import {Store, Stores, UIEventSource} from "../../Logic/UIEventSource";
import Combine from "../Base/Combine";
import {InputElement, ReadonlyInputElement} from "../Input/InputElement";
import ValidatedTextField from "../Input/ValidatedTextField";
import {FixedInputElement} from "../Input/FixedInputElement";
import {RadioButton} from "../Input/RadioButton";
import {Utils} from "../../Utils";
import CheckBoxes from "../Input/Checkboxes";
import InputElementMap from "../Input/InputElementMap";
import {SaveButton} from "./SaveButton";
import {VariableUiElement} from "../Base/VariableUIElement";
import Translations from "../i18n/Translations";
import {FixedUiElement} from "../Base/FixedUiElement";
import {Translation} from "../i18n/Translation";
import Constants from "../../Models/Constants";
import {SubstitutedTranslation} from "../SubstitutedTranslation";
import {TagsFilter} from "../../Logic/Tags/TagsFilter";
import {Tag} from "../../Logic/Tags/Tag";
import {And} from "../../Logic/Tags/And";
import {TagUtils} from "../../Logic/Tags/TagUtils";
import BaseUIElement from "../BaseUIElement";
import {DropDown} from "../Input/DropDown";
import InputElementWrapper from "../Input/InputElementWrapper";
import ChangeTagAction from "../../Logic/Osm/Actions/ChangeTagAction";
import TagRenderingConfig, {Mapping} from "../../Models/ThemeConfig/TagRenderingConfig";
import {Unit} from "../../Models/Unit";
import VariableInputElement from "../Input/VariableInputElement";
import Toggle from "../Input/Toggle";
import Img from "../Base/Img";
import FeaturePipelineState from "../../Logic/State/FeaturePipelineState";
import Title from "../Base/Title";
import {OsmConnection} from "../../Logic/Osm/OsmConnection";
import {GeoOperations} from "../../Logic/GeoOperations";
import {SearchablePillsSelector} from "../Input/SearchableMappingsSelector";
import {OsmTags} from "../../Models/OsmFeature";

/**
 * Shows the question element.
 * Note that the value _migh_ already be known, e.g. when selected or when changing the value
 */
export default class TagRenderingQuestion extends Combine {

    constructor(tags: UIEventSource<Record<string, string> & { id: string }>,
                configuration: TagRenderingConfig,
                state?: FeaturePipelineState,
                options?: {
                    units?: Unit[],
                    afterSave?: () => void,
                    cancelButton?: BaseUIElement,
                    saveButtonConstr?: (src: Store<TagsFilter>) => BaseUIElement,
                    bottomText?: (src: Store<TagsFilter>) => BaseUIElement
                }
    ) {

        const applicableMappingsSrc =
            Stores.ListStabilized(tags.map(tags => {
                const applicableMappings: Mapping[] = []
                for (const mapping of configuration.mappings ?? []) {
                    if (mapping.hideInAnswer === true) {
                        continue
                    }
                    if (mapping.hideInAnswer === false || mapping.hideInAnswer === undefined) {
                        applicableMappings.push(mapping)
                        continue
                    }
                    const condition = <TagsFilter>mapping.hideInAnswer;
                    const isShown = !condition.matchesProperties(tags)
                    if (isShown) {
                        applicableMappings.push(mapping)
                    }
                }
                return applicableMappings
            }));

        if (configuration === undefined) {
            throw "A question is needed for a question visualization"
        }
        options = options ?? {}
        const applicableUnit = (options.units ?? []).filter(unit => unit.isApplicableToKey(configuration.freeform?.key))[0];
        const question = new Title(new SubstitutedTranslation(configuration.question, tags, state)
            .SetClass("question-text"), 3);


        const feedback = new UIEventSource<Translation>(undefined)
        const inputElement: ReadonlyInputElement<TagsFilter> =
            new VariableInputElement(applicableMappingsSrc.map(applicableMappings => {
                    return TagRenderingQuestion.GenerateInputElement(state, configuration, applicableMappings, applicableUnit, tags, feedback)
                }
            ))

