using Cryville.Common.Culture;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Cryville.Common.Font {
	public abstract class FontMatcher {
		protected FontManager Manager { get; private set; }
		public FontMatcher(FontManager manafer) { Manager = manafer; }
		public abstract IEnumerable<Typeface> MatchScript(string script = null, bool distinctFamily = false);
	}
	public class FallbackListFontMatcher : FontMatcher {
		public Dictionary<string, List<string>> MapScriptToTypefaces = new Dictionary<string, List<string>>();
		public void LoadDefaultWindowsFallbackList() {
			if (Environment.OSVersion.Platform != PlatformID.Win32NT) return;
			MapScriptToTypefaces.Clear();
			ScriptUtils.FillKeysWithScripts(MapScriptToTypefaces, () => new List<string>());
			// Reference: https://github.com/chromium/chromium/blob/main/third_party/blink/renderer/platform/fonts/win/font_fallback_win.cc
			MapScriptToTypefaces["zyyy"].Insert(0, "SimSun"); // Custom
			MapScriptToTypefaces["zyyy"].Insert(0, "SimHei"); // Custom
			MapScriptToTypefaces["zyyy"].Insert(0, "Microsoft YaHei"); // Custom
			MapScriptToTypefaces["zyyy"].Insert(0, "Arial");
			MapScriptToTypefaces["zyyy"].Insert(0, "Times New Roman");
			MapScriptToTypefaces["zyyy"].Insert(0, "Segoe UI"); // Custom
			MapScriptToTypefaces["arab"].Insert(0, "Tahoma");
			MapScriptToTypefaces["cyrl"].Insert(0, "Times New Roman");
			MapScriptToTypefaces["grek"].Insert(0, "Times New Roman");
			MapScriptToTypefaces["hebr"].Insert(0, "David");
			MapScriptToTypefaces["jpan"].Insert(0, "MS PGothic");
			MapScriptToTypefaces["latn"].Insert(0, "Times New Roman");
			MapScriptToTypefaces["hans"].Insert(0, "SimSun");
			MapScriptToTypefaces["hans"].Insert(0, "SimHei"); // Custom
			MapScriptToTypefaces["thai"].Insert(0, "Tahoma");
			MapScriptToTypefaces["hans"].Insert(0, "PMingLiU");
			// Reference: https://learn.microsoft.com/en-us/globalization/input/font-support
			var ver = Environment.OSVersion.Version;
			if (ver >= new Version(5, 0)) { // Windows 2000
				MapScriptToTypefaces["armn"].Insert(0, "Sylfaen");
				MapScriptToTypefaces["deva"].Insert(0, "Mangal");
				MapScriptToTypefaces["geor"].Insert(0, "Sylfaen");
				MapScriptToTypefaces["taml"].Insert(0, "Latha");
			}
			if (ver >= new Version(5, 1)) { // Windows XP
				MapScriptToTypefaces["gujr"].Insert(0, "Shruti");
				MapScriptToTypefaces["guru"].Insert(0, "Raavi");
				MapScriptToTypefaces["knda"].Insert(0, "Tunga");
				MapScriptToTypefaces["syrc"].Insert(0, "Estrangelo Edessa");
				MapScriptToTypefaces["telu"].Insert(0, "Gautami");
				MapScriptToTypefaces["thaa"].Insert(0, "MV Boli");
				// SP2
				MapScriptToTypefaces["beng"].Insert(0, "Vrinda");
				MapScriptToTypefaces["mlym"].Insert(0, "Kartika");
			}
			if (ver >= new Version(6, 0)) { // Windows Vista
				MapScriptToTypefaces["cans"].Insert(0, "Euphemia");
				MapScriptToTypefaces["cher"].Insert(0, "Plantagenet");
				MapScriptToTypefaces["ethi"].Insert(0, "Nyala");
				MapScriptToTypefaces["khmr"].Insert(0, "DaunPenh MoolBoran");
				MapScriptToTypefaces["laoo"].Insert(0, "DokChampa");
				MapScriptToTypefaces["mong"].Insert(0, "Mongolian Baiti");
