Fix CM3000 driver returning 0 channels on first poll

The status page cache was cleared after get_device_info() consumed it,
forcing get_docsis_data() to make a second HTTP request that could
return different data. The cache now persists for the entire collect
cycle so all methods use the same validated HTML.

Also made regex patterns robust against nested JS braces and added
diagnostic logging when 0 channels are parsed.

Ref #164

Author: itsDNNS

app/drivers/cm3000.py

@@ -28,28 +28,30 @@
 # Match the single-quoted live tagValueList in each function.
 # Commented-out examples use double quotes or /* */ blocks, so
 # targeting single quotes skips them reliably.
+# Uses .*? (lazy) instead of [^}]*? to support nested braces in
+# function bodies (e.g. if-blocks in some firmware versions).
 _RE_DS_QAM = re.compile(
-    r"function\s+InitDsTableTagValue\s*\(\)\s*\{[^}]*?"
+    r"function\s+InitDsTableTagValue\s*\(\)\s*\{.*?"
     r"var\s+tagValueList\s*=\s*'([^']+)';",
     re.DOTALL,
 )
 _RE_US_ATDMA = re.compile(
-    r"function\s+InitUsTableTagValue\s*\(\)\s*\{[^}]*?"
+    r"function\s+InitUsTableTagValue\s*\(\)\s*\{.*?"
     r"var\s+tagValueList\s*=\s*'([^']+)';",
     re.DOTALL,
 )
 _RE_DS_OFDM = re.compile(
-    r"function\s+InitDsOfdmTableTagValue\s*\(\)\s*\{[^}]*?"
+    r"function\s+InitDsOfdmTableTagValue\s*\(\)\s*\{.*?"
     r"var\s+tagValueList\s*=\s*'([^']+)';",
     re.DOTALL,
 )
 _RE_US_OFDMA = re.compile(
-    r"function\s+InitUsOfdmaTableTagValue\s*\(\)\s*\{[^}]*?"
+    r"function\s+InitUsOfdmaTableTagValue\s*\(\)\s*\{.*?"
     r"var\s+tagValueList\s*=\s*'([^']+)';",
     re.DOTALL,
 )
 _RE_SYS_INFO = re.compile(
-    r"function\s+InitTagValue\s*\(\)\s*\{[^}]*?"
+    r"function\s+InitTagValue\s*\(\)\s*\{.*?"
     r"var\s+tagValueList\s*=\s*'([^']+)';",
     re.DOTALL,
 )
@@ -120,6 +122,18 @@ def get_docsis_data(self) -> dict:
         ds31 = self._parse_ds_ofdm(html)
         us31 = self._parse_us_ofdma(html)
 
+        total = len(ds30) + len(us30) + len(ds31) + len(us31)
+        if total == 0:
+            log.warning(
+                "CM3000 parsed 0 channels (DS QAM regex=%s, US ATDMA regex=%s, "
+                "DS OFDM regex=%s, US OFDMA regex=%s, page length=%d)",
+                _RE_DS_QAM.search(html) is not None,
+                _RE_US_ATDMA.search(html) is not None,
+                _RE_DS_OFDM.search(html) is not None,
+                _RE_US_OFDMA.search(html) is not None,
+                len(html),
+            )
+
         return {
             "channelDs": {"docsis30": ds30, "docsis31": ds31},
             "channelUs": {"docsis30": us30, "docsis31": us31},
@@ -160,11 +174,11 @@ def _fetch_status_page(self) -> str:
         """Fetch the raw HTML of /DocsisStatus.htm.
 
         Reuses the validated HTML captured during login when available.
+        The cache persists until the next login() call overwrites it,
+        so all methods in a single collect cycle use the same page.
         """
         if self._status_html is not None:
-            html = self._status_html
-            self._status_html = None
-            return html
+            return self._status_html
 
         try:
             r = self._session.get(

tests/test_cm3000_driver.py

@@ -474,7 +474,8 @@ def test_fetch_status_page_uses_cached_login_html(self, driver):
         with patch.object(driver._session, "get") as mock_get:
             assert driver._fetch_status_page() == STATUS_HTML
             mock_get.assert_not_called()
-            assert driver._status_html is None
+            # Cache persists for the entire collect cycle
+            assert driver._status_html == STATUS_HTML
 
 
 # -- Regex patterns --
@@ -503,6 +504,34 @@ def test_all_patterns_match(self):
         assert _RE_SYS_INFO.search(html) is not None
 
 
+# -- Collect cycle (cache reuse) --
+
+class TestCollectCycle:
+    def test_device_info_and_docsis_data_share_cached_html(self, driver):
+        """Both get_device_info() and get_docsis_data() must use the same
+        cached HTML from login(), without a second HTTP fetch."""
+        driver._status_html = STATUS_HTML
+
+        with patch.object(driver._session, "get") as mock_get:
+            info = driver.get_device_info()
+            data = driver.get_docsis_data()
+            mock_get.assert_not_called()
+
+        assert info["model"] == "CM3000"
+        assert len(data["channelDs"]["docsis30"]) == 32
+        assert len(data["channelUs"]["docsis30"]) == 4
+
+    def test_regex_handles_nested_braces(self, driver):
+        """Functions with nested braces (if-blocks) must still parse."""
+        html = _build_status_html().replace(
+            "function InitDsTableTagValue()\n{",
+            "function InitDsTableTagValue()\n{\n    if (true) { console.log('ok'); }",
+        )
+        driver._status_html = html
+        data = driver.get_docsis_data()
+        assert len(data["channelDs"]["docsis30"]) == 32
+
+
 # -- Analyzer integration --
 
 class TestAnalyzerIntegration: