/**
 * Generates a collection of geojson files based on an overpass query for a given theme
 */
import { Utils } from "../Utils"
import { Overpass } from "../Logic/Osm/Overpass"
import { existsSync, readFileSync, writeFileSync } from "fs"
import { TagsFilter } from "../Logic/Tags/TagsFilter"
import { Or } from "../Logic/Tags/Or"
import { AllKnownLayouts } from "../Customizations/AllKnownLayouts"
import RelationsTracker from "../Logic/Osm/RelationsTracker"
import * as OsmToGeoJson from "osmtogeojson"
import MetaTagging from "../Logic/MetaTagging"
import { ImmutableStore, UIEventSource } from "../Logic/UIEventSource"
import { TileRange, Tiles } from "../Models/TileRange"
import LayoutConfig from "../Models/ThemeConfig/LayoutConfig"
import ScriptUtils from "./ScriptUtils"
import PerLayerFeatureSourceSplitter from "../Logic/FeatureSource/PerLayerFeatureSourceSplitter"
import FilteredLayer from "../Models/FilteredLayer"
import FeatureSource, { FeatureSourceForLayer } from "../Logic/FeatureSource/FeatureSource"
import StaticFeatureSource from "../Logic/FeatureSource/Sources/StaticFeatureSource"
import TiledFeatureSource from "../Logic/FeatureSource/TiledFeatureSource/TiledFeatureSource"
import Constants from "../Models/Constants"
import { GeoOperations } from "../Logic/GeoOperations"
import SimpleMetaTaggers from "../Logic/SimpleMetaTagger"
import FilteringFeatureSource from "../Logic/FeatureSource/Sources/FilteringFeatureSource"
import Loc from "../Models/Loc"

ScriptUtils.fixUtils()

function createOverpassObject(
    theme: LayoutConfig,
    relationTracker: RelationsTracker,
    backend: string
) {
    let filters: TagsFilter[] = []
    let extraScripts: string[] = []
    for (const layer of theme.layers) {
        if (typeof layer === "string") {
            throw "A layer was not expanded!"
        }
        if (layer.doNotDownload) {
            continue
        }
        if (layer.source.geojsonSource !== undefined) {
            // This layer defines a geoJson-source
            // SHould it be cached?
            if (layer.source.isOsmCacheLayer !== true) {
                continue
            }
        }

        // Check if data for this layer has already been loaded
        if (layer.source.overpassScript !== undefined) {
            extraScripts.push(layer.source.overpassScript)
        } else {
            filters.push(layer.source.osmTags)
        }
    }
    filters = Utils.NoNull(filters)
    extraScripts = Utils.NoNull(extraScripts)
    if (filters.length + extraScripts.length === 0) {
        throw "Nothing to download! The theme doesn't declare anything to download"
    }
    return new Overpass(
        new Or(filters),
        extraScripts,
        backend,
        new UIEventSource<number>(60),
        relationTracker
    )
}

function rawJsonName(targetDir: string, x: number, y: number, z: number): string {
    return targetDir + "_" + z + "_" + x + "_" + y + ".json"
}

function geoJsonName(targetDir: string, x: number, y: number, z: number): string {
    return targetDir + "_" + z + "_" + x + "_" + y + ".geojson"
}

/// Downloads the given feature and saves them to disk
async function downloadRaw(
    targetdir: string,
    r: TileRange,
    theme: LayoutConfig,
    relationTracker: RelationsTracker
) /* : {failed: number, skipped :number} */ {
    let downloaded = 0
    let failed = 0
    let skipped = 0
    const startTime = new Date().getTime()
    for (let x = r.xstart; x <= r.xend; x++) {
        for (let y = r.ystart; y <= r.yend; y++) {
            downloaded++
            const filename = rawJsonName(targetdir, x, y, r.zoomlevel)
            if (existsSync(filename)) {
                console.log("Already exists (not downloading again): ", filename)
                skipped++
                continue
            }
            const runningSeconds = (new Date().getTime() - startTime) / 1000
            const resting = failed + (r.total - downloaded)
            const perTile = runningSeconds / (downloaded - skipped)
            const estimated = Math.floor(resting * perTile)
            console.log(
                "total: ",
                downloaded,
                "/",
                r.total,
                "failed: ",
                failed,
                "skipped: ",
                skipped,
                "running time: ",
                Utils.toHumanTime(runningSeconds) + "s",
                "estimated left: ",
                Utils.toHumanTime(estimated),
                "(" + Math.floor(perTile) + "s/tile)"
            )

