import {Concat, Conversion, DesugaringContext, DesugaringStep, Each, FirstOf, Fuse, On, SetDefault} from "./Conversion";
import {LayerConfigJson} from "../Json/LayerConfigJson";
import {TagRenderingConfigJson} from "../Json/TagRenderingConfigJson";
import {Utils} from "../../../Utils";
import RewritableConfigJson from "../Json/RewritableConfigJson";
import SpecialVisualizations from "../../../UI/SpecialVisualizations";
import Translations from "../../../UI/i18n/Translations";
import {Translation} from "../../../UI/i18n/Translation";
import * as tagrenderingconfigmeta from "../../../assets/tagrenderingconfigmeta.json"
import {AddContextToTranslations} from "./AddContextToTranslations";


class ExpandTagRendering extends Conversion<string | TagRenderingConfigJson | { builtin: string | string[], override: any }, TagRenderingConfigJson[]> {
    private readonly _state: DesugaringContext;
    private readonly _self: LayerConfigJson;

    constructor(state: DesugaringContext, self: LayerConfigJson) {
        super("Converts a tagRenderingSpec into the full tagRendering, e.g. by substituting the tagRendering by the shared-question", [], "ExpandTagRendering");
        this._state = state;
        this._self = self;
    }

    convert(json: string | TagRenderingConfigJson | { builtin: string | string[]; override: any }, context: string): { result: TagRenderingConfigJson[]; errors: string[]; warnings: string[] } {
        const errors = []
        const warnings = []

        return {
            result: this.convertUntilStable(json, warnings, errors, context),
            errors, warnings
        };
    }

    private lookup(name: string): TagRenderingConfigJson[] {
        const state = this._state;
        if (state.tagRenderings.has(name)) {
            return [state.tagRenderings.get(name)]
        }
        if (name.indexOf(".") < 0) {
            return undefined;
        }
        
        const spl = name.split(".");
        let layer = state.sharedLayers.get(spl[0])
        if (spl[0] === this._self.id) {
            layer = this._self
        }

        if (spl.length !== 2 || layer === undefined) {
            return undefined
        }
        
        const id = spl[1];

        const layerTrs = <TagRenderingConfigJson[]>layer.tagRenderings.filter(tr => tr["id"] !== undefined)
        let matchingTrs: TagRenderingConfigJson[]
        if (id === "*") {
            matchingTrs = layerTrs
        } else if (id.startsWith("*")) {
            const id_ = id.substring(1)
            matchingTrs = layerTrs.filter(tr => tr.group === id_ || tr.labels?.indexOf(id_) >= 0)
        } else {
            matchingTrs = layerTrs.filter(tr => tr.id === id)
        }


        const contextWriter = new AddContextToTranslations<TagRenderingConfigJson>("layers:")
        for (let i = 0; i < matchingTrs.length; i++) {
            // The matched tagRenderings are 'stolen' from another layer. This means that they must match the layer condition before being shown
            let found: TagRenderingConfigJson = Utils.Clone(matchingTrs[i]);
            if (found.condition === undefined) {
                found.condition = layer.source.osmTags
            } else {
                found.condition = {and: [found.condition, layer.source.osmTags]}
            }

            found = contextWriter.convertStrict(found, layer.id + ".tagRenderings." + found["id"])
            matchingTrs[i] = found
        }

        if (matchingTrs.length !== 0) {
            return matchingTrs
        }
        return undefined;
    }

    private convertOnce(tr: string | any, warnings: string[], errors: string[], ctx: string): TagRenderingConfigJson[] {
        const state = this._state
        if (tr === "questions") {
            return [{
                id: "questions"
            }]
        }


        if (typeof tr === "string") {
            const lookup = this.lookup(tr);
            if (lookup === undefined) {
                const isTagRendering = ctx.indexOf("On(mapRendering") < 0
                if (isTagRendering) {
                    warnings.push(ctx + "A literal rendering was detected: " + tr)
                }
                return [{
                    render: tr,
                    id: tr.replace(/[^a-zA-Z0-9]/g, "")
                }]
            }
            return lookup
        }

        if (tr["builtin"] !== undefined) {
            let names: string | string[] = tr["builtin"]
            if (typeof names === "string") {
                names = [names]
            }

            for (const key of Object.keys(tr)) {
                if (key === "builtin" || key === "override" || key === "id" || key.startsWith("#")) {
                    continue
                }
                errors.push("At " + ctx + ": an object calling a builtin can only have keys `builtin` or `override`, but a key with name `" + key + "` was found. This won't be picked up! The full object is: " + JSON.stringify(tr))
            }

            const trs: TagRenderingConfigJson[] = []
            for (const name of names) {
                const lookup = this.lookup(name)
                if (lookup === undefined) {
                    let candidates = Array.from(state.tagRenderings.keys())
                    if (name.indexOf(".") > 0) {
                        const [layerName, search] = name.split(".")
                        let layer = state.sharedLayers.get(layerName)
                        if (layerName === this._self.id) {
                            layer = this._self;
                        }
                        if (layer === undefined) {
                            const candidates = Utils.sortedByLevenshteinDistance(layerName, Array.from(state.sharedLayers.keys()), s => s)
                           if(state.sharedLayers.size === 0){
                               warnings.push(ctx + ": BOOTSTRAPPING. Rerun generate layeroverview. While reusing tagrendering: " + name + ": layer " + layerName + " not found. Maybe you meant on of " + candidates.slice(0, 3).join(", "))
                           }else{
                               errors.push(ctx + ": While reusing tagrendering: " + name + ": layer " + layerName + " not found. Maybe you meant on of " + candidates.slice(0, 3).join(", "))
                           }
                            continue
                        }
                        candidates = Utils.NoNull(layer.tagRenderings.map(tr => tr["id"])).map(id => layerName + "." + id)
                    }
                    candidates = Utils.sortedByLevenshteinDistance(name, candidates, i => i);
                    errors.push(ctx + ": The tagRendering with identifier " + name + " was not found.\n\tDid you mean one of " + candidates.join(", ") + "?")
                    continue
                }
                for (let foundTr of lookup) {
                    foundTr = Utils.Clone<any>(foundTr)
                    Utils.Merge(tr["override"] ?? {}, foundTr)
                    trs.push(foundTr)
                }
            }
            return trs;
        }

        return [tr]
    }

    private convertUntilStable(spec: string | any, warnings: string[], errors: string[], ctx: string): TagRenderingConfigJson[] {
        const trs = this.convertOnce(spec, warnings, errors, ctx);

        const result = []
        for (const tr of trs) {
            if (typeof tr === "string" || tr["builtin"] !== undefined) {
                const stable = this.convertUntilStable(tr, warnings, errors, ctx + "(RECURSIVE RESOLVE)")
                result.push(...stable)
            } else {
                result.push(tr)
            }
        }

        return result;
    }
}

export class ExpandRewrite<T> extends Conversion<T | RewritableConfigJson<T>, T[]> {

    constructor() {
        super("Applies a rewrite", [], "ExpandRewrite");
    }


    /**
     * Used for left|right group creation and replacement.
     * Every 'keyToRewrite' will be replaced with 'target' recursively. This substitution will happen in place in the object 'tr'
     *
     * // should substitute strings
     * const spec = {
     *   "someKey": "somevalue {xyz}"
     * }
     * ExpandRewrite.RewriteParts("{xyz}", "rewritten", spec) // => {"someKey": "somevalue rewritten"}
     *
     * // should substitute all occurances in strings
     * const spec = {
     *   "someKey": "The left|right side has {key:left|right}"
     * }
     * ExpandRewrite.RewriteParts("left|right", "left", spec) // => {"someKey": "The left side has {key:left}"}
     *
     */
    public static RewriteParts<T>(keyToRewrite: string, target: string | any, tr: T): T {
        const targetIsTranslation = Translations.isProbablyATranslation(target)

        function replaceRecursive(obj: string | any, target) {

            if (obj === keyToRewrite) {
                return target
            }

            if (typeof obj === "string") {
                // This is a simple string - we do a simple replace
                while (obj.indexOf(keyToRewrite) >= 0) {
                    obj = obj.replace(keyToRewrite, target)
                }
                return obj
            }
            if (Array.isArray(obj)) {
                // This is a list of items
                return obj.map(o => replaceRecursive(o, target))
            }

