13 files changed, 303 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c795b05
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build
+\ No newline at end of file
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..1231968
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,13 @@
+{
+    "C_Cpp.default.configurationProvider": "vector-of-bool.cmake-tools",
+    "C_Cpp.default.cppStandard": "c++17",
+    "C_Cpp.configurationWarnings": "Disabled",
+    "files.associations": {
+        "optional": "cpp",
+        "exception": "cpp",
+        "initializer_list": "cpp",
+        "type_traits": "cpp",
+        "utility": "cpp",
+        "string": "cpp"
+    }
+}
+\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..1257c68
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,32 @@
+cmake_minimum_required(VERSION 3.10)
+project("wanda" LANGUAGES CXX)
+
+set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_STANDARD "17")
+
+# if(NOT CMAKE_BUILD_TYPE)
+#   set(CMAKE_BUILD_TYPE "Release")
+# endif()
+
+if(NOT CMAKE_EXPORT_COMPILE_COMMANDS)
+  set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+endif()
+
+list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/Modules")
+
+include("ConanDependencies")
+include("SystemDependencies")
+
+add_executable("wanda"
+  "src/main.cpp"
+  "src/setting.cpp"
+  "src/setting.hpp"
+  "src/variant.cpp"
+  "src/variant.hpp"
+  )
+target_link_libraries("wanda"
+  "CONAN_PKG::boost_config"
+  "SYSTEM::GIO"
+  )
+\ No newline at end of file
diff --git a/cmake/Modules/ConanDependencies.cmake b/cmake/Modules/ConanDependencies.cmake
new file mode 100644
index 0000000..1aa589d
--- /dev/null
+++ b/cmake/Modules/ConanDependencies.cmake
@@ -0,0 +1,9 @@
+if(NOT EXISTS "${CMAKE_BINARY_DIR}/conan.cmake")
+  message(STATUS "Downloading 'conan' integration")
+  file(DOWNLOAD "https://raw.githubusercontent.com/conan-io/cmake-conan/master/conan.cmake" "${CMAKE_BINARY_DIR}/conan.cmake")
+endif()
+
+include("${CMAKE_BINARY_DIR}/conan.cmake")
+
+conan_add_remote(NAME "bincrafters" URL "https://api.bintray.com/conan/bincrafters/public-conan")
+conan_cmake_run(CONANFILE "conanfile.py" BASIC_SETUP CMAKE_TARGETS BUILD "missing" OUTPUT_QUIET)
diff --git a/cmake/Modules/SystemDependencies.cmake b/cmake/Modules/SystemDependencies.cmake
new file mode 100644
index 0000000..0b1321f
--- /dev/null
+++ b/cmake/Modules/SystemDependencies.cmake
@@ -0,0 +1,7 @@
+find_package("PkgConfig" REQUIRED)
+
+pkg_check_modules("GIO" "gio-2.0" REQUIRED)
+add_library("SYSTEM::GIO" INTERFACE IMPORTED)
+set_property(TARGET "SYSTEM::GIO" PROPERTY INTERFACE_LINK_LIBRARIES ${GIO_LIBRARIES})
+set_property(TARGET "SYSTEM::GIO" PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${GIO_INCLUDE_DIRS})
+set_property(TARGET "SYSTEM::GIO" PROPERTY INTERFACE_COMPILE_OPTIONS ${GIO_CFLAGS} ${GIO_CFLAGS_OTHER})
diff --git a/conanfile.py b/conanfile.py
new file mode 100644
index 0000000..ddb17e8
--- /dev/null
+++ b/conanfile.py
@@ -0,0 +1,25 @@
+# pylint:  disable=missing-docstring
+
+from conans import ConanFile, CMake
+
+class Wanda(ConanFile):
+    name = "wanda"
+    version = "0.1"
+    license = "BSD 3-clause"
+    description = "A wallpaper changer for the GNOME"
+    generators = "cmake"
+    export_sources = (
+        "CMakeLists.txt",
+        "src/*",
+    )
+    requires = (
+        "boost_program_options/1.67.0@bincrafters/stable",
+    )
+
+    def build(self):
+        cmake = CMake(self)
+        cmake.configure(source_folder="src")
+        cmake.build()
+
+    def package(self):
+        pass
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..fb2e0bf
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,16 @@
+#include "setting.hpp"
+#include "optional.hpp"
+
+#include <iostream>
+#include <string>
+
+int main() {
+  using namespace wanda::literals;
+  using namespace wanda::std_ext;
+
+  with("org.gnome.desktop.background"_setting, [](auto & setting){
+    with(setting.template get<std::string>("picture-uri"_key), [](auto & value){
+      std::cout << value << '\n';
+    }) || []{ std::cerr << "No such key!\n"; };
+  }) || []{ std::cerr << "No such setting!\n"; };
+}
diff --git a/src/optional.hpp b/src/optional.hpp
new file mode 100644
index 0000000..c178d59
--- /dev/null
+++ b/src/optional.hpp
@@ -0,0 +1,36 @@
+#ifndef WANDA_OPTIONAL_HPP
+#define WANDA_OPTIONAL_HPP
+
+#include <optional>
+
+namespace wanda::std_ext {
+
+struct failable {
+
+    constexpr static auto success() { return failable{false}; }
+    constexpr static auto failure() { return failable{true}; }
+
+    template<typename Handler>
+    constexpr auto operator ||(Handler handler) const {
+        if(m_failed) {
+            handler();
+        }
+    }
+
+private:
+    constexpr explicit failable(bool failed) : m_failed{failed} { };
+    bool const m_failed;
+};
+
+template<typename ObjectType, typename HandlerType>
