import { Enum, type EnumItem } from "@keybr/lang";
import { type CodePoint, toCodePoints } from "@keybr/unicode";

export class Language implements EnumItem {
  static readonly AR = new Language(
    /* id= */ "ar",
    /* script= */ "arabic",
    /* direction= */ "rtl",
    /* alphabet= */ "ابجدهوزحطيكلمنسعفصقرشتثخذضظغ",
  );
  static readonly BE = new Language(
    /* id= */ "be",
    /* script= */ "cyrillic",
    /* direction= */ "ltr",
    /* alphabet= */ "абвгдежзійклмнопрстуўфхцчшыьэюя",
  );
  static readonly BR = new Language(
    /* id= */ "br",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aàâbchdeêfghijklmnñoôprstuüûùvwyz’", // TODO Add ligature "c’h".
  );
  static readonly CS = new Language(
    /* id= */ "cs",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aábcčdďeéěfghiíjklmnňoóprřsštťuúůvxyýzž",
  );
  static readonly DA = new Language(
    /* id= */ "da",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcdefghijklmnopqrstuvwxyzæøå",
  );
  static readonly DE = new Language(
    /* id= */ "de",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aäbcdefghijklmnoöpqrstuüvwxyzß",
  );
  static readonly EL = new Language(
    /* id= */ "el",
    /* script= */ "greek",
    /* direction= */ "ltr",
    /* alphabet= */ "αάβγδεέζηήθιίκλμνξοόπρσςτυύφχψωώ",
  );
  static readonly EN = new Language(
    /* id= */ "en",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcdefghijklmnopqrstuvwxyz",
  );
  static readonly EN_GB = new Language(
    /* id= */ "en-GB",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcdefghijklmnopqrstuvwxyz",
  );
  static readonly ES = new Language(
    /* id= */ "es",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aábcdeéfghiíjlmnñoópqrstuúvxyz",
  );
  static readonly ET = new Language(
    /* id= */ "et",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abdefghijklmnoprstuvõäöüš",
  );
  static readonly FA = new Language(
    /* id= */ "fa",
    /* script= */ "arabic",
    /* direction= */ "rtl",
    /* alphabet= */ "ابپتثجچحخدذرزژسشصضطظعغفقکگلمنوهی",
  );
  static readonly FI = new Language(
    /* id= */ "fi",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abdefghijklmnoprstuvyäö",
  );
  static readonly FR = new Language(
    /* id= */ "fr",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcçdeéèfghijlmnopqrstuvxyz",
  );
  static readonly HE = new Language(
    /* id= */ "he",
    /* script= */ "hebrew",
    /* direction= */ "rtl",
    /* alphabet= */ "אבגדהוזחטיכךלמםנןסעפףצץקרשת",
  );
  static readonly HR = new Language(
    /* id= */ "hr",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcćčdđefghijklmnoprsštuvzž",
  );
  static readonly HU = new Language(
    /* id= */ "hu",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aábcdeéfghiíjklmnoóöőpqrstuúüűvwxyz",
  );
  static readonly IT = new Language(
    /* id= */ "it",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcdefghijklmnopqrstuvwxyz",
  );
  static readonly JA = new Language(
    /* id= */ "ja",
    /* script= */ "hiragana",
    /* direction= */ "ltr",
    /* alphabet= */ "あいうえおかきくけこさしすせそたちつてとなにぬねのはひふへほまみむめもやゆよらりるれろわをんがぎぐげござじずぜぞだぢづでどばびぶべぼぱぴぷぺぽぁぃぇぉゃゅょっー",
  );
  static readonly LT = new Language(
    /* id= */ "lt",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aąbcčdeęėfghiįyjklmnoprsštuųūvzž",
  );
  static readonly LV = new Language(
    /* id= */ "lv",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aābcčdeēfgģhiījkķlļmnņoprsštuūvzž",
  );
  static readonly NB = new Language(
    /* id= */ "nb",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcdefghijklmnoprstuvwyæøå",
  );
  static readonly NL = new Language(
    /* id= */ "nl",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcdefghijklmnopqrstuvwxyz",
  );
  static readonly PL = new Language(
    /* id= */ "pl",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aąbcćdeęfghijklłmnńoóprsśtuwyzźż",
  );
  static readonly PT = new Language(
    /* id= */ "pt",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aáâãàbcçdeéêfghiíjlmnoóôõpqrstuúvxz",
  );
  static readonly RO = new Language(
    /* id= */ "ro",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aăâbcdefghiîjlmnoprsștțuvxz",
  );
  static readonly RU = new Language(
    /* id= */ "ru",
    /* script= */ "cyrillic",
    /* direction= */ "ltr",
    /* alphabet= */ "абвгдежзийклмнопрстуфхцчшщъыьэюя",
  );
  static readonly SL = new Language(
    /* id= */ "sl",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcčdefghijklmnoprsštuvzž",
  );
  static readonly SV = new Language(
    /* id= */ "sv",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcdefghijklmnoprstuvwxyåäö",
  );
  static readonly TH = new Language(
    /* id= */ "th",
    /* script= */ "thai",
    /* direction= */ "ltr",
    /* alphabet= */ "กขคฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลวศษสหฬอฮฯะัาำิีึืุูเแโใไๅ็่้๊๋์",
  );
  static readonly TR = new Language(
    /* id= */ "tr",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "abcçdefgğhıijklmnoöprsştuüvyz",
  );
  static readonly UK = new Language(
    /* id= */ "uk",
    /* script= */ "cyrillic",
    /* direction= */ "ltr",
    /* alphabet= */ "абвгґдеєжзиіїйклмнопрстуфхцчшщьюя",
  );
  static readonly VI = new Language(
    /* id= */ "vi",
    /* script= */ "latin",
    /* direction= */ "ltr",
    /* alphabet= */ "aáàảãạăắằẳẵặâấầẩẫậbcdđeéèẻẽẹêếềểễệghiíìỉĩịklmnoóòỏõọôốồổỗộơớờởỡợpqrstuúùủũụưứừửữựvxyýỳỷỹỵ",
  );