            if (typeof obj === "object") {
                obj = {...obj}

                const isTr = targetIsTranslation && Translations.isProbablyATranslation(obj)

                for (const key in obj) {
                    let subtarget = target
                    if (isTr && target[key] !== undefined) {
                        // The target is a translation AND the current object is a translation
                        // This means we should recursively replace with the translated value
                        subtarget = target[key]
                    }

                    obj[key] = replaceRecursive(obj[key], subtarget)
                }
                return obj
            }
            return obj
        }

        return replaceRecursive(tr, target)
    }

    /**
     * // should convert simple strings
     * const spec = <RewritableConfigJson<string>>{
     *     rewrite: {
     *         sourceString: ["xyz","abc"],
     *         into: [
     *             ["X", "A"],
     *             ["Y", "B"], 
     *             ["Z", "C"]],
     *     },
     *     renderings: "The value of xyz is abc"
     * }
     * new ExpandRewrite().convertStrict(spec, "test") // => ["The value of X is A", "The value of Y is B", "The value of Z is C"]
     *
     * // should rewrite with translations
     * const spec = <RewritableConfigJson<any>>{
     *     rewrite: {
     *         sourceString: ["xyz","abc"],
     *         into: [
     *             ["X", {en: "value", nl: "waarde"}],
     *             ["Y", {en: "some other value", nl: "een andere waarde"}],
     *     },
     *     renderings: {en: "The value of xyz is abc", nl: "De waarde van xyz is abc"}
     * }
     * const expected = [
     *  {
     *      en: "The value of X is value",
     *      nl: "De waarde van X is waarde"
     *  },
     *  {
     *      en: "The value of Y is some other value",
     *      nl: "De waarde van Y is een andere waarde"
     *  }
     * ]
     * new ExpandRewrite().convertStrict(spec, "test") // => expected
     */
    convert(json: T | RewritableConfigJson<T>, context: string): { result: T[]; errors?: string[]; warnings?: string[]; information?: string[] } {

        if (json === null || json === undefined) {
            return {result: []}
        }

        if (json["rewrite"] === undefined) {

            // not a rewrite
            return {result: [(<T>json)]}
        }

        const rewrite = <RewritableConfigJson<T>>json;
        const keysToRewrite = rewrite.rewrite
        const ts: T[] = []

        {// sanity check: rewrite: ["xyz", "longer_xyz"] is not allowed as "longer_xyz" will never be triggered
            for (let i = 0; i < keysToRewrite.sourceString.length; i++) {
                const guard = keysToRewrite.sourceString[i];
                for (let j = i + 1; j < keysToRewrite.sourceString.length; j++) {
                    const toRewrite = keysToRewrite.sourceString[j]
                    if (toRewrite.indexOf(guard) >= 0) {
                        throw `${context} Error in rewrite: sourcestring[${i}] is a substring of sourcestring[${j}]: ${guard} will be substituted away before ${toRewrite} is reached.`
                    }
                }
            }
        }

        {// sanity check: {rewrite: ["a", "b"] should have the right amount of 'intos' in every case
            for (let i = 0; i < rewrite.rewrite.into.length; i++) {
                const into = keysToRewrite.into[i]
                if (into.length !== rewrite.rewrite.sourceString.length) {
                    throw `${context}.into.${i} Error in rewrite: there are ${rewrite.rewrite.sourceString.length} keys to rewrite, but entry ${i} has only ${into.length} values`

                }
            }
        }

        for (let i = 0; i < keysToRewrite.into.length; i++) {
            let t = Utils.Clone(rewrite.renderings)
            for (let j = 0; j < keysToRewrite.sourceString.length; j++) {
                const key = keysToRewrite.sourceString[j];
                const target = keysToRewrite.into[i][j]
                t = ExpandRewrite.RewriteParts(key, target, t)
            }
            ts.push(t)
        }


        return {result: ts};
    }

}

/**
 * Converts a 'special' translation into a regular translation which uses parameters
 */
export class RewriteSpecial extends DesugaringStep<TagRenderingConfigJson> {
    constructor() {
        super("Converts a 'special' translation into a regular translation which uses parameters", ["special"], "RewriteSpecial");
    }