        const save = () => {
            const selection = TagUtils.FlattenMultiAnswer([inputElement.GetValue().data]);
            if (selection) {
                (state?.changes)
                    .applyAction(new ChangeTagAction(
                        tags.data.id, selection, tags.data, {
                            theme: state?.layoutToUse?.id ?? "unkown",
                            changeType: "answer",
                        }
                    )).then(_ => {
                    console.log("Tagchanges applied")
                })
                if (options.afterSave) {
                    options.afterSave();
                }
            }
        }

        if (options.saveButtonConstr === undefined) {
            options.saveButtonConstr = v => new SaveButton(v,
                state?.osmConnection)
                .onClick(save)
        }

        const saveButton = new Combine([
            options.saveButtonConstr(inputElement.GetValue()),
        ])

        let bottomTags: BaseUIElement;
        if (options.bottomText !== undefined) {
            bottomTags = options.bottomText(inputElement.GetValue())
        } else {
            bottomTags = TagRenderingQuestion.CreateTagExplanation(inputElement.GetValue(), tags, state)
        }
        super([
            question,
            inputElement,
            new Combine([
                new VariableUiElement(feedback.map(t => t?.SetStyle("padding-left: 0.75rem; padding-right: 0.75rem")?.SetClass("alert flex") ?? bottomTags)),
                new Combine([
                    new Combine([options.cancelButton]),
                    saveButton]).SetClass("flex justify-end flex-wrap-reverse")

            ]).SetClass("flex mt-2 justify-between"),
            new Toggle(Translations.t.general.testing.SetClass("alert"), undefined, state?.featureSwitchIsTesting)
        ])


        this.SetClass("question disable-links")
    }


    private static GenerateInputElement(
        state: FeaturePipelineState,
        configuration: TagRenderingConfig,
        applicableMappings: Mapping[],
        applicableUnit: Unit,
        tagsSource: UIEventSource<any>,
        feedback: UIEventSource<Translation>
    ): ReadonlyInputElement<TagsFilter> {


        const hasImages = applicableMappings.findIndex(mapping => mapping.icon !== undefined) >= 0
        let inputEls: InputElement<TagsFilter>[];

        const ifNotsPresent = applicableMappings.some(mapping => mapping.ifnot !== undefined)

        if (applicableMappings.length > 8 &&
            (configuration.freeform?.type === undefined || configuration.freeform?.type === "string") &&
            (!configuration.multiAnswer || configuration.freeform === undefined)) {

            return TagRenderingQuestion.GenerateSearchableSelector(state, configuration, applicableMappings, tagsSource)
        }


        // FreeForm input will be undefined if not present; will already contain a special input element if applicable
        const ff = TagRenderingQuestion.GenerateFreeform(state, configuration, applicableUnit, tagsSource, feedback);

        function allIfNotsExcept(excludeIndex: number): TagsFilter[] {
            if (configuration.mappings === undefined || configuration.mappings.length === 0) {
                return undefined
            }
            if (!ifNotsPresent) {
                return []
            }
            if (configuration.multiAnswer) {
                // The multianswer will do the ifnot configuration themself
                return []
            }

            const negativeMappings = []

            for (let i = 0; i < applicableMappings.length; i++) {
                const mapping = applicableMappings[i];
                if (i === excludeIndex || mapping.ifnot === undefined) {
                    continue
                }
                negativeMappings.push(mapping.ifnot)
            }
            return Utils.NoNull(negativeMappings)

