//
// Created by kikab on 04.06.2018.
//

#include <DatSubsystems/DatFileSystem.h>
#include <EasyLogging++/easylogging++.h>
#include <BinaryData.h>
#include <DatFile.h>
#include <SubFile.h>

namespace LOTRO_DAT{
    DatFileSystem::DatFileSystem(DatFile *datFilePtr) : dat(datFilePtr) {
        LOG(INFO) << "Initialization of empty DatFileSystem";
    }

    DatOperationResult<BinaryData> DatFileSystem::GetFileData(long long file_id, long long int offset) {
        if (!dat)
            return DatOperationResult<BinaryData>(BinaryData(), ERROR, "DatFileSystem error: no connection with Dat (dat is nullptr)");

        if (dictionary_.count(file_id))
            return DatOperationResult<BinaryData>(BinaryData(), ERROR, "DatFileSystem error: no file found with id = " + std::to_string(file_id));

        auto file = dictionary_[file_id];
        LOG(DEBUG) << "Getting file " << file->file_id() << " data";

        BinaryData mfile_id(20);
        auto operation = dat->getIO().ReadData(mfile_id, 20, file->file_offset() + 8);
        if (operation.result == ERROR) {
            LOG(ERROR) << "Error while reading file " << file->file_id() << " header (offset = "
                       << file->file_offset() << "); Message: " << operation.msg << "Aborting.";
            return DatOperationResult<BinaryData>(BinaryData(), ERROR, std::string("DatFileSystem error: Read ") + std::to_string(file_id) + " error." + operation.msg);
        }

        if (!mfile_id.CheckCompression() && file->file_id() != mfile_id.ToNumber<4>(0)) {
            LOG(ERROR) << "Bad DatFile::GetFileData() - file_id in SubFile ("
                       << file->file_id()
                       << ") doesn't match to file_id (" << mfile_id.ToNumber<4>(0) << ")in DatFile.";
            return DatOperationResult<BinaryData>(BinaryData(), ERROR, std::string("DatFileSystem error: Read ") + std::to_string(file_id) + " error: SubFile value differs from value in dict");
        }

        BinaryData data((unsigned)(file->file_size() + (8 - offset)));
        if (file->block_size() >= file->file_size() + 8) {
            dat->getIO().ReadData(data, file->file_size() + (8 - offset), file->file_offset() + offset);
            return DatOperationResult<BinaryData>(data, SUCCESS);
        }

        BinaryData fragments_count(4);
        dat->getIO().ReadData(fragments_count, 4, file->file_offset());

        long long fragments_number = fragments_count.ToNumber<4>(0);

        long long current_block_size = file->block_size() - offset - 8 * fragments_number;

        dat->getIO().ReadData(data, current_block_size, file->file_offset() + offset);

        BinaryData FragmentsDictionary(8 * unsigned(fragments_number));
        dat->getIO().ReadData(FragmentsDictionary, 8 * unsigned(fragments_number),
                 file->file_offset() + file->block_size() - 8 * fragments_number);


        for (long long i = 0; i < fragments_number; i++) {
            long long fragment_size = FragmentsDictionary.ToNumber<4>(8 * i);
            long long fragment_offset = FragmentsDictionary.ToNumber<4>(8 * i + 4);
            dat->getIO().ReadData(data, std::min(fragment_size, file->file_size() - current_block_size), fragment_offset,
                     current_block_size);
            current_block_size += fragment_size;
        }
        LOG(DEBUG) << "Successfully got file " << file->file_id() << " data";
        return DatOperationResult<BinaryData>(data, SUCCESS);
    }

    DatOperationResult<SubFile> DatFileSystem::GetFile(long long file_id) {

    }

    DatOperationResult<> DatFileSystem::UpdateFile(const SubFile &file) {
    }

    DatOperationResult<> DatFileSystem::MakeDirectories() {
    }

    DatOperationResult<> DatFileSystem::MakeDictionary() {
    }

    DatOperationResult<> DatFileSystem::CommitDirectories() {
    }

    DatOperationResult<> DatFileSystem::Init() {}

    DatOperationResult<> DatFileSystem::DeInit() {}
}