+auto with(std::optional<ObjectType> && object, HandlerType handler) {
+  if(object) {
+    handler(object.value());
+    return failable::success();
+  }
+  return failable::failure();
+}
+
+}
+
+#endif
+\ No newline at end of file
diff --git a/src/setting.cpp b/src/setting.cpp
new file mode 100644
index 0000000..9ddbfe8
--- /dev/null
+++ b/src/setting.cpp
@@ -0,0 +1,29 @@
+#include "setting.hpp"
+
+namespace wanda {
+
+namespace literals {
+    key operator""_key(char const * str, std::size_t len) {
+        return key{{str, len}};
+    }
+
+    std::optional<setting> operator""_setting(char const * str, std::size_t len) {
+        auto source = g_settings_schema_source_get_default();
+        auto schema = g_settings_schema_source_lookup(source, str, true);
+        if(schema) {
+            g_settings_schema_unref(schema);
+            return setting{::wanda::schema{{str, len}}};
+        }
+        return std::nullopt;
+    }
+}
+
+setting::setting(schema schema) : m_value{g_settings_new(schema.get().c_str())} { }
+
+setting::setting(setting const & other) : m_value{reinterpret_cast<GSettings *>(g_object_ref(other.m_value))} { }
+
+setting::~setting() {
+    g_clear_object(&m_value);
+}
+
+}
+\ No newline at end of file
diff --git a/src/setting.hpp b/src/setting.hpp
new file mode 100644
index 0000000..6293dd3
--- /dev/null
+++ b/src/setting.hpp
@@ -0,0 +1,48 @@
+#ifndef WANDA_setting_HPP
+#define WANDA_setting_HPP
+
+#include <gio/gio.h>
+
+#include <cstddef>
+#include <optional>
+#include <string>
+#include <type_traits>
+
+#include "type_wrapper.hpp"
+#include "variant.hpp"
+#include <iostream>
+
+namespace wanda {
+
+struct setting;
+using schema = type_wrapper<std::string, struct SchemaTag>;
+using key = type_wrapper<std::string, struct KeyTag>;
+
+namespace literals {
+key operator""_key(char const * str, std::size_t len);
+std::optional<setting> operator""_setting(char const * str, std::size_t len);
+}
+
+struct setting {
+    ~setting();
+
+    setting(setting const & other);
+
+    template<typename TargetType> std::optional<TargetType> get(key key) const {
+        auto value = variant{g_settings_get_value(m_value, key.get().c_str())};
+        return value.get<TargetType>();
+    }
+
+private:
+    explicit setting(schema schema);
+
+    GSettings * m_value;
+
+    friend std::optional<setting> literals::operator""_setting(char const *, std::size_t);
+};
+
+
+}
+
+
+#endif
+\ No newline at end of file
diff --git a/src/type_wrapper.hpp b/src/type_wrapper.hpp
new file mode 100644
index 0000000..d3bf694
--- /dev/null
+++ b/src/type_wrapper.hpp
@@ -0,0 +1,23 @@
+#ifndef WANDA_TYPE_WRAPPER_HPP
+#define WANDA_TYPE_WRAPPER_HPP
+
+#include <utility>
+
+namespace wanda {
+
+template<typename InnerType, typename TagType>
+struct type_wrapper {
+
+    explicit type_wrapper(InnerType value) : m_value{std::move(value)} { }
+
+    constexpr explicit operator InnerType const & () const { return get(); }
+
+    constexpr InnerType const & get() const { return m_value; }
+
+private:
+    InnerType const m_value;
+};
+
+}
+
+#endif
+\ No newline at end of file
diff --git a/src/variant.cpp b/src/variant.cpp
new file mode 100644
index 0000000..54e484e
--- /dev/null
+++ b/src/variant.cpp
@@ -0,0 +1,17 @@
+#include "variant.hpp"
+
+namespace wanda {
+
+variant::variant(GVariant * value) : m_value{value} { }
+
+variant::~variant() {
+    if(m_value) {
+        g_variant_unref(m_value);
+    }
+}
+
+bool variant::is_of_type(GVariantType const * const type) const {
+    return g_variant_is_of_type(m_value, type);
+}
+
+}
+\ No newline at end of file
diff --git a/src/variant.hpp b/src/variant.hpp
new file mode 100644
index 0000000..8a5fb03
--- /dev/null
+++ b/src/variant.hpp
@@ -0,0 +1,47 @@
+#ifndef WANDA_VARIANT_HPP
+#define WANDA_VARIANT_HPP
+
+#include <gio/gio.h>
+
+#include <optional>
+#include <string>
+#include <type_traits>
+
+namespace wanda {
+
+struct variant {
+
+    explicit variant(GVariant * variant);
+
+    ~variant();
+
+    template<typename Type> std::optional<Type> get() const {
+        if(!m_value) {
+            return std::nullopt;
+        }
+
+        if constexpr(std::is_same_v<Type, bool>) {
+            if(is_of_type(G_VARIANT_TYPE_BOOLEAN)) {
+                return static_cast<bool>(g_variant_get_boolean(m_value));
+            }
+        } else if constexpr(std::is_same_v<Type, std::string>) {
+            if(is_of_type(G_VARIANT_TYPE_STRING)) {
+                auto length = gsize{};
+                auto value = g_variant_get_string(m_value, &length);
+                return std::string(value, static_cast<std::size_t>(length));
+            }
+        }
+
+        return std::nullopt;
+    }
+
+
+private:
+    bool is_of_type(GVariantType const * const type) const;
+
+    GVariant * const m_value;
+};
+
+}
+
+#endif
+\ No newline at end of file