const rootEndingPair = (str) => ({root: str.slice(0, -1), ending: str.slice(-1)});

type SaimiarDeclension = {
    abs: string;
    erg: string;
    adp: string;
    all: string;
    loc: string;
    ell: string;
    inst: string;
    rel: string;
};

function declineSaimiar(entry): SaimiarDeclension {
    const split = entry.sai.split(" ");
    const sai = split.at(-1);
    const morph = entry.morph_type;

    if (morph === "-V") {
        return vowelDeclension(sai);
    }

    if (morph === "-a/i") {
        return aiDeclension(sai);
    }

    if (morph === "e-") {
        return initalDeclension(sai);
    }

    if (morph === "-C") {
        return consonantDeclension(sai);
    }

    console.warn(`Can't decline entry '${entry.sai}'`);
    console.log(entry);
    return null;
}

function vowelDeclension(sai: string): SaimiarDeclension {
    const {root, ending} = rootEndingPair(sai);
    const adpEnding = ending === "u" ? "ys" : `${ending}s`;

    return {
        abs: `${root}${ending}`,
        erg: `${root}${ending}na`,
        adp: `${root}${adpEnding}`,
        all: `so${root}${adpEnding}`,
        loc: `${root}${ending}xa`,
        ell: `tlê${root}${adpEnding}`,
        inst: `${root}${ending}ŕa`,
        rel: `${root}${ending}źi`,
    };
}

function aiDeclension(sai: string): SaimiarDeclension {
    const {root, ending} = rootEndingPair(sai);
    return {
        abs: `${root}${ending}`,
        erg: `${root}iad`,
        adp: `${root}i`,
        all: `so${root}i`,
        loc: `${root}iath`,
        ell: `tlê${root}i`,
        inst: `${root}iar`,
        rel: `${root}iai`,
    };
}

function consonantDeclension(sai: string): SaimiarDeclension {
    const split = rootEndingPair(sai);
    const root = split.ending === "ø" ? split.root : sai;
    const absFinal = split.ending === "ø" ? "ø" : "";

    return {
        abs: `${root}${absFinal}`,
        erg: `${root}ad`,
        adp: `${root}e`,
        all: `so${root}i`,
        loc: `${root}ak`,
        ell: `tlê${root}i`,
        inst: `${root}ar`,
        rel: `${root}ai`,
    };
}

const vowels = ["a", "e", "ê", "i", "o", "ô", "u", "y"];

function initalDeclension(sai: string): SaimiarDeclension {
    const initial = sai.slice(0, 1);
    const root = sai.slice(1);

    const finalRootSound = root.slice(-1);
    const finalVowel = vowels.includes(finalRootSound);
    const instEnding = finalVowel ? "ŕø" : "ar";
    const relEnding = finalVowel ? "źi" : "ai";

    return {
        abs: `${initial}${root}`,
        erg: `da${root}`,
        adp: `i${root}`,
        all: `so${root}`,
        loc: `xa${root}`,
        ell: `tlê${root}`,
        inst: `i${root}${instEnding}`,
        rel: `${initial}${root}${relEnding}`,
    };
}

export {declineSaimiar, SaimiarDeclension};