From 6a6ab6529a253b1fd56b30ee2ed6cab9ad95fd70 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Sat, 9 Jul 2022 00:14:48 +1000
Subject: [PATCH] Backport SettingsInterface

---
 src/common/CMakeLists.txt                     |   3 +
 src/common/common.vcxproj                     |   3 +
 src/common/common.vcxproj.filters             |   3 +
 src/common/layered_settings_interface.cpp     | 189 ++++++++++++++++
 src/common/layered_settings_interface.h       |  62 +++++
 src/common/settings_interface.h               | 213 ++++++++++++++++++
 src/core/settings.cpp                         |   2 -
 src/core/settings.h                           |  28 +--
 .../regtest_settings_interface.cpp            | 122 ++++++----
 .../regtest_settings_interface.h              |  29 ++-
 src/frontend-common/common_host_interface.cpp |  17 +-
 .../ini_settings_interface.cpp                | 146 ++++++++++--
 src/frontend-common/ini_settings_interface.h  |  45 +++-
 13 files changed, 749 insertions(+), 113 deletions(-)
 create mode 100644 src/common/layered_settings_interface.cpp
 create mode 100644 src/common/layered_settings_interface.h
 create mode 100644 src/common/settings_interface.h

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index a68e453ec..a0ff3d5f4 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -30,6 +30,8 @@ add_library(common
   gl/texture.h
   hash_combine.h
   heap_array.h
+  layered_settings_interface.cpp
+  layered_settings_interface.h
   log.cpp
   log.h
   make_array.h
@@ -43,6 +45,7 @@ add_library(common
   progress_callback.h
   rectangle.h
   scope_guard.h
+  settings_interface.h
   string.cpp
   string.h
   string_util.cpp
diff --git a/src/common/common.vcxproj b/src/common/common.vcxproj
index f26b94d5e..8623a9b67 100644
--- a/src/common/common.vcxproj
+++ b/src/common/common.vcxproj
@@ -45,6 +45,7 @@
       <ExcludedFromBuild Condition="'$(BuildingForUWP)'=='true'">true</ExcludedFromBuild>
     </ClInclude>
     <ClInclude Include="image.h" />
+    <ClInclude Include="layered_settings_interface.h" />
     <ClInclude Include="log.h" />
     <ClInclude Include="lru_cache.h" />
     <ClInclude Include="make_array.h" />
@@ -55,6 +56,7 @@
     <ClInclude Include="progress_callback.h" />
     <ClInclude Include="rectangle.h" />
     <ClInclude Include="scope_guard.h" />
+    <ClInclude Include="settings_interface.h" />
     <ClInclude Include="string.h" />
     <ClInclude Include="string_util.h" />
     <ClInclude Include="thirdparty\StackWalker.h">
@@ -116,6 +118,7 @@
       <ExcludedFromBuild Condition="'$(BuildingForUWP)'=='true'">true</ExcludedFromBuild>
     </ClCompile>
     <ClCompile Include="image.cpp" />
+    <ClCompile Include="layered_settings_interface.cpp" />
     <ClCompile Include="log.cpp" />
     <ClCompile Include="md5_digest.cpp" />
     <ClCompile Include="minizip_helpers.cpp" />
diff --git a/src/common/common.vcxproj.filters b/src/common/common.vcxproj.filters
index 08727e67b..85eb5dc60 100644
--- a/src/common/common.vcxproj.filters
+++ b/src/common/common.vcxproj.filters
@@ -133,6 +133,8 @@
     <ClInclude Include="gl\loader.h">
       <Filter>gl</Filter>
     </ClInclude>
+    <ClInclude Include="settings_interface.h" />
+    <ClInclude Include="layered_settings_interface.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="gl\program.cpp">
@@ -244,6 +246,7 @@
     <ClCompile Include="vulkan\loader.cpp">
       <Filter>vulkan</Filter>
     </ClCompile>
+    <ClCompile Include="layered_settings_interface.cpp" />
   </ItemGroup>
   <ItemGroup>
     <Natvis Include="bitfield.natvis" />
diff --git a/src/common/layered_settings_interface.cpp b/src/common/layered_settings_interface.cpp
new file mode 100644
index 000000000..922db3f82
--- /dev/null
+++ b/src/common/layered_settings_interface.cpp
@@ -0,0 +1,189 @@
+#include "layered_settings_interface.h"
+#include "common/assert.h"
+
+LayeredSettingsInterface::LayeredSettingsInterface() = default;
+
+LayeredSettingsInterface::~LayeredSettingsInterface() = default;
+
+bool LayeredSettingsInterface::Save()
+{
+  Panic("Attempting to save layered settings interface");
+  return false;
+}
+
+void LayeredSettingsInterface::Clear()
+{
+  Panic("Attempting to clear layered settings interface");
+}
+
+bool LayeredSettingsInterface::GetIntValue(const char* section, const char* key, s32* value) const
+{
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      if (sif->GetIntValue(section, key, value))
+        return true;
+    }
+  }
+
+  return false;
+}
+
+bool LayeredSettingsInterface::GetUIntValue(const char* section, const char* key, u32* value) const
+{
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      if (sif->GetUIntValue(section, key, value))
+        return true;
+    }
+  }
+
+  return false;
+}
+
+bool LayeredSettingsInterface::GetFloatValue(const char* section, const char* key, float* value) const
+{
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      if (sif->GetFloatValue(section, key, value))
+        return true;
+    }
+  }
+
+  return false;
+}
+
+bool LayeredSettingsInterface::GetDoubleValue(const char* section, const char* key, double* value) const
+{
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      if (sif->GetDoubleValue(section, key, value))
+        return true;
+    }
+  }
+
+  return false;
+}
+
+bool LayeredSettingsInterface::GetBoolValue(const char* section, const char* key, bool* value) const
+{
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      if (sif->GetBoolValue(section, key, value))
+        return true;
+    }
+  }
+
+  return false;
+}
+
+bool LayeredSettingsInterface::GetStringValue(const char* section, const char* key, std::string* value) const
+{
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      if (sif->GetStringValue(section, key, value))
+        return true;
+    }
+  }
+
+  return false;
+}
+
+void LayeredSettingsInterface::SetIntValue(const char* section, const char* key, int value)
+{
+  Panic("Attempt to call SetIntValue() on layered settings interface");
+}
+
+void LayeredSettingsInterface::SetUIntValue(const char* section, const char* key, u32 value)
+{
+  Panic("Attempt to call SetUIntValue() on layered settings interface");
+}
+
+void LayeredSettingsInterface::SetFloatValue(const char* section, const char* key, float value)
+{
+  Panic("Attempt to call SetFloatValue() on layered settings interface");
+}
+
+void LayeredSettingsInterface::SetDoubleValue(const char* section, const char* key, double value)
+{
+  Panic("Attempt to call SetDoubleValue() on layered settings interface");
+}
+
+void LayeredSettingsInterface::SetBoolValue(const char* section, const char* key, bool value)
+{
+  Panic("Attempt to call SetBoolValue() on layered settings interface");
+}
+
