
                }
            ]
        });

        openmct.telemetry.addProvider(getRealtimeProvider());
        openmct.telemetry.addProvider(getHistoricalProvider());
        openmct.telemetry.addProvider(getLadProvider());
    };
}

function getCompassValues(min, max) {
    return min + Math.random() * (max - min);
}

function getImageSamples(configuration) {
    let imageSamples = DEFAULT_IMAGE_SAMPLES;

    if (configuration.imageLocation && configuration.imageLocation.length) {
        imageSamples = getImageUrlListFromConfig(configuration);
    }

    return imageSamples;
}

function getImageUrlListFromConfig(configuration) {
    return configuration.imageLocation.split(',');
}

function getImageLoadDelay(domainObject) {
    const imageLoadDelay = domainObject.configuration.imageLoadDelayInMilliSeconds;
    if (!imageLoadDelay) {
        openmctInstance.objects.mutate(domainObject, 'configuration.imageLoadDelayInMilliSeconds', DEFAULT_IMAGE_LOAD_DELAY_IN_MILISECONDS);

        return DEFAULT_IMAGE_LOAD_DELAY_IN_MILISECONDS;
    }

    if (imageLoadDelay < MIN_IMAGE_LOAD_DELAY_IN_MILISECONDS) {
        openmctInstance.objects.mutate(domainObject, 'configuration.imageLoadDelayInMilliSeconds', MIN_IMAGE_LOAD_DELAY_IN_MILISECONDS);

        return MIN_IMAGE_LOAD_DELAY_IN_MILISECONDS;
    }

    return imageLoadDelay;
}

function getRealtimeProvider() {
    return {
        supportsSubscribe: domainObject => domainObject.type === 'example.imagery',
        subscribe: (domainObject, callback) => {
            const delay = getImageLoadDelay(domainObject);
            const interval = setInterval(() => {
                callback(pointForTimestamp(Date.now(), domainObject.name, getImageSamples(domainObject.configuration), delay));
            }, delay);

            return () => {
                clearInterval(interval);
            };
        }
    };
}

function getHistoricalProvider() {
    return {
        supportsRequest: (domainObject, options) => {
            return domainObject.type === 'example.imagery'
                && options.strategy !== 'latest';
        },
        request: (domainObject, options) => {
            const delay = getImageLoadDelay(domainObject);
            let start = options.start;
            const end = Math.min(options.end, Date.now());
            const data = [];
            while (start <= end && data.length < delay) {
                data.push(pointForTimestamp(start, domainObject.name, getImageSamples(domainObject.configuration), delay));
                start += delay;
            }

            return Promise.resolve(data);
        }
    };
}

function getLadProvider() {
    return {
        supportsRequest: (domainObject, options) => {
            return domainObject.type === 'example.imagery'
                && options.strategy === 'latest';
        },
        request: (domainObject, options) => {
            const delay = getImageLoadDelay(domainObject);

            return Promise.resolve([pointForTimestamp(Date.now(), domainObject.name, delay)]);
        }
    };
}

function pointForTimestamp(timestamp, name, imageSamples, delay) {
    const url = imageSamples[Math.floor(timestamp / delay) % imageSamples.length];
    const urlItems = url.split('/');
    const imageDownloadName = `example.imagery.${urlItems[urlItems.length - 1]}`;

    return {
        name,
        utc: Math.floor(timestamp / delay) * delay,
        local: Math.floor(timestamp / delay) * delay,
        url,
        sunOrientation: getCompassValues(0, 360),
        cameraPan: getCompassValues(0, 360),
        heading: getCompassValues(0, 360),
        imageDownloadName
    };
}
