Add xdgpp (xdg)

include/xdg.hpp

@@ -0,0 +1,216 @@
+/*
+ * Copyright © 2020 Danilo Spinella <oss@danyspin97.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#pragma once
+
+#include <algorithm>
+#include <filesystem>
+#include <optional>
+#include <set>
+#include <string>
+#include <vector>
+
+#include <unistd.h>
+
+namespace xdg {
+
+class BaseDirectoryException : public std::exception {
+public:
+    explicit BaseDirectoryException(std::string msg) : msg_(std::move(msg)) {}
+
+    [[nodiscard]] auto what() const noexcept -> const char * override {
+        return msg_.c_str();
+    }
+    [[nodiscard]] auto msg() const noexcept -> std::string { return msg_; }
+
+private:
+    const std::string msg_;
+};
+
+class BaseDirectories {
+public:
+    BaseDirectories() {
+        const char *home_env = getenv("HOME");
+        if (home_env == nullptr) {
+            throw BaseDirectoryException("$HOME must be set");
+        }
+        home_ = std::filesystem::path{home_env};
+
+        data_home_ = GetAbsolutePathFromEnvOrDefault(
+            "XDG_DATA_HOME", home_ / ".local" / "share");
+        config_home_ = GetAbsolutePathFromEnvOrDefault("XDG_CONFIG_HOME",
+                                                       home_ / ".config");
+        data_ = GetPathsFromEnvOrDefault("XDG_DATA_DIRS",
+                                         std::vector<std::filesystem::path>{
+                                             "/usr/local/share", "/usr/share"});
+        config_ = GetPathsFromEnvOrDefault(
+            "XDG_CONFIG_DIRS", std::vector<std::filesystem::path>{"/etc/xdg"});
+        cache_home_ =
+            GetAbsolutePathFromEnvOrDefault("XDG_CACHE_HOME", home_ / ".cache");
+
+        SetRuntimeDir();
+    }
+
+    static auto GetInstance() -> BaseDirectories & {
+        static BaseDirectories dirs;
+
+        return dirs;
+    }
+
+    [[nodiscard]] auto DataHome() -> const std::filesystem::path & {
+        return data_home_;
+    }
+    [[nodiscard]] auto ConfigHome() -> const std::filesystem::path & {
+        return config_home_;
+    }
+    [[nodiscard]] auto Data() -> const std::vector<std::filesystem::path> & {
+        return data_;
+    }
+    [[nodiscard]] auto Config() -> const std::vector<std::filesystem::path> & {
+        return config_;
+    }
+    [[nodiscard]] auto CacheHome() -> const std::filesystem::path & {
+        return cache_home_;
+    }
+    [[nodiscard]] auto Runtime()
+        -> const std::optional<std::filesystem::path> & {
+        return runtime_;
+    }
+
+private:
+    void SetRuntimeDir() {
+        const char *runtime_env = getenv("XDG_RUNTIME_DIR");
+        if (runtime_env != nullptr) {
+            std::filesystem::path runtime_dir{runtime_env};
+            if (runtime_dir.is_absolute()) {
+                if (!std::filesystem::exists(runtime_dir)) {
+                    throw BaseDirectoryException(
+                        "$XDG_RUNTIME_DIR must exist on the system");
+                }
+
+                auto runtime_dir_perms =
+                    std::filesystem::status(runtime_dir).permissions();
+                using perms = std::filesystem::perms;
+                // Check XDG_RUNTIME_DIR permissions are 0700
+                if (((runtime_dir_perms & perms::owner_all) == perms::none) ||
+                    ((runtime_dir_perms & perms::group_all) != perms::none) ||
+                    ((runtime_dir_perms & perms::others_all) != perms::none)) {
+                    throw BaseDirectoryException(
+                        "$XDG_RUNTIME_DIR must have 0700 as permissions");
+                }
+                runtime_.emplace(runtime_dir);
+            }
+        }
+    }
+
+    static auto
+    GetAbsolutePathFromEnvOrDefault(const char *env_name,
+                                    std::filesystem::path &&default_path)
+        -> std::filesystem::path {
+        const char *env_var = getenv(env_name);
+        if (env_var == nullptr) {
+            return std::move(default_path);
+        }
+        auto path = std::filesystem::path{env_var};
+        if (!path.is_absolute()) {
+            return std::move(default_path);
+        }
+
+        return path;
+    }
+
+    static auto
+    GetPathsFromEnvOrDefault(const char *env_name,
+                             std::vector<std::filesystem::path> &&default_paths)
+        -> std::vector<std::filesystem::path> {
+        auto *env = getenv(env_name);
+        if (env == nullptr) {
+            return std::move(default_paths);
+        }
+        std::string paths{env};
+
+        std::vector<std::filesystem::path> dirs{};
+        size_t start = 0;
+        size_t pos = 0;
+        while ((pos = paths.find_first_of(':', start)) != std::string::npos) {
+            std::filesystem::path current_path{
+                paths.substr(start, pos - start)};
+            if (current_path.is_absolute() &&
+                !VectorContainsPath(dirs, current_path)) {
+                dirs.emplace_back(current_path);
+            }
+            start = pos + 1;
+        }
+        std::filesystem::path current_path{paths.substr(start, pos - start)};
+        if (current_path.is_absolute() &&
+            !VectorContainsPath(dirs, current_path)) {
+            dirs.emplace_back(current_path);
+        }
+
+        if (dirs.empty()) {
+            return std::move(default_paths);
+        }
+
+        return dirs;
+    }
+
+    static auto
+    VectorContainsPath(const std::vector<std::filesystem::path> &paths,
+                       const std::filesystem::path &path) -> bool {
+        return std::find(std::begin(paths), std::end(paths), path) !=
+               paths.end();
+    }
+
+    std::filesystem::path home_;
+
+    std::filesystem::path data_home_;
+    std::filesystem::path config_home_;
+    std::vector<std::filesystem::path> data_;
+    std::vector<std::filesystem::path> config_;
+    std::filesystem::path cache_home_;
+    std::optional<std::filesystem::path> runtime_;
+
+}; // namespace xdg
+
+[[nodiscard]] inline auto DataHomeDir() -> const std::filesystem::path & {
+    return BaseDirectories::GetInstance().DataHome();
+}
+[[nodiscard]] inline auto ConfigHomeDir() -> const std::filesystem::path & {
+    return BaseDirectories::GetInstance().ConfigHome();
+}
+[[nodiscard]] inline auto DataDirs()
+    -> const std::vector<std::filesystem::path> & {
+    return BaseDirectories::GetInstance().Data();
+}
+[[nodiscard]] inline auto ConfigDirs()
+    -> const std::vector<std::filesystem::path> & {
+    return BaseDirectories::GetInstance().Config();
+}
+[[nodiscard]] inline auto CacheHomeDir() -> const std::filesystem::path & {
+    return BaseDirectories::GetInstance().CacheHome();
+}
+[[nodiscard]] inline auto RuntimeDir()
+    -> const std::optional<std::filesystem::path> & {
+    return BaseDirectories::GetInstance().Runtime();
+}
+
+} // namespace xdg

src/main.cpp

@@ -1,9 +1,19 @@
 #include <iostream>
+#include <string>
 
 #include "config/config.h"
 
+#include "xdg.hpp"
+
 int main() {
+
+#ifndef __DEBUG__
     Config config("config.toml");
+#else
+    std::string path = xdg::ConfigHomeDir();
+    path += "/swm/config.toml";
+    Config config(path);
+#endif
 
     std::cout << "Terminal: \"" << config.programs.terminal << "\" - Launcher: \"" << config.programs.launcher << "\"" << std::endl;