import {Concat, Conversion, DesugaringContext, DesugaringStep, Each, Fuse, On, Pass, SetDefault} from "./Conversion";
import {LayoutConfigJson} from "../Json/LayoutConfigJson";
import {PrepareLayer} from "./PrepareLayer";
import {LayerConfigJson} from "../Json/LayerConfigJson";
import {Utils} from "../../../Utils";
import Constants from "../../Constants";
import CreateNoteImportLayer from "./CreateNoteImportLayer";
import LayerConfig from "../LayerConfig";
import {TagRenderingConfigJson} from "../Json/TagRenderingConfigJson";
import {SubstitutedTranslation} from "../../../UI/SubstitutedTranslation";
import DependencyCalculator from "../DependencyCalculator";
import {AddContextToTranslations} from "./AddContextToTranslations";

class SubstituteLayer extends Conversion<(string | LayerConfigJson), LayerConfigJson[]> {
    private readonly _state: DesugaringContext;

    constructor(
        state: DesugaringContext,
    ) {
        super("Converts the identifier of a builtin layer into the actual layer, or converts a 'builtin' syntax with override in the fully expanded form", [], "SubstituteLayer");
        this._state = state;
    }

    convert(json: string | LayerConfigJson, context: string): { result: LayerConfigJson[]; errors: string[], information?: string[] } {
        const errors = []
        const information = []
        const state = this._state

        function reportNotFound(name: string) {
            const knownLayers = Array.from(state.sharedLayers.keys())
            const withDistance = knownLayers.map(lname => [lname, Utils.levenshteinDistance(name, lname)])
            withDistance.sort((a, b) => a[1] - b[1])
            const ids = withDistance.map(n => n[0])
            // Known builtin layers are "+.join(",")+"\n    For more information, see "
            errors.push(`${context}: The layer with name ${name} was not found as a builtin layer. Perhaps you meant ${ids[0]}, ${ids[1]} or ${ids[2]}?
 For an overview of all available layers, refer to https://github.com/pietervdvn/MapComplete/blob/develop/Docs/BuiltinLayers.md`)
        }


        if (typeof json === "string") {
            const found = state.sharedLayers.get(json)
            if (found === undefined) {
                reportNotFound(json)
                return {
                    result: null,
                    errors,
                }
            }
            return {
                result: [found],
                errors
            }
        }

        if (json["builtin"] !== undefined) {
            let names = json["builtin"]
            if (typeof names === "string") {
                names = [names]
            }
            const layers = []

            for (const name of names) {
                const found = Utils.Clone(state.sharedLayers.get(name))
                if (found === undefined) {
                    reportNotFound(name)
                    continue
                }
                if (json["override"]["tagRenderings"] !== undefined && (found["tagRenderings"] ?? []).length > 0) {
                    errors.push(`At ${context}: when overriding a layer, an override is not allowed to override into tagRenderings. Use "+tagRenderings" or "tagRenderings+" instead to prepend or append some questions.`)
                }
                try {
                    Utils.Merge(json["override"], found);
                    layers.push(found)
                } catch (e) {
                    errors.push(`At ${context}: could not apply an override due to: ${e}.\nThe override is: ${JSON.stringify(json["override"],)}`)
                }

                if (json["hideTagRenderingsWithLabels"]) {
                    const hideLabels: Set<string> = new Set(json["hideTagRenderingsWithLabels"])
                    // These labels caused at least one deletion
                    const usedLabels: Set<string> = new Set<string>();
                    const filtered = []
                    for (const tr of found.tagRenderings) {
                        const labels = tr["labels"]
                        if (labels !== undefined) {
                            const forbiddenLabel = labels.findIndex(l => hideLabels.has(l))
                            if (forbiddenLabel >= 0) {
                                usedLabels.add(labels[forbiddenLabel])
                                information.push(context + ": Dropping tagRendering " + tr["id"] + " as it has a forbidden label: " + labels[forbiddenLabel])
                                continue
                            }
                        }