  static readonly ALL = new Enum<Language>(
    Language.AR,
    Language.BE,
    Language.BR,
    Language.CS,
    Language.DA,
    Language.DE,
    Language.EL,
    Language.EN,
    Language.EN_GB,
    Language.ES,
    Language.ET,
    Language.FA,
    Language.FI,
    Language.FR,
    Language.HE,
    Language.HR,
    Language.HU,
    Language.IT,
    // Language.JA,
    Language.LT,
    Language.LV,
    Language.NB,
    Language.NL,
    Language.PL,
    Language.PT,
    Language.RO,
    Language.RU,
    Language.SL,
    Language.SV,
    Language.TH,
    Language.TR,
    Language.UK,
    Language.VI,
  );

  /** ISO 639-1 language code, https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes */
  readonly id: string;
  /** The writing system, such as Cyrillic, Georgian, Greek, Hebrew, Latin, Thai, etc. */
  readonly script:
    | "arabic"
    | "cyrillic"
    | "greek"
    | "hebrew"
    | "hiragana"
    | "latin"
    | "thai";
  /** The direction of the writing system, either "ltr" for left-to-right, or "rtl" for right-to-left. */
  readonly direction: "ltr" | "rtl";
  /** The list of alphabet code points. */
  readonly alphabet: readonly CodePoint[];
  /** The locale. */
  readonly locale: Intl.Locale;
  /** The collator for sorting strings. */
  readonly collator: Intl.Collator;
  /** A locale-sensitive string comparison function. */
  readonly compare: (a: string, b: string) => number;
  /** A locale-sensitive string uppercase function. */
  readonly upperCase: (v: string) => string;
  /** A locale-sensitive string lowercase function. */
  readonly lowerCase: (v: string) => string;
  /** A locale-sensitive string capitalize function. */
  readonly capitalCase: (v: string) => string;

  private constructor(
    id: string,
    script:
      | "arabic"
      | "cyrillic"
      | "greek"
      | "hebrew"
      | "hiragana"
      | "latin"
      | "thai",
    direction: "ltr" | "rtl",
    alphabet: string,
  ) {
    const locale = new Intl.Locale(id).maximize();
    const collator = new Intl.Collator(locale);
    this.id = id;
    this.script = script;
    this.direction = direction;
    this.alphabet = Object.freeze([...toCodePoints(alphabet)]);
    this.locale = locale;
    this.collator = collator;
    this.compare = (a, b) => collator.compare(a, b);
    this.upperCase = (v) => v.toLocaleUpperCase(locale);
    this.lowerCase = (v) => v.toLocaleLowerCase(locale);
    this.capitalCase = (v) =>
      v.substring(0, 1).toLocaleUpperCase(locale) +
      v.substring(1).toLocaleLowerCase(locale);
    Object.freeze(this);
  }