+void LayeredSettingsInterface::SetStringValue(const char* section, const char* key, const char* value)
+{
+  Panic("Attempt to call SetStringValue() on layered settings interface");
+}
+
+bool LayeredSettingsInterface::ContainsValue(const char* section, const char* key) const
+{
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      if (sif->ContainsValue(key, section))
+        return true;
+    }
+  }
+  return false;
+}
+
+void LayeredSettingsInterface::DeleteValue(const char* section, const char* key)
+{
+  Panic("Attempt to call DeleteValue() on layered settings interface");
+}
+
+void LayeredSettingsInterface::ClearSection(const char* section)
+{
+  Panic("Attempt to call ClearSection() on layered settings interface");
+}
+
+std::vector<std::string> LayeredSettingsInterface::GetStringList(const char* section, const char* key) const
+{
+  std::vector<std::string> ret;
+
+  for (u32 layer = FIRST_LAYER; layer <= LAST_LAYER; layer++)
+  {
+    if (SettingsInterface* sif = m_layers[layer]; sif != nullptr)
+    {
+      ret = sif->GetStringList(section, key);
+      if (!ret.empty())
+        break;
+    }
+  }
+
+  return ret;
+}
+
+void LayeredSettingsInterface::SetStringList(const char* section, const char* key,
+                                             const std::vector<std::string>& items)
+{
+  Panic("Attempt to call SetStringList() on layered settings interface");
+}
+
+bool LayeredSettingsInterface::RemoveFromStringList(const char* section, const char* key, const char* item)
+{
+  Panic("Attempt to call RemoveFromStringList() on layered settings interface");
+  return false;
+}
+
+bool LayeredSettingsInterface::AddToStringList(const char* section, const char* key, const char* item)
+{
+  Panic("Attempt to call AddToStringList() on layered settings interface");
+  return true;
+}
diff --git a/src/common/layered_settings_interface.h b/src/common/layered_settings_interface.h
new file mode 100644
index 000000000..982871048
--- /dev/null
+++ b/src/common/layered_settings_interface.h
@@ -0,0 +1,62 @@
+#pragma once
+#include "settings_interface.h"
+#include <array>
+
+class LayeredSettingsInterface final : public SettingsInterface
+{
+public:
+  enum Layer : u32
+  {
+    LAYER_CMDLINE,
+    LAYER_GAME,
+    LAYER_INPUT,
+    LAYER_BASE,
+    NUM_LAYERS
+  };
+
+  LayeredSettingsInterface();
+  ~LayeredSettingsInterface() override;
+
+  SettingsInterface* GetLayer(Layer layer) const { return m_layers[layer]; }
+  void SetLayer(Layer layer, SettingsInterface* sif) { m_layers[layer] = sif; }
+
+  bool Save() override;
+
+  void Clear() override;
+
+  bool GetIntValue(const char* section, const char* key, s32* value) const override;
+  bool GetUIntValue(const char* section, const char* key, u32* value) const override;
+  bool GetFloatValue(const char* section, const char* key, float* value) const override;
+  bool GetDoubleValue(const char* section, const char* key, double* value) const override;
+  bool GetBoolValue(const char* section, const char* key, bool* value) const override;
+  bool GetStringValue(const char* section, const char* key, std::string* value) const override;
+
+  void SetIntValue(const char* section, const char* key, s32 value) override;
+  void SetUIntValue(const char* section, const char* key, u32 value) override;
+  void SetFloatValue(const char* section, const char* key, float value) override;
+  void SetDoubleValue(const char* section, const char* key, double value) override;
+  void SetBoolValue(const char* section, const char* key, bool value) override;
+  void SetStringValue(const char* section, const char* key, const char* value) override;
+  bool ContainsValue(const char* section, const char* key) const override;
+  void DeleteValue(const char* section, const char* key) override;
+  void ClearSection(const char* section) override;
+
+  std::vector<std::string> GetStringList(const char* section, const char* key) const override;
+  void SetStringList(const char* section, const char* key, const std::vector<std::string>& items) override;
+  bool RemoveFromStringList(const char* section, const char* key, const char* item) override;
+  bool AddToStringList(const char* section, const char* key, const char* item) override;
+
+  // default parameter overloads
+  using SettingsInterface::GetBoolValue;
+  using SettingsInterface::GetDoubleValue;
+  using SettingsInterface::GetFloatValue;
+  using SettingsInterface::GetIntValue;
+  using SettingsInterface::GetStringValue;
+  using SettingsInterface::GetUIntValue;
+
+private:
+  static constexpr Layer FIRST_LAYER = LAYER_CMDLINE;
+  static constexpr Layer LAST_LAYER = LAYER_BASE;
+
+  std::array<SettingsInterface*, NUM_LAYERS> m_layers{};
+};
diff --git a/src/common/settings_interface.h b/src/common/settings_interface.h
new file mode 100644
index 000000000..80fab415a
--- /dev/null
+++ b/src/common/settings_interface.h
@@ -0,0 +1,213 @@
+#pragma once
+
+#include "types.h"
+#include <optional>
+#include <string>
+#include <vector>
+
+class SettingsInterface
+{
+public:
+  virtual ~SettingsInterface() = default;
+
+  virtual bool Save() = 0;
+  virtual void Clear() = 0;
+
+  virtual bool GetIntValue(const char* section, const char* key, s32* value) const = 0;
+  virtual bool GetUIntValue(const char* section, const char* key, u32* value) const = 0;
+  virtual bool GetFloatValue(const char* section, const char* key, float* value) const = 0;
+  virtual bool GetDoubleValue(const char* section, const char* key, double* value) const = 0;
+  virtual bool GetBoolValue(const char* section, const char* key, bool* value) const = 0;
+  virtual bool GetStringValue(const char* section, const char* key, std::string* value) const = 0;
+
+  virtual void SetIntValue(const char* section, const char* key, s32 value) = 0;
+  virtual void SetUIntValue(const char* section, const char* key, u32 value) = 0;
+  virtual void SetFloatValue(const char* section, const char* key, float value) = 0;
+  virtual void SetDoubleValue(const char* section, const char* key, double value) = 0;
+  virtual void SetBoolValue(const char* section, const char* key, bool value) = 0;
+  virtual void SetStringValue(const char* section, const char* key, const char* value) = 0;
+
+  virtual std::vector<std::string> GetStringList(const char* section, const char* key) const = 0;
+  virtual void SetStringList(const char* section, const char* key, const std::vector<std::string>& items) = 0;
+  virtual bool RemoveFromStringList(const char* section, const char* key, const char* item) = 0;
+  virtual bool AddToStringList(const char* section, const char* key, const char* item) = 0;
+
+  virtual bool ContainsValue(const char* section, const char* key) const = 0;
+  virtual void DeleteValue(const char* section, const char* key) = 0;
+  virtual void ClearSection(const char* section) = 0;
