/**
 * Copyright (c) 2021 lingdocs.com
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */

import {
    inflectRegularYeyUnisex,
} from "./pashto-inflector";
import { baParticle } from "./grammar-units";
import {
    getBlockRowCol,
    getPersonInflectionsKey,
} from "./misc-helpers";
import * as T from "../types";

// export function concatPsStringWithVars(...items: Array<T.PsString | " " | "">): T.PsString[] {

// }

/**
 * Concats sections of Pashto text with Pashto and Phonetics
 * in PsString type, also accepts spaces as " "
 * 
 * @param items
 */
export function concatPsString(...items: Array<T.PsString | " " | "">): T.PsString;
export function concatPsString(...items: Array<T.PsString | T.LengthOptions<T.PsString> | " " | "">): T.LengthOptions<T.PsString>;
export function concatPsString(...items: Array<T.PsString | T.LengthOptions<T.PsString> | T.OptionalPersonInflections<T.LengthOptions<T.PsString>> | " " | "">): T.OptionalPersonInflections<T.LengthOptions<T.PsString>>;
export function concatPsString(...items: Array<T.PsString | T.FullForm<T.PsString> | " " | "">): T.FullForm<T.PsString>;
export function concatPsString(...items: Array<T.PsString | T.LengthOptions<T.PsString> | T.FullForm<T.PsString> | " " | "">): T.FullForm<T.PsString> {
    const hasPersonInflections = items.some((x) => ((typeof x !== "string") && ("mascSing" in x)));
    if (hasPersonInflections) {
        const forceInflection = (
            arr: Array<T.FullForm<T.PsString> | " " | "">,
            inflection: T.PersonInflectionsField,
        ): Array<T.SingleOrLengthOpts<T.PsString> | " " | ""> => (
            arr.map((element) => (typeof element !== "string" && "mascSing" in element)
                ? element[inflection]
                : element
            )
        )
        return {
            mascSing: concatPsString(...forceInflection(items, "mascSing")),
            mascPlur: concatPsString(...forceInflection(items, "mascPlur")),
            femSing: concatPsString(...forceInflection(items, "femSing")),
            femPlur: concatPsString(...forceInflection(items, "femPlur")),
        };
    }
    const itemsWOutPersInfs = items as ("" | " " | T.SingleOrLengthOpts<T.PsString>)[];
    const hasLengthOptions = itemsWOutPersInfs.some((x) => (typeof x !== "string") && ("long" in x));
    if (hasLengthOptions) {
        const forceLength = (
            arr: Array<T.SingleOrLengthOpts<T.PsString> | " ">,
            length: "long" | "short" | "mini",
        ): Array<T.PsString | " "> => (
            arr.map((element) => (element !== " " && "long" in element)
                ? element[length] || element.short
                : element
            )
        );
        const hasMini = itemsWOutPersInfs.some((x) => typeof x !== "string" && ("mini" in x));
        return {
            ...hasMini ? {
                mini: concatPsString(...forceLength(items as Array<T.SingleOrLengthOpts<T.PsString> | " ">, "mini")),
            } : {},
            short: concatPsString(...forceLength(items as Array<T.SingleOrLengthOpts<T.PsString> | " ">, "short")),
            long: concatPsString(...forceLength(items as Array<T.SingleOrLengthOpts<T.PsString> | " ">, "long")),
        };
    }
    const itemsWOutLengthOptions = itemsWOutPersInfs as ("" | " " | T.PsString)[];
    const concatField = (k: T.PsStringField): string => (
        itemsWOutLengthOptions.map((item): string => {
            if (item === " ") return " ";
            if (item === "") return "";
            return item[k];
        }).join("")
    );
    return {
        p: concatField("p"),
        f: concatField("f"),
    };
}

