[windows] try to use APPDATA

Author: tstack

src/base/paths.cc

@@ -27,28 +27,118 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
+#include <filesystem>
 
-#ifdef __CYGWIN__
-#    include <algorithm>
-#    include <iostream>
-#    include <sstream>
-#endif
+#include "paths.hh"
 
 #include <unistd.h>
 
+#include "config.h"
 #include "fmt/format.h"
-#include "paths.hh"
+#include "opt_util.hh"
+
+#ifdef _WIN32
+// Make sure we don't bring in all the extra junk with windows.h
+#    ifndef WIN32_LEAN_AND_MEAN
+#        define WIN32_LEAN_AND_MEAN
+#    endif
+// stringapiset.h depends on this
+#    include <windows.h>
+// For SUCCEEDED macro
+#    include <winerror.h>
+// For WideCharToMultiByte
+#    include <stringapiset.h>
+// For SHGetFolderPathW and various CSIDL "magic numbers"
+#    include <shlobj.h>
+
+namespace sago {
+namespace internal {
+
+std::string
+win32_utf16_to_utf8(const wchar_t* wstr)
+{
+    std::string res;
+    // If the 6th parameter is 0 then WideCharToMultiByte returns the number of
+    // bytes needed to store the result.
+    int actualSize = WideCharToMultiByte(
+        CP_UTF8, 0, wstr, -1, nullptr, 0, nullptr, nullptr);
+    if (actualSize > 0) {
+        // If the converted UTF-8 string could not be in the initial buffer.
+        // Allocate one that can hold it.
+        std::vector<char> buffer(actualSize);
+        actualSize = WideCharToMultiByte(CP_UTF8,
+                                         0,
+                                         wstr,
+                                         -1,
+                                         &buffer[0],
+                                         static_cast<int>(buffer.size()),
+                                         nullptr,
+                                         nullptr);
+        res = buffer.data();
+    }
+    if (actualSize == 0) {
+        // WideCharToMultiByte return 0 for errors.
+        throw std::runtime_error("UTF16 to UTF8 failed with error code: "
+                                 + std::to_string(GetLastError()));
+    }
+    return res;
+}
 
-namespace lnav::paths {
+}  // namespace internal
+}  // namespace sago
+
+class FreeCoTaskMemory {
+    LPWSTR pointer = NULL;
+
+public:
+    explicit FreeCoTaskMemory(LPWSTR pointer) : pointer(pointer) {};
+    ~FreeCoTaskMemory() { CoTaskMemFree(pointer); }
+};
 
-#ifdef __CYGWIN__
-char*
-windows_to_unix_file_path(char* input)
+static std::string
+GetKnownWindowsFolder(REFKNOWNFOLDERID folderId, const char* errorMsg)
 {
-    if (input == nullptr) {
-        return nullptr;
+    LPWSTR wszPath = NULL;
+    HRESULT hr;
+    hr = SHGetKnownFolderPath(folderId, KF_FLAG_CREATE, NULL, &wszPath);
+    FreeCoTaskMemory scopeBoundMemory(wszPath);
+
+    if (!SUCCEEDED(hr)) {
+        throw std::runtime_error(errorMsg);
     }
+    return sago::internal::win32_utf16_to_utf8(wszPath);
+}
+
+static std::string
+GetAppData()
+{
+    return GetKnownWindowsFolder(FOLDERID_RoamingAppData,
+                                 "RoamingAppData could not be found");
+}
+
+static std::string
+GetAppDataCommon()
+{
+    return GetKnownWindowsFolder(FOLDERID_ProgramData,
+                                 "ProgramData could not be found");
+}
+
+static std::string
+GetAppDataLocal()
+{
+    return GetKnownWindowsFolder(FOLDERID_LocalAppData,
+                                 "LocalAppData could not be found");
+}
+#endif
+
+namespace lnav::paths {
+
+#ifdef _WIN32
+std::string
+windows_to_unix_file_path(const std::string& input)
+{
+    static const auto CYGDRIVE = std::filesystem::path("cygdrive");
+
     std::string file_path;
     file_path.assign(input);
 
@@ -70,25 +160,21 @@ windows_to_unix_file_path(char* input)
     const auto remaining_path = file_path.substr(2, file_path.size() - 2);
     file_path = drive_letter + remaining_path;
 
-    std::stringstream stringstream;
-    stringstream << "/cygdrive/";
-    stringstream << file_path;
-
-    return const_cast<char*>(stringstream.str().c_str());
+    return (CYGDRIVE / file_path).string();
 }
 #endif
 
 std::filesystem::path
 dotlnav()
 {
-#ifdef __CYGWIN__
-    auto home_env = windows_to_unix_file_path(getenv("APPDATA"));
+#ifdef _WIN32
+    auto home_env = windows_to_unix_file_path(GetAppDataLocal());
 #else
-    auto home_env = getenv("HOME");
+    auto home_env = std::string(getenv_opt("HOME").value_or(""));
 #endif
-    auto xdg_config_home = getenv("XDG_CONFIG_HOME");
+    const auto* xdg_config_home = getenv("XDG_CONFIG_HOME");
 
-    if (home_env != nullptr) {
+    if (!home_env.empty()) {
         auto home_path = std::filesystem::path(home_env);
 
         if (std::filesystem::is_directory(home_path)) {