+
+  ALWAYS_INLINE s32 GetIntValue(const char* section, const char* key, s32 default_value = 0) const
+  {
+    s32 value;
+    return GetIntValue(section, key, &value) ? value : default_value;
+  }
+
+  ALWAYS_INLINE u32 GetUIntValue(const char* section, const char* key, u32 default_value = 0) const
+  {
+    u32 value;
+    return GetUIntValue(section, key, &value) ? value : default_value;
+  }
+
+  ALWAYS_INLINE float GetFloatValue(const char* section, const char* key, float default_value = 0.0f) const
+  {
+    float value;
+    return GetFloatValue(section, key, &value) ? value : default_value;
+  }
+
+  ALWAYS_INLINE double GetDoubleValue(const char* section, const char* key, double default_value = 0.0) const
+  {
+    double value;
+    return GetDoubleValue(section, key, &value) ? value : default_value;
+  }
+
+  ALWAYS_INLINE bool GetBoolValue(const char* section, const char* key, bool default_value = false) const
+  {
+    bool value;
+    return GetBoolValue(section, key, &value) ? value : default_value;
+  }
+
+  ALWAYS_INLINE std::string GetStringValue(const char* section, const char* key, const char* default_value = "") const
+  {
+    std::string value;
+    if (!GetStringValue(section, key, &value))
+      value.assign(default_value);
+    return value;
+  }
+
+  ALWAYS_INLINE std::optional<s32> GetOptionalIntValue(const char* section, const char* key,
+                                                       std::optional<s32> default_value = std::nullopt)
+  {
+    s32 ret;
+    return GetIntValue(section, key, &ret) ? std::optional<s32>(ret) : default_value;
+  }
+
+  ALWAYS_INLINE std::optional<u32> GetOptionalUIntValue(const char* section, const char* key,
+                                                        std::optional<u32> default_value = std::nullopt)
+  {
+    u32 ret;
+    return GetUIntValue(section, key, &ret) ? std::optional<u32>(ret) : default_value;
+  }
+
+  ALWAYS_INLINE std::optional<float> GetOptionalFloatValue(const char* section, const char* key,
+                                                           std::optional<float> default_value = std::nullopt)
+  {
+    float ret;
+    return GetFloatValue(section, key, &ret) ? std::optional<float>(ret) : default_value;
+  }
+
+  ALWAYS_INLINE std::optional<double> GetOptionalDoubleValue(const char* section, const char* key,
+                                                             std::optional<double> default_value = std::nullopt)
+  {
+    double ret;
+    return GetDoubleValue(section, key, &ret) ? std::optional<double>(ret) : default_value;
+  }
+
+  ALWAYS_INLINE std::optional<bool> GetOptionalBoolValue(const char* section, const char* key,
+                                                         std::optional<bool> default_value = std::nullopt)
+  {
+    bool ret;
+    return GetBoolValue(section, key, &ret) ? std::optional<bool>(ret) : default_value;
+  }
+
+  ALWAYS_INLINE std::optional<std::string>
+  GetOptionalStringValue(const char* section, const char* key,
+                         std::optional<const char*> default_value = std::nullopt) const
+  {
+    std::string ret;
+    return GetStringValue(section, key, &ret) ? std::optional<std::string>(ret) : default_value;
+  }
+
+  ALWAYS_INLINE void SetOptionalIntValue(const char* section, const char* key, const std::optional<s32>& value)
+  {
+    value.has_value() ? SetIntValue(section, key, value.value()) : DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void SetOptionalUIntValue(const char* section, const char* key, const std::optional<u32>& value)
+  {
+    value.has_value() ? SetUIntValue(section, key, value.value()) : DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void SetOptionalFloatValue(const char* section, const char* key, const std::optional<float>& value)
+  {
+    value.has_value() ? SetFloatValue(section, key, value.value()) : DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void SetOptionalDoubleValue(const char* section, const char* key, const std::optional<double>& value)
+  {
+    value.has_value() ? SetDoubleValue(section, key, value.value()) : DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void SetOptionalBoolValue(const char* section, const char* key, const std::optional<bool>& value)
+  {
+    value.has_value() ? SetBoolValue(section, key, value.value()) : DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void SetOptionalStringValue(const char* section, const char* key,
+                                            const std::optional<const char*>& value)
+  {
+    value.has_value() ? SetStringValue(section, key, value.value()) : DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void CopyBoolValue(const SettingsInterface& si, const char* section, const char* key)
+  {
+    bool value;
+    if (si.GetBoolValue(section, key, &value))
+      SetBoolValue(section, key, value);
+    else
+      DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void CopyIntValue(const SettingsInterface& si, const char* section, const char* key)
+  {
+    s32 value;
+    if (si.GetIntValue(section, key, &value))
+      SetIntValue(section, key, value);
+    else
+      DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void CopyUIntValue(const SettingsInterface& si, const char* section, const char* key)
+  {
+    u32 value;
+    if (si.GetUIntValue(section, key, &value))
+      SetUIntValue(section, key, value);
+    else
+      DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void CopyFloatValue(const SettingsInterface& si, const char* section, const char* key)
+  {
+    float value;
+    if (si.GetFloatValue(section, key, &value))
+      SetFloatValue(section, key, value);
+    else
+      DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void CopyDoubleValue(const SettingsInterface& si, const char* section, const char* key)
+  {
+    double value;
+    if (si.GetDoubleValue(section, key, &value))
+      SetDoubleValue(section, key, value);
+    else
+      DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void CopyStringValue(const SettingsInterface& si, const char* section, const char* key)
+  {
+    std::string value;
+    if (si.GetStringValue(section, key, &value))
+      SetStringValue(section, key, value.c_str());
+    else
+      DeleteValue(section, key);
+  }
+
+  ALWAYS_INLINE void CopyStringListValue(const SettingsInterface& si, const char* section, const char* key)
+  {
+    std::vector<std::string> value(si.GetStringList(section, key));
+    if (!value.empty())
+      SetStringList(section, key, value);
+    else
+      DeleteValue(section, key);
+  }
+};
diff --git a/src/core/settings.cpp b/src/core/settings.cpp
index 833b6b9f6..93227ca3f 100644
--- a/src/core/settings.cpp
+++ b/src/core/settings.cpp
@@ -12,8 +12,6 @@
 