        }


        if (applicableMappings.length < 8 || configuration.multiAnswer || (hasImages && applicableMappings.length < 16) || ifNotsPresent) {
            inputEls = (applicableMappings ?? []).map((mapping, i) => TagRenderingQuestion.GenerateMappingElement(state, tagsSource, mapping, allIfNotsExcept(i)));
            inputEls = Utils.NoNull(inputEls);
        } else {
            const dropdown: InputElement<TagsFilter> = new DropDown("",
                applicableMappings.map((mapping, i) => {
                    return {
                        value: new And([mapping.if, ...allIfNotsExcept(i)]),
                        shown: mapping.then.Subs(tagsSource.data)
                    }
                })
            )

            if (ff == undefined) {
                return dropdown;
            } else {
                inputEls = [dropdown]
            }
        }


        if (inputEls.length == 0) {
            if (ff === undefined) {
                throw "Error: could not generate a question: freeform and all mappings are undefined"
            }
            return ff;
        }

        if (ff) {
            inputEls.push(ff);
        }

        if (configuration.multiAnswer) {
            return TagRenderingQuestion.GenerateMultiAnswer(configuration, inputEls, ff, applicableMappings.map(mp => mp.ifnot))
        } else {
            return new RadioButton(inputEls, {selectFirstAsDefault: false})
        }

    }

    private static MappingToPillValue(applicableMappings: Mapping[], tagsSource: UIEventSource<OsmTags>, state: FeaturePipelineState): { show: BaseUIElement, value: number, mainTerm: Record<string, string>, searchTerms?: Record<string, string[]>, original: Mapping }[] {
        const values: { show: BaseUIElement, value: number, mainTerm: Record<string, string>, searchTerms?: Record<string, string[]>, original: Mapping }[] = []
        const addIcons = applicableMappings.some(m => m.icon !== undefined)
        for (let i = 0; i < applicableMappings.length; i++) {
            const mapping = applicableMappings[i];
            const tr = mapping.then.Subs(tagsSource.data)
            const patchedMapping = <Mapping>{
                ...mapping,
                iconClass: `small-height`,
                icon: mapping.icon ?? (addIcons ? "./assets/svg/none.svg" : undefined)
            }
            const fancy = TagRenderingQuestion.GenerateMappingContent(patchedMapping, tagsSource, state).SetClass("normal-background")
            values.push({
                show: fancy,
                value: i,
                mainTerm: tr.translations,
                searchTerms: mapping.searchTerms,
                original: mapping
            })
        }
        return values
    }

    /**
     *
     * // Should return the search as freeform value
     * const source = new UIEventSource({id: "1234"})
     * const tr =  new TagRenderingConfig({
     *      id:"test",
     *      render:"The value is {key}",
     *      freeform: {
     *          key:"key"
     *      },
     *    
     *      mappings: [
     *          {
     *            if:"x=y",
     *            then:"z",
     *            searchTerms: {
     *              "en" : ["z"]
     *            }
     *          }
     *      ]
     * }, "test");
     * const selector = TagRenderingQuestion.GenerateSearchableSelector(
     *          undefined,
     *          tr,
     *          tr.mappings,
     *          source,
     *          {
     *              search: new UIEventSource<string>("value")
     *          }
     *      );
     * selector.GetValue().data // => new And([new Tag("key","value")])
     *
     * // Should return the search as freeform value, even if a previous search matched
     * const source = new UIEventSource({id: "1234"})
     * const search = new UIEventSource<string>("")
     * const tr =  new TagRenderingConfig({
     *      id:"test",
     *      render:"The value is {key}",
     *      freeform: {
     *          key:"key"
     *      },
     *    
     *      mappings: [
     *          {
     *            if:"x=y",
     *            then:"z",
     *            searchTerms: {
     *              "en" : ["z"]
     *            }
     *          }
     *      ]
     * }, "test");
     * const selector = TagRenderingQuestion.GenerateSearchableSelector(
     *          undefined,
     *          tr,
     *          tr.mappings,
     *          source,
     *          {
     *              search
     *          }
     *      );
     * search.setData("z")
     * search.setData("zx")
     * selector.GetValue().data // => new And([new Tag("key","zx")])
     */
    private static GenerateSearchableSelector(
        state: FeaturePipelineState,
        configuration: TagRenderingConfig,
        applicableMappings: Mapping[],
        tagsSource: UIEventSource<OsmTags>,
        options?: {
            search: UIEventSource<string>
        }): InputElement<TagsFilter> {


