// ======================================================================
// \title Os/File.cpp
// \brief common function implementation for Os::File
// ======================================================================
#include <Os/File.hpp>
#include <Fw/Types/Assert.hpp>

extern "C" {
#include <Utils/Hash/libcrc/lib_crc.h> // borrow CRC
}
namespace Os {

File::File() : m_crc_buffer(), m_handle_storage(), m_delegate(*FileInterface::getDelegate(&m_handle_storage[0])) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
}

File::~File() {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    if (this->m_mode != OPEN_NO_MODE) {
        this->close();
    }
    m_delegate.~FileInterface();
}

File::File(const File& other) :
    m_mode(other.m_mode),
    m_path(other.m_path),
    m_crc(other.m_crc),
    m_crc_buffer(),
    m_handle_storage(),
    m_delegate(*FileInterface::getDelegate(&m_handle_storage[0], &other.m_delegate)) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
}

File& File::operator=(const File& other) {
    if (this != &other) {
        this->m_mode = other.m_mode;
        this->m_path = other.m_path;
        this->m_crc = other.m_crc;
        this->m_delegate = *FileInterface::getDelegate(&m_handle_storage[0], &other.m_delegate);
    }
    return *this;
}

File::Status File::open(const CHAR* filepath, File::Mode requested_mode) {
    return this->open(filepath, requested_mode, OverwriteType::NO_OVERWRITE);
}

File::Status File::open(const CHAR* filepath, File::Mode requested_mode, File::OverwriteType overwrite) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT(nullptr != filepath);
    FW_ASSERT(File::Mode::OPEN_NO_MODE < requested_mode && File::Mode::MAX_OPEN_MODE > requested_mode);
    FW_ASSERT((0 <= this->m_mode) && (this->m_mode < Mode::MAX_OPEN_MODE));
    FW_ASSERT((0 <= overwrite) && (overwrite < OverwriteType::MAX_OVERWRITE_TYPE));
    // Check for already opened file
    if (this->isOpen()) {
        return File::Status::INVALID_MODE;
    }
    File::Status status = this->m_delegate.open(filepath, requested_mode, overwrite);
    if (status == File::Status::OP_OK) {
        this->m_mode = requested_mode;
        this->m_path = filepath;
    }
    // Reset any open CRC calculations
    this->m_crc = File::INITIAL_CRC;
    return status;
}

void File::close() {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT(this->m_mode < Mode::MAX_OPEN_MODE);
    FW_ASSERT((0 <= this->m_mode) && (this->m_mode < Mode::MAX_OPEN_MODE));
    this->m_delegate.close();
    this->m_mode = Mode::OPEN_NO_MODE;
    this->m_path = nullptr;
}

bool File::isOpen() const {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<const FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT((0 <= this->m_mode) && (this->m_mode < Mode::MAX_OPEN_MODE));
    return this->m_mode != Mode::OPEN_NO_MODE;
}

File::Status File::size(FwSignedSizeType& size_result) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT((0 <= this->m_mode) && (this->m_mode < Mode::MAX_OPEN_MODE));
    if (OPEN_NO_MODE == this->m_mode) {
        return File::Status::NOT_OPENED;
    }
    return this->m_delegate.size(size_result);
}

File::Status File::position(FwSignedSizeType &position_result) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT((0 <= this->m_mode) && (this->m_mode < Mode::MAX_OPEN_MODE));
    // Check that the file is open before attempting operation
    if (OPEN_NO_MODE == this->m_mode) {
        return File::Status::NOT_OPENED;
    }
    return this->m_delegate.position(position_result);
}

File::Status File::preallocate(FwSignedSizeType offset, FwSignedSizeType length) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT(offset >= 0);
    FW_ASSERT(length >= 0);
    FW_ASSERT((0 <= this->m_mode) && (this->m_mode < Mode::MAX_OPEN_MODE));
    // Check that the file is open before attempting operation
    if (OPEN_NO_MODE == this->m_mode) {
        return File::Status::NOT_OPENED;
    } else if (OPEN_READ == this->m_mode) {
        return File::Status::INVALID_MODE;
    }
    return this->m_delegate.preallocate(offset, length);
}