 Settings g_settings;
 
-SettingsInterface::~SettingsInterface() = default;
-
 const char* SettingInfo::StringDefaultValue() const
 {
   return default_value ? default_value : "";
diff --git a/src/core/settings.h b/src/core/settings.h
index e837f8b26..bcba2c08f 100644
--- a/src/core/settings.h
+++ b/src/core/settings.h
@@ -1,5 +1,6 @@
 #pragma once
 #include "common/log.h"
+#include "common/settings_interface.h"
 #include "common/string.h"
 #include "types.h"
 #include <array>
@@ -7,33 +8,6 @@
 #include <string>
 #include <vector>
 
-class SettingsInterface
-{
-public:
-  virtual ~SettingsInterface();
-
-  virtual bool Save() = 0;
-  virtual void Clear() = 0;
-
-  virtual int GetIntValue(const char* section, const char* key, int default_value = 0) = 0;
-  virtual float GetFloatValue(const char* section, const char* key, float default_value = 0.0f) = 0;
-  virtual bool GetBoolValue(const char* section, const char* key, bool default_value = false) = 0;
-  virtual std::string GetStringValue(const char* section, const char* key, const char* default_value = "") = 0;
-
-  virtual void SetIntValue(const char* section, const char* key, int value) = 0;
-  virtual void SetFloatValue(const char* section, const char* key, float value) = 0;
-  virtual void SetBoolValue(const char* section, const char* key, bool value) = 0;
-  virtual void SetStringValue(const char* section, const char* key, const char* value) = 0;
-
-  virtual std::vector<std::string> GetStringList(const char* section, const char* key) = 0;
-  virtual void SetStringList(const char* section, const char* key, const std::vector<std::string>& items) = 0;
-  virtual bool RemoveFromStringList(const char* section, const char* key, const char* item) = 0;
-  virtual bool AddToStringList(const char* section, const char* key, const char* item) = 0;
-
-  virtual void DeleteValue(const char* section, const char* key) = 0;
-  virtual void ClearSection(const char* section) = 0;
-};
-
 struct SettingInfo
 {
   enum class Type
diff --git a/src/duckstation-regtest/regtest_settings_interface.cpp b/src/duckstation-regtest/regtest_settings_interface.cpp
index e41fa45dd..c7d210d85 100644
--- a/src/duckstation-regtest/regtest_settings_interface.cpp
+++ b/src/duckstation-regtest/regtest_settings_interface.cpp
@@ -23,90 +23,129 @@ static std::string GetFullKey(const char* section, const char* key)
   return StringUtil::StdStringFromFormat("%s/%s", section, key);
 }
 