        const values = TagRenderingQuestion.MappingToPillValue(applicableMappings, tagsSource, state)

        const searchValue: UIEventSource<string> = options?.search ?? new UIEventSource<string>(undefined)
        const ff = configuration.freeform
        let onEmpty: BaseUIElement = undefined
        if (ff !== undefined) {
            onEmpty = new VariableUiElement(searchValue.map(search => configuration.render.Subs({[ff.key]: search})))
        }
        const mode = configuration.multiAnswer ? "select-many" : "select-one";

        const tooMuchElementsValue = new UIEventSource<number[]>([]);


        let priorityPresets: BaseUIElement = undefined;
        const classes = "h-64 overflow-scroll"

        if (applicableMappings.some(m => m.priorityIf !== undefined)) {
            const priorityValues = tagsSource.map(tags =>
                TagRenderingQuestion.MappingToPillValue(applicableMappings, tagsSource, state)
                    .filter(v => v.original.priorityIf?.matchesProperties(tags)))
            priorityPresets = new VariableUiElement(priorityValues.map(priority => {
                if (priority.length === 0) {
                    return Translations.t.general.useSearch;
                }
                return new Combine([
                    Translations.t.general.useSearchForMore.Subs({total: applicableMappings.length}),
                    new SearchablePillsSelector(priority, {
                        selectedElements: tooMuchElementsValue,
                        hideSearchBar: true,
                        mode
                    })]).SetClass("flex flex-col items-center ").SetClass(classes);
            }));
        }
        const presetSearch = new SearchablePillsSelector<number>(values, {
            selectIfSingle: true,
            mode,
            searchValue,
            onNoMatches: onEmpty?.SetClass(classes).SetClass("flex justify-center items-center"),
            searchAreaClass: classes,
            onManyElementsValue: tooMuchElementsValue,
            onManyElements: priorityPresets
        })
        const fallbackTag = searchValue.map(s => {
            if (s === undefined || ff?.key === undefined) {
                return undefined
            }
            return new Tag(ff.key, s)
        });
        return new InputElementMap<number[], And>(presetSearch,
            (x0, x1) => {
                if (x0 == x1) {
                    return true;
                }
                if (x0 === undefined || x1 === undefined) {
                    return false;
                }
                if (x0.and.length !== x1.and.length) {
                    return false;
                }
                for (let i = 0; i < x0.and.length; i++) {
                    if (x1.and[i] != x0.and[i]) {
                        return false
                    }
                }
                return true;
            },
            (selected) => {
                if (ff !== undefined && searchValue.data?.length > 0 && !presetSearch.someMatchFound.data) {
                    const t = fallbackTag.data;
                    if (ff.addExtraTags) {
                        return new And([t, ...ff.addExtraTags])
                    }
                    return new And([t]);
                }

                if (selected === undefined || selected.length == 0) {
                    return undefined;
                }

                const tfs = Utils.NoNull(applicableMappings.map((mapping, i) => {
                    if (selected.indexOf(i) >= 0) {
                        return mapping.if
                    } else {
                        return mapping.ifnot
                    }
                }))
                console.log("Got tags", tfs)
                return new And(tfs);
            },
            (tf) => {
                if (tf === undefined) {
                    return []
                }
                const selected: number[] = []
                for (let i = 0; i < applicableMappings.length; i++) {
                    const mapping = applicableMappings[i]
                    if (tf.and.some(t => mapping.if == t)) {
                        selected.push(i)
                    }
                }
                return selected;
            },
            [searchValue, presetSearch.someMatchFound]
        );
    }

    private static GenerateMultiAnswer(
        configuration: TagRenderingConfig,
        elements: InputElement<TagsFilter>[], freeformField: InputElement<TagsFilter>, ifNotSelected: TagsFilter[]): InputElement<TagsFilter> {
        const checkBoxes = new CheckBoxes(elements);

