Let a downloaded program be downloaded again

The button disappeared the moment anything landed, and nothing else on
the window asks for that download. So a machine that got the processor
build before its graphics driver was installed can never be given the
Vulkan one, and nobody can pick up a newer whisper.cpp either: both of
those are the same missing control.

It reads "Download again" once a copy is here, and stays hidden while a
system one is on the PATH, because that is the copy that would run.

dikte/i18n.py

@@ -779,6 +779,7 @@ TR = {
     "Local model": "Yerel model",
     "Not installed.": "Kurulu değil.",
     "Installed on the system: {path}": "Sistemde kurulu: {path}",
+    "Download again": "Yeniden indir",
     "Downloaded, version {version}.": "İndirildi, sürüm {version}.",
     "Downloaded, version {version}. There was no Vulkan build, "
     "so this one runs on the processor.":

dikte/settings_ui.py

@@ -349,10 +349,18 @@ class LocalModelBox(QGroupBox):
         path = ggml.program_path(self.program)
         if not path:
             self.program_label.setText(t("Not installed."))
+            self.install_button.setText(t("Download"))
             self.install_button.setVisible(True)
             return
-        self.install_button.setVisible(not ggml.installed_program(self.program)
-                                       and not ggml.system_program(self.program))
+        # A copy that is here is not a copy that is right. whisper.cpp releases
+        # every few weeks, and a graphics card installed after Dikte was
+        # changes which build this machine should be running; the button was
+        # hidden the moment anything landed, and nothing else on this window
+        # asks for the download again.
+        self.install_button.setText(t("Download again")
+                                    if ggml.installed_program(self.program)
+                                    else t("Download"))
+        self.install_button.setVisible(not ggml.system_program(self.program))
         if ggml.system_program(self.program):
             # Worth saying which one is running: a distribution package is built
             # for this machine and may reach the graphics card, while the

tests/test_ui.py

@@ -22,6 +22,7 @@ from dikte import cleanup
 from dikte import config as cfg
 from dikte import ggml
 from dikte import hotkey
+from dikte.i18n import t
 from dikte import ipc
 from dikte import overlay as overlay_module
 from dikte import paste
@@ -1243,6 +1244,27 @@ class LocalModels(DikteTest):
         self.assertIn("v1.9.3", label)
         self.assertNotIn("Vulkan", label)
 
+    def test_a_downloaded_program_can_still_be_asked_for_again(self):
+        # The button used to disappear the moment anything landed, which left
+        # no way to pick up a newer whisper.cpp, or the Vulkan build on a
+        # machine whose driver was installed after Dikte was.
+        binary = self.path("bin/whisper/v1.9.3/whisper-server")
+        binary.parent.mkdir(parents=True)
+        binary.write_text("")
+        binary.chmod(0o755)
+        self.path("bin/whisper/installed.json").write_text(json.dumps(
+            {"tag": "v1.9.3", "binary": str(binary)}))
+        self.patch_attr(ggml.shutil, "which", lambda name: None)
+        box = self.window(cfg.Config()).local_whisper
+        self.assertTrue(box.install_button.isVisibleTo(box))
+        self.assertEqual(box.install_button.text(), t("Download again"))
+
+    def test_a_system_copy_is_not_offered_for_download(self):
+        # Nothing Dikte downloads would be run while one is on the PATH.
+        self.patch_attr(ggml.shutil, "which", lambda name: "/usr/bin/" + name)
+        box = self.window(cfg.Config()).local_whisper
+        self.assertFalse(box.install_button.isVisibleTo(box))
+
     def test_only_the_chosen_transcriber_is_on_screen(self):
         window = self.window(self.config(transcribe_provider="openai"))
         self.assertTrue(window.stt_form.isRowVisible(window.transcribe_model_row))