/**
 * breaks a dictionary entry with a double wording (ie. ګډ وډ) into two seperate words
 * 
 * @param w 
 * @returns 
 */
export function splitDoubleWord(w: T.DictionaryEntry): [T.DictionaryEntry, T.DictionaryEntry] {
    const pSplit = w.p.split(" ");
    const fSplit = w.f.split(" ");
    const c = w.c?.replace(" doub.", "");
    return [{
        ...w,
        p: pSplit[0],
        f: fSplit[0],
        c,
    }, {
        ...w,
        p: pSplit[1],
        f: fSplit[1],
        c,
    }];
}

export function psFunction(ps: T.PsString, func: (s: string) => string): T.PsString {
    return makePsString(
        func(ps.p),
        func(ps.f),
    );
}

export function psIncludes(ps: T.PsString, inc: T.PsString): boolean {
    return ps.p.includes(inc.p) && ps.f.includes(inc.f);
}

export function hasBaParticle(ps: T.PsString): boolean {
    return psIncludes(ps, concatPsString(baParticle, " "));
}

export function psRemove(ps: T.PsString, remove: T.PsString): T.PsString {
    return makePsString(
        ps.p.replace(remove.p, ""),
        ps.f.replace(remove.f, ""),
    );
}

export function psInsertWord(ps: T.PsString, toInsert: T.PsString, pos: number): T.PsString {
    const pWords = ps.p.split(" ");
    const fWords = ps.f.split(" ");
    const pIns = [...pWords.slice(0, pos), toInsert.p, ...pWords.slice(pos)]; 
    const fIns = [...fWords.slice(0, pos), toInsert.f, ...fWords.slice(pos)]; 
    return makePsString(
        pIns.join(" "),
        fIns.join(" "),
    );
}

/**
 * If a به - ba particle is present in a PsString form, ensure that it is placed in word pos
 * If no به - ba is present, return as is
 * 
 * @param ps 
 * @param pos 
 */
export function ensureBaAt(ps: T.PsString, pos: number): T.PsString;
export function ensureBaAt(ps: T.SingleOrLengthOpts<T.PsString>, pos: number): T.SingleOrLengthOpts<T.PsString>;
export function ensureBaAt(ps: T.FullForm<T.PsString>, pos: number): T.FullForm<T.PsString>;
export function ensureBaAt(ps: T.FullForm<T.PsString>, pos: number): T.FullForm<T.PsString> {
    if ("mascSing" in ps) {
        return {
            mascSing: ensureBaAt(ps.mascSing, pos),
            mascPlur: ensureBaAt(ps.mascPlur, pos),
            femSing: ensureBaAt(ps.femSing, pos),
            femPlur: ensureBaAt(ps.femPlur, pos),
        };
    }
    if ("long" in ps) {
        return {
            long: ensureBaAt(ps.long, pos),
            short: ensureBaAt(ps.short, pos),
            ...ps.mini ? {
                mini: ensureBaAt(ps.mini, pos),
            } : {},
        };
    }
    if (!psIncludes(ps, concatPsString(baParticle, " "))) {
        return ps;
    }
    const baRemoved = psRemove(ps, concatPsString(baParticle, " "));
    const baInserted = psInsertWord(baRemoved, baParticle, pos);
    return baInserted;
}

/**
 * Returns the first phonetics value in a comma-seperated list
 * 
 * @param f - a phonetics string 
 */
export function firstPhonetics(f: string): string {
    return f.split(",")[0];
}

/**
 * returs a PsString or DictionaryEntry ensuring only one phonetics variation
 * 
 * @param ps 
 */
export function removeFVariants(ps: T.PsString): T.PsString {
    return {
        ...ps,
        f: firstPhonetics(ps.f),
    };
}

/**
 * Lets us know if all the forms of a verb block are the same
 * 
 * @param block 
 */
export function isAllOne (block: T.VerbBlock | T.ImperativeBlock): boolean {
    return block.reduce((isTheSame, row, i, src) => (
        isTheSame &&
        psStringEquals(row[0][0], src[0][0][0]) &&
        psStringEquals(row[1][0], src[1][0][0])
    ), true) as unknown as boolean;
}

/**
 * Creates a Pashto string structure
 * 
 * @param p - the Pashto text
 * @param f - the phonetics text
 */
export function makePsString(p: string, f: string): T.PsString {
    return { p, f };
}