        const inputEl = new InputElementMap<number[], TagsFilter>(
            checkBoxes,
            (t0, t1) => {
                return t0?.shadows(t1) ?? false
            },
            (indices) => {
                if (indices.length === 0) {
                    return undefined;
                }
                const tags: TagsFilter[] = indices.map(i => elements[i].GetValue().data);
                const oppositeTags: TagsFilter[] = [];
                for (let i = 0; i < ifNotSelected.length; i++) {
                    if (indices.indexOf(i) >= 0) {
                        continue;
                    }
                    const notSelected = ifNotSelected[i];
                    if (notSelected === undefined) {
                        continue;
                    }
                    oppositeTags.push(notSelected);
                }
                tags.push(TagUtils.FlattenMultiAnswer(oppositeTags));
                return TagUtils.FlattenMultiAnswer(tags);
            },
            (tags: TagsFilter) => {
                // {key --> values[]}
                const presentTags = TagUtils.SplitKeys([tags]);
                const indices: number[] = []
                // We also collect the values that have to be added to the freeform field
                let freeformExtras: string[] = []
                if (configuration.freeform?.key) {
                    freeformExtras = [...(presentTags[configuration.freeform.key] ?? [])]
                }

                for (let j = 0; j < elements.length; j++) {
                    const inputElement = elements[j];
                    if (inputElement === freeformField) {
                        continue;
                    }
                    const val = inputElement.GetValue();
                    const neededTags = TagUtils.SplitKeys([val.data]);

                    // if every 'neededKeys'-value is present in presentKeys, we have a match and enable the index
                    if (TagUtils.AllKeysAreContained(presentTags, neededTags)) {
                        indices.push(j);
                        if (freeformExtras.length > 0) {
                            const freeformsToRemove: string[] = (neededTags[configuration.freeform.key] ?? []);
                            for (const toRm of freeformsToRemove) {
                                const i = freeformExtras.indexOf(toRm);
                                if (i >= 0) {
                                    freeformExtras.splice(i, 1);
                                }
                            }
                        }
                    }

                }
                if (freeformField) {
                    if (freeformExtras.length > 0) {
                        freeformField.GetValue().setData(new Tag(configuration.freeform.key, freeformExtras.join(";")));
                        indices.push(elements.indexOf(freeformField))
                    } else {
                        freeformField.GetValue().setData(undefined);
                    }
                }


                return indices;
            },
            elements.map(el => el.GetValue())
        );

        freeformField?.GetValue()?.addCallbackAndRun(value => {
            // The list of indices of the selected elements
            const es = checkBoxes.GetValue();
            const i = elements.length - 1;
            // The actual index of the freeform-element
            const index = es.data.indexOf(i);
            if (value === undefined) {
                // No data is set in the freeform text field; so we delete the checkmark if it is selected
                if (index >= 0) {
                    es.data.splice(index, 1);
                    es.ping();
                }
            } else if (index < 0) {
                // There is data defined in the checkmark, but the checkmark isn't checked, so we check it
                // This is of course because the data changed
                es.data.push(i);
                es.ping();
            }
        });

        return inputEl;
    }


    /**
     * Generates a (Fixed) input element for this mapping.
     * Note that the mapping might hide itself if the condition is not met anymore.
     *
     * Returns: [the element itself, the value to select if not selected. The contents of this UIEventSource might swap to undefined if the conditions to show the answer are unmet]
     */
    private static GenerateMappingElement(
        state,
        tagsSource: UIEventSource<any>,
        mapping: Mapping, ifNot?: TagsFilter[]): InputElement<TagsFilter> {

        let tagging: TagsFilter = mapping.if;
        if (ifNot !== undefined) {
            tagging = new And([mapping.if, ...ifNot])
        }
        if (mapping.addExtraTags) {
            tagging = new And([tagging, ...mapping.addExtraTags])
        }


        return new FixedInputElement(
            TagRenderingQuestion.GenerateMappingContent(mapping, tagsSource, state),
            tagging,
            (t0, t1) => t1.shadows(t0));
    }