-int RegTestSettingsInterface::GetIntValue(const char* section, const char* key, int default_value /*= 0*/)
+bool RegTestSettingsInterface::GetIntValue(const char* section, const char* key, s32* value) const
 {
-  int retval = default_value;
-
   const std::string fullkey(GetFullKey(section, key));
   auto iter = m_keys.find(fullkey);
-  if (iter != m_keys.end())
-    retval = StringUtil::FromChars<int>(iter->second, 10).value_or(default_value);
+  if (iter == m_keys.end())
+    return false;
 
-  Log_DevPrintf("GetIntValue(%s) -> %d", fullkey.c_str(), retval);
-  return retval;
+  std::optional<s32> parsed = StringUtil::FromChars<s32>(iter->second, 10);
+  if (!parsed.has_value())
+    return false;
+
+  *value = parsed.value();
+  return true;
 }
 
-float RegTestSettingsInterface::GetFloatValue(const char* section, const char* key, float default_value /*= 0.0f*/)
+bool RegTestSettingsInterface::GetUIntValue(const char* section, const char* key, u32* value) const
 {
-  float retval = default_value;
-
   const std::string fullkey(GetFullKey(section, key));
   auto iter = m_keys.find(fullkey);
-  if (iter != m_keys.end())
-    retval = StringUtil::FromChars<float>(iter->second).value_or(default_value);
+  if (iter == m_keys.end())
+    return false;
 
-  Log_DevPrintf("GetFloatValue(%s) -> %f", fullkey.c_str(), retval);
-  return retval;
+  std::optional<u32> parsed = StringUtil::FromChars<u32>(iter->second, 10);
+  if (!parsed.has_value())
+    return false;
+
+  *value = parsed.value();
+  return true;
 }
 
-bool RegTestSettingsInterface::GetBoolValue(const char* section, const char* key, bool default_value /*= false*/)
+bool RegTestSettingsInterface::GetFloatValue(const char* section, const char* key, float* value) const
 {
-  bool retval = default_value;
-
   const std::string fullkey(GetFullKey(section, key));
   auto iter = m_keys.find(fullkey);
-  if (iter != m_keys.end())
-    retval = StringUtil::FromChars<bool>(iter->second).value_or(default_value);
+  if (iter == m_keys.end())
+    return false;
 
-  Log_DevPrintf("GetBoolValue(%s) -> %s", fullkey.c_str(), retval ? "true" : "false");
-  return retval;
+  std::optional<float> parsed = StringUtil::FromChars<float>(iter->second);
+  if (!parsed.has_value())
+    return false;
+
+  *value = parsed.value();
+  return true;
 }
 
-std::string RegTestSettingsInterface::GetStringValue(const char* section, const char* key,
-                                                     const char* default_value /*= ""*/)
+bool RegTestSettingsInterface::GetDoubleValue(const char* section, const char* key, double* value) const
 {
-  std::string retval;
-
   const std::string fullkey(GetFullKey(section, key));
   auto iter = m_keys.find(fullkey);
-  if (iter != m_keys.end())
-    retval = iter->second;
-  else
-    retval = default_value;
+  if (iter == m_keys.end())
+    return false;
 
-  Log_DevPrintf("GetStringValue(%s) -> %s", fullkey.c_str(), retval.c_str());
-  return retval;
+  std::optional<double> parsed = StringUtil::FromChars<double>(iter->second);
+  if (!parsed.has_value())
+    return false;
+
+  *value = parsed.value();
+  return true;
 }
 
-void RegTestSettingsInterface::SetIntValue(const char* section, const char* key, int value)
+bool RegTestSettingsInterface::GetBoolValue(const char* section, const char* key, bool* value) const
+{
+  const std::string fullkey(GetFullKey(section, key));
+  auto iter = m_keys.find(fullkey);
+  if (iter == m_keys.end())
+    return false;
+
+  std::optional<bool> parsed = StringUtil::FromChars<bool>(iter->second);
+  if (!parsed.has_value())
+    return false;
+
+  *value = parsed.value();
+  return true;
+}
+
+bool RegTestSettingsInterface::GetStringValue(const char* section, const char* key, std::string* value) const
+{
+  const std::string fullkey(GetFullKey(section, key));
+  auto iter = m_keys.find(fullkey);
+  if (iter == m_keys.end())
+    return false;
+
+  *value = iter->second;
+  return true;
+}
+
+void RegTestSettingsInterface::SetIntValue(const char* section, const char* key, s32 value)
+{
+  const std::string fullkey(GetFullKey(section, key));
+  m_keys[std::move(fullkey)] = std::to_string(value);
+}
+
+void RegTestSettingsInterface::SetUIntValue(const char* section, const char* key, u32 value)
 {
   const std::string fullkey(GetFullKey(section, key));
-  Log_DevPrintf("SetIntValue(%s, %d)", fullkey.c_str(), value);
   m_keys[std::move(fullkey)] = std::to_string(value);
 }
 
 void RegTestSettingsInterface::SetFloatValue(const char* section, const char* key, float value)
 {
   const std::string fullkey(GetFullKey(section, key));
-  Log_DevPrintf("SetFloatValue(%s, %f)", fullkey.c_str(), value);
+  m_keys[std::move(fullkey)] = std::to_string(value);
+}
+
+void RegTestSettingsInterface::SetDoubleValue(const char* section, const char* key, double value)
+{
+  const std::string fullkey(GetFullKey(section, key));
   m_keys[std::move(fullkey)] = std::to_string(value);
 }
 
 void RegTestSettingsInterface::SetBoolValue(const char* section, const char* key, bool value)
 {
   const std::string fullkey(GetFullKey(section, key));
-  Log_DevPrintf("SetBoolValue(%s, %s)", fullkey.c_str(), value ? "true" : "false");
   m_keys[std::move(fullkey)] = std::string(value ? "true" : "false");
 }
 
 void RegTestSettingsInterface::SetStringValue(const char* section, const char* key, const char* value)
 {
   const std::string fullkey(GetFullKey(section, key));
-  Log_DevPrintf("SetStringValue(%s, %s)", fullkey.c_str(), value);
   m_keys[std::move(fullkey)] = value;
 }
 
