Bluetooth (Windows): detect battery level

src/detection/bluetooth/bluetooth_windows.c

@@ -121,5 +121,8 @@ const char* ffDetectBluetooth(FFlist* devices /* FFBluetoothResult */)
 
     ffBluetoothFindDeviceClose(hFind);
 
+    const char* ffBluetoothDetectBattery(FFlist* result);
+    ffBluetoothDetectBattery(devices);
+
     return NULL;
 }

src/detection/bluetooth/bluetooth_windows.cpp

@@ -5,27 +5,118 @@ extern "C"
 #include "util/windows/wmi.hpp"
 #include "util/windows/unicode.hpp"
 
-#include <propvarutil.h>
-
 STDAPI InitVariantFromStringArray(_In_reads_(cElems) PCWSTR *prgsz, _In_ ULONG cElems, _Out_ VARIANT *pvar);
 
-static const char* detectWithWmi(FFlist* result)
+template <typename Fn>
+struct on_scope_exit {
+    on_scope_exit(Fn &&fn): _fn(std::move(fn)) {}
+    ~on_scope_exit() { this->_fn(); }
+
+private:
+    Fn _fn;
+};
+
+extern "C"
+const char* ffBluetoothDetectBattery(FFlist* devices)
 {
     FFWmiQuery query(L"SELECT __PATH FROM Win32_PnPEntity WHERE Service = 'BthHFEnum'", nullptr, FFWmiNamespace::CIMV2);
     if(!query)
         return "Query WMI service failed";
 