            const boundsArr = Tiles.tile_bounds(r.zoomlevel, x, y)
            const bounds = {
                north: Math.max(boundsArr[0][0], boundsArr[1][0]),
                south: Math.min(boundsArr[0][0], boundsArr[1][0]),
                east: Math.max(boundsArr[0][1], boundsArr[1][1]),
                west: Math.min(boundsArr[0][1], boundsArr[1][1]),
            }
            const overpass = createOverpassObject(
                theme,
                relationTracker,
                Constants.defaultOverpassUrls[failed % Constants.defaultOverpassUrls.length]
            )
            const url = overpass.buildQuery(
                "[bbox:" +
                    bounds.south +
                    "," +
                    bounds.west +
                    "," +
                    bounds.north +
                    "," +
                    bounds.east +
                    "]"
            )

            try {
                const json = await Utils.downloadJson(url)
                if ((<string>json.remark ?? "").startsWith("runtime error")) {
                    console.error("Got a runtime error: ", json.remark)
                    failed++
                } else if (json.elements.length === 0) {
                    console.log("Got an empty response! Writing anyway")
                }

                console.log(
                    "Got the response - writing ",
                    json.elements.length,
                    " elements to ",
                    filename
                )
                writeFileSync(filename, JSON.stringify(json, null, "  "))
            } catch (err) {
                console.log(url)
                console.log(
                    "Could not download - probably hit the rate limit; waiting a bit. (" + err + ")"
                )
                failed++
                await ScriptUtils.sleep(1000)
            }
        }
    }

    return { failed: failed, skipped: skipped }
}

/*
 * Downloads extra geojson sources and returns the features.
 * Extra geojson layers should not be tiled
 */
async function downloadExtraData(theme: LayoutConfig) /* : any[] */ {
    const allFeatures: any[] = []
    for (const layer of theme.layers) {
        const source = layer.source.geojsonSource
        if (source === undefined) {
            continue
        }
        if (layer.source.isOsmCacheLayer !== undefined && layer.source.isOsmCacheLayer !== false) {
            // Cached layers are not considered here
            continue
        }
        console.log("Downloading extra data: ", source)
        await Utils.downloadJson(source).then((json) => allFeatures.push(...json.features))
    }
    return allFeatures
}

function loadAllTiles(
    targetdir: string,
    r: TileRange,
    theme: LayoutConfig,
    extraFeatures: any[]
): FeatureSource {
    let allFeatures = [...extraFeatures]
    let processed = 0
    for (let x = r.xstart; x <= r.xend; x++) {
        for (let y = r.ystart; y <= r.yend; y++) {
            processed++
            const filename = rawJsonName(targetdir, x, y, r.zoomlevel)
            console.log(" Loading and processing", processed, "/", r.total, filename)
            if (!existsSync(filename)) {
                console.error("Not found - and not downloaded. Run this script again!: " + filename)
                continue
            }

            // We read the raw OSM-file and convert it to a geojson
            const rawOsm = JSON.parse(readFileSync(filename, { encoding: "utf8" }))

            // Create and save the geojson file - which is the main chunk of the data
            const geojson = OsmToGeoJson.default(rawOsm)
            console.log(" which as", geojson.features.length, "features")

            allFeatures.push(...geojson.features)
        }
    }
    return StaticFeatureSource.fromGeojson(allFeatures)
}

/**
 * Load all the tiles into memory from disk
 */
function sliceToTiles(
    allFeatures: FeatureSource,
    theme: LayoutConfig,
    relationsTracker: RelationsTracker,
    targetdir: string,
    pointsOnlyLayers: string[]
) {
    const skippedLayers = new Set<string>()

    const indexedFeatures: Map<string, any> = new Map<string, any>()
    let indexisBuilt = false

    function buildIndex() {
        for (const ff of allFeatures.features.data) {
            const f = ff.feature
            indexedFeatures.set(f.properties.id, f)
        }
        indexisBuilt = true
    }

    function getFeatureById(id) {
        if (!indexisBuilt) {
            buildIndex()
        }
        return indexedFeatures.get(id)
    }

    async function handleLayer(source: FeatureSourceForLayer) {
        const layer = source.layer.layerDef
        const targetZoomLevel = layer.source.geojsonZoomLevel ?? 0

        const layerId = layer.id
        if (layer.source.isOsmCacheLayer !== true) {
            console.log("Skipping layer ", layerId, ": not a caching layer")
            skippedLayers.add(layer.id)
            return
        }
        console.log(
            "Handling layer ",
            layerId,
            "which has",
            source.features.data.length,
            "features"
        )
        if (source.features.data.length === 0) {
            return
        }
        MetaTagging.addMetatags(
            source.features.data,
            {
                memberships: relationsTracker,
                getFeaturesWithin: (_) => {
                    return [allFeatures.features.data.map((f) => f.feature)]
                },
                getFeatureById: getFeatureById,
            },
            layer,
            {},
            {
                includeDates: false,
                includeNonDates: true,
                evaluateStrict: true,
            }
        )