-std::vector<std::string> RegTestSettingsInterface::GetStringList(const char* section, const char* key)
+std::vector<std::string> RegTestSettingsInterface::GetStringList(const char* section, const char* key) const
 {
   std::vector<std::string> ret;
   Panic("Not implemented");
@@ -131,10 +170,15 @@ bool RegTestSettingsInterface::AddToStringList(const char* section, const char*
   return false;
 }
 
+bool RegTestSettingsInterface::ContainsValue(const char* section, const char* key) const
+{
+  const std::string fullkey(GetFullKey(section, key));
+  return (m_keys.find(fullkey) != m_keys.end());
+}
+
 void RegTestSettingsInterface::DeleteValue(const char* section, const char* key)
 {
   const std::string fullkey(GetFullKey(section, key));
-  Log_DevPrintf("DeleteValue(%s)", fullkey.c_str());
 
   auto iter = m_keys.find(fullkey);
   if (iter != m_keys.end())
@@ -143,8 +187,6 @@ void RegTestSettingsInterface::DeleteValue(const char* section, const char* key)
 
 void RegTestSettingsInterface::ClearSection(const char* section)
 {
-  Log_DevPrintf("ClearSection(%s)", section);
-
   const std::string start(StringUtil::StdStringFromFormat("%s/", section));
   for (auto iter = m_keys.begin(); iter != m_keys.end();)
   {
diff --git a/src/duckstation-regtest/regtest_settings_interface.h b/src/duckstation-regtest/regtest_settings_interface.h
index 7f5d312f0..ccbf6930b 100644
--- a/src/duckstation-regtest/regtest_settings_interface.h
+++ b/src/duckstation-regtest/regtest_settings_interface.h
@@ -10,25 +10,38 @@ public:
   ~RegTestSettingsInterface();
 
   bool Save() override;
+
   void Clear() override;
 
-  int GetIntValue(const char* section, const char* key, int default_value = 0) override;
-  float GetFloatValue(const char* section, const char* key, float default_value = 0.0f) override;
-  bool GetBoolValue(const char* section, const char* key, bool default_value = false) override;
+  bool GetIntValue(const char* section, const char* key, s32* value) const override;
+  bool GetUIntValue(const char* section, const char* key, u32* value) const override;
+  bool GetFloatValue(const char* section, const char* key, float* value) const override;
+  bool GetDoubleValue(const char* section, const char* key, double* value) const override;
+  bool GetBoolValue(const char* section, const char* key, bool* value) const override;
+  bool GetStringValue(const char* section, const char* key, std::string* value) const override;
 
-  std::string GetStringValue(const char* section, const char* key, const char* default_value = "") override;
-  void SetIntValue(const char* section, const char* key, int value) override;
+  void SetIntValue(const char* section, const char* key, s32 value) override;
+  void SetUIntValue(const char* section, const char* key, u32 value) override;
   void SetFloatValue(const char* section, const char* key, float value) override;
+  void SetDoubleValue(const char* section, const char* key, double value) override;
   void SetBoolValue(const char* section, const char* key, bool value) override;
   void SetStringValue(const char* section, const char* key, const char* value) override;
+  bool ContainsValue(const char* section, const char* key) const override;
+  void DeleteValue(const char* section, const char* key) override;
+  void ClearSection(const char* section) override;
 
-  std::vector<std::string> GetStringList(const char* section, const char* key) override;
+  std::vector<std::string> GetStringList(const char* section, const char* key) const override;
   void SetStringList(const char* section, const char* key, const std::vector<std::string>& items) override;
   bool RemoveFromStringList(const char* section, const char* key, const char* item) override;
   bool AddToStringList(const char* section, const char* key, const char* item) override;
 
-  void DeleteValue(const char* section, const char* key) override;
-  void ClearSection(const char* section) override;
+  // default parameter overloads
+  using SettingsInterface::GetBoolValue;
+  using SettingsInterface::GetDoubleValue;
+  using SettingsInterface::GetFloatValue;
+  using SettingsInterface::GetIntValue;
+  using SettingsInterface::GetStringValue;
+  using SettingsInterface::GetUIntValue;
 
 private:
   using KeyMap = std::unordered_map<std::string, std::string>;
diff --git a/src/frontend-common/common_host_interface.cpp b/src/frontend-common/common_host_interface.cpp
index 81408490f..f6c2e8603 100644
--- a/src/frontend-common/common_host_interface.cpp
+++ b/src/frontend-common/common_host_interface.cpp
@@ -2866,10 +2866,9 @@ void CommonHostInterface::ClearAllControllerBindings()
 
 bool CommonHostInterface::ApplyInputProfile(const char* profile_path)
 {
-  if (!FileSystem::FileExists(profile_path))
-    return false;
-
   INISettingsInterface profile(profile_path);
+  if (!profile.Load())
+    return false;
 
   std::lock_guard<std::recursive_mutex> guard(m_settings_mutex);
 
@@ -2966,7 +2965,6 @@ bool CommonHostInterface::SaveInputProfile(const char* profile_path)
     Log_WarningPrintf("Input profile at '%s' does not exist, new input profile will be created", profile_path);
 
   INISettingsInterface profile(profile_path);
-  profile.Clear();
 
   for (u32 controller_index = 1; controller_index <= NUM_CONTROLLER_AND_CARD_PORTS; controller_index++)
   {
@@ -3309,6 +3307,10 @@ void CommonHostInterface::LoadSettings()
 #ifndef __ANDROID__
   // we don't check the settings version on android, because it's not using the ini yet..
   // we can re-enable this once we move it over.. eventually.
+  const bool loaded = static_cast<INISettingsInterface*>(m_settings_interface.get())->Load();
+  if (!loaded)
+    SetDefaultSettings(*m_settings_interface);
+
   const int settings_version = m_settings_interface->GetIntValue("Main", "SettingsVersion", -1);
   if (settings_version != SETTINGS_VERSION)
   {
@@ -3876,6 +3878,13 @@ bool CommonHostInterface::UpdateControllerInputMapFromGameSettings()
   }
 
