kotlin-pluralizer/library/src/main/java/com/cesarferreira/pluralize/Pluralize.kt

package com.cesarferreira.pluralize

import com.cesarferreira.pluralize.utils.Plurality
import java.util.regex.Pattern


fun String.pluralize(plurality: Plurality = Plurality.Singular): String {
    if (plurality == Plurality.Plural) return this

    if (plurality == Plurality.Singular)
        return this.pluralizer()

    if (this.singularizer() != this && this.singularizer() + "s" != this &&
            this.singularizer().pluralizer() == this && this.pluralizer() != this)
        return this

    return this.pluralizer()
}

fun String.singularize(plurality: Plurality = Plurality.Plural): String {

    if (plurality == Plurality.Singular) return this

    if (plurality == Plurality.Plural) return this.singularizer()

    if (this.pluralizer() != this && this + "s" != this.pluralizer() &&
            this.pluralizer().singularize() == this && this.singularizer() != this)
        return this;

    return this.singularize()
}

private fun String.pluralizer(): String {
    if (unCountable().contains(this)) return this
    val rule = pluralizeRules().last { Pattern.compile(it.component1(), Pattern.CASE_INSENSITIVE).matcher(this).find() }
    var found = Pattern.compile(rule.component1(), Pattern.CASE_INSENSITIVE).matcher(this).replaceAll(rule.component2())
    val endswith = exceptions().firstOrNull { this.endsWith(it.component1()) }
    if (endswith != null) found = this.replace(endswith.component1(), endswith.component2())
    val excep = exceptions().firstOrNull() { this.equals(it.component1()) }
    if (excep != null) found = excep.component2()
    return found
}

private fun String.singularizer(): String {
    if (unCountable().contains(this)) {
        return this
    }
    val excepions = exceptions().firstOrNull() { this.equals(it.component2()) }

    if (excepions != null) {
        return excepions.component1()
    }
    val endswith = exceptions().firstOrNull { this.endsWith(it.component2()) }

    if (endswith != null) return this.replace(endswith.component2(), endswith.component1())

    try {
        if (singularizeRules().count {
            Pattern.compile(it.component1(), Pattern.CASE_INSENSITIVE).matcher(this).find()
        } == 0) return this
        val rule = singularizeRules().last {
            Pattern.compile(it.component1(), Pattern.CASE_INSENSITIVE).matcher(this).find()
        }
        return Pattern.compile(rule.component1(), Pattern.CASE_INSENSITIVE).matcher(this).replaceAll(rule.component2())
    } catch(ex: IllegalArgumentException) {
        Exception("Can't singularize this word, could not find a rule to match.")
    }
    return this
}

fun unCountable(): List<String> {
    return listOf("equipment", "information", "rice", "money",
            "species", "series", "fish", "sheep", "aircraft", "bison",
            "flounder", "pliers", "bream",
            "gallows", "proceedings", "breeches", "graffiti", "rabies",
            "britches", "headquarters", "salmon", "carp", "herpes",
            "scissors", "chassis", "high-jinks", "sea-bass", "clippers",
            "homework", "cod", "innings", "shears",
            "contretemps", "jackanapes", "corps", "mackerel",
            "swine", "debris", "measles", "trout", "diabetes", "mews",
            "tuna", "djinn", "mumps", "whiting", "eland", "news",
            "wildebeest", "elk", "pincers", "sugar")
}