-    while(FFWmiRecord record = query.next())
+    IWbemClassObject* pInParams = nullptr;
+    on_scope_exit releaseInParams([&] { pInParams && pInParams->Release(); });
     {
-        IWbemClassObject* pInParams = nullptr;
-        PCWSTR props[] = { L"{104EA319-6EE2-4701-BD47-8DDBF425BBE5} 2" };
+        IWbemClassObject* pnpEntityClass = nullptr;
+
+        if (FAILED(query.pService->GetObjectW(bstr_t(L"Win32_PnPEntity"), 0, nullptr, &pnpEntityClass, nullptr)))
+            return "Failed to get PnP entity class";
+        on_scope_exit releasePnpEntityClass([&] { pnpEntityClass && pnpEntityClass->Release(); });
+
+        if (FAILED(pnpEntityClass->GetMethod(bstr_t(L"GetDeviceProperties"), 0, &pInParams, NULL)))
+            return "Failed to get GetDeviceProperties method";
+
         VARIANT devicePropertyKeys;
-        InitVariantFromStringArray(props, ARRAY_SIZE(props), &devicePropertyKeys);
-        record.obj->GetMethod(bstr_t(L"GetDeviceProperties"), 0, &pInParams, NULL);
-        pInParams->Put(L"devicePropertyKeys", 0, &devicePropertyKeys, CIM_FLAG_ARRAY | CIM_STRING);
-        IWbemCallResult* pResult = nullptr;
-        query.pService->ExecMethod(bstr_t(record.get(L"__PATH").bstrVal), bstr_t(L"GetDeviceProperties"), 0, nullptr, pInParams, nullptr, &pResult);
-        // TODO: parse result
+        PCWSTR props[] = { L"{104EA319-6EE2-4701-BD47-8DDBF425BBE5} 2", L"DEVPKEY_Bluetooth_DeviceAddress" };
+
+        if (FAILED(InitVariantFromStringArray(props, ARRAY_SIZE(props), &devicePropertyKeys)))
+            return "Failed to init variant from string array";
+        on_scope_exit releaseDevicePropertyKeys([&] { VariantClear(&devicePropertyKeys); });
+
+        if (FAILED(pInParams->Put(L"devicePropertyKeys", 0, &devicePropertyKeys, CIM_FLAG_ARRAY | CIM_STRING)))
+            return "Failed to put devicePropertyKeys";
     }
+
+    while (FFWmiRecord record = query.next())
+    {
+        IWbemCallResult* pCallResult = nullptr;
+
+        if (FAILED(query.pService->ExecMethod(record.get(L"__PATH").bstrVal, bstr_t(L"GetDeviceProperties"), 0, nullptr, pInParams, nullptr, &pCallResult)))
+            continue;
+        on_scope_exit releaseCallResult([&] { pCallResult && pCallResult->Release(); });
+
+        IWbemClassObject* pResultObject = nullptr;
+        if (FAILED(pCallResult->GetResultObject(WBEM_INFINITE, &pResultObject)))
+            continue;
+        on_scope_exit releaseResultObject([&] { pResultObject && pResultObject->Release(); });
+
+        VARIANT propArray;
+        if (FAILED(pResultObject->Get(L"deviceProperties", 0, &propArray, nullptr, nullptr)))
+            continue;
+        on_scope_exit releasePropArray([&] { VariantClear(&propArray); });
+
+        if (propArray.vt != (VT_ARRAY | VT_UNKNOWN) ||
+            (propArray.parray->fFeatures & FADF_UNKNOWN) == 0 ||
+            propArray.parray->cDims != 1 ||
+            propArray.parray->rgsabound[0].cElements != 2
+        )
+            continue;
+
+        uint8_t batt = 0;
+        for (LONG i = 0; i < 2; i++)
+        {
+            IWbemClassObject* object = nullptr;
+            if (FAILED(SafeArrayGetElement(propArray.parray, &i, &object)))
+                continue;
+
+            FFWmiRecord rec(object);
+            auto data = rec.get(L"Data");
+            if (data.vt == VT_EMPTY)
+                break;
+
+            if (i == 0)
+                batt = data.get<uint8_t>();
+            else
+            {
+                FF_STRBUF_AUTO_DESTROY addr; // MAC address without colon
+                ffStrbufInitWSV(&addr, data.get<std::wstring_view>());
+                if (__builtin_expect(addr.length != 12, 0))
+                    continue;
+
+                FF_LIST_FOR_EACH(FFBluetoothResult, bt, *devices)
+                {
+                    if (bt->address.length != 12 + 5)
+                        continue;
+
+                    if (addr.chars[0] == bt->address.chars[0] &&
+                        addr.chars[1] == bt->address.chars[1] &&
+                        addr.chars[2] == bt->address.chars[3] &&
+                        addr.chars[3] == bt->address.chars[4] &&
+                        addr.chars[4] == bt->address.chars[6] &&
+                        addr.chars[5] == bt->address.chars[7] &&
+                        addr.chars[6] == bt->address.chars[9] &&
+                        addr.chars[7] == bt->address.chars[10] &&
+                        addr.chars[8] == bt->address.chars[12] &&
+                        addr.chars[9] == bt->address.chars[13] &&
+                        addr.chars[10] == bt->address.chars[15] &&
+                        addr.chars[11] == bt->address.chars[16])
+                    {
+                        bt->battery = batt;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
     return NULL;
 }

src/util/windows/wmi.hpp

@@ -22,13 +22,7 @@ struct FFWmiRecord
 {
     IWbemClassObject* obj = nullptr;
 
-    explicit FFWmiRecord(IEnumWbemClassObject* pEnumerator) {
-        if(!pEnumerator) return;
-
-        ULONG ret;
-        bool ok = SUCCEEDED(pEnumerator->Next(instance.config.general.wmiTimeout, 1, &obj, &ret)) && ret;
-        if(!ok) obj = nullptr;
-    }
+    explicit FFWmiRecord(IWbemClassObject* obj): obj(obj) {};
     FFWmiRecord(const FFWmiRecord&) = delete;
     FFWmiRecord(FFWmiRecord&& other) { *this = (FFWmiRecord&&)other; }
     ~FFWmiRecord() { if(obj) obj->Release(); }
@@ -71,7 +65,11 @@ struct FFWmiQuery
     }
 
     FFWmiRecord next() {
-        FFWmiRecord result(pEnumerator);
+        IWbemClassObject* obj = nullptr;
+        ULONG ret;
+        pEnumerator->Next(instance.config.general.wmiTimeout, 1, &obj, &ret);
+
+        FFWmiRecord result(obj);
         return result;
     }
 };