  /**
   * Checks whether the given string is composed only of the language letters,
   * case-insensitive.
   */
  test = (v: string): boolean => {
    for (const codePoint of toCodePoints(this.lowerCase(v))) {
      if (!this.alphabet.includes(codePoint)) {
        return false;
      }
    }
    return true;
  };

  letterName = (codePoint: CodePoint): string => {
    if (codePoint === /* "ß" */ 0x00df) {
      // German uppercase letter Eszett.
      return "ẞ";
    }
    if (codePoint >= 0x0590 && codePoint <= 0x05ff) {
      // Hebrew Unicode block.
      // There are no lower or uppercase letters in the Hebrew script.
      return String.fromCodePoint(codePoint);
    }
    if (codePoint >= 0x0600 && codePoint <= 0x06ff) {
      // Arabic Unicode block.
      // There are no lower or uppercase letters in the Arabic script.
      // Arabic script is cursive, which means that the letters
      // change shape when joined together.
      // Here we break letters apart by prepending them with
      // the Zero Width Non-Joiner character.
      return String.fromCodePoint(
        /* ZERO WIDTH NON-JOINER */ 0x200c,
        codePoint,
      );
    }
    if (codePoint >= 0x0e00 && codePoint <= 0x0e7f) {
      // Thai Unicode block.
      if (
        codePoint === 0x0e31 ||
        (codePoint >= 0x0e34 && codePoint <= 0x0e3a) ||
        (codePoint >= 0x0e47 && codePoint <= 0x0e4e)
      ) {
        // Thai combining marks.
        return String.fromCodePoint(/* DOTTED CIRCLE */ 0x25cc, codePoint);
      }
    }
    // Locale-specific uppercase variant of a letter.
    // For example in Turkish there are dotted and dotless letter I,
    // each with its own lower and uppercase variant.
    return this.upperCase(String.fromCodePoint(codePoint));
  };

  /**
   * Returns a value indicating whether the given code point
   * can be a letter of this language.
   */
  includes(codePoint: CodePoint): boolean {
    // We consider these Unicode ranges to contain letters only in a given script.
    // The ranges were manually built from Unicode tables and may not be accurate.
    switch (this.script) {
      case "arabic":
        return codePoint >= 0x0600 && codePoint <= 0x06ff;
      case "cyrillic":
        return codePoint >= 0x0400 && codePoint <= 0x04ff;
      case "greek":
        return codePoint >= 0x0370 && codePoint <= 0x03ff;
      case "hebrew":
        return codePoint >= 0x0590 && codePoint <= 0x05ff;
      case "latin":
        // A few Unicode blocks of the Latin script to include only
        // a reasonable list of letter codepoints.
        return (
          (codePoint >= /* "A" */ 0x0041 && codePoint <= /* "Z" */ 0x005a) ||
          (codePoint >= /* "a" */ 0x0061 && codePoint <= /* "z" */ 0x007a) ||
          (codePoint >= /* "À" */ 0x00c0 && codePoint <= /* "Ö" */ 0x00d6) ||
          (codePoint >= /* "Ø" */ 0x00d8 && codePoint <= /* "ö" */ 0x00f6) ||
          (codePoint >= /* "ø" */ 0x00f8 && codePoint <= /* "ÿ" */ 0x00ff) ||
          (codePoint >= /* "Ā" */ 0x0100 && codePoint <= /* "ſ" */ 0x017f) ||
          (codePoint >= /* "ƀ" */ 0x0180 && codePoint <= /* "ɏ" */ 0x024f)
        );
      case "thai":
        return codePoint >= 0x0e00 && codePoint <= 0x0e7f;
      default:
        return false;
    }
  }

  toString() {
    return this.id;
  }

  toJSON() {
    return this.id;
  }
}

export function getExampleText({ script }: Language): string {
  switch (script) {
    case "arabic":
      return "تناول المزيد من التفاح والبرتقال.";
    case "cyrillic":
      return "Яжте повече ябълки и портокали.";
    case "greek":
      return "Τρώτε περισσότερα μήλα και πορτοκάλια.";
    case "hebrew":
      return "תאכל יותר תפוחים ותפוזים.";
    case "hiragana":
      return "リンゴとオレンジをもっと食べましょう。";
    case "latin":
      return "Eat more apples and oranges.";
    case "thai":
      return "กินส้มกับแอปเปิลเยอะ ๆ";
  }
}

export function getExampleLetters({ script }: Language): CodePoint[] {
  switch (script) {
    case "arabic":
      return [0x0627, 0x0628, 0x067e, 0x062a, 0x062b, 0x062c];
    case "cyrillic":
      return [0x0430, 0x0431, 0x0432, 0x0433, 0x0434, 0x0435];
    case "greek":
      return [0x03b1, 0x03b2, 0x03b3, 0x03b4, 0x03b5, 0x03b6];
    case "hebrew":
      return [0x05d0, 0x05d1, 0x05d2, 0x05d3, 0x05d4, 0x05d5];
    case "hiragana":
      return [0x3041, 0x3043, 0x3045, 0x3047, 0x3049, 0x304b];
    case "latin":
      return [0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066];
    case "thai":
      return [0x0e01, 0x0e02, 0x0e04, 0x0e06, 0x0e07, 0x0e08];
  }
}