				MapScriptToTypefaces["orya"].Insert(0, "Kalinga");
				MapScriptToTypefaces["sinh"].Insert(0, "Iskoola Pota");
				MapScriptToTypefaces["tibt"].Insert(0, "Microsoft Himalaya");
				MapScriptToTypefaces["yiii"].Insert(0, "Microsoft Yi Baiti");
				MapScriptToTypefaces["arab"].Insert(0, "Segoe UI");
				MapScriptToTypefaces["cyrl"].Insert(0, "Segoe UI");
				MapScriptToTypefaces["grek"].Insert(0, "Segoe UI");
				MapScriptToTypefaces["latn"].Insert(0, "Segoe UI");
				MapScriptToTypefaces["hans"].Add("SimSun-ExtB");
				MapScriptToTypefaces["hant"].Add("MingLiU-ExtB");
				MapScriptToTypefaces["hant"].Add("MingLiU_HKSCS-ExtB");
				MapScriptToTypefaces["arab"].Add("Microsoft Uighur");
				MapScriptToTypefaces["zmth"].Insert(0, "Cambria Math");
				// Reference: https://en.wikipedia.org/wiki/List_of_CJK_fonts
				MapScriptToTypefaces["jpan"].Insert(0, "Meiryo");
				MapScriptToTypefaces["hans"].Insert(0, "Microsoft YaHei");
			}
			if (ver >= new Version(6, 1)) { // Windows 7
				MapScriptToTypefaces["brai"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["dsrt"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["talu"].Insert(0, "Microsoft New Tai Lue");
				MapScriptToTypefaces["ogam"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["osma"].Insert(0, "Ebrima");
				MapScriptToTypefaces["phag"].Insert(0, "Microsoft PhagsPa");
				MapScriptToTypefaces["runr"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["zsym"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["tale"].Insert(0, "Microsoft Tai Le");
				MapScriptToTypefaces["tfng"].Insert(0, "Ebrima");
				MapScriptToTypefaces["vaii"].Insert(0, "Ebrima");
			}
			if (ver >= new Version(6, 2)) { // Windows 8
				MapScriptToTypefaces["glag"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["goth"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["hang"].Add("Malgun Gothic");
				MapScriptToTypefaces["ital"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["lisu"].Insert(0, "Segoe UI");
				MapScriptToTypefaces["mymr"].Insert(0, "Myanmar Text");
				MapScriptToTypefaces["nkoo"].Insert(0, "Ebrima");
				MapScriptToTypefaces["orkh"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["ethi"].Insert(0, "Ebrima");
				MapScriptToTypefaces["cans"].Insert(0, "Gadugi");
				MapScriptToTypefaces["hant"].Insert(0, "Microsoft JhengHei UI");
				MapScriptToTypefaces["hans"].Insert(0, "Microsoft YaHei UI");
				MapScriptToTypefaces["beng"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["deva"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["gujr"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["guru"].Insert(0, "Nirmala UI"); // NOT DOCUMENTED, UNVERIFIED
				MapScriptToTypefaces["knda"].Insert(0, "Nirmala UI"); // NOT DOCUMENTED, UNVERIFIED
				MapScriptToTypefaces["mlym"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["orya"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["sinh"].Insert(0, "Nirmala UI"); // NOT DOCUMENTED, UNVERIFIED
				MapScriptToTypefaces["taml"].Insert(0, "Nirmala UI"); // NOT DOCUMENTED, UNVERIFIED
				MapScriptToTypefaces["telu"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["armn"].Insert(0, "Segoe UI");
