From 404de2dfde39ca181db531427638f249c6e334e7 Mon Sep 17 00:00:00 2001
From: Dominick Allen <djallen@librehumanitas.org>
Date: Mon, 23 Sep 2024 22:46:38 -0500
Subject: Expand CBinaryFile interface.

---
 CMakeLists.txt         |  5 ++-
 include/fud_c_file.hpp | 48 +++++++++++++++++++++++---
 source/fud_c_file.cpp  | 91 ++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 137 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4d3e399..d5ebb4e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -50,9 +50,12 @@ if (FUD_DOC)
         REQUIRED dot
         OPTIONAL_COMPONENTS mscgen dia)
 
-    doxygen_add_docs(docs
+    set(DOXYGEN_GENERATE_HTML YES)
+    set(DOXYGEN_GENERATE_MAN YES)
+    doxygen_add_docs(fudDocs
         include
         # CONFIG_FILE "Doxyfile"
+        Comment "Generate man pages and html"
     )
 endif()
 
diff --git a/include/fud_c_file.hpp b/include/fud_c_file.hpp
index 281d216..b48e8a0 100644
--- a/include/fud_c_file.hpp
+++ b/include/fud_c_file.hpp
@@ -26,6 +26,7 @@
 
 namespace fud {
 
+/** \brief Access Modes for */
 enum class CFileMode : uint8_t
 {
     ReadOnly,
@@ -76,12 +77,35 @@ constexpr const char* CTextFileModeFromFlags(CFileMode mode)
     }
 }
 
-enum class FileResult
+enum class FileStatus
 {
     Success,
+    InvalidName,
+    InvalidArgument,
+    InvalidState,
+    NullPointer,
     Error,
 };
 
+static inline const char* FileStatusToString(FileStatus status) {
+    switch (status) {
+    case FileStatus::Success:
+        return "Success";
+    case FileStatus::InvalidName:
+        return "InvalidName";
+    case FileStatus::InvalidArgument:
+        return "InvalidArgument";
+    case FileStatus::InvalidState:
+        return "InvalidState";
+    case FileStatus::NullPointer:
+        return "NullPointer";
+    case FileStatus::Error:
+        return "Error";
+    default:
+        return "Unknown";
+    }
+}
+
 class CBinaryFile {
   public:
     CBinaryFile(const String& filename, CFileMode mode);
@@ -89,13 +113,29 @@ class CBinaryFile {
     CBinaryFile(const CBinaryFile& rhs) = delete;
     ~CBinaryFile();
     CBinaryFile& operator=(const CBinaryFile& rhs) = delete;
-    FileResult open();
+    FileStatus open();
     void close();
     const FILE* file() const;
-    FILE* file();
+    [[nodiscard]] FILE* file();
+
+    [[nodiscard]] bool isOpen() const;
+
+    [[nodiscard]] Result<size_t, FileStatus> size() const;
+
+    template <typename T>
+    [[nodiscard]] FileStatus read(T& destination, size_t length);
+
+    template <typename T>
+    [[nodiscard]] FileStatus read(T& destination, size_t length, size_t offset);
+
+    [[nodiscard]] FileStatus read(void* destination, size_t destinationSize, size_t length);
+
+    [[nodiscard]] FileStatus read(void* destination, size_t destinationSize, size_t length, size_t offset);
 
   private:
-    String m_filename;
+    FileStatus reset() const;
+
+    const String m_filename;
     String m_extraFlags{};
     String m_mode;
     CFileMode m_modeFlags;
diff --git a/source/fud_c_file.cpp b/source/fud_c_file.cpp
index 24186bf..3d15431 100644
--- a/source/fud_c_file.cpp
+++ b/source/fud_c_file.cpp
@@ -38,10 +38,13 @@ CBinaryFile::~CBinaryFile() {
     close();
 }
 
-FileResult CBinaryFile::open()
+FileStatus CBinaryFile::open()
 {
+    if (!m_filename.valid()) {
+        return FileStatus::InvalidName;
+    }
     m_file = fopen(m_filename.c_str(), m_mode.c_str());
-    return m_file != nullptr ? FileResult::Success : FileResult::Error;
+    return m_file != nullptr ? FileStatus::Success : FileStatus::Error;
 }
 
 void CBinaryFile::close()
@@ -62,4 +65,88 @@ FILE* CBinaryFile::file()
     return m_file;
 }
 
+bool CBinaryFile::isOpen() const
+{
+    return m_file != nullptr;
+}
+
+Result<size_t, FileStatus> CBinaryFile::size() const
+{
+    using RetType = Result<size_t, FileStatus>;
+    if (!isOpen()) {
+        return RetType::error(FileStatus::InvalidState);
+    }
+
+    auto seekStatus = fseek(m_file, 0, SEEK_END);
+    if (seekStatus != 0) {
+        return RetType::error(FileStatus::Error);
+    }
+
+    auto fileSizeResult = ftell(m_file);
+    if (fileSizeResult < 0) {
+        return RetType::error(FileStatus::Error);
+    }
+
+    auto fileSize = static_cast<size_t>(fileSizeResult);
+
+    auto resetStatus = reset();
+    if (resetStatus != FileStatus::Success) {
+        return RetType::error(resetStatus);
+    }
+
+    return RetType::okay(fileSize);
+}
+
+FileStatus CBinaryFile::read(void* destination, size_t destinationSize, size_t length)
+{
+    return read(destination, destinationSize, length, 0);
+}
+
+FileStatus CBinaryFile::read(void* destination, size_t destinationSize, size_t length, size_t offset)
+{
+    if (length == 0) {
+        return FileStatus::Success;
+    }
+
+    if (destination == nullptr) {
+        return FileStatus::NullPointer;
+    }
+
+    if (offset > LONG_MAX || SIZE_MAX - offset < length || destinationSize < length) {
+        return FileStatus::InvalidArgument;
+    }
+
+    auto fileSizeResult = size();
+    if (fileSizeResult.isError()) {
+        return fileSizeResult.getError();
+    }
+
+    auto fileSize = fileSizeResult.getOkay();
+    if (offset + length > fileSize) {
+        return FileStatus::InvalidArgument;
+    }
+
+    auto seekResult = fseek(m_file, static_cast<long>(offset), SEEK_SET);
+    if (seekResult != 0) {
+        return FileStatus::Error;
+    }
+
+    auto* destPtr = static_cast<char*>(destination);
+    auto readResult = fread(destPtr, length, 1, m_file);
+    if (readResult != 1) {
+        static_cast<void>(reset());
+        return FileStatus::Error;
+    }
+
+    return FileStatus::Success;
+}
+
+FileStatus CBinaryFile::reset() const {
+    if (!isOpen()) {
+        return FileStatus::InvalidState;
+    }
+    auto result = fseek(m_file, 0, SEEK_SET);
+    return result == 0 ? FileStatus::Success : FileStatus::Error;
+}
+
 } // namespace fud
-- 
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