chore: import upstream snapshot with attribution

servers/fastapi/utils/ocr_language.py

@@ -0,0 +1,126 @@
+"""
+Map presentation UI language strings (LanguageType enum values from Next.js) to
+Tesseract / LiteParse OCR language codes (ISO 639-3 where applicable).
+
+Keep keys in sync with:
+servers/nextjs/app/(presentation-generator)/upload/type.ts → LanguageType
+"""
+
+from __future__ import annotations
+
+import re
+from typing import Optional
+
+# Values must match `LanguageType` string literals in the upload UI.
+PRESENTATION_LANGUAGE_TO_TESSERACT: dict[str, str] = {
+    "English": "eng",
+    "Spanish (Español)": "spa",
+    "French (Français)": "fra",
+    "German (Deutsch)": "deu",
+    "Portuguese (Português)": "por",
+    "Italian (Italiano)": "ita",
+    "Dutch (Nederlands)": "nld",
+    "Russian (Русский)": "rus",
+    "Chinese (Simplified - 中文, 汉语)": "chi_sim",
+    "Chinese (Traditional - 中文, 漢語)": "chi_tra",
+    "Japanese (日本語)": "jpn",
+    "Korean (한국어)": "kor",
+    "Arabic (العربية)": "ara",
+    "Hindi (हिन्दी)": "hin",
+    "Bengali (বাংলা)": "ben",
+    "Polish (Polski)": "pol",
+    "Czech (Čeština)": "ces",
+    "Slovak (Slovenčina)": "slk",
+    "Hungarian (Magyar)": "hun",
+    "Romanian (Română)": "ron",
+    "Bulgarian (Български)": "bul",
+    "Greek (Ελληνικά)": "ell",
+    "Serbian (Српски / Srpski)": "srp",
+    "Croatian (Hrvatski)": "hrv",
+    "Bosnian (Bosanski)": "bos",
+    "Slovenian (Slovenščina)": "slv",
+    "Finnish (Suomi)": "fin",
+    "Swedish (Svenska)": "swe",
+    "Danish (Dansk)": "dan",
+    "Norwegian (Norsk)": "nor",
+    "Icelandic (Íslenska)": "isl",
+    "Lithuanian (Lietuvių)": "lit",
+    "Latvian (Latviešu)": "lav",
+    "Estonian (Eesti)": "est",
+    "Maltese (Malti)": "mlt",
+    "Welsh (Cymraeg)": "cym",
+    "Irish (Gaeilge)": "gle",
+    "Scottish Gaelic (Gàidhlig)": "gla",
+    "Ukrainian (Українська)": "ukr",
+    "Hebrew (עברית)": "heb",
+    "Persian/Farsi (فارسی)": "fas",
+    "Turkish (Türkçe)": "tur",
+    "Kurdish (Kurdî / کوردی)": "kmr",
+    "Pashto (پښتو)": "pus",
+    "Dari (دری)": "prs",
+    "Uzbek (Oʻzbek)": "uzb",
+    "Kazakh (Қазақша)": "kaz",
+    "Tajik (Тоҷикӣ)": "tgk",
+    "Turkmen (Türkmençe)": "tuk",
+    "Azerbaijani (Azərbaycan dili)": "aze",
+    "Urdu (اردو)": "urd",
+    "Tamil (தமிழ்)": "tam",
+    "Telugu (తెలుగు)": "tel",
+    "Marathi (मराठी)": "mar",
+    "Punjabi (ਪੰਜਾਬੀ / پنجابی)": "pan",
+    "Gujarati (ગુજરાતી)": "guj",
+    "Malayalam (മലയാളം)": "mal",
+    "Kannada (ಕನ್ನಡ)": "kan",
+    "Odia (ଓଡ଼ିଆ)": "ori",
+    "Sinhala (සිංහල)": "sin",
+    "Nepali (नेपाली)": "nep",
+    "Thai (ไทย)": "tha",
+    "Vietnamese (Tiếng Việt)": "vie",
+    "Lao (ລາວ)": "lao",
+    "Khmer (ភាសាខ្មែរ)": "khm",
+    "Burmese (မြန်မာစာ)": "mya",
+    "Tagalog/Filipino (Tagalog/Filipino)": "tgl",
+    "Javanese (Basa Jawa)": "jav",
+    "Sundanese (Basa Sunda)": "sun",
+    "Malay (Bahasa Melayu)": "msa",
+    "Mongolian (Монгол)": "mon",
+    "Swahili (Kiswahili)": "swa",
+    "Hausa (Hausa)": "hau",
+    "Yoruba (Yorùbá)": "yor",
+    "Igbo (Igbo)": "ibo",
+    "Amharic (አማርኛ)": "amh",
+    "Zulu (isiZulu)": "zul",
+    "Xhosa (isiXhosa)": "xho",
+    "Shona (ChiShona)": "sna",
+    "Somali (Soomaaliga)": "som",
+    "Basque (Euskara)": "eus",
+    "Catalan (Català)": "cat",
+    "Galician (Galego)": "glg",
+    "Quechua (Runasimi)": "que",
+    "Nahuatl (Nāhuatl)": "nah",
+    "Hawaiian (ʻŌlelo Hawaiʻi)": "haw",
+    "Maori (Te Reo Māori)": "mri",
+    # No dedicated Tahitian traineddata in default Tesseract bundles.
+    "Tahitian (Reo Tahiti)": "eng",
+    "Samoan (Gagana Samoa)": "smo",
+}
+
+_LOWER_MAP = {k.lower(): v for k, v in PRESENTATION_LANGUAGE_TO_TESSERACT.items()}
+
+_OCR_CODE_RE = re.compile(r"^[a-zA-Z0-9_,+]+$")
+
+
+def presentation_language_to_ocr_code(language: Optional[str]) -> str:
+    """Resolve UI language label to a Tesseract language code; default English."""
+    if language is None:
+        return "eng"
+    s = str(language).strip()
+    if not s:
+        return "eng"
+    if s in PRESENTATION_LANGUAGE_TO_TESSERACT:
+        code = PRESENTATION_LANGUAGE_TO_TESSERACT[s]
+    else:
+        code = _LOWER_MAP.get(s.lower(), "eng")
+    if not _OCR_CODE_RE.fullmatch(code):
+        return "eng"
+    return code