				MapScriptToTypefaces["geor"].Insert(0, "Segoe UI");
				MapScriptToTypefaces["hebr"].Insert(0, "Segoe UI");
			}
			if (ver >= new Version(6, 3)) { // Windows 8.1
				MapScriptToTypefaces["bugi"].Insert(0, "Leelawadee UI");
				MapScriptToTypefaces["copt"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["java"].Insert(0, "Javanese Text");
				MapScriptToTypefaces["merc"].Insert(0, "Segoe UI Symbol");
				MapScriptToTypefaces["olck"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["sora"].Insert(0, "Nirmala UI");
				MapScriptToTypefaces["khmr"].Insert(0, "Leelawadee UI");
				MapScriptToTypefaces["laoo"].Insert(0, "Leelawadee UI");
				MapScriptToTypefaces["thai"].Insert(0, "Leelawadee UI");
				MapScriptToTypefaces["zsye"].Insert(0, "Segoe UI Emoji");
			}
			if (ver >= new Version(10, 0)) { // Windows 10
				MapScriptToTypefaces["brah"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["cari"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["cprt"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["egyp"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["armi"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["phli"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["prti"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["khar"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["lyci"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["lydi"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["phnx"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["xpeo"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["sarb"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["shaw"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["xsux"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["ugar"].Insert(0, "Segoe UI Historic");
				// Segoe UI Symbol -> Segoe UI Historic
				MapScriptToTypefaces["glag"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["goth"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["merc"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["ogam"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["ital"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["orkh"].Insert(0, "Segoe UI Historic");
				MapScriptToTypefaces["runr"].Insert(0, "Segoe UI Historic");
				//
				MapScriptToTypefaces["jpan"].Insert(0, "Yu Gothic UI");
				MapScriptToTypefaces["zsym"].Add("Segoe MDL2 Assets");
			}
		}
		public void LoadDefaultAndroidFallbackList() {
			if (Environment.OSVersion.Platform != PlatformID.Unix) return;
			MapScriptToTypefaces.Clear();
			ScriptUtils.FillKeysWithScripts(MapScriptToTypefaces, () => new List<string>());
			MapScriptToTypefaces["zyyy"].Insert(0, "Noto Sans CJK TC"); // TODO Modify default fallback
			MapScriptToTypefaces["zyyy"].Insert(0, "Noto Sans CJK JP");
			MapScriptToTypefaces["zyyy"].Insert(0, "Noto Sans CJK SC");
			MapScriptToTypefaces["zyyy"].Insert(0, "Roboto");
			MapScriptToTypefaces["zsye"].Insert(0, "Noto Color Emoji");
			MapScriptToTypefaces["zsye"].Add("Noto Color Emoji Flags");
			MapScriptToTypefaces["arab"].Insert(0, "Noto Naskh Arabic");
			MapScriptToTypefaces["adlm"].Insert(0, "Noto Sans Adlam");