    /**
     * Does the heavy lifting and conversion
     *
     * // should not do anything if no 'special'-key is present
     * RewriteSpecial.convertIfNeeded({"en": "xyz", "nl": "abc"}, [], "test") // => {"en": "xyz", "nl": "abc"}
     *
     * // should handle a simple special case
     * RewriteSpecial.convertIfNeeded({"special": {"type":"image_carousel"}}, [], "test") // => {'*': "{image_carousel()}"}
     *
     * // should handle special case with a parameter
     * RewriteSpecial.convertIfNeeded({"special": {"type":"image_carousel", "image_key": "some_image_key"}}, [], "test") // =>  {'*': "{image_carousel(some_image_key)}"}
     *
     * // should handle special case with a translated parameter
     * const spec = {"special": {"type":"image_upload", "label": {"en": "Add a picture to this object", "nl": "Voeg een afbeelding toe"}}}
     * const r = RewriteSpecial.convertIfNeeded(spec, [], "test")
     * r // => {"en": "{image_upload(,Add a picture to this object)}", "nl": "{image_upload(,Voeg een afbeelding toe)}" }
     *
     * // should handle special case with a prefix and postfix
     * const spec = {"special": {"type":"image_upload" }, before: {"en": "PREFIX "}, after: {"en": " POSTFIX", nl: " Achtervoegsel"} }
     * const r = RewriteSpecial.convertIfNeeded(spec, [], "test")
     * r // => {"en": "PREFIX {image_upload(,)} POSTFIX", "nl": "PREFIX {image_upload(,)} Achtervoegsel" }
     *
     * // should warn for unexpected keys
     * const errors = []
     * RewriteSpecial.convertIfNeeded({"special": {type: "image_carousel"}, "en": "xyz"}, errors, "test") // =>  {'*': "{image_carousel()}"}
     * errors // => ["At test: Unexpected key in a special block: en"]
     *
     * // should give an error on unknown visualisations
     * const errors = []
     * RewriteSpecial.convertIfNeeded({"special": {type: "qsdf"}}, errors, "test") // => undefined
     * errors.length // => 1
     * errors[0].indexOf("Special visualisation 'qsdf' not found") >= 0 // => true
     *
     * // should give an error is 'type' is missing
     * const errors = []
     * RewriteSpecial.convertIfNeeded({"special": {}}, errors, "test") // => undefined
     * errors // => ["A 'special'-block should define 'type' to indicate which visualisation should be used"]
     */
    private static convertIfNeeded(input: (object & { special: { type: string } }) | any, errors: string[], context: string): any {
        const special = input["special"]
        if (special === undefined) {
            return input
        }

        for (const wrongKey of Object.keys(input).filter(k => k !== "special" && k !== "before" && k !== "after")) {
            errors.push(`At ${context}: Unexpected key in a special block: ${wrongKey}`)
        }

        const type = special["type"]
        if (type === undefined) {
            errors.push("A 'special'-block should define 'type' to indicate which visualisation should be used")
            return undefined
        }
        const vis = SpecialVisualizations.specialVisualizations.find(sp => sp.funcName === type)
        if (vis === undefined) {
            const options = Utils.sortedByLevenshteinDistance(type, SpecialVisualizations.specialVisualizations, sp => sp.funcName)
            errors.push(`Special visualisation '${type}' not found. Did you perhaps mean ${options[0].funcName}, ${options[1].funcName} or ${options[2].funcName}?\n\tFor all known special visualisations, please see https://github.com/pietervdvn/MapComplete/blob/develop/Docs/SpecialRenderings.md`)
            return undefined
        }

        const argNamesList = vis.args.map(a => a.name)
        const argNames = new Set<string>(argNamesList)
        // Check for obsolete and misspelled arguments
        errors.push(...Object.keys(special)
            .filter(k => !argNames.has(k))
            .filter(k => k !== "type")
            .map(wrongArg => {
                const byDistance = Utils.sortedByLevenshteinDistance(wrongArg, argNamesList, x => x)
                return `Unexpected argument with name '${wrongArg}'. Did you mean ${byDistance[0]}?\n\tAll known arguments are ${argNamesList.join(", ")}`;
            }))

