tajik api fix

RMuseum/Services/Implementation/GanjoorService-Partials/GanjoorService-Tajik.cs

@@ -149,7 +149,17 @@ namespace RMuseum.Services.Implementation
                         var nextPoem = await _context.TajikPoems.AsNoTracking().Where(p => p.Id == page.Poem.Next.Id).SingleOrDefaultAsync();
                         if(nextPoem != null)
                         {
+                            // real Tajik translation exists for the neighbouring poem - use it
                             page.Poem.Next.Title = nextPoem.TajikTitle;
+                            page.Poem.Next.Excerpt = ExtractExcerpt(nextPoem.TajikPlainText);
+                        }
+                        else
+                        {
+                            // no Tajik translation for this poem yet - fall back to a simple
+                            // best-effort letter transliteration rather than showing raw
+                            // Perso-Arabic script (see LanguageUtils.TransliteratePersianToTajik)
+                            page.Poem.Next.Title = LanguageUtils.TransliteratePersianToTajik(page.Poem.Next.Title);
+                            page.Poem.Next.Excerpt = LanguageUtils.TransliteratePersianToTajik(page.Poem.Next.Excerpt);
                         }
                     }
                     if (page.Poem.Previous != null)
@@ -158,6 +168,12 @@ namespace RMuseum.Services.Implementation
                         if (prePoem != null)
                         {
                             page.Poem.Previous.Title = prePoem.TajikTitle;
+                            page.Poem.Previous.Excerpt = ExtractExcerpt(prePoem.TajikPlainText);
+                        }
+                        else
+                        {
+                            page.Poem.Previous.Title = LanguageUtils.TransliteratePersianToTajik(page.Poem.Previous.Title);
+                            page.Poem.Previous.Excerpt = LanguageUtils.TransliteratePersianToTajik(page.Poem.Previous.Excerpt);
                         }
                     }
                 }
@@ -169,6 +185,16 @@ namespace RMuseum.Services.Implementation
             }
         }
 
+        /// <summary>
+        /// short plain-text excerpt (first non-empty line) for a Tajik poem's next/previous nav link
+        /// </summary>
+        private static string ExtractExcerpt(string plainText)
+        {
+            if (string.IsNullOrWhiteSpace(plainText)) return "";
+            var firstLine = plainText.Split(new[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries).FirstOrDefault() ?? "";
+            return firstLine.Length > 80 ? firstLine.Substring(0, 80) + "…" : firstLine;
+        }
+
 
 
         /// <summary>

RMuseum/Services/Implementation/LanguageUtils.cs

@@ -92,6 +92,85 @@ namespace RMuseum.Services.Implementation
                        ;
         }
 
+        /// <summary>
+        /// simple, best-effort Perso-Arabic -> Tajik Cyrillic letter substitution.
+        /// NOT a linguistically correct transliteration: Perso-Arabic script does not
+        /// write short vowels, so a letter-by-letter map cannot recover them (that's
+        /// why a dedicated tool like persian-tajik.ir exists, and why the bulk of
+        /// TajikGanjoor's content comes from real TajikPoems/TajikCats/TajikPoets rows
+        /// rather than on-the-fly conversion). This exists only as a fallback for
+        /// spots - like a neighbouring poem's excerpt on the next/previous nav - that
+        /// don't have a proper Tajik translation in the database yet, so at least
+        /// something in Cyrillic is shown instead of raw Perso-Arabic script.
+        /// </summary>
+        private static readonly Dictionary<char, string> _persianToTajikMap = new Dictionary<char, string>()
+        {
+            ['آ'] = "о",
+            ['ا'] = "о",
+            ['ب'] = "б",
+            ['پ'] = "п",
+            ['ت'] = "т",
+            ['ث'] = "с",
+            ['ج'] = "ҷ",
+            ['چ'] = "ч",
+            ['ح'] = "ҳ",
+            ['خ'] = "х",
+            ['د'] = "д",
+            ['ذ'] = "з",
+            ['ر'] = "р",
+            ['ز'] = "з",
+            ['ژ'] = "ж",
+            ['س'] = "с",
+            ['ش'] = "ш",
+            ['ص'] = "с",
+            ['ض'] = "з",
+            ['ط'] = "т",
+            ['ظ'] = "з",
+            ['ع'] = "ъ",
+            ['غ'] = "ғ",
+            ['ف'] = "ф",
+            ['ق'] = "қ",
+            ['ک'] = "к",
+            ['ك'] = "к",
+            ['گ'] = "г",
+            ['ل'] = "л",
+            ['م'] = "м",
+            ['ن'] = "н",
+            ['و'] = "в",
+            ['ه'] = "ҳ",
+            ['ی'] = "ӣ",
+            ['ي'] = "ӣ",
+            ['ئ'] = "ъ",
+            ['ؤ'] = "в",
+            ['ء'] = "ъ",
+            ['ة'] = "ат",
+            ['؟'] = "?",
+            ['،'] = ",",
+            ['؛'] = ";",
+            ['۰'] = "0",
+            ['۱'] = "1",
+            ['۲'] = "2",
+            ['۳'] = "3",
+            ['۴'] = "4",
+            ['۵'] = "5",
+            ['۶'] = "6",
+            ['۷'] = "7",
+            ['۸'] = "8",
+            ['۹'] = "9",
+        };
+
+        public static string TransliteratePersianToTajik(string text)
+        {
+            if (string.IsNullOrEmpty(text)) return text;
+            text = CleanTextForTransileration(text);
+            var sb = new System.Text.StringBuilder(text.Length);
+            foreach (char c in text)
+            {
+                sb.Append(_persianToTajikMap.TryGetValue(c, out string mapped) ? mapped : c.ToString());
+            }
+            return sb.ToString();
+        }
+
 
         public static string SameSoundLetters(string text)
         {