feat: check OLLAMA_HOST reachability before starting translationv1.6

Non-blocking QThread check hits /api/tags on the resolved ollama host
before launching TranslationWorker. Shows QMessageBox.warning() if
unreachable; proceeds silently if reachable. Adds ollama_host field to
Config with env-var fallback to http://localhost:11434.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 33 insertions, 2 deletions

diff --git a/ui/translation_view.py b/ui/translation_view.py
index cf72ce5..06767cb 100644
--- a/ui/translation_view.py
+++ b/ui/translation_view.py
@@ -1,14 +1,16 @@
 from __future__ import annotations
+import os
 import subprocess
 from pathlib import Path
 from PyQt6.QtWidgets import (
     QWidget, QVBoxLayout, QHBoxLayout, QLabel,
-    QPushButton, QPlainTextEdit, QTextBrowser,
+    QPushButton, QPlainTextEdit, QTextBrowser, QMessageBox,
 )
 from PyQt6.QtCore import pyqtSignal
 from core.models import Article
 from core.frontmatter import parse_frontmatter
 from workers.translation_worker import TranslationWorker
+from workers.ollama_check_worker import OllamaCheckWorker
 import re
 
 def _strip_shortcodes(text: str) -> str:
@@ -18,13 +20,17 @@ class TranslationView(QWidget):
     push_master = pyqtSignal()
     publish = pyqtSignal()
 
-    def __init__(self, transart_script: str, typora_bin: str, typora_args: str = "", parent=None):
+    def __init__(self, transart_script: str, typora_bin: str, typora_args: str = "",
+                 ollama_host: str = "", parent=None):
         super().__init__(parent)
         self._transart_script = transart_script
         self._typora_bin = typora_bin
         self._typora_args = typora_args
+        self._ollama_host = ollama_host
         self._article: Article | None = None
+        self._pending_article: Article | None = None
         self._worker: TranslationWorker | None = None
+        self._check_worker: OllamaCheckWorker | None = None
         self._output_path: str = ""
         self._build_ui()
 
@@ -72,6 +78,8 @@ class TranslationView(QWidget):
         layout.addWidget(self._action_bar)
 
     def start_translation(self, article: Article):
+        if self._check_worker and self._check_worker.isRunning():
+            return
         if self._worker is not None:
             self._worker.log_line.disconnect()
             self._worker.finished.disconnect()
@@ -84,6 +92,29 @@ class TranslationView(QWidget):
         direction = "it-en" if article.lang == "it" else "en-it"
         self._header.setText(f"Traduzione: {article.slug} ({article.lang.upper()} → {('EN' if article.lang == 'it' else 'IT')})")
 
+        self._log.appendPlainText("Controllo backend ollama...")
+        self._pending_article = article
+        resolved = self._ollama_host or os.environ.get("OLLAMA_HOST", "http://localhost:11434")
+        self._check_worker = OllamaCheckWorker(resolved, parent=self)
+        self._check_worker.reachable.connect(self._on_backend_checked)
+        self._check_worker.start()
+
+    def _on_backend_checked(self, ok: bool, url: str):
+        if not ok:
+            self._log.appendPlainText(f"[ERRORE] Backend non raggiungibile: {url}")
+            QMessageBox.warning(
+                self,
+                "Backend non disponibile",
+                f"Il backend transart non è raggiungibile a:\n{url}\n\nAttiva RunPod e riprova.",
+            )
+            self._pending_article = None
+            return
+        if self._pending_article is not None:
+            self._start_worker(self._pending_article)
+            self._pending_article = None
+
+    def _start_worker(self, article: Article):
+        direction = "it-en" if article.lang == "it" else "en-it"
         self._worker = TranslationWorker(
             Path(self._transart_script),
             article.path,