        while (SimpleMetaTaggers.country.runningTasks.size > 0) {
            console.log(
                "Still waiting for ",
                SimpleMetaTaggers.country.runningTasks.size,
                " features which don't have a country yet"
            )
            await ScriptUtils.sleep(1)
        }

        const createdTiles = []
        // At this point, we have all the features of the entire area.
        // However, we want to export them per tile of a fixed size, so we use a dynamicTileSOurce to split it up
        TiledFeatureSource.createHierarchy(source, {
            minZoomLevel: targetZoomLevel,
            maxZoomLevel: targetZoomLevel,
            maxFeatureCount: undefined,
            registerTile: (tile) => {
                const tileIndex = tile.tileIndex
                console.log("Got tile:", tileIndex, tile.layer.layerDef.id)
                if (tile.features.data.length === 0) {
                    return
                }

                const filteredTile = new FilteringFeatureSource(
                    {
                        locationControl: new ImmutableStore<Loc>(undefined),
                        allElements: undefined,
                        selectedElement: new ImmutableStore<any>(undefined),
                        globalFilters: new ImmutableStore([]),
                    },
                    tileIndex,
                    tile,
                    new UIEventSource<any>(undefined)
                )

                console.log(
                    "Tile " +
                        layer.id +
                        "." +
                        tileIndex +
                        " contains " +
                        filteredTile.features.data.length +
                        " features after filtering (" +
                        tile.features.data.length +
                        ") features before"
                )
                if (filteredTile.features.data.length === 0) {
                    return
                }
                let strictlyCalculated = 0
                let featureCount = 0
                for (const feature of filteredTile.features.data) {
                    // Some cleanup
                    delete feature.feature["bbox"]

                    if (tile.layer.layerDef.calculatedTags !== undefined) {
                        // Evaluate all the calculated tags strictly
                        const calculatedTagKeys = tile.layer.layerDef.calculatedTags.map(
                            (ct) => ct[0]
                        )
                        featureCount++
                        const props = feature.feature.properties
                        for (const calculatedTagKey of calculatedTagKeys) {
                            const strict = props[calculatedTagKey]

                            if (props.hasOwnProperty(calculatedTagKey)) {
                                delete props[calculatedTagKey]
                            }

                            props[calculatedTagKey] = strict
                            strictlyCalculated++
                            if (strictlyCalculated % 100 === 0) {
                                console.log(
                                    "Strictly calculated ",
                                    strictlyCalculated,
                                    "values for tile",
                                    tileIndex,
                                    ": now at ",
                                    featureCount,
                                    "/",
                                    filteredTile.features.data.length,
                                    "examle value: ",
                                    strict
                                )
                            }
                        }
                    }
                }
                // Lets save this tile!
                const [z, x, y] = Tiles.tile_from_index(tileIndex)
                // console.log("Writing tile ", z, x, y, layerId)
                const targetPath = geoJsonName(targetdir + "_" + layerId, x, y, z)
                createdTiles.push(tileIndex)
                // This is the geojson file containing all features for this tile
                writeFileSync(
                    targetPath,
                    JSON.stringify(
                        {
                            type: "FeatureCollection",
                            features: filteredTile.features.data.map((f) => f.feature),
                        },
                        null,
                        " "
                    )
                )
                console.log("Written tile", targetPath, "with", filteredTile.features.data.length)
            },
        })

        // All the tiles are written at this point
        // Only thing left to do is to create the index
        const path = targetdir + "_" + layerId + "_" + targetZoomLevel + "_overview.json"
        const perX = {}
        createdTiles
            .map((i) => Tiles.tile_from_index(i))
            .forEach(([z, x, y]) => {
                const key = "" + x
                if (perX[key] === undefined) {
                    perX[key] = []
                }
                perX[key].push(y)
            })
        console.log("Written overview: ", path, "with ", createdTiles.length, "tiles")
        writeFileSync(path, JSON.stringify(perX))