/**
 * Retuns a Pashto string with the ل - ul on the end removed
 * 
 * @param s 
 */
export function removeEndingL(s: T.PsString): T.PsString {
    const lOnEnd = (): boolean => {
        const lastPLetter = s.p.slice(-1);
        const lastFLetters = s.f.slice(-2);
        return lastPLetter === "ل" && ["ul", "úl"].includes(lastFLetters);
    };
    if (!lOnEnd()) return s;
    return {
        p: s.p.substr(0, s.p.length-1),
        f: s.f.substr(0, s.f.length-2),
    };
}

function getMatchingInflection(
    infs: T.UnisexInflections,
    persNum: number,
    singPlur: number,
): T.PsString {
    return infs[persNum % 2 === 0 ? "masc" : "fem"][singPlur][0];
}

export function isVerbBlock(x: unknown): x is T.VerbBlock {
    return (
        Array.isArray(x) &&
        (x.length === 6) &&
        "p" in x[0][0][0]
    );
}

export function isImperativeBlock(x: unknown): x is T.ImperativeBlock {
    return (
        Array.isArray(x) &&
        (x.length === 2) &&
        "p" in x[0][0][0]
    );
}

export function isInflectionSet(x: any): x is T.InflectionSet {
    return (
        Array.isArray(x)
        && (x.length === 3)
        && "p" in x[0][0]
    );
}


