chore: minor adjustments

src/core/common/error.hpp

@@ -0,0 +1,266 @@
+#ifndef CLRSYNC_CORE_ERROR_HPP
+#define CLRSYNC_CORE_ERROR_HPP
+
+#include <optional>
+#include <string>
+#include <variant>
+
+namespace clrsync::core
+{
+
+enum class error_code
+{
+    unknown,
+
+    file_not_found,
+    file_open_failed,
+    file_write_failed,
+    file_read_failed,
+    dir_create_failed,
+
+    parse_failed,
+    invalid_format,
+
+    config_missing,
+    config_invalid,
+
+    template_not_found,
+    template_load_failed,
+    template_apply_failed,
+
+    palette_not_found,
+    palette_load_failed,
+
+    init_failed,
+    invalid_arg,
+    resource_missing,
+};
+
+inline const char *error_code_string(error_code code)
+{
+    switch (code)
+    {
+    case error_code::unknown:
+        return "Unknown error";
+    case error_code::file_not_found:
+        return "File not found";
+    case error_code::file_open_failed:
+        return "Failed to open file";
+    case error_code::file_write_failed:
+        return "Failed to write file";
+    case error_code::file_read_failed:
+        return "Failed to read file";
+    case error_code::dir_create_failed:
+        return "Failed to create directory";
+    case error_code::parse_failed:
+        return "Parse failed";
+    case error_code::invalid_format:
+        return "Invalid format";
+    case error_code::config_missing:
+        return "Configuration missing";
+    case error_code::config_invalid:
+        return "Configuration invalid";
+    case error_code::template_not_found:
+        return "Template not found";
+    case error_code::template_load_failed:
+        return "Failed to load template";
+    case error_code::template_apply_failed:
+        return "Failed to apply template";
+    case error_code::palette_not_found:
+        return "Palette not found";
+    case error_code::palette_load_failed:
+        return "Failed to load palette";
+    case error_code::init_failed:
+        return "Initialization failed";
+    case error_code::invalid_arg:
+        return "Invalid argument";
+    case error_code::resource_missing:
+        return "Resource missing";
+    default:
+        return "Unknown error code";
+    }
+}
+
+struct Error
+{
+    error_code code;
+    std::string message;
+    std::string context;
+
+    Error(error_code c) : code(c), message(error_code_string(c))
+    {
+    }
+
+    Error(error_code c, std::string msg) : code(c), message(std::move(msg))
+    {
+    }
+
+    Error(error_code c, std::string msg, std::string ctx)
+        : code(c), message(std::move(msg)), context(std::move(ctx))
+    {
+    }
+
+    std::string description() const
+    {
+        if (context.empty())
+            return message;
+        return message + " [" + context + "]";
+    }
+};
+
+template <typename T> class [[nodiscard]] Result
+{
+  private:
+    std::variant<T, Error> m_data;
+
+  public:
+    Result(T value) : m_data(std::move(value))
+    {
+    }
+
+    Result(Error error) : m_data(std::move(error))
+    {
+    }
+
+    bool is_ok() const
+    {
+        return std::holds_alternative<T>(m_data);
+    }
+
+    bool is_error() const
+    {
+        return std::holds_alternative<Error>(m_data);
+    }
+
+    explicit operator bool() const
+    {
+        return is_ok();
+    }
+
+    T &value() &
+    {
+        return std::get<T>(m_data);
+    }
+    const T &value() const &
+    {
+        return std::get<T>(m_data);
+    }
+    T &&value() &&
+    {
+        return std::get<T>(std::move(m_data));
+    }
+
+    const Error &error() const
+    {
+        return std::get<Error>(m_data);
+    }
+
+    T value_or(T default_value) const
+    {
+        return is_ok() ? std::get<T>(m_data) : std::move(default_value);
+    }
+
+    std::optional<T> ok() const
+    {
+        if (is_ok())
+            return std::get<T>(m_data);
+        return std::nullopt;
+    }
+
+    std::optional<Error> err() const
+    {
+        if (is_error())
+            return std::get<Error>(m_data);
+        return std::nullopt;
+    }
+
+    template <typename F> auto map(F &&func) -> Result<decltype(func(std::declval<T>()))>
+    {
+        using U = decltype(func(std::declval<T>()));
+        if (is_ok())
+            return Result<U>(func(std::get<T>(m_data)));
+        return Result<U>(std::get<Error>(m_data));
+    }
+
+    template <typename F> auto and_then(F &&func) -> decltype(func(std::declval<T>()))
+    {
+        if (is_ok())
+            return func(std::get<T>(m_data));
+        using ResultType = decltype(func(std::declval<T>()));
+        return ResultType(std::get<Error>(m_data));
+    }
+};
+
+template <> class [[nodiscard]] Result<void>
+{
+  private:
+    std::optional<Error> m_error;
+
+  public:
+    Result() : m_error(std::nullopt)
+    {
+    }
+
+    Result(Error error) : m_error(std::move(error))
+    {
+    }
+
+    bool is_ok() const
+    {
+        return !m_error.has_value();
+    }
+
+    bool is_error() const
+    {
+        return m_error.has_value();
+    }
+
+    explicit operator bool() const
+    {
+        return is_ok();
+    }
+
+    const Error &error() const
+    {
+        return *m_error;
+    }
+
+    std::optional<Error> err() const
+    {
+        return m_error;
+    }
+};
+
+template <typename T> Result<T> Ok(T value)
+{
+    return Result<T>(std::move(value));
+}
+
+inline Result<void> Ok()
+{
+    return Result<void>();
+}
+
+template <typename T> Result<T> Err(Error error)
+{
+    return Result<T>(std::move(error));
+}
+
+template <typename T> Result<T> Err(error_code code)
+{
+    return Result<T>(Error(code));
+}
+
+template <typename T> Result<T> Err(error_code code, std::string message)
+{
+    return Result<T>(Error(code, std::move(message)));
+}
+
+template <typename T> Result<T> Err(error_code code, std::string message, std::string context)
+{
+    return Result<T>(Error(code, std::move(message), std::move(context)));
+}
+
+} // namespace clrsync::core
+
+#endif // CLRSYNC_CORE_ERROR_HPP