        // And, if needed, to create a points-only layer
        if (pointsOnlyLayers.indexOf(layer.id) >= 0) {
            const filtered = new FilteringFeatureSource(
                {
                    locationControl: new ImmutableStore<Loc>(undefined),
                    allElements: undefined,
                    selectedElement: new ImmutableStore<any>(undefined),
                    globalFilters: new ImmutableStore([]),
                },
                Tiles.tile_index(0, 0, 0),
                source,
                new UIEventSource<any>(undefined)
            )
            const features = filtered.features.data.map((f) => f.feature)

            const points = features.map((feature) => GeoOperations.centerpoint(feature))
            console.log("Writing points overview for ", layerId)
            const targetPath = targetdir + "_" + layerId + "_points.geojson"
            // This is the geojson file containing all features for this tile
            writeFileSync(
                targetPath,
                JSON.stringify(
                    {
                        type: "FeatureCollection",
                        features: points,
                    },
                    null,
                    " "
                )
            )
        }
    }

    new PerLayerFeatureSourceSplitter(
        new UIEventSource<FilteredLayer[]>(
            theme.layers.map((l) => ({
                layerDef: l,
                isDisplayed: new UIEventSource<boolean>(true),
                appliedFilters: new UIEventSource(undefined),
            }))
        ),
        handleLayer,
        allFeatures
    )

    const skipped = Array.from(skippedLayers)
    if (skipped.length > 0) {
        console.warn(
            "Did not save any cache files for layers " +
                skipped.join(", ") +
                " as these didn't set the flag `isOsmCache` to true"
        )
    }
}

export async function main(args: string[]) {
    console.log("Cache builder started with args ", args.join(", "))
    if (args.length < 6) {
        console.error(
            "Expected arguments are: theme zoomlevel targetdirectory lat0 lon0 lat1 lon1 [--generate-point-overview layer-name,layer-name,...] [--force-zoom-level z] \n" +
                "Note: a new directory named <theme> will be created in targetdirectory"
        )
        return
    }
    const themeName = args[0]
    const zoomlevel = Number(args[1])

    const targetdir = args[2] + "/" + themeName
    if (!existsSync(args[2])) {
        console.log("Directory not found")
        throw `The directory ${args[2]} does not exist`
    }

    const lat0 = Number(args[3])
    const lon0 = Number(args[4])
    const lat1 = Number(args[5])
    const lon1 = Number(args[6])

    if (isNaN(lat0)) {
        throw "The first number (a latitude) is not a valid number"
    }

    if (isNaN(lon0)) {
        throw "The second number (a longitude) is not a valid number"
    }
    if (isNaN(lat1)) {
        throw "The third number (a latitude) is not a valid number"
    }

    if (isNaN(lon1)) {
        throw "The fourth number (a longitude) is not a valid number"
    }

    const tileRange = Tiles.TileRangeBetween(zoomlevel, lat0, lon0, lat1, lon1)

    if (isNaN(tileRange.total)) {
        throw "Something has gone wrong: tilerange is NAN"
    }

    if (tileRange.total === 0) {
        console.log("Tilerange has zero tiles - this is probably an error")
        return
    }

    const theme = AllKnownLayouts.allKnownLayouts.get(themeName)
    if (theme === undefined) {
        const keys = []
        AllKnownLayouts.allKnownLayouts.forEach((_, key) => {
            keys.push(key)
        })
        console.error("The theme " + theme + " was not found; try one of ", keys)
        return
    }

    let generatePointLayersFor = []
    if (args[7] == "--generate-point-overview") {
        if (args[8] === undefined) {
            throw "--generate-point-overview needs a list of layers to generate the overview for (or * for all)"
        } else if (args[8] === "*") {
            generatePointLayersFor = theme.layers.map((l) => l.id)
        } else {
            generatePointLayersFor = args[8].split(",")
        }
        console.log(
            "Also generating a point overview for layers ",
            generatePointLayersFor.join(",")
        )
    }
    {
        const index = args.indexOf("--force-zoom-level")
        if (index >= 0) {
            const forcedZoomLevel = Number(args[index + 1])
            for (const layer of theme.layers) {
                layer.source.geojsonSource = "https://127.0.0.1/cache_{layer}_{z}_{x}_{y}.geojson"
                layer.source.isOsmCacheLayer = true
                layer.source.geojsonZoomLevel = forcedZoomLevel
            }
        }
    }

    const relationTracker = new RelationsTracker()

    let failed = 0
    do {
        const cachingResult = await downloadRaw(targetdir, tileRange, theme, relationTracker)
        failed = cachingResult.failed
        if (failed > 0) {
            await ScriptUtils.sleep(30000)
        }
    } while (failed > 0)

    const extraFeatures = await downloadExtraData(theme)
    const allFeaturesSource = loadAllTiles(targetdir, tileRange, theme, extraFeatures)
    sliceToTiles(allFeaturesSource, theme, relationTracker, targetdir, generatePointLayersFor)
}

let args = [...process.argv]
if (!args[1]?.endsWith("test/TestAll.ts")) {
    args.splice(0, 2)
    try {
        main(args)
            .then(() => console.log("All done!"))
            .catch((e) => console.error("Error building cache:", e))
    } catch (e) {
        console.error("Error building cache:", e)
    }
}