        // Check that all obligated arguments are present. They are obligated if they don't have a preset value
        for (const arg of vis.args) {
            if (arg.required !== true) {
                continue;
            }
            const param = special[arg.name]
            if (param === undefined) {
                errors.push(`Obligated parameter '${arg.name}' not found`)
            }
        }

        const foundLanguages = new Set<string>()
        const translatedArgs = argNamesList.map(nm => special[nm])
            .filter(v => v !== undefined)
            .filter(v => Translations.isProbablyATranslation(v))
        for (const translatedArg of translatedArgs) {
            for (const ln of Object.keys(translatedArg)) {
                foundLanguages.add(ln)
            }
        }

        const before = Translations.T(input.before)
        const after = Translations.T(input.after)

        for (const ln of Object.keys(before?.translations ?? {})) {
            foundLanguages.add(ln)
        }
        for (const ln of Object.keys(after?.translations ?? {})) {
            foundLanguages.add(ln)
        }

        if (foundLanguages.size === 0) {
            const args = argNamesList.map(nm => special[nm] ?? "").join(",")
            return {
                '*': `{${type}(${args})}`
            }
        }

        const result = {}
        const languages = Array.from(foundLanguages)
        languages.sort()
        for (const ln of languages) {
            const args = []
            for (const argName of argNamesList) {
                const v = special[argName] ?? ""
                if (Translations.isProbablyATranslation(v)) {
                    args.push(new Translation(v).textFor(ln))
                } else {
                    args.push(v)
                }
            }
            const beforeText = before?.textFor(ln) ?? ""
            const afterText = after?.textFor(ln) ?? ""
            result[ln] = `${beforeText}{${type}(${args.join(",")})}${afterText}`
        }
        return result
    }

    /**
     * const tr = {
     *     render: {special: {type: "image_carousel", image_key: "image" }},
     *     mappings: [
     *         {
     *             if: "other_image_key",
     *             then: {special: {type: "image_carousel", image_key: "other_image_key"}}
     *         }
     *     ]
     * }
     * const result = new RewriteSpecial().convert(tr,"test").result
     * const expected = {render:  {'*': "{image_carousel(image)}"}, mappings: [{if: "other_image_key", then:  {'*': "{image_carousel(other_image_key)}"}} ]}
     * result // => expected
     *
     * const tr = {
     *     render: {special: {type: "image_carousel", image_key: "image"}, before: {en: "Some introduction"} },
     * }
     * const result = new RewriteSpecial().convert(tr,"test").result
     * const expected = {render:  {'en': "Some introduction{image_carousel(image)}"}}
     * result // => expected
     */
    convert(json: TagRenderingConfigJson, context: string): { result: TagRenderingConfigJson; errors?: string[]; warnings?: string[]; information?: string[] } {
        const errors = []
        json = Utils.Clone(json)
        const paths: { path: string[], type?: any, typeHint?: string }[] = tagrenderingconfigmeta["default"] ?? tagrenderingconfigmeta
        for (const path of paths) {
            if (path.typeHint !== "rendered") {
                continue
            }
            Utils.WalkPath(path.path, json, ((leaf, travelled) => RewriteSpecial.convertIfNeeded(leaf, errors, travelled.join("."))))
        }

        return {
            result: json,
            errors
        };
    }

}

export class PrepareLayer extends Fuse<LayerConfigJson> {
    constructor(state: DesugaringContext) {
        super(
            "Fully prepares and expands a layer for the LayerConfig.",
            new On("tagRenderings", new Each(new RewriteSpecial())),
            new On("tagRenderings", new Concat(new ExpandRewrite()).andThenF(Utils.Flatten)),
            new On("tagRenderings", layer => new Concat(new ExpandTagRendering(state, layer))),
            new On("mapRendering", new Concat(new ExpandRewrite()).andThenF(Utils.Flatten)),
            new On("mapRendering", layer => new Each(new On("icon", new FirstOf(new ExpandTagRendering(state, layer))))),
            new SetDefault("titleIcons", ["defaults"]),
            new On("titleIcons", layer => new Concat(new ExpandTagRendering(state, layer)))
        );
    }
}