File::Status File::seek(FwSignedSizeType offset, File::SeekType seekType) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT((0 <= seekType) && (seekType < SeekType::MAX_SEEK_TYPE));
    // Cannot do a seek with a negative offset in absolute mode
    FW_ASSERT((seekType == File::SeekType::RELATIVE) || (offset >= 0));
    FW_ASSERT((0 <= this->m_mode) && (this->m_mode < Mode::MAX_OPEN_MODE));
    // Check that the file is open before attempting operation
    if (OPEN_NO_MODE == this->m_mode) {
        return File::Status::NOT_OPENED;
    }
    return this->m_delegate.seek(offset, seekType);
}

File::Status File::flush() {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT(this->m_mode < Mode::MAX_OPEN_MODE);
    // Check that the file is open before attempting operation
    if (OPEN_NO_MODE == this->m_mode) {
        return File::Status::NOT_OPENED;
    } else if (OPEN_READ == this->m_mode) {
        return File::Status::INVALID_MODE;
    }
    return this->m_delegate.flush();
}

File::Status File::read(U8* buffer, FwSignedSizeType &size) {
    return this->read(buffer, size, WaitType::WAIT);
}

File::Status File::read(U8* buffer, FwSignedSizeType &size, File::WaitType wait) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT(buffer != nullptr);
    FW_ASSERT(size >= 0);
    FW_ASSERT(this->m_mode < Mode::MAX_OPEN_MODE);
    // Check that the file is open before attempting operation
    if (OPEN_NO_MODE == this->m_mode) {
        size = 0;
        return File::Status::NOT_OPENED;
    } else if (OPEN_READ != this->m_mode) {
        size = 0;
        return File::Status::INVALID_MODE;
    }
    return this->m_delegate.read(buffer, size, wait);
}

File::Status File::write(const U8* buffer, FwSignedSizeType &size) {
    return this->write(buffer, size, WaitType::WAIT);
}


File::Status File::write(const U8* buffer, FwSignedSizeType &size, File::WaitType wait) {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    FW_ASSERT(buffer != nullptr);
    FW_ASSERT(size >= 0);
    FW_ASSERT(this->m_mode < Mode::MAX_OPEN_MODE);
    // Check that the file is open before attempting operation
    if (OPEN_NO_MODE == this->m_mode) {
        size = 0;
        return File::Status::NOT_OPENED;
    } else if (OPEN_READ == this->m_mode) {
        size = 0;
        return File::Status::INVALID_MODE;
    }
    return this->m_delegate.write(buffer, size, wait);
}

FileHandle* File::getHandle() {
    FW_ASSERT(&this->m_delegate == reinterpret_cast<FileInterface*>(&this->m_handle_storage[0]));
    return this->m_delegate.getHandle();
}

File::Status File::calculateCrc(U32 &crc) {
    File::Status status = File::Status::OP_OK;
    FwSignedSizeType size = FW_FILE_CHUNK_SIZE;
    crc = 0;
    for (FwSizeType i = 0; i < std::numeric_limits<FwSizeType>::max(); i++) {
        status = this->incrementalCrc(size);
        // Break on eof or error
        if ((size != FW_FILE_CHUNK_SIZE) || (status != File::OP_OK)) {
            break;
        }
    }
    // When successful, finalize the CRC
    if (status == File::OP_OK) {
        status = this->finalizeCrc(crc);
    }
    return status;
}

File::Status File::incrementalCrc(FwSignedSizeType &size) {
    File::Status status = File::Status::OP_OK;
    FW_ASSERT(size >= 0);
    FW_ASSERT(size <= FW_FILE_CHUNK_SIZE);
    if (OPEN_NO_MODE == this->m_mode) {
        status = File::Status::NOT_OPENED;
    } else if  (OPEN_READ != this->m_mode) {
        status = File::Status::INVALID_MODE;
    } else {
        // Read data without waiting for additional data to be available
        status = this->read(this->m_crc_buffer, size, File::WaitType::NO_WAIT);
        if (OP_OK == status) {
            for (FwSignedSizeType i = 0; i < size && i < FW_FILE_CHUNK_SIZE; i++) {
                this->m_crc = update_crc_32(this->m_crc, static_cast<CHAR>(this->m_crc_buffer[i]));
            }
        }
    }
    return status;
}

File::Status File::finalizeCrc(U32 &crc) {
    File::Status status = File::Status::OP_OK;
    crc = this->m_crc;
    this->m_crc = File::INITIAL_CRC;
    return status;
}
} // Os