   INISettingsInterface si(std::move(path));
+  if (!si.Load())
+  {
+    AddFormattedOSDMessage(10.0f, TranslateString("OSDMessage", "Input profile '%s' cannot be loaded."),
+                           gs->input_profile_name.c_str());
+    return false;
+  }
+
   UpdateControllerInputMap(si);
   return true;
 }
diff --git a/src/frontend-common/ini_settings_interface.cpp b/src/frontend-common/ini_settings_interface.cpp
index 35146f828..1bf92cdd5 100644
--- a/src/frontend-common/ini_settings_interface.cpp
+++ b/src/frontend-common/ini_settings_interface.cpp
@@ -1,24 +1,28 @@
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2021  PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include "ini_settings_interface.h"
 #include "common/file_system.h"
 #include "common/log.h"
+#include "common/string_util.h"
 #include <algorithm>
 #include <iterator>
 
 Log_SetChannel(INISettingsInterface);
 
-INISettingsInterface::INISettingsInterface(std::string filename) : m_filename(std::move(filename)), m_ini(true, true)
-{
-  SI_Error err = SI_FAIL;
-  std::FILE* fp = FileSystem::OpenCFile(m_filename.c_str(), "rb");
-  if (fp)
-  {
-    err = m_ini.LoadFile(fp);
-    std::fclose(fp);
-  }
-
-  if (err != SI_OK)
-    Log_WarningPrintf("Settings could not be loaded from '%s', defaults will be used.", m_filename.c_str());
-}
+INISettingsInterface::INISettingsInterface(std::string filename) : m_filename(std::move(filename)), m_ini(true, true) {}
 
 INISettingsInterface::~INISettingsInterface()
 {
@@ -26,8 +30,24 @@ INISettingsInterface::~INISettingsInterface()
     Save();
 }
 
+bool INISettingsInterface::Load()
+{
+  if (m_filename.empty())
+    return false;
+
+  SI_Error err = SI_FAIL;
+  auto fp = FileSystem::OpenManagedCFile(m_filename.c_str(), "rb");
+  if (fp)
+    err = m_ini.LoadFile(fp.get());
+
+  return (err == SI_OK);
+}
+
 bool INISettingsInterface::Save()
 {
+  if (m_filename.empty())
+    return false;
+
   SI_Error err = SI_FAIL;
   std::FILE* fp = FileSystem::OpenCFile(m_filename.c_str(), "wb");
   if (fp)
@@ -51,25 +71,84 @@ void INISettingsInterface::Clear()
   m_ini.Reset();
 }
 
-int INISettingsInterface::GetIntValue(const char* section, const char* key, int default_value /*= 0*/)
+bool INISettingsInterface::GetIntValue(const char* section, const char* key, s32* value) const
 {
-  return static_cast<int>(m_ini.GetLongValue(section, key, default_value));
+  const char* str_value = m_ini.GetValue(section, key);
+  if (!str_value)
+    return false;
+
+  std::optional<s32> parsed_value = StringUtil::FromChars<s32>(str_value, 10);
+  if (!parsed_value.has_value())
+    return false;
+
+  *value = parsed_value.value();
+  return true;
 }
 
-float INISettingsInterface::GetFloatValue(const char* section, const char* key, float default_value /*= 0.0f*/)
+bool INISettingsInterface::GetUIntValue(const char* section, const char* key, u32* value) const
 {
-  return static_cast<float>(m_ini.GetDoubleValue(section, key, default_value));
+  const char* str_value = m_ini.GetValue(section, key);
+  if (!str_value)
+    return false;
+
+  std::optional<u32> parsed_value = StringUtil::FromChars<u32>(str_value, 10);
+  if (!parsed_value.has_value())
+    return false;
+
+  *value = parsed_value.value();
+  return true;
 }
 
-bool INISettingsInterface::GetBoolValue(const char* section, const char* key, bool default_value /*= false*/)
+bool INISettingsInterface::GetFloatValue(const char* section, const char* key, float* value) const
 {
-  return m_ini.GetBoolValue(section, key, default_value);
+  const char* str_value = m_ini.GetValue(section, key);
+  if (!str_value)
+    return false;
+
+  std::optional<float> parsed_value = StringUtil::FromChars<float>(str_value);
+  if (!parsed_value.has_value())
+    return false;
+
+  *value = parsed_value.value();
+  return true;
 }
 
-std::string INISettingsInterface::GetStringValue(const char* section, const char* key,
-                                                 const char* default_value /*= ""*/)
+bool INISettingsInterface::GetDoubleValue(const char* section, const char* key, double* value) const
 {
-  return m_ini.GetValue(section, key, default_value);
+  const char* str_value = m_ini.GetValue(section, key);
+  if (!str_value)
+    return false;
+
+  std::optional<double> parsed_value = StringUtil::FromChars<double>(str_value);
+  if (!parsed_value.has_value())
+    return false;
+
+  *value = parsed_value.value();
+  return true;
+}
+
+bool INISettingsInterface::GetBoolValue(const char* section, const char* key, bool* value) const
+{
+  const char* str_value = m_ini.GetValue(section, key);
+  if (!str_value)
+    return false;
+
+  std::optional<bool> parsed_value = StringUtil::FromChars<bool>(str_value);
+  if (!parsed_value.has_value())
+    return false;
+
+  *value = parsed_value.value();
+  return true;
+}
+
+bool INISettingsInterface::GetStringValue(const char* section, const char* key, std::string* value) const
+{
+  const char* str_value = m_ini.GetValue(section, key);
+  if (!str_value)
+    return false;
+
+  value->assign(str_value);
+  return true;
 }
 
 void INISettingsInterface::SetIntValue(const char* section, const char* key, int value)
@@ -78,12 +157,24 @@ void INISettingsInterface::SetIntValue(const char* section, const char* key, int
   m_ini.SetLongValue(section, key, static_cast<long>(value), nullptr, false, true);
 }
 