type toAddToForm = Array<" " | T.SingleOrLengthOpts<T.PsString> | T.SingleOrLengthOpts<T.UnisexInflections> | T.SingleOrLengthOpts<T.PsString>[] | T.SingleOrLengthOpts<T.PsString[]> | T.OptionalPersonInflections<T.PsString> | T.VerbBlock>;
type toAddToFormLengthChosen = Array<" " | T.PsString | T.UnisexInflections | T.PsString[] | T.OptionalPersonInflections<T.PsString> | T.VerbBlock>;
export function addToForm(
    toAdd: toAddToForm,
    base: T.VerbForm,
    disableLCheck?: boolean,
): T.VerbForm;
export function addToForm(
    toAdd: toAddToForm,
    base: T.ImperativeForm,
    disableLCheck?: boolean,
): T.ImperativeForm;
export function addToForm(
    toAdd: toAddToForm,
    base: T.VerbForm | T.ImperativeForm,
    disableLCheck?: boolean,
): T.VerbForm | T.ImperativeForm {
    function startsWithBa(ps: T.PsString): boolean {
        const start = makePsString(
            ps.p.slice(0, 3),
            ps.f.slice(0, 3),
        );
        return psStringEquals(
            start,
            concatPsString(baParticle, " "),
        );
    }
    function removeBa(ps: T.PsString): T.PsString {
        return makePsString(
            ps.p.slice(3),
            ps.f.slice(3),
        );
    }
    const toAddIncludesObjectMatrix = () => (
        toAdd.some((x) => x !== " " && "mascSing" in x)
    );
    // TODO: Weird stuff with overloading throwing errors
    function makeNonObjectMatrixForm(
        base: T.VerbBlock | T.LengthOptions<T.VerbBlock>,
        presObject?: "mascSing" | "mascPlur" | "femSing" | "femPlur",
    ): T.SingleOrLengthOpts<T.VerbBlock>;
    function makeNonObjectMatrixForm(
        base: T.ImperativeBlock | T.LengthOptions<T.ImperativeBlock> | T.VerbBlock | T.LengthOptions<T.VerbBlock>,
        presObject?: "mascSing" | "mascPlur" | "femSing" | "femPlur",
    ): T.SingleOrLengthOpts<T.ImperativeBlock>;
    function makeNonObjectMatrixForm(
        base: T.SingleOrLengthOpts<T.VerbBlock> | T.SingleOrLengthOpts<T.ImperativeBlock>,
        presObject?: "mascSing" | "mascPlur" | "femSing" | "femPlur",
    ): T.SingleOrLengthOpts<T.VerbBlock> | T.SingleOrLengthOpts<T.ImperativeBlock> {
        function makeLengthOption(length: "short" | "long" | "mini"): T.ImperativeBlock;
        function makeLengthOption(length: "short" | "long" | "mini"): T.VerbBlock;
        function makeLengthOption(length: "short" | "long" | "mini"): T.ImperativeForm | T.VerbBlock {
            // If the base is long and there are also length options in toAdd,
            // then make the short and long versions of the base as variations on each item
            const multiplyEachVariationBy = toAdd.reduce((acc, cur) => (
                // make sure we don't make 6 variations when concating a verb block to a verb block!
                (Array.isArray(cur) && !isVerbBlock(cur)) ? Math.max(acc, cur.length) : acc
            ), 1);
            const b = "long" in base
                ? base[length] || base.short // in case mini does not exist
                : base;
            const addingLengthChosen: toAddToFormLengthChosen = toAdd.map((element) => {
                if (element !== " " && "long" in element) {
                    return element[length] || element.short;
                }
                if (Array.isArray(element)) {
                    const arr = element as T.SingleOrLengthOpts<T.PsString>[] | T.VerbBlock;
                    return arr.map((e: any) => "long" in e ? (e[length] || e.short) : e)
                }
                return element;
            });
            const makeItem = (ps: T.PsString, persNum: number, singPlur: number, variation: number, verbBlock?: boolean): T.PsString => {
                const add = addingLengthChosen.map((e) => {
                    if (e === " ") return e;
                    if (isVerbBlock(e)) {
                        return e[persNum][singPlur][0];
                    }
                    const f = e as T.UnisexInflections | T.PsString[] | T.OptionalPersonInflections<T.PsString>;
                    if (Array.isArray(f)) {
                        return f[Math.min(variation, f.length-1)];
                    }
                    if ("masc" in f) {
                        return getMatchingInflection(f, persNum as number, singPlur as number);
                    }
                    if ("mascSing" in f) {
                        return f[presObject || /* istanbul ignore next */ "mascSing"];
                    }
                    return f;
                });
                // avoid adding the redundant ل on past verb endings
                // TODO: If there's a ba in front, remove it and put it on the front
                return (length === "long") && verbBlock && (ps.p === "ل") && !disableLCheck
                    ? concatPsString(...add)
                    : startsWithBa(ps)
                    ? concatPsString(baParticle, " ", ...add, removeBa(ps))
                    : concatPsString(...add, ps);
            }
            if (b.length === 6) {
                return b.map((person, persNum) => (
                    person.map((item, singPlur) => (
                        // @ts-ignore
                        item.reduce((vars, ps) => {
                            const varIndexes = [...Array(multiplyEachVariationBy).keys()];
                            return [
                                ...vars,
                                ...varIndexes.map((varIndex) => (
                                    makeItem(ps, persNum, singPlur, varIndex, true) 
                                )),
                            ];
                        }, []) as unknown as T.ArrayOneOrMore<T.PsString>
                    ))
                )) as T.VerbBlock;
            }
            // TODO: CHECK IF THE IMPERATIVE BLOCKS WORK??
            return mapImperativeBlock((ps, persNumber, singPlur) => (
                makeItem(ps, persNumber as number, singPlur as number, 0)
            ), b);
        }
        const useLengthOptions = (
            ("long" in base) ||
            toAdd.some((element) => (
                (element !== " " && "long" in element)
                ||
                // @ts-ignore
                (Array.isArray(element) && element.some((e) => "long" in e))
            ))
        );
        if (useLengthOptions) {
            // might be totally unneccessary...
            const miniInToAdd = toAdd.some((x) => (
                x !== " " && "mini" in x
            ));
            return {
                long: makeLengthOption("long"),
                short: makeLengthOption("short"),
                ...("mini" in base || miniInToAdd) ? {
                    mini: makeLengthOption("mini"),
                } : {},
            };
        }
        // there are no length options in any of the elements or base
        return makeLengthOption("long");
    }
    if (toAddIncludesObjectMatrix() && !("mascSing" in base)) {
        return {
            mascSing: makeNonObjectMatrixForm(base, "mascSing"),
            mascPlur: makeNonObjectMatrixForm(base, "mascPlur"),
            femSing: makeNonObjectMatrixForm(base, "femSing"),
            femPlur: makeNonObjectMatrixForm(base, "femPlur"),
        };
    }
    if ("mascSing" in base) {
        return {
            // TODO: Is this really what we want to do?
            // is there ever a case where we would want the object matrix of a compliment
            // to line up with the object matrix of a base verb?
            mascSing: makeNonObjectMatrixForm(base.mascSing, "mascSing"),
            mascPlur: makeNonObjectMatrixForm(base.mascPlur, "mascPlur"),
            femSing: makeNonObjectMatrixForm(base.femSing, "femSing"),
            femPlur: makeNonObjectMatrixForm(base.femPlur, "femPlur"),
        };
    }
    return makeNonObjectMatrixForm(base);
}

function mapImperativeBlock(f: (ps: T.PsString, i?: number, j?: number) => T.PsString, block: T.ImperativeBlock): T.ImperativeBlock {
    return block.map((person, i) => (
        person.map((item, j) => (
            item.map((variation) => (
                f(variation, i, j)
            ))
        ))
    )) as T.ImperativeBlock;
}

export function mapVerbBlock(f: (ps: T.PsString, i?: number, j?: number) => T.PsString, block: T.VerbBlock): T.VerbBlock {
    return block.map((person, i) => (
        person.map((item, j) => (
            item.map((variation) => (
                f(variation, i, j)
            ))
        ))
    )) as T.VerbBlock;
}

export function unisexInfToObjectMatrix(inf: T.UnisexInflections): T.OptionalPersonInflections<T.PsString> {
    return {
        mascSing: inf.masc[0][0],
        mascPlur: inf.masc[1][0],
        femSing: inf.fem[0][0],
        femPlur: inf.fem[1][0],
    };
}

export function concatInflections(
    comp: T.PsString | T.SingleOrLengthOpts<T.UnisexInflections>, infs: T.SingleOrLengthOpts<T.UnisexInflections>
): T.SingleOrLengthOpts<T.UnisexInflections> {
    const containsLengthOptions = "long" in infs || "long" in comp;
    const ensureL = <T>(x: T.SingleOrLengthOpts<T>, length: "short" | "long"): T => (
        ("long" in x) ? x[length] : x
    );
    if (containsLengthOptions) {
        return {
            short: concatInflections(
                ensureL(comp, "short"),
                ensureL(infs, "short"),
            ) as T.UnisexInflections,
            long: concatInflections(
                ensureL(comp, "long"),
                ensureL(infs, "long"),
            ) as T.UnisexInflections,
        };
    }
    // now length options are removed
    const complement = comp as T.PsString | T.UnisexInflections;
    const infsOneL = infs as T.UnisexInflections;
    const mapGender = (gender: "masc" | "fem") => (
        infsOneL[gender].map((inf: T.ArrayOneOrMore<T.PsString>, i) => (
            inf.map((variation) => {
                const c = ("masc" in complement)
                    ? complement[gender][i][0]
                    : complement;
                return concatPsString(c, " ", variation)
            })
        )) as T.ArrayFixed<T.ArrayOneOrMore<T.PsString>, 3>
    );
    return {
        masc: mapGender("masc"),
        fem: mapGender("fem"),
    };
}

/**
 * Checks if a given infinitive ends in یل - yul such as وایل - waayul etc.
 * 
 * @param s 
 */
export function yulEndingInfinitive(s: T.PsString): boolean {
    const pEnding = s.p.slice(-2);
    const fEnding = s.f.slice(-3);
    return ((pEnding === "یل") && (["yul", "yúl"].includes(fEnding)));
}

export function psStringFromEntry(entry: T.DictionaryEntry): T.PsString {
    return makePsString(
        entry.p,
        firstPhonetics(entry.f),
    );
}

export function allOnePersonInflection(block: T.ImperativeForm, person: T.Person): T.SingleOrLengthOpts<T.ImperativeBlock>;
export function allOnePersonInflection(block: T.VerbForm, person: T.Person): T.SingleOrLengthOpts<T.VerbBlock>;
export function allOnePersonInflection(block: T.SingleOrLengthOpts<T.UnisexInflections>, person: T.Person): T.SingleOrLengthOpts<T.UnisexInflections>;
export function allOnePersonInflection(
    block: T.VerbForm | T.ImperativeForm | T.SingleOrLengthOpts<T.UnisexInflections>, person: T.Person
): T.SingleOrLengthOpts<T.VerbBlock> | T.SingleOrLengthOpts<T.ImperativeBlock> | T.SingleOrLengthOpts<T.UnisexInflections> {
    if ("mascSing" in block) {
        const key = getPersonInflectionsKey(person);
        return block[key];
    }
    return block;
}