			MapScriptToTypefaces["ahom"].Insert(0, "Noto Sans Ahom");
			MapScriptToTypefaces["hluw"].Insert(0, "Noto Sans Anatolian Hieroglyphs");
			MapScriptToTypefaces["armn"].Insert(0, "Noto Sans Armenian");
			MapScriptToTypefaces["avst"].Insert(0, "Noto Sans Avestan");
			MapScriptToTypefaces["bali"].Insert(0, "Noto Sans Balinese");
			MapScriptToTypefaces["bamu"].Insert(0, "Noto Sans Bamum");
			MapScriptToTypefaces["bass"].Insert(0, "Noto Sans Bassa Vah");
			MapScriptToTypefaces["batk"].Insert(0, "Noto Sans Batak");
			MapScriptToTypefaces["beng"].Insert(0, "Noto Sans Bengali");
			MapScriptToTypefaces["bhks"].Insert(0, "Noto Sans Bhaiksuki");
			MapScriptToTypefaces["brah"].Insert(0, "Noto Sans Brahmi");
			MapScriptToTypefaces["bugi"].Insert(0, "Noto Sans Buginese");
			MapScriptToTypefaces["buhd"].Insert(0, "Noto Sans Buhid");
			MapScriptToTypefaces["jpan"].Insert(0, "Noto Sans CJK JP");
			MapScriptToTypefaces["kore"].Insert(0, "Noto Sans CJK KR");
			MapScriptToTypefaces["hans"].Insert(0, "Noto Sans CJK SC");
			MapScriptToTypefaces["hant"].Insert(0, "Noto Sans CJK TC");
			MapScriptToTypefaces["hant"].Add("Noto Sans CJK HK");
			MapScriptToTypefaces["cans"].Insert(0, "Noto Sans Canadian Aboriginal");
			MapScriptToTypefaces["cari"].Insert(0, "Noto Sans Carian");
			MapScriptToTypefaces["cakm"].Insert(0, "Noto Sans Chakma");
			MapScriptToTypefaces["cham"].Insert(0, "Noto Sans Cham");
			MapScriptToTypefaces["cher"].Insert(0, "Noto Sans Cherokee");
			MapScriptToTypefaces["copt"].Insert(0, "Noto Sans Coptic");
			MapScriptToTypefaces["xsux"].Insert(0, "Noto Sans Cuneiform");
			MapScriptToTypefaces["cprt"].Insert(0, "Noto Sans Cypriot");
			MapScriptToTypefaces["dsrt"].Insert(0, "Noto Sans Deseret");
			MapScriptToTypefaces["deva"].Insert(0, "Noto Sans Devanagari");
			MapScriptToTypefaces["egyp"].Insert(0, "Noto Sans Egyptian Hieroglyphs");
			MapScriptToTypefaces["elba"].Insert(0, "Noto Sans Elbasan");
			MapScriptToTypefaces["ethi"].Insert(0, "Noto Sans Ethiopic");
			MapScriptToTypefaces["geor"].Insert(0, "Noto Sans Georgian");
			MapScriptToTypefaces["glag"].Insert(0, "Noto Sans Glagolitic");
			MapScriptToTypefaces["goth"].Insert(0, "Noto Sans Gothic");
			MapScriptToTypefaces["gran"].Insert(0, "Noto Sans Grantha");
			MapScriptToTypefaces["gujr"].Insert(0, "Noto Sans Gujarati");
			MapScriptToTypefaces["gong"].Insert(0, "Noto Sans Gunjala Gondi");
			MapScriptToTypefaces["guru"].Insert(0, "Noto Sans Gurmukhi");
			MapScriptToTypefaces["rohg"].Insert(0, "Noto Sans Hanifi Rohingya");
			MapScriptToTypefaces["hano"].Insert(0, "Noto Sans Hanunoo");
			MapScriptToTypefaces["hatr"].Insert(0, "Noto Sans Hatran");
			MapScriptToTypefaces["hebr"].Insert(0, "Noto Sans Hebrew");
			MapScriptToTypefaces["armi"].Insert(0, "Noto Sans Imperial Aramaic");
			MapScriptToTypefaces["phli"].Insert(0, "Noto Sans Inscriptional Pahlavi");
			MapScriptToTypefaces["prti"].Insert(0, "Noto Sans Inscriptional Parthian");
			MapScriptToTypefaces["java"].Insert(0, "Noto Sans Javanese");
			MapScriptToTypefaces["kthi"].Insert(0, "Noto Sans Kaithi");
			MapScriptToTypefaces["knda"].Insert(0, "Noto Sans Kannada");