    private static GenerateMappingContent(mapping: Mapping, tagsSource: UIEventSource<any>, state: FeaturePipelineState): BaseUIElement {
        const text = new SubstitutedTranslation(mapping.then, tagsSource, state)
        if (mapping.icon === undefined) {
            return text;
        }
        return new Combine([new Img(mapping.icon).SetClass("mr-1 mapping-icon-" + (mapping.iconClass ?? "small")), text]).SetClass("flex items-center")
    }

    private static GenerateFreeform(state: FeaturePipelineState, configuration: TagRenderingConfig, applicableUnit: Unit, tags: UIEventSource<any>, feedback: UIEventSource<Translation>)
        : InputElement<TagsFilter> {
        const freeform = configuration.freeform;
        if (freeform === undefined) {
            return undefined;
        }

        const pickString =
            (string: any) => {
                if (string === "" || string === undefined) {
                    return undefined;
                }
                if (string.length >= 255) {
                    return undefined
                }

                const tag = new Tag(freeform.key, string);

                if (freeform.addExtraTags === undefined) {
                    return tag;
                }
                return new And([
                        tag,
                        ...freeform.addExtraTags
                    ]
                );
            };

        const toString = (tag) => {
            if (tag instanceof And) {
                for (const subtag of tag.and) {
                    if (subtag instanceof Tag && subtag.key === freeform.key) {
                        return subtag.value;
                    }
                }

                return undefined;
            } else if (tag instanceof Tag) {
                return tag.value
            }
            return undefined;
        }

        const tagsData = tags.data;
        const feature = state?.allElements?.ContainingFeatures?.get(tagsData.id)
        const center = feature != undefined ? GeoOperations.centerpointCoordinates(feature) : [0, 0]
        console.log("Creating a tr-question with applicableUnit", applicableUnit)
        const input: InputElement<string> = ValidatedTextField.ForType(configuration.freeform.type)?.ConstructInputElement({
            country: () => tagsData._country,
            location: [center[1], center[0]],
            mapBackgroundLayer: state?.backgroundLayer,
            unit: applicableUnit,
            args: configuration.freeform.helperArgs,
            feature,
            placeholder: configuration.freeform.placeholder,
            feedback
        });

        // Init with correct value
        input?.GetValue().setData(tagsData[freeform.key] ?? freeform.default);

        // Add a length check
        input?.GetValue().addCallbackD((v: string | undefined) => {
            if (v?.length >= 255) {
                feedback.setData(Translations.t.validation.tooLong.Subs({count: v.length}))
            }
        })

        let inputTagsFilter: InputElement<TagsFilter> = new InputElementMap(
            input, (a, b) => a === b || (a?.shadows(b) ?? false),
            pickString, toString
        );

        if (freeform.inline) {
            inputTagsFilter.SetClass("w-48-imp")
            inputTagsFilter = new InputElementWrapper(inputTagsFilter, configuration.render, freeform.key, tags, state)
            inputTagsFilter.SetClass("block")
        }

        return inputTagsFilter;

    }

    public static CreateTagExplanation(selectedValue: Store<TagsFilter>,
                                       tags: Store<object>,
                                       state?: { osmConnection?: OsmConnection }) {
        return new VariableUiElement(
            selectedValue.map(
                (tagsFilter: TagsFilter) => {
                    const csCount = state?.osmConnection?.userDetails?.data?.csCount ?? Constants.userJourney.tagsVisibleAndWikiLinked + 1;
                    if (csCount < Constants.userJourney.tagsVisibleAt) {
                        return "";
                    }
                    if (tagsFilter === undefined) {
                        return Translations.t.general.noTagsSelected.SetClass("subtle");
                    }
                    if (csCount < Constants.userJourney.tagsVisibleAndWikiLinked) {
                        const tagsStr = tagsFilter.asHumanString(false, true, tags.data);
                        return new FixedUiElement(tagsStr).SetClass("subtle");
                    }
                    return tagsFilter.asHumanString(true, true, tags.data);
                },
                [state?.osmConnection?.userDetails]
            )
        ).SetClass("block break-all")
    }

}