fun exceptions(): List<Pair<String, String>> {
    return listOf("person" to "people",
            "man" to "men",
            "goose" to "geese",
            "child" to "children",
            "sex" to "sexes",
            "move" to "moves",
            "stadium" to "stadiums",
            "deer" to "deer",
            "codex" to "codices",
            "murex" to "murices",
            "silex" to "silices",
            "radix" to "radices",
            "helix" to "helices",
            "alumna" to "alumnae",
            "alga" to "algae",
            "vertebra" to "vertebrae",
            "persona" to "personae",
            "stamen" to "stamina",
            "foramen" to "foramina",
            "lumen" to "lumina",
            "afreet" to "afreeti",
            "afrit" to "afriti",
            "efreet" to "efreeti",
            "cherub" to "cherubim",
            "goy" to "goyim",
            "human" to "humans",
            "lumen" to "lumina",
            "seraph" to "seraphim",
            "Alabaman" to "Alabamans",
            "Bahaman" to "Bahamans",
            "Burman" to "Burmans",
            "German" to "Germans",
            "Hiroshiman" to "Hiroshimans",
            "Liman" to "Limans",
            "Nakayaman" to "Nakayamans",
            "Oklahoman" to "Oklahomans",
            "Panaman" to "Panamans",
            "Selman" to "Selmans",
            "Sonaman" to "Sonamans",
            "Tacoman" to "Tacomans",
            "Yakiman" to "Yakimans",
            "Yokohaman" to "Yokohamans",
            "Yuman" to "Yumans", "criterion" to "criteria",
            "perihelion" to "perihelia",
            "aphelion" to "aphelia",
            "phenomenon" to "phenomena",
            "prolegomenon" to "prolegomena",
            "noumenon" to "noumena",
            "organon" to "organa",
            "asyndeton" to "asyndeta",
            "hyperbaton" to "hyperbata")
}

fun pluralizeRules(): List<Pair<String, String>> {
    return listOf(
            "$" to "s",
            "s$" to "s",
            "(ax|test)is$" to "$1es",
            "us$" to "i",
            "(octop|vir)us$" to "$1i",
            "(octop|vir)i$" to "$1i",
            "(alias|status)$" to "$1es",
            "(bu)s$" to "$1ses",
            "(buffal|tomat)o$" to "$1oes",
            "([ti])um$" to "$1a",
            "([ti])a$" to "$1a",
            "sis$" to "ses",
            "(,:([^f])fe|([lr])f)$" to "$1$2ves",
            "(hive)$" to "$1s",
            "([^aeiouy]|qu)y$" to "$1ies",
            "(x|ch|ss|sh)$" to "$1es",
            "(matr|vert|ind)ix|ex$" to "$1ices",
            "([m|l])ouse$" to "$1ice",
            "([m|l])ice$" to "$1ice",
            "^(ox)$" to "$1en",
            "(quiz)$" to "$1zes",
            "f$" to "ves",
            "fe$" to "ves",
            "um$" to "a",
            "on$" to "a")
}

fun singularizeRules(): List<Pair<String, String>> {
    return listOf(
            "s$" to "",
            "(s|si|u)s$" to "$1s",
            "(n)ews$" to "$1ews",
            "([ti])a$" to "$1um",
            "((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$" to "$1$2sis",
            "(^analy)ses$" to "$1sis",
            "(^analy)sis$" to "$1sis",
            "([^f])ves$" to "$1fe",
            "(hive)s$" to "$1",
            "(tive)s$" to "$1",
            "([lr])ves$" to "$1f",
            "([^aeiouy]|qu)ies$" to "$1y",
            "(s)eries$" to "$1eries",
            "(m)ovies$" to "$1ovie",
            "(x|ch|ss|sh)es$" to "$1",
            "([m|l])ice$" to "$1ouse",
            "(bus)es$" to "$1",
            "(o)es$" to "$1",
            "(shoe)s$" to "$1",
            "(cris|ax|test)is$" to "$1is",
            "(cris|ax|test)es$" to "$1is",
            "(octop|vir)i$" to "$1us",
            "(octop|vir)us$" to "$1us",
            "(alias|status)es$" to "$1",
            "(alias|status)$" to "$1",
            "^(ox)en" to "$1",
            "(vert|ind)ices$" to "$1ex",
            "(matr)ices$" to "$1ix",
            "(quiz)zes$" to "$1",
            "a$" to "um",
            "i$" to "us",
            "ae$" to "a")
}