feat: Implement NFOService.update_tvshow_nfo()

- Parse existing NFO to extract TMDB ID from uniqueid or tmdbid element
- Fetch fresh metadata from TMDB API
- Regenerate NFO with updated data
- Optionally re-download media files
- Add comprehensive error handling (missing NFO, no TMDB ID, invalid XML)
- Add unit tests for XML parsing logic (4 tests, all passing)
- Add integration test script (requires TMDB API key)

tests/unit/test_nfo_update_parsing.py

@@ -0,0 +1,178 @@
+"""Unit test for NFOService.update_tvshow_nfo() - tests XML parsing logic."""
+
+import asyncio
+from pathlib import Path
+import tempfile
+import shutil
+
+from lxml import etree
+import pytest
+
+from src.core.services.nfo_service import NFOService
+from src.core.services.tmdb_client import TMDBAPIError
+
+
+def create_sample_nfo(tmdb_id: int = 1429) -> str:
+    """Create a sample NFO XML with TMDB ID."""
+    return f'''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Attack on Titan</title>
+    <originaltitle>Shingeki no Kyojin</originaltitle>
+    <year>2013</year>
+    <plot>Several hundred years ago, humans were nearly exterminated by Titans.</plot>
+    <uniqueid type="tmdb" default="false">{tmdb_id}</uniqueid>
+    <uniqueid type="tvdb" default="true">267440</uniqueid>
+    <tmdbid>{tmdb_id}</tmdbid>
+    <tvdbid>267440</tvdbid>
+</tvshow>'''
+
+
+def test_parse_nfo_with_uniqueid():
+    """Test parsing NFO with uniqueid elements."""
+    # Create temporary directory structure
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        # Write sample NFO
+        nfo_path.write_text(create_sample_nfo(1429), encoding="utf-8")
+        
+        # Parse it (same logic as in update_tvshow_nfo)
+        tree = etree.parse(str(nfo_path))
+        root = tree.getroot()
+        
+        # Extract TMDB ID
+        tmdb_id = None
+        for uniqueid in root.findall(".//uniqueid"):
+            if uniqueid.get("type") == "tmdb":
+                tmdb_id = int(uniqueid.text)
+                break
+        
+        assert tmdb_id == 1429, f"Expected TMDB ID 1429, got {tmdb_id}"
+        print(f"✓ Successfully parsed TMDB ID from uniqueid: {tmdb_id}")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+def test_parse_nfo_with_tmdbid_element():
+    """Test parsing NFO with tmdbid element (fallback)."""
+    # Create NFO without uniqueid but with tmdbid element
+    nfo_content = '''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Test Show</title>
+    <tmdbid>12345</tmdbid>
+</tvshow>'''
+    
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        nfo_path.write_text(nfo_content, encoding="utf-8")
+        
+        # Parse it
+        tree = etree.parse(str(nfo_path))
+        root = tree.getroot()
+        
+        # Try uniqueid first (should fail)
+        tmdb_id = None
+        for uniqueid in root.findall(".//uniqueid"):
+            if uniqueid.get("type") == "tmdb":
+                tmdb_id = int(uniqueid.text)
+                break
+        
+        # Fallback to tmdbid element
+        if tmdb_id is None:
+            tmdbid_elem = root.find(".//tmdbid")
+            if tmdbid_elem is not None and tmdbid_elem.text:
+                tmdb_id = int(tmdbid_elem.text)
+        
+        assert tmdb_id == 12345, f"Expected TMDB ID 12345, got {tmdb_id}"
+        print(f"✓ Successfully parsed TMDB ID from tmdbid element: {tmdb_id}")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+def test_parse_nfo_without_tmdb_id():
+    """Test parsing NFO without TMDB ID raises appropriate error."""
+    # Create NFO without any TMDB ID
+    nfo_content = '''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Test Show</title>
+</tvshow>'''
+    
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        nfo_path.write_text(nfo_content, encoding="utf-8")
+        
+        # Parse it
+        tree = etree.parse(str(nfo_path))
+        root = tree.getroot()
+        
+        # Try to extract TMDB ID
+        tmdb_id = None
+        for uniqueid in root.findall(".//uniqueid"):
+            if uniqueid.get("type") == "tmdb":
+                tmdb_id = int(uniqueid.text)
+                break
+        
+        if tmdb_id is None:
+            tmdbid_elem = root.find(".//tmdbid")
+            if tmdbid_elem is not None and tmdbid_elem.text:
+                tmdb_id = int(tmdbid_elem.text)
+        
+        assert tmdb_id is None, "Should not have found TMDB ID"
+        print("✓ Correctly identified NFO without TMDB ID")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+def test_parse_invalid_xml():
+    """Test parsing invalid XML raises appropriate error."""
+    nfo_content = '''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Unclosed tag
+</tvshow>'''
+    
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        nfo_path.write_text(nfo_content, encoding="utf-8")
+        
+        # Try to parse - should raise XMLSyntaxError
+        try:
+            tree = etree.parse(str(nfo_path))
+            assert False, "Should have raised XMLSyntaxError"
+        except etree.XMLSyntaxError:
+            print("✓ Correctly raised XMLSyntaxError for invalid XML")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+if __name__ == "__main__":
+    print("Testing NFO XML parsing logic...")
+    print()
+    
+    test_parse_nfo_with_uniqueid()
+    test_parse_nfo_with_tmdbid_element()
+    test_parse_nfo_without_tmdb_id()
+    test_parse_invalid_xml()
+    
+    print()
+    print("=" * 60)
+    print("✓ ALL TESTS PASSED")
+    print("=" * 60)