                        if (hideLabels.has(tr["id"])) {
                            usedLabels.add(tr["id"])
                            information.push(context + ": Dropping tagRendering " + tr["id"] + " as its id is a forbidden label")
                            continue
                        }

                        if (hideLabels.has(tr["group"])) {
                            usedLabels.add(tr["group"])
                            information.push(context + ": Dropping tagRendering " + tr["id"] + " as its group `" + tr["group"] + "` is a forbidden label")
                            continue
                        }

                        filtered.push(tr)
                    }
                    const unused = Array.from(hideLabels).filter(l => !usedLabels.has(l))
                    if (unused.length > 0) {
                        errors.push("This theme specifies that certain tagrenderings have to be removed based on forbidden layers. One or more of these layers did not match any tagRenderings and caused no deletions: " + unused.join(", ") + "\n   This means that this label can be removed or that the original tagRendering that should be deleted does not have this label anymore")
                    }
                    found.tagRenderings = filtered
                }
            }
            return {
                result: layers,
                errors,
                information
            }

        }

        return {
            result: [json],
            errors
        };
    }

}

class AddDefaultLayers extends DesugaringStep<LayoutConfigJson> {
    private _state: DesugaringContext;

    constructor(state: DesugaringContext) {
        super("Adds the default layers, namely: " + Constants.added_by_default.join(", "), ["layers"], "AddDefaultLayers");
        this._state = state;
    }

    convert(json: LayoutConfigJson, context: string): { result: LayoutConfigJson; errors: string[]; warnings: string[] } {
        const errors = []
        const warnings = []
        const state = this._state
        json.layers = [...json.layers]
        const alreadyLoaded = new Set(json.layers.map(l => l["id"]))

        for (const layerName of Constants.added_by_default) {
            const v = state.sharedLayers.get(layerName)
            if (v === undefined) {
                errors.push("Default layer " + layerName + " not found")
                continue
            }
            if (alreadyLoaded.has(v.id)) {
                warnings.push("Layout " + context + " already has a layer with name " + v.id + "; skipping inclusion of this builtin layer")
                continue
            }
            json.layers.push(v)
        }

        return {
            result: json,
            errors,
            warnings
        };
    }

}

class AddImportLayers extends DesugaringStep<LayoutConfigJson> {
    constructor() {
        super("For every layer in the 'layers'-list, create a new layer which'll import notes. (Note that priviliged layers and layers which have a geojson-source set are ignored)", ["layers"], "AddImportLayers");
    }

    convert(json: LayoutConfigJson, context: string): { result: LayoutConfigJson; errors?: string[], warnings?: string[] } {
        if (!(json.enableNoteImports ?? true)) {
            return {
                warnings: ["Not creating a note import layers for theme "+json.id+" as they are disabled"],
                result: json
            };
        }
        const errors = []

        json = {...json}
        const allLayers: LayerConfigJson[] = <LayerConfigJson[]>json.layers;
        json.layers = [...json.layers]


        const creator = new CreateNoteImportLayer()
        for (let i1 = 0; i1 < allLayers.length; i1++) {
            const layer = allLayers[i1];
            if (Constants.priviliged_layers.indexOf(layer.id) >= 0) {
                // Priviliged layers are skipped
                continue
            }

            if (layer.source["geoJson"] !== undefined) {
                // Layer which don't get their data from OSM are skipped
                continue
            }

            if (layer.title === undefined || layer.name === undefined) {
                // Anonymous layers and layers without popup are skipped
                continue
            }

            if (layer.presets === undefined || layer.presets.length == 0) {
                // A preset is needed to be able to generate a new point
                continue;
            }

            try {

                const importLayerResult = creator.convert(layer, context + ".(noteimportlayer)[" + i1 + "]")
                if (importLayerResult.result !== undefined) {
                    json.layers.push(importLayerResult.result)
                }
            } catch (e) {
                errors.push("Could not generate an import-layer for " + layer.id + " due to " + e)
            }
        }

        return {
            errors,
            result: json
        };
    }
}


export class AddMiniMap extends DesugaringStep<LayerConfigJson> {
    private readonly _state: DesugaringContext;

    constructor(state: DesugaringContext,) {
        super("Adds a default 'minimap'-element to the tagrenderings if none of the elements define such a minimap", ["tagRenderings"], "AddMiniMap");
        this._state = state;
    }

