Fix volume covers behaviour

Ref: #105

mangadex_downloader/format/utils.py

@@ -29,6 +29,7 @@
 
 from enum import Enum
 from .chinfo import get_chapter_info as get_chinfo
+from ..language import Language
 from ..downloader import FileDownloader
 from ..utils import get_cover_art_url
 from .. import __repository__, __url_repository__, json_op
@@ -66,17 +67,39 @@ def find_volume_cover(cover):
 
         return volume == cover.volume
 
-    f = filter(find_volume_cover, CoverArtIterator(manga.id))
-
-    try:
-        cover = next(f)
-    except StopIteration:
-        if download:
-            pbm.logger.warning(
-                f"Failed to find volume cover for volume {volume}. "
-                "Falling back to manga cover..."
-            )
-        cover = manga.cover
+    cover_art_iter_kwargs = [
+        # Fix default volume covers behaviour
+        # See https://github.com/mansuf/mangadex-downloader/issues/105
+        {"language_override": None},  # --volume-cover-language or --language
+        {
+            "language_override": manga.original_language.value,
+        },  # volume cover from manga original language
+        {
+            "language_override": "all",
+        },  # Volume cover from any languages that exists
+    ]
+
+    cover = None
+    for kwargs in cover_art_iter_kwargs:
+        kwargs["manga_id"] = manga.id
+        iterator = CoverArtIterator(**kwargs)
+        f = filter(find_volume_cover, iterator)
+
+        try:
+            cover = next(f)
+        except StopIteration:
+            lang = Language(iterator.language)
+            log.debug(f"Failed to find volume cover in {lang.name} language")
+            continue
+        else:
+            break
+
+    if download and cover is None:
+        pbm.logger.warning(
+            f"Failed to find volume cover for volume {volume}. "
+            "Falling back to manga cover..."
+        )
+    cover = manga.cover
 
     url = get_cover_art_url(manga.id, cover, "original")
 

mangadex_downloader/iterator.py

@@ -457,7 +457,7 @@ def iter_random_manga(**filters):
 class CoverArtIterator(BaseIterator):
     cache = {}
 
-    def __init__(self, manga_id):
+    def __init__(self, manga_id, language_override=None):
         super().__init__()
 
         self.limit = 100
@@ -467,6 +467,16 @@ def __init__(self, manga_id):
             # Data is not cached
             self.cache[manga_id] = []
 
+        self.language = None
+
+        if language_override:
+            self.language = language_override
+        else:
+            vol_cover_lang = config.volume_cover_language
+            cover_locale = vol_cover_lang if vol_cover_lang else config.language
+
+            self.language = cover_locale
+
     def _make_cache_iterator(self):
         for item in self.cache.get(self.manga_id):
             yield item
@@ -485,9 +495,6 @@ def fill_data(self):
         if self.cache.get(self.manga_id):
             return
 
-        vol_cover_lang = config.volume_cover_language
-        cover_locale = vol_cover_lang if vol_cover_lang else config.language
-
         # One-shot filling covers in single function call
         # So cache can be used
         while True:
@@ -497,8 +504,8 @@ def fill_data(self):
                 "limit": self.limit,
             }
 
-            if cover_locale != "all":
-                params.update({"locales[]": cover_locale})
+            if self.language != "all" and self.language is not None:
+                params.update({"locales[]": self.language})
 
             url = f"{base_url}/cover"
             r = Net.mangadex.get(url, params=params)

mangadex_downloader/manga.py

@@ -123,6 +123,11 @@ def title(self):
         """:class:`str`: Return title of the manga"""
         return self._title
 
+    @property
+    def original_language(self):
+        """:class:`str`: Return original language of the manga"""
+        return Language(self._attr.get("originalLanguage"))
+
     @property
     def alternative_titles(self):
         """List[:class:`str`]: List of alternative titles"""