			MapScriptToTypefaces["kali"].Insert(0, "Noto Sans KayahLi");
			MapScriptToTypefaces["khar"].Insert(0, "Noto Sans Kharoshthi");
			MapScriptToTypefaces["khmr"].Insert(0, "Noto Sans Khmer");
			MapScriptToTypefaces["khoj"].Insert(0, "Noto Sans Khojki");
			MapScriptToTypefaces["laoo"].Insert(0, "Noto Sans Lao");
			MapScriptToTypefaces["lepc"].Insert(0, "Noto Sans Lepcha");
			MapScriptToTypefaces["limb"].Insert(0, "Noto Sans Limbu");
			MapScriptToTypefaces["lina"].Insert(0, "Noto Sans Linear A");
			MapScriptToTypefaces["linb"].Insert(0, "Noto Sans Linear B");
			MapScriptToTypefaces["lisu"].Insert(0, "Noto Sans Lisu");
			MapScriptToTypefaces["lyci"].Insert(0, "Noto Sans Lycian");
			MapScriptToTypefaces["lydi"].Insert(0, "Noto Sans Lydian");
			MapScriptToTypefaces["mlym"].Insert(0, "Noto Sans Malayalam");
			MapScriptToTypefaces["mand"].Insert(0, "Noto Sans Mandiac");
			MapScriptToTypefaces["mani"].Insert(0, "Noto Sans Manichaean");
			MapScriptToTypefaces["marc"].Insert(0, "Noto Sans Marchen");
			MapScriptToTypefaces["gonm"].Insert(0, "Noto Sans Masaram Gondi");
			MapScriptToTypefaces["medf"].Insert(0, "Noto Sans Medefaidrin");
			MapScriptToTypefaces["mtei"].Insert(0, "Noto Sans Meetei Mayek");
			MapScriptToTypefaces["merc"].Insert(0, "Noto Sans Meroitic");
			MapScriptToTypefaces["mero"].Insert(0, "Noto Sans Meroitic");
			MapScriptToTypefaces["plrd"].Insert(0, "Noto Sans Miao");
			MapScriptToTypefaces["modi"].Insert(0, "Noto Sans Modi");
			MapScriptToTypefaces["mong"].Insert(0, "Noto Sans Mongolian");
			MapScriptToTypefaces["mroo"].Insert(0, "Noto Sans Mro");
			MapScriptToTypefaces["mult"].Insert(0, "Noto Sans Multani");
			MapScriptToTypefaces["mymr"].Insert(0, "Noto Sans Myanmar");
			MapScriptToTypefaces["nkoo"].Insert(0, "Noto Sans Nko");
			MapScriptToTypefaces["nbat"].Insert(0, "Noto Sans Nabataean");
			MapScriptToTypefaces["talu"].Insert(0, "Noto Sans New Tai Lue");
			MapScriptToTypefaces["newa"].Insert(0, "Noto Sans Newa");
			MapScriptToTypefaces["ogam"].Insert(0, "Noto Sans Ogham");
			MapScriptToTypefaces["olck"].Insert(0, "Noto Sans Ol Chiki");
			MapScriptToTypefaces["ital"].Insert(0, "Noto Sans Old Italian");
			MapScriptToTypefaces["narb"].Insert(0, "Noto Sans Old North Arabian");
			MapScriptToTypefaces["perm"].Insert(0, "Noto Sans Old Permic");
			MapScriptToTypefaces["xpeo"].Insert(0, "Noto Sans Old Persian");
			MapScriptToTypefaces["sarb"].Insert(0, "Noto Sans Old South Arabian");
			MapScriptToTypefaces["orkh"].Insert(0, "Noto Sans Old Turkic");
			MapScriptToTypefaces["orya"].Insert(0, "Noto Sans Oriya");
			MapScriptToTypefaces["osge"].Insert(0, "Noto Sans Osage");
			MapScriptToTypefaces["osma"].Insert(0, "Noto Sans Osmanya");
			MapScriptToTypefaces["hmng"].Insert(0, "Noto Sans Pahawh Hmong");
			MapScriptToTypefaces["palm"].Insert(0, "Noto Sans Palmyrene");
			MapScriptToTypefaces["pauc"].Insert(0, "Noto Sans Pau Cin Hau");
			MapScriptToTypefaces["phag"].Insert(0, "Noto Sans Phags Pa");
			MapScriptToTypefaces["phnx"].Insert(0, "Noto Sans Phoenician");
			MapScriptToTypefaces["rjng"].Insert(0, "Noto Sans Rejang");