    /**
     * Returns true if this tag rendering has a minimap in some language.
     * Note: this minimap can be hidden by conditions
     *
     * AddMiniMap.hasMinimap({render: "{minimap()}"}) // => true
     * AddMiniMap.hasMinimap({render: {en: "{minimap()}"}}) // => true
     * AddMiniMap.hasMinimap({render: {en: "{minimap()}", nl: "{minimap()}"}}) // => true
     * AddMiniMap.hasMinimap({render: {en: "{minimap()}", nl: "No map for the dutch!"}}) // => true
     * AddMiniMap.hasMinimap({render: "{minimap()}"}) // => true
     * AddMiniMap.hasMinimap({render: "{minimap(18,featurelist)}"}) // => true
     * AddMiniMap.hasMinimap({mappings: [{if: "xyz=abc",then: "{minimap(18,featurelist)}"}]}) // => true
     * AddMiniMap.hasMinimap({render: "Some random value {key}"}) // => false
     * AddMiniMap.hasMinimap({render: "Some random value {minimap}"}) // => false
     */
    static hasMinimap(renderingConfig: TagRenderingConfigJson): boolean {
        const translations: any[] = Utils.NoNull([renderingConfig.render, ...(renderingConfig.mappings ?? []).map(m => m.then)]);
        for (let translation of translations) {
            if (typeof translation == "string") {
                translation = {"*": translation}
            }

            for (const key in translation) {
                if (!translation.hasOwnProperty(key)) {
                    continue
                }
                
                const template = translation[key]
                const parts = SubstitutedTranslation.ExtractSpecialComponents(template)
                const hasMiniMap = parts.filter(part => part.special !== undefined).some(special => special.special.func.funcName === "minimap")
                if (hasMiniMap) {
                    return true;
                }
            }
        }
        return false;
    }

    convert(layerConfig: LayerConfigJson, context: string): { result: LayerConfigJson } {

        const state = this._state;
        const hasMinimap = layerConfig.tagRenderings?.some(tr => AddMiniMap.hasMinimap(<TagRenderingConfigJson>tr)) ?? true
        if (!hasMinimap) {
            layerConfig = {...layerConfig}
            layerConfig.tagRenderings = [...layerConfig.tagRenderings]
            layerConfig.tagRenderings.push(state.tagRenderings.get("questions"))
            layerConfig.tagRenderings.push(state.tagRenderings.get("minimap"))
        }

        return {
            result: layerConfig
        };
    }
}

class AddContextToTransltionsInLayout extends DesugaringStep <LayoutConfigJson> {

    constructor() {
        super("Adds context to translations, including the prefix 'themes:json.id'; this is to make sure terms in an 'overrides' or inline layer are linkable too", ["_context"], "AddContextToTranlationsInLayout");
    }

    convert(json: LayoutConfigJson, context: string): { result: LayoutConfigJson; errors?: string[]; warnings?: string[]; information?: string[] } {
        const conversion = new AddContextToTranslations<LayoutConfigJson>("themes:")
        return conversion.convert(json, json.id);
    }

