/*
 * libfud
 * Copyright 2024 Dominick Allen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "fud_c_file.hpp"

namespace fud {

CBinaryFile::CBinaryFile(const String& filename, CFileMode mode)
    : m_filename{filename},
      m_mode{CBinaryFileModeFromFlags(mode)},
      m_modeFlags{mode}
{
}

CBinaryFile::CBinaryFile(const String& filename, CFileMode mode, const String& extraFlags)
    : m_filename{filename},
      m_extraFlags{extraFlags},
      m_mode{String(CBinaryFileModeFromFlags(mode)).append(extraFlags)},
      m_modeFlags{mode}
{
}

CBinaryFile::~CBinaryFile() {
    close();
}

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 ? FileStatus::Success : FileStatus::Error;
}

void CBinaryFile::close()
{
    if (m_file != nullptr) {
        fclose(m_file);
        m_file = nullptr;
    }
}

const FILE* CBinaryFile::file() const
{
    return m_file;
}

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