			MapScriptToTypefaces["runr"].Insert(0, "Noto Sans Runic");
			MapScriptToTypefaces["samr"].Insert(0, "Noto Sans Samaritan");
			MapScriptToTypefaces["saur"].Insert(0, "Noto Sans Saurashtra");
			MapScriptToTypefaces["shrd"].Insert(0, "Noto Sans Sharada");
			MapScriptToTypefaces["shaw"].Insert(0, "Noto Sans Shavian");
			MapScriptToTypefaces["sinh"].Insert(0, "Noto Sans Sinhala");
			MapScriptToTypefaces["sora"].Insert(0, "Noto Sans Sora Sompeng");
			MapScriptToTypefaces["soyo"].Insert(0, "Noto Sans Soyombo");
			MapScriptToTypefaces["sund"].Insert(0, "Noto Sans Sundanese");
			MapScriptToTypefaces["sylo"].Insert(0, "Noto Sans Syloti Nagri");
			MapScriptToTypefaces["zsym"].Insert(0, "Noto Sans Symbols");
			MapScriptToTypefaces["syrn"].Insert(0, "Noto Sans Syriac Eastern");
			MapScriptToTypefaces["syre"].Insert(0, "Noto Sans Syriac Estrangela");
			MapScriptToTypefaces["syrj"].Insert(0, "Noto Sans Syriac Western");
			MapScriptToTypefaces["tglg"].Insert(0, "Noto Sans Tagalog");
			MapScriptToTypefaces["tagb"].Insert(0, "Noto Sans Tagbanwa");
			MapScriptToTypefaces["tale"].Insert(0, "Noto Sans Tai Le");
			MapScriptToTypefaces["lana"].Insert(0, "Noto Sans Tai Tham");
			MapScriptToTypefaces["tavt"].Insert(0, "Noto Sans Tai Viet");
			MapScriptToTypefaces["takr"].Insert(0, "Noto Sans Takri");
			MapScriptToTypefaces["taml"].Insert(0, "Noto Sans Tamil");
			MapScriptToTypefaces["telu"].Insert(0, "Noto Sans Telugu");
			MapScriptToTypefaces["thaa"].Insert(0, "Noto Sans Thaana");
			MapScriptToTypefaces["thai"].Insert(0, "Noto Sans Thai");
			MapScriptToTypefaces["tfng"].Insert(0, "Noto Sans Tifinagh");
			MapScriptToTypefaces["ugar"].Insert(0, "Noto Sans Ugaritic");
			MapScriptToTypefaces["vaii"].Insert(0, "Noto Sans Vai");
			MapScriptToTypefaces["wcho"].Insert(0, "Noto Sans Wancho");
			MapScriptToTypefaces["wara"].Insert(0, "Noto Sans Warang Citi");
			MapScriptToTypefaces["yiii"].Insert(0, "Noto Sans Yi");
		}
		public FallbackListFontMatcher(FontManager manager) : base(manager) { }
		public override IEnumerable<Typeface> MatchScript(string script = null, bool distinctFamily = false) {
			if (string.IsNullOrEmpty(script)) script = ScriptUtils.UltimateFallbackScript;
			List<string> candidates;
			IEnumerable<string> candidateScripts = new string[] { script };
			while (candidateScripts != null) {
				foreach (var candidateScript in candidateScripts) {
					if (MapScriptToTypefaces.TryGetValue(candidateScript, out candidates)) {
						foreach (var candidate in candidates) {
							IReadOnlyCollection<Typeface> typefaces1;
							if (Manager.MapFullNameToTypeface.TryGetValue(candidate, out typefaces1)) {
								foreach (var typeface in typefaces1) {
									yield return typeface;
								}
							}
							if (distinctFamily) continue;
							IReadOnlyCollection<Typeface> typefaces2;
							if (Manager.MapNameToTypefaces.TryGetValue(candidate, out typefaces2)) {
								foreach (var typeface in typefaces2) {
									if (typefaces1.Contains(typeface)) continue;
									yield return typeface;
								}
							}
						}
					}
				}
				candidateScripts = ScriptUtils.EnumerateFallbackScripts(script);
			}
		}
	}
}