import { IndexedFeatureSource } from "../FeatureSource/FeatureSource"
import { GeoOperations } from "../GeoOperations"
import { Store, UIEventSource } from "../UIEventSource"
import P4C from "pic4carto"
import { Tiles } from "../../Models/TileRange"
import { BBox } from "../BBox"
import Constants from "../../Models/Constants"
import { Utils } from "../../Utils"
import { Point } from "geojson"

interface ImageFetcher {
    /**
     * Returns images, null if an error happened
     * @param lat
     * @param lon
     */
    fetchImages(lat: number, lon: number): Promise<P4CPicture[]>

    readonly name: string

}


class CachedFetcher implements ImageFetcher {
    private readonly _fetcher: ImageFetcher
    private readonly _zoomlevel: number
    private readonly cache: Map<number, Promise<P4CPicture[]>> = new Map<number, Promise<P4CPicture[]>>()
    public readonly name: string

    constructor(fetcher: ImageFetcher, zoomlevel: number = 19) {
        this._fetcher = fetcher
        this._zoomlevel = zoomlevel
        this.name = fetcher.name
    }

    fetchImages(lat: number, lon: number): Promise<P4CPicture[]> {
        const tile = Tiles.embedded_tile(lat, lon, this._zoomlevel)
        const tileIndex = Tiles.tile_index(tile.z, tile.x, tile.y)
        if (this.cache.has(tileIndex)) {
            return this.cache.get(tileIndex)
        }
        const call = this._fetcher.fetchImages(lat, lon)
        this.cache.set(tileIndex, call)
        return call
    }
}

export interface P4CPicture {
    pictureUrl: string
    date?: number
    coordinates: { lat: number; lng: number }
    provider: "Mapillary" | string
    author?
    license?
    detailsUrl?: string
    direction?
    osmTags?: object /*To copy straight into OSM!*/
    thumbUrl: string
    details: {
        isSpherical: boolean
    }
}

class NearbyImageUtils {
    /**
     * In place sorting of the given array, by distance. Closest element will be first
     */
    public static sortByDistance(result: P4CPicture[], lon: number, lat: number) {
        const c = [lon, lat]
        result.sort((a, b) => {
            const da = GeoOperations.distanceBetween([a.coordinates.lng, a.coordinates.lat], c)
            const db = GeoOperations.distanceBetween([b.coordinates.lng, b.coordinates.lat], c)
            return da - db

        })
    }
}


class P4CImageFetcher implements ImageFetcher {

    public static readonly services = ["mapillary", "flickr", "kartaview", "wikicommons"] as const
    public static readonly apiUrls = ["https://api.flickr.com"]
    private _options: { maxDaysOld: number, searchRadius: number }
    public readonly name: P4CService

    constructor(service: P4CService, options?: { maxDaysOld: number, searchRadius: number }) {
        this.name = service
        this._options = options
    }

    async fetchImages(lat: number, lon: number): Promise<P4CPicture[]> {
        const picManager = new P4C.PicturesManager({ usefetchers: [this.name] })
        const maxAgeSeconds = (this._options?.maxDaysOld ?? 3 * 365) * 24 * 60 * 60 * 1000
        const searchRadius = this._options?.searchRadius ?? 100

        try {

            return await picManager.startPicsRetrievalAround(
                new P4C.LatLng(lat, lon),
                searchRadius,
                {
                    mindate: new Date().getTime() - maxAgeSeconds,
                    towardscenter: false,

                },
            )
        } catch (e) {
            console.log("P4C image fetcher failed with", e)
            throw e
        }
    }

}

/**
 * Extracts pictures from currently loaded features
 */
class ImagesInLoadedDataFetcher implements ImageFetcher {
    private indexedFeatures: IndexedFeatureSource
    private readonly _searchRadius: number
    public readonly name = "inLoadedData"

    constructor(indexedFeatures: IndexedFeatureSource, searchRadius: number = 500) {
        this.indexedFeatures = indexedFeatures
        this._searchRadius = searchRadius
    }

    async fetchImages(lat: number, lon: number): Promise<P4CPicture[]> {
        const foundImages: P4CPicture[] = []
        this.indexedFeatures.features.data.forEach((feature) => {
            const props = feature.properties
            const images = []
            if (props.image) {
                images.push(props.image)
            }
            for (let i = 0; i < 10; i++) {
                if (props["image:" + i]) {
                    images.push(props["image:" + i])
                }
            }
            if (images.length == 0) {
                return
            }
            const centerpoint = GeoOperations.centerpointCoordinates(feature)
            const d = GeoOperations.distanceBetween(centerpoint, [lon, lat])
            if (this._searchRadius !== undefined && d > this._searchRadius) {
                return
            }
            for (const image of images) {
                foundImages.push({
                    pictureUrl: image,
                    thumbUrl: image,
                    coordinates: { lng: centerpoint[0], lat: centerpoint[1] },
                    provider: "OpenStreetMap",
                    details: {
                        isSpherical: false,
                    },
                    osmTags: { image },
                })
            }
        })