}

class ApplyOverrideAll extends DesugaringStep<LayoutConfigJson> {

    constructor() {
        super("Applies 'overrideAll' onto every 'layer'. The 'overrideAll'-field is removed afterwards", ["overrideAll", "layers"], "ApplyOverrideAll");
    }

    convert(json: LayoutConfigJson, context: string): { result: LayoutConfigJson; errors: string[]; warnings: string[] } {

        const overrideAll = json.overrideAll;
        if (overrideAll === undefined) {
            return {result: json, warnings: [], errors: []}
        }

        json = {...json}

        delete json.overrideAll
        const newLayers = []
        for (let layer of json.layers) {
            layer = Utils.Clone(<LayerConfigJson>layer)
            Utils.Merge(overrideAll, layer)
            newLayers.push(layer)
        }
        json.layers = newLayers


        return {result: json, warnings: [], errors: []};
    }

}

class AddDependencyLayersToTheme extends DesugaringStep<LayoutConfigJson> {
    private readonly _state: DesugaringContext;

    constructor(state: DesugaringContext,) {
        super(
            `If a layer has a dependency on another layer, these layers are added automatically on the theme. (For example: defibrillator depends on 'walls_and_buildings' to snap onto. This layer is added automatically)
            
            Note that these layers are added _at the start_ of the layer list, meaning that they will see _every_ feature.
            Furthermore, \`passAllFeatures\` will be set, so that they won't steal away features from further layers.
            Some layers (e.g. \`all_buildings_and_walls\' or \'streets_with_a_name\') are invisible, so by default, \'force_load\' is set too.
            `, ["layers"], "AddDependencyLayersToTheme");
        this._state = state;
    }

    private static CalculateDependencies(alreadyLoaded: LayerConfigJson[], allKnownLayers: Map<string, LayerConfigJson>, themeId: string):
        {config: LayerConfigJson, reason: string}[] {
        const dependenciesToAdd:  {config: LayerConfigJson, reason: string}[]  = []
        const loadedLayerIds: Set<string> = new Set<string>(alreadyLoaded.map(l => l.id));

        // Verify cross-dependencies
        let unmetDependencies: { neededLayer: string, neededBy: string, reason: string, context?: string }[] = []
        do {
            const dependencies: { neededLayer: string, reason: string, context?: string, neededBy: string }[] = []

            for (const layerConfig of alreadyLoaded) {
                try {
                    const layerDeps = DependencyCalculator.getLayerDependencies(new LayerConfig(layerConfig, themeId+"(dependencies)"))
                    dependencies.push(...layerDeps)
                } catch (e) {
                    console.error(e)
                    throw "Detecting layer dependencies for " + layerConfig.id + " failed due to " + e
                }
            }

            for (const dependency of dependencies) {
                if (loadedLayerIds.has(dependency.neededLayer)) {
                    // We mark the needed layer as 'mustLoad'
                    alreadyLoaded.find(l => l.id === dependency.neededLayer).forceLoad = true
                }
            }

            // During the generate script, builtin layers are verified but not loaded - so we have to add them manually here
            // Their existence is checked elsewhere, so this is fine
            unmetDependencies = dependencies.filter(dep => !loadedLayerIds.has(dep.neededLayer))
            for (const unmetDependency of unmetDependencies) {
                if (loadedLayerIds.has(unmetDependency.neededLayer)) {
                    continue
                }
                const dep = Utils.Clone(allKnownLayers.get(unmetDependency.neededLayer))
                const reason =  "This layer is needed by " + unmetDependency.neededBy +" because " +
                    unmetDependency.reason + " (at " + unmetDependency.context + ")";
                if (dep === undefined) {
                    const message =
                        ["Loading a dependency failed: layer " + unmetDependency.neededLayer + " is not found, neither as layer of " + themeId + " nor as builtin layer.",
                            reason,
                            "Loaded layers are: " + alreadyLoaded.map(l => l.id).join(",")

                        ]
                    throw message.join("\n\t");
                }
                
                dep.forceLoad = true;
                dep.passAllFeatures = true;
                dep.description = reason;
                dependenciesToAdd.unshift({
                    config: dep,
                    reason
                })
                loadedLayerIds.add(dep.id);
                unmetDependencies = unmetDependencies.filter(d => d.neededLayer !== unmetDependency.neededLayer)
            }

