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

#include "BinaryData.h"
#include "DatFile.h"
#include "DatSubsystems/DatIO.h"
#include "EasyLogging++/easylogging++.h"
#include "SubDirectory.h"
#include "SubFile.h"

#include <algorithm>
#include <iterator>
#include <locale>
#include <DatOperationResult.h>
#include <DatSubsystems/DatIO.h>


#ifdef WIN32
#define fseek _fseeki64
#define ftell _ftelli64
#endif

extern "C++"
{
namespace LOTRO_DAT {

    DatIO::DatIO(DatFile *datFile) : dat(datFile), file_handler_(nullptr), filename_(),
                                             actual_dat_size_(0) {
    }


    //------------------------------------------------//
    // INIT SECTION
    //------------------------------------------------//

    DatOperationResult<> DatIO::Init(const std::string &filename) {
        LOG(INFO) << "Initializing IO: " << filename;

        filename_ = filename;

        auto result = OpenDatFile();
        if (result.result == ERROR) {
            LOG(ERROR) << "Error in OpenDatFile: " << result.msg;
            DeInit();
            return result;
        }

        result = ReadSuperBlock();
        if (result.result == ERROR) {
            LOG(ERROR) << "Error in ReadSuperBlock: " << result.msg;
            DeInit();
            return result;
        }

        LOG(INFO) << "Successfull initializing IO: " << filename;
        return DatOperationResult<>(SUCCESS, "DatIO initialized successfully");
    }

    DatOperationResult<> DatIO::OpenDatFile() {
        LOG(DEBUG) << "DatIO: Started opening DatFile";

        file_handler_ = fopen(filename_.c_str(), "r+b");

        if (file_handler_ == nullptr) {
            LOG(ERROR) << "DatIO: Unable to open file " << filename_ << ". Presumably - no file found...";
            return DatOperationResult<>(ERROR, std::string("Unable to locate and open file " + filename_));
        }

        fseek(file_handler_, 0, SEEK_END);
        actual_dat_size_ = ftell(file_handler_);
        fseek(file_handler_, 0, SEEK_SET);

        LOG(INFO) << "DatIO: file opened";
        return DatOperationResult<>(SUCCESS, std::string("Successfully opened file " + filename_));
    }

    DatOperationResult<> DatIO::ReadSuperBlock() {
        LOG(INFO) << "DatIO: Started reading superblock";

        BinaryData data(1024);
        ReadData(data, 1024);

        constant1 = data.ToNumber<4>(0x100);
        constant2 = data.ToNumber<4>(0x140);
        version1 = data.ToNumber<4>(0x14C);
        file_size = data.ToNumber<4>(0x148);
        version2 = data.ToNumber<4>(0x150);
        fragmentation_journal_offset = data.ToNumber<4>(0x154);
        fragmentation_journal_end = data.ToNumber<4>(0x158);
        fragmentation_journal_size = data.ToNumber<4>(0x15C);
        root_directory_offset = data.ToNumber<4>(0x160);
        free_dat_size = data.ToNumber<4>(0x19C);

        if (constant1 != 0x4C5000) {
            LOG(ERROR) << "Variable at position 0x100 is not equal to .dat file constant!";
            return DatOperationResult<>(ERROR, std::string("Variable at position 0x100 is not equal to .dat file constant!"));
        }
        if (constant2 != 0x5442) {
            LOG(ERROR) << "Variable at position 0x140 is not equal to .dat file constant!";
            return DatOperationResult<>(ERROR, std::string("Variable at position 0x140 is not equal to .dat file constant!"));
        }

        if (file_size != actual_dat_size_) {
            LOG(INFO) << "Variable at 0x148 position is not equal to .dat file size!";
            //return CORRUPTED_FILE_WARNING;
        }

        LOG(INFO) << "DatIO: Superblock read successfully";
        return DatOperationResult<>(SUCCESS, std::string("Superblock read successfully."));
    }


    //------------------------------------------------//
    // PUBLIC READ/WRITE SECTION
    //------------------------------------------------//

    DatOperationResult<>
    DatIO::ReadData(BinaryData &data, long long size, long long offset, long long data_offset) const {
        if (file_handler_ == nullptr) {
            LOG(ERROR) << "IOError: file handler is null pointer on reading data.";
            data = BinaryData(0);
            return DatOperationResult<>(ERROR, "IOError: file handler is null pointer on reading data.");
        }

        if (data_offset + size > data.size()) {
            LOG(ERROR) << "Trying to read more than BinaryData size: Reading " << size << " bytes from " << offset
                       << " position.";
            data = BinaryData(0);
            return DatOperationResult<>(ERROR, "IOError: Parameters: offset, size are out of range.");
        }

        if (offset + size > actual_dat_size_) {
            LOG(ERROR) << "Trying to read more than DatFile size elapsed: Reading " << size << " bytes from " << offset
                       << " position.";
            data = BinaryData(0);
            return DatOperationResult<>(ERROR, "IOError: Reading from end of file.");
        }

        if (offset != ftell(file_handler_))
            fseek(file_handler_, offset, SEEK_SET);
        fread(data.data() + data_offset, unsigned(size), 1, file_handler_);
        return DatOperationResult<>(SUCCESS, "Read data successful.");
    }

    DatOperationResult<>
    DatIO::WriteData(const BinaryData &data, long long size, long long offset, long long data_offset) {
        if (file_handler_ == nullptr) {
            LOG(ERROR) << "IOError: file handler is null pointer on writing data";
            return DatOperationResult<>(ERROR,
                                      "IOError: file handler is null pointer on writing data.");
        }

        if (offset != ftell(file_handler_))
            fseek(file_handler_, offset, SEEK_SET);

        if (data_offset + size > data.size()) {
            LOG(ERROR) << "Trying to write more than BinaryData size";
            return DatOperationResult<>(ERROR, "IOError: writing more than BinaryData size.");
        }

        fwrite(data.data() + data_offset, unsigned(size), 1, file_handler_);

        if (offset + size > actual_dat_size_) {
            actual_dat_size_ = offset + size;
        }

        return DatOperationResult<>(SUCCESS, "Data writing successful.");
    }


    //------------------------------------------------//
    // DEINIT SECTION
    //------------------------------------------------//

    DatOperationResult<> DatIO::DeInit() {
        if (file_handler_ != nullptr) {
            fclose(file_handler_);
        }

        filename_ = "none";
        file_handler_ = nullptr;

        constant1 = 0;
        constant2 = 0;
        file_size = 0;
        version1 = 0;
        version2 = 0;
        fragmentation_journal_size = 0;
        fragmentation_journal_end = 0;
        root_directory_offset = 0;
        fragmentation_journal_offset = 0;

        return DatOperationResult<>(SUCCESS, "File deinitialisation successfull");
    }

    DatOperationResult<> DatIO::ModifyFragmentationJournal() {
        if (fragmentation_journal_size == 0)
            return DatOperationResult<>(SUCCESS,
                                      "DatIO: Fragmentation journal is empty. Nothing