[disambiguation] Adding best_country_and_language

scripts/geodata/language_id/polygon_lookup.py

@@ -1,5 +1,7 @@
 import operator
 
+from geodata.language_id.disambiguation import disambiguate_language, UNKNOWN_LANGUAGE, WELL_REPRESENTED_LANGUAGES
+
 
 def country_and_languages(language_rtree, latitude, longitude):
     props = language_rtree.point_in_poly(latitude, longitude, return_all=True)
@@ -28,3 +30,40 @@ def country_and_languages(language_rtree, latitude, longitude):
     # it means the default language of the region overrides the country default
     default_languages = sorted(languages, key=operator.itemgetter('default'), reverse=True)
     return country, default_languages, props
+
+
+def best_country_and_language(language_rtree, latitude, longitude, name):
+    country, candidate_languages, language_props = country_and_languages(language_rtree, latitude, longitude)
+    if not (country and candidate_languages):
+        return None, None
+
+    num_langs = len(candidate_languages)
+    default_langs = set([l['lang'] for l in candidate_languages if l.get('default')])
+    num_defaults = len(default_langs)
+
+    regional_defaults = 0
+    country_defaults = 0
+    regional_langs = set()
+    country_langs = set()
+    for p in language_props:
+        if p['admin_level'] > 0:
+            regional_defaults += sum((1 for lang in p['languages'] if lang.get('default')))
+            regional_langs |= set([l['lang'] for l in p['languages']])
+        else:
+            country_defaults += sum((1 for lang in p['languages'] if lang.get('default')))
+            country_langs |= set([l['lang'] for l in p['languages']])
+
+    if num_langs == 1:
+        return country, candidate_languages[0]['lang']
+    else:
+        lang = disambiguate_language(name, [(l['lang'], l['default']) for l in candidate_languages])
+        default_lang = candidate_languages[0]['lang']
+
+        if lang == UNKNOWN_LANGUAGE and num_defaults == 1:
+            return country, default_lang
+        elif lang != UNKNOWN_LANGUAGE:
+            if lang != default_lang and lang in country_langs and country_defaults > 1 and regional_defaults > 0 and lang in WELL_REPRESENTED_LANGUAGES:
+                return country, UNKNOWN_LANGUAGE
+            return country, lang
+        else:
+            return None, None