        } while (unmetDependencies.length > 0)

        return dependenciesToAdd
    }

    convert(theme: LayoutConfigJson, context: string): { result: LayoutConfigJson; information: string[] } {
        const state = this._state
        const allKnownLayers: Map<string, LayerConfigJson> = state.sharedLayers;
        const knownTagRenderings: Map<string, TagRenderingConfigJson> = state.tagRenderings;
        const information = [];
        const layers: LayerConfigJson[] = <LayerConfigJson[]>theme.layers; // Layers should be expanded at this point

        knownTagRenderings.forEach((value, key) => {
            value.id = key;
        })

        const dependencies = AddDependencyLayersToTheme.CalculateDependencies(layers, allKnownLayers, theme.id);
        for (const dependency of dependencies) {
            
        }
        if (dependencies.length > 0) {
            for (const dependency of dependencies) {
            information.push(context + ": added " + dependency.config.id + " to the theme. "+dependency.reason)
                
            }
        }
        layers.unshift(...dependencies.map(l => l.config));

        return {
            result: {
                ...theme,
                layers: layers
            },
            information
        };
    }
}

class PreparePersonalTheme extends DesugaringStep<LayoutConfigJson> {
    private readonly _state: DesugaringContext;

    constructor(state: DesugaringContext) {
        super("Adds every public layer to the personal theme", ["layers"], "PreparePersonalTheme");
        this._state = state;
    }

    convert(json: LayoutConfigJson, context: string): { result: LayoutConfigJson; errors?: string[]; warnings?: string[]; information?: string[] } {
        if (json.id !== "personal") {
            return {result: json}
        }
        
        // The only thing this _really_ does, is adding the layer-ids into 'layers'
        // All other preparations are done by the 'override-all'-block in personal.json

        json.layers = Array.from(this._state.sharedLayers.keys())
            .filter(l => Constants.priviliged_layers.indexOf(l) < 0)
            .filter(l => this._state.publicLayers.has(l))
        return {result: json, information: [
            "The personal theme has "+json.layers.length+" public layers"
            ]};
    }

}

class WarnForUnsubstitutedLayersInTheme extends DesugaringStep<LayoutConfigJson> {

    constructor() {
        super("Generates a warning if a theme uses an unsubstituted layer", ["layers"], "WarnForUnsubstitutedLayersInTheme");
    }

    convert(json: LayoutConfigJson, context: string): { result: LayoutConfigJson; errors?: string[]; warnings?: string[]; information?: string[] } {
        if (json.hideFromOverview === true) {
            return {result: json}
        }
        const warnings = []
        for (const layer of json.layers) {
            if (typeof layer === "string") {
                continue
            }
            if (layer["builtin"] !== undefined) {
                continue
            }
            if (layer["source"]["geojson"] !== undefined) {
                // We turn a blind eye for import layers
                continue
            }

            const wrn = "The theme " + json.id + " has an inline layer: " + layer["id"] + ". This is discouraged."
            warnings.push(wrn)
        }
        return {
            result: json,
            warnings
        };
    }

}

export class PrepareTheme extends Fuse<LayoutConfigJson> {
    constructor(state: DesugaringContext, options?: {
        skipDefaultLayers: false | boolean
    }) {
        super(
            "Fully prepares and expands a theme",

            new AddContextToTransltionsInLayout(),
            new PreparePersonalTheme(state),
            new WarnForUnsubstitutedLayersInTheme(),
            new On("layers", new Concat(new SubstituteLayer(state))),
            new SetDefault("socialImage", "assets/SocialImage.png", true),
            // We expand all tagrenderings first...
            new On("layers", new Each(new PrepareLayer(state))),
            // Then we apply the override all
            new ApplyOverrideAll(),
            // And then we prepare all the layers _again_ in case that an override all contained unexpanded tagrenderings!
            new On("layers", new Each(new PrepareLayer(state))),
            options?.skipDefaultLayers ? new Pass("AddDefaultLayers is disabled due to the set flag") : new AddDefaultLayers(state),
            new AddDependencyLayersToTheme(state),
            new AddImportLayers(),
            new On("layers", new Each(new AddMiniMap(state)))
        );
    }
}