        return foundImages
    }
}


class MapillaryFetcher implements ImageFetcher {

    public readonly name = "mapillary_new"
    private readonly _panoramas: "only" | "no" | undefined
    private readonly _max_images: 100 | number

    private readonly start_captured_at?: Date
    private readonly end_captured_at?: Date

    constructor(options?: {
        panoramas: undefined | "only" | "no",
        max_images?: 100 | number,
        start_captured_at?: Date,
        end_captured_at?: Date
    }) {
        this._panoramas = options?.panoramas
        this._max_images = options?.max_images ?? 100
        this.start_captured_at = options?.start_captured_at
        this.end_captured_at = options?.end_captured_at
    }

    async fetchImages(lat: number, lon: number): Promise<P4CPicture[]> {

        const boundingBox = new BBox([[lon, lat]]).padAbsolute(0.003)
        let url = "https://graph.mapillary.com/images?fields=computed_geometry,creator,id,thumb_256_url,thumb_original_url,compass_angle&bbox="
            + [boundingBox.getWest(), boundingBox.getSouth(), boundingBox.getEast(), boundingBox.getNorth()].join(",")
            + "&access_token=" + encodeURIComponent(Constants.mapillary_client_token_v4)
            + "&limit=" + this._max_images
        {
            if (this._panoramas === "no") {
                url += "&is_pano=false"
            } else if (this._panoramas === "only") {
                url += "&is_pano=true"
            }
            if (this.start_captured_at) {
                url += "&start_captured_at="+ this.start_captured_at?.toISOString()
            }
            if (this.end_captured_at) {
                url += "&end_captured_at="+ this.end_captured_at?.toISOString()
            }
        }

        const response = await Utils.downloadJson<{
            data: { id: string, creator: string, computed_geometry: Point, is_pano: boolean,thumb_256_url: string, thumb_original_url: string, compass_angle: number }[]
        }>(url)
        const pics: P4CPicture[] = []
        for (const img of response.data) {

            const c = img.computed_geometry.coordinates
            if(img.thumb_original_url === undefined){
                continue
            }
            pics.push({
                pictureUrl: img.thumb_original_url,
                provider: "Mapillary",
                coordinates: { lng: c[0], lat: c[1] },
                thumbUrl: img.thumb_256_url,
                osmTags: {
                    "mapillary":img.id
                },
                details: {
                    isSpherical: img.is_pano,
                },
            })
        }
        return pics
    }
}

type P4CService = (typeof P4CImageFetcher.services)[number]

export class CombinedFetcher {
    private readonly sources: ReadonlyArray<CachedFetcher>
    public static apiUrls = P4CImageFetcher.apiUrls


    constructor(radius: number, maxage: Date, indexedFeatures: IndexedFeatureSource) {
        this.sources = [
            new ImagesInLoadedDataFetcher(indexedFeatures, radius),
            new MapillaryFetcher({
                panoramas: "no",
                max_images: 25,
                start_captured_at : maxage
            }),
            new P4CImageFetcher("mapillary"),
            new P4CImageFetcher("wikicommons"),
        ].map(f => new CachedFetcher(f))
    }

    public getImagesAround(lon: number, lat: number): {
        images: Store<P4CPicture[]>,
        state: Store<Record<string, "loading" | "done" | "error">>
    } {
        const src = new UIEventSource<P4CPicture[]>([])
        const state = new UIEventSource<Record<string, "loading" | "done" | "error">>({})
        for (const source of this.sources) {
            state.data[source.name] = "loading"
            state.ping()
            source.fetchImages(lat, lon)
                .then(pics => {
                    console.log(source.name,"==>>",pics)
                    state.data[source.name] = "done"
                    state.ping()
                    if (src.data === undefined) {
                        src.setData(pics)
                    } else {
                        const newList = []
                        const seenIds = new Set<string>()
                        for (const p4CPicture of [...src.data, ...pics]) {
                            const id = p4CPicture.pictureUrl
                            if(seenIds.has(id)){
                                continue
                            }
                            newList.push(p4CPicture)
                            seenIds.add(id)
                            if(id === undefined){

                            console.log("Img:", p4CPicture)
                            }
                        }
                        NearbyImageUtils.sortByDistance(newList, lon, lat)
                        src.setData(newList)
                    }
                }, err => {
                    console.error("Could not load images from", source.name, "due to", err)
                    state.data[source.name] = "error"
                    state.ping()
                })
        }
        return { images: src, state }
    }

}