export function choosePersInf<T>(x: T.FullForm<T>, persInf: T.PersonInflectionsField): T.SingleOrLengthOpts<T> {
    if ("mascSing" in x) {
        return x[persInf];
    }
    return x;
} 

export function allOnePersonVerbForm(block: T.VerbForm, person: T.Person): T.VerbForm {
    if ("mascSing" in block) {
        return {
            mascSing: allOnePersonVerbForm(block.mascSing, person) as T.SingleOrLengthOpts<T.VerbBlock>,
            mascPlur: allOnePersonVerbForm(block.mascPlur, person) as T.SingleOrLengthOpts<T.VerbBlock>,
            femSing: allOnePersonVerbForm(block.femSing, person) as T.SingleOrLengthOpts<T.VerbBlock>,
            femPlur: allOnePersonVerbForm(block.femPlur, person) as T.SingleOrLengthOpts<T.VerbBlock>,
        };
    }
    if ("long" in block) {
        return {
            long: allOnePersonVerbForm(block.long, person) as T.VerbBlock,
            short: allOnePersonVerbForm(block.short, person) as T.VerbBlock,
            ...block.mini ? {
                mini: allOnePersonVerbForm(block.mini, person) as T.VerbBlock,
            } : {},
        };
    }
    const [row, col] = getBlockRowCol(person)
    const p = block[row][col];
    return [
        [p, p],
        [p, p],
        [p, p],
        [p, p],
        [p, p],
        [p, p],
    ];
}

/**
 * Returns a set of inflections that are all masculine plural
 * (for conjugating the past participle of gramatically transitive verbs)
 * 
 * @param inflections 
 */
export function allMascFirstInflection(inflections: T.SingleOrLengthOpts<T.UnisexInflections>): T.SingleOrLengthOpts<T.UnisexInflections> {
    if ("long" in inflections) {
        return {
            long: allMascFirstInflection(inflections.long) as T.UnisexInflections,
            short: allMascFirstInflection(inflections.short) as T.UnisexInflections,
        };
    }
    const mp = inflections.masc[1];
    return {
        masc: [
            mp,
            mp,
            mp,
        ],
        fem: [
            mp,
            mp,
            mp,
        ],
    };
}

export function complementInflects(inf: T.UnisexInflections): boolean {
    return (
        (inf.masc[0][0].p !== inf.masc[2][0].p)
        ||
        (inf.fem[0][0].p !== inf.fem[1][0].p)
        ||
        (inf.masc[0][0].p !== inf.fem[0][0].p)
    );
    // OR MORE THOROUGH?
    // const fm = inf.masc[0][0];
    // return !(
    //     psStringEquals(inf.masc[1][0], fm) &&
    //     psStringEquals(inf.masc[2][0], fm) &&
    //     psStringEquals(inf.fem[1][0], fm) &&
    //     psStringEquals(inf.fem[2][0], fm)
    // );
}

export function psStringEquals(ps1: T.PsString, ps2: T.PsString): boolean {
    return (ps1.p === ps2.p) && (ps1.f === ps2.f);
}

export function removeRetroflexR(ps: T.PsString): T.PsString {
    return {
        p: ps.p.replace("ړ", ""),
        f: ps.f.replace("R", ""),
    };
}

export function inflectYey(ps: T.SingleOrLengthOpts<T.PsString>): T.SingleOrLengthOpts<T.UnisexInflections> {
    if ("long" in ps) {
        return {
            long: inflectYey(ps.long) as T.UnisexInflections,
            short: inflectYey(ps.short) as T.UnisexInflections,
        }
    }
    return inflectRegularYeyUnisex(ps.p, ps.f);
}

export function clamp(s: string, chars: number): string {
    return `${s.slice(0, 20)}${s.length > 20 ? "..." : ""}`;
}

