pypi: stop guessing the pypi name based on the package name

To avoid false positives in case there is "python-foo" and "foo" in the repo.
Also rename/comment some things to make them more clear.

app/appstate.py

@@ -26,8 +26,16 @@ PackageKey = tuple[str, str, str, str, str]
 
 class ExtId(NamedTuple):
     id: str
+    """Internal ID"""
+
     name: str
-    fallback: bool
+    """Display name of the external system"""
+
+    fallback_only: bool
+    """Only use this as a fallback if no other match is found"""
+
+    guess_name: bool
+    """Guess the external package name, if none is explicitely specified"""
 
 
 class ExtInfo(NamedTuple):
@@ -527,7 +535,7 @@ class Source:
         for ext_id, info in self.external_infos:
             if info.version is None:
                 continue
-            if ext_id.fallback:
+            if ext_id.fallback_only:
                 if fallback is None or version_is_newer_than(info.version, fallback.version):
                     fallback = info
             else:
@@ -561,12 +569,13 @@ class Source:
 
         ext = []
         for ext_id in state.ext_info_ids:
+            variants = []
             if ext_id.id in self.pkgextra.references:
                 mapped = self.pkgextra.references[ext_id.id]
                 if mapped is None:
                     continue
                 variants = [mapped]
-            else:
+            elif ext_id.guess_name:
                 variants = get_realname_variants(self)
 
             infos = state.get_ext_infos(ext_id)
@@ -578,7 +587,7 @@ class Source:
         # XXX: let repology do the mapping for us
         repology_repo = "msys2_msys2" if self._package.repo == "msys" else "msys2_mingw"
         ext.append((
-            ExtId("repology", "Repology", True),
+            ExtId("repology", "Repology", True, True),
             ExtInfo(self.realname, None, 0,
                     f"https://repology.org/tools/project-by?repo={quote(repology_repo)}&name_type=srcname&target_page=project_versions&name={quote(self.name)}", {})))
 
@@ -586,7 +595,7 @@ class Source:
         project_id = self.pkgextra.references.get("anitya", self.realname)
         if project_id is not None:
             ext.append((
-                ExtId("anitya", "Anitya", True),
+                ExtId("anitya", "Anitya", True, True),
                 ExtInfo(self.realname, None, 0,
                         f"https://release-monitoring.org/project/{quote(project_id)}", {})))
 

app/fetch/arch.py

@@ -62,7 +62,7 @@ async def update_arch_versions() -> None:
                         arch_versions[provides] = ExtInfo(provides, version, p.builddate, url, {})
 
     logger.info("done")
-    state.set_ext_infos(ExtId("archlinux", "Arch Linux", False), arch_versions)
+    state.set_ext_infos(ExtId("archlinux", "Arch Linux", False, True), arch_versions)
 
     logger.info("update versions from AUR")
     aur_versions: dict[str, ExtInfo] = {}
@@ -91,4 +91,4 @@ async def update_arch_versions() -> None:
             aur_versions[provides] = ExtInfo(provides, msys_ver, last_modified, url, {})
 
     logger.info("done")
-    state.set_ext_infos(ExtId("aur", "AUR", True), aur_versions)
+    state.set_ext_infos(ExtId("aur", "AUR", True, True), aur_versions)

app/fetch/cygwin.py

@@ -65,5 +65,5 @@ async def update_cygwin_versions() -> None:
     data = await get_content_cached(url, timeout=REQUEST_TIMEOUT)
     data = zstandard.ZstdDecompressor().decompress(data)
     cygwin_versions, cygwin_versions_mingw64 = await asyncio.to_thread(parse_cygwin_versions, url, data)
-    state.set_ext_infos(ExtId("cygwin", "Cygwin", True), cygwin_versions)
-    state.set_ext_infos(ExtId("cygwin-mingw64", "Cygwin-mingw64", False), cygwin_versions_mingw64)
+    state.set_ext_infos(ExtId("cygwin", "Cygwin", True, True), cygwin_versions)
+    state.set_ext_infos(ExtId("cygwin-mingw64", "Cygwin-mingw64", False, True), cygwin_versions_mingw64)

app/fetch/gentoo.py

@@ -21,7 +21,7 @@ async def update_gentoo_versions() -> None:
     data = await get_content_cached(url, timeout=REQUEST_TIMEOUT)
     gentoo_versions = await asyncio.to_thread(parse_gentoo_versions, data)
     # fallback, since parsing isn't perfect and we include unstable versions
-    state.set_ext_infos(ExtId("gentoo", "Gentoo", True), gentoo_versions)
+    state.set_ext_infos(ExtId("gentoo", "Gentoo", True, True), gentoo_versions)
 
 
 def parse_gentoo_versions(data: bytes) -> dict[str, ExtInfo]:

app/fetch/pypi.py

@@ -51,4 +51,4 @@ async def update_pypi_versions(pkgextra: PkgExtra) -> None:
             pypi_versions[pypi_name] = ExtInfo(
                 pypi_name, info["version"], oldest_timestamp, info["project_url"], {})
 
-    state.set_ext_infos(ExtId("pypi", "PyPI", False), pypi_versions)
+    state.set_ext_infos(ExtId("pypi", "PyPI", False, False), pypi_versions)