+void INISettingsInterface::SetUIntValue(const char* section, const char* key, u32 value)
+{
+  m_dirty = true;
+  m_ini.SetLongValue(section, key, static_cast<long>(value), nullptr, false, true);
+}
+
 void INISettingsInterface::SetFloatValue(const char* section, const char* key, float value)
 {
   m_dirty = true;
   m_ini.SetDoubleValue(section, key, static_cast<double>(value), nullptr, true);
 }
 
+void INISettingsInterface::SetDoubleValue(const char* section, const char* key, double value)
+{
+  m_dirty = true;
+  m_ini.SetDoubleValue(section, key, value, nullptr, true);
+}
+
 void INISettingsInterface::SetBoolValue(const char* section, const char* key, bool value)
 {
   m_dirty = true;
@@ -96,6 +187,11 @@ void INISettingsInterface::SetStringValue(const char* section, const char* key,
   m_ini.SetValue(section, key, value, nullptr, true);
 }
 
+bool INISettingsInterface::ContainsValue(const char* section, const char* key) const
+{
+  return (m_ini.GetValue(section, key, nullptr) != nullptr);
+}
+
 void INISettingsInterface::DeleteValue(const char* section, const char* key)
 {
   m_dirty = true;
@@ -109,7 +205,7 @@ void INISettingsInterface::ClearSection(const char* section)
   m_ini.SetValue(section, nullptr, nullptr);
 }
 
-std::vector<std::string> INISettingsInterface::GetStringList(const char* section, const char* key)
+std::vector<std::string> INISettingsInterface::GetStringList(const char* section, const char* key) const
 {
   std::list<CSimpleIniA::Entry> entries;
   if (!m_ini.GetAllValues(section, key, entries))
@@ -117,8 +213,8 @@ std::vector<std::string> INISettingsInterface::GetStringList(const char* section
 
   std::vector<std::string> ret;
   ret.reserve(entries.size());
-  std::transform(entries.begin(), entries.end(), std::back_inserter(ret),
-                 [](const CSimpleIniA::Entry& it) { return std::string(it.pItem); });
+  for (const CSimpleIniA::Entry& entry : entries)
+    ret.emplace_back(entry.pItem);
   return ret;
 }
 
diff --git a/src/frontend-common/ini_settings_interface.h b/src/frontend-common/ini_settings_interface.h
index 2faa3ed6e..09bf62e76 100644
--- a/src/frontend-common/ini_settings_interface.h
+++ b/src/frontend-common/ini_settings_interface.h
@@ -1,5 +1,20 @@
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2021  PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
-#include "core/settings.h"
+#include "common/settings_interface.h"
 
 // being a pain here...
 #ifdef _WIN32
@@ -13,27 +28,43 @@ public:
   INISettingsInterface(std::string filename);
   ~INISettingsInterface() override;
 
+  const std::string& GetFileName() const { return m_filename; }
+
+  bool Load();
   bool Save() override;
 
   void Clear() override;
 
-  int GetIntValue(const char* section, const char* key, int default_value = 0) override;
-  float GetFloatValue(const char* section, const char* key, float default_value = 0.0f) override;
-  bool GetBoolValue(const char* section, const char* key, bool default_value = false) override;
-  std::string GetStringValue(const char* section, const char* key, const char* default_value = "") override;
+  bool GetIntValue(const char* section, const char* key, s32* value) const override;
+  bool GetUIntValue(const char* section, const char* key, u32* value) const override;
+  bool GetFloatValue(const char* section, const char* key, float* value) const override;
+  bool GetDoubleValue(const char* section, const char* key, double* value) const override;
+  bool GetBoolValue(const char* section, const char* key, bool* value) const override;
+  bool GetStringValue(const char* section, const char* key, std::string* value) const override;
 
-  void SetIntValue(const char* section, const char* key, int value) override;
+  void SetIntValue(const char* section, const char* key, s32 value) override;
+  void SetUIntValue(const char* section, const char* key, u32 value) override;
   void SetFloatValue(const char* section, const char* key, float value) override;
+  void SetDoubleValue(const char* section, const char* key, double value) override;
   void SetBoolValue(const char* section, const char* key, bool value) override;
   void SetStringValue(const char* section, const char* key, const char* value) override;
+  bool ContainsValue(const char* section, const char* key) const override;
   void DeleteValue(const char* section, const char* key) override;
   void ClearSection(const char* section) override;
 
-  std::vector<std::string> GetStringList(const char* section, const char* key) override;
+  std::vector<std::string> GetStringList(const char* section, const char* key) const override;
   void SetStringList(const char* section, const char* key, const std::vector<std::string>& items) override;
   bool RemoveFromStringList(const char* section, const char* key, const char* item) override;
   bool AddToStringList(const char* section, const char* key, const char* item) override;
 
+  // default parameter overloads
+  using SettingsInterface::GetBoolValue;
+  using SettingsInterface::GetDoubleValue;
+  using SettingsInterface::GetFloatValue;
+  using SettingsInterface::GetIntValue;
+  using SettingsInterface::GetStringValue;
+  using SettingsInterface::GetUIntValue;
+
 private:
   std::string m_filename;
   CSimpleIniA m_ini;