export function addEnglish(
    english: T.EnglishBlock | string,
    ps: T.VerbBlock | T.ImperativeBlock | T.ArrayOneOrMore<T.PsString>,
) {
    if (Array.isArray(ps[0]) && ps.length === 6) {
        return mapVerbBlock((psString, i, j) => ({
            ...psString,
            // @ts-ignore
            e: typeof english === "string" ? english : english[i][j],
        }), ps as T.VerbBlock)
    }
    if (Array.isArray(ps[0]) && ps.length === 2) {
        return mapImperativeBlock((psString, i, j) => ({
            ...psString,
            // @ts-ignore
            e: typeof english === "string" ? english : english[i][j],
        }), ps as T.ImperativeBlock)
    }
    const line = ps as T.ArrayOneOrMore<T.PsString>;
    return line.map((psString) => (
        { ...psString, e: typeof english === "string" ? english : english[0][0] }
    ));
}

export function beginsWithDirectionalPronoun(ps: T.PsString): boolean {
    const beginning = ps.p.slice(0, 2);
    return ["را", "در", "ور"].includes(beginning);
}

export function checkForOoPrefix(ps: T.PsString): boolean {
    return ps.p[0] === "و" && ["oo", "óo"].includes(ps.f.slice(0, 2));
}

export function startsWithBa(ps: T.PsString): boolean {
    return (ps.p.slice(0, 3) === "به " && ps.f.slice(0, 3) === "ba ");
}

/**
 * Removes a given head from a verb form, returning just the second half of the split
 * It keeps به in front if there is a به at the beginning of the form
 * 
 * @param head - the first part of a verb split
 * @param ps - the whole verb form that needs the head removed
 */
export function removeHead(head: T.PsString, ps: T.PsString): T.PsString {
    const hasBa = startsWithBa(ps);
    const base = hasBa ? psRemove(ps, concatPsString(baParticle, " ")) : ps;
    const chopped = {
        p: base.p.slice(head.p.length),
        f: base.f.slice(head.f.length),
    };
    return hasBa
        ? concatPsString(baParticle, " ", chopped)
        : chopped;
}

export function uniquePsStringArray(arr: T.PsString[]): T.PsString[] {
    return [
        // @ts-ignore
        ...new Set(arr.map((o) => JSON.stringify(o))),
    ].map((string) => JSON.parse(string)) as T.PsString[];
}

export function splitOffLeapfrogWord(ps: T.PsString): [T.PsString, T.PsString] {
    const pWords = ps.p.split(" ");
    const fWords = ps.f.split(" ");
    const beginning = makePsString(
        pWords.slice(0, -1).join(" "),
        fWords.slice(0, -1).join(" "),
    );
    const end = makePsString(
        pWords.slice(-1).join(" "),
        fWords.slice(-1).join(" "),
    );
    return [beginning, end];
}

export function removeObjComp(comp: T.PsString | undefined, ps: T.PsString): T.PsString {
    if (!comp) {
        return ps;
    }
    return makePsString(
        ps.p.replace(comp.p + " ", ""),
        ps.f.replace(comp.f + " ", ""),
    );
}

export function psStringContains(ps: T.PsString, searchFor: T.PsString): boolean {
    return (
        ps.p.includes(searchFor.p)
        &&
        ps.f.includes(searchFor.f)
    );
}

export function removeStartingTick(f: string): string {
    if (f[0] === "`") {
        return f.slice(1);
    }
    return f;
}

export function ensureShortWurShwaShift(ps: T.PsString): T.PsString {
    if (ps.p.slice(-2) === "وړ" && ps.f.slice(-2) === "wR") {
        return {
            p: ps.p,
            f: ps.f.slice(0, -2) + "wuR", 
        };
    }
    return ps;
}

export function ensureUnisexInflections(infs: T.Inflections | false, w: T.DictionaryEntry): T.UnisexInflections {
    const ps = { p: w.p, f: firstPhonetics(w.f) };
    if (infs === false) {
        return {
            masc: [
                [ps],
                [ps],
                [ps],
            ],
            fem: [
                [ps],
                [ps],
                [ps],
            ],
        };
    }
    if (!("fem" in infs)) {
        return {
            ...infs,
            fem: [[ps], [ps], [ps]],
        };
    }
    if (!("masc" in infs)) {
        return {
            ...infs,
            masc: [[ps], [ps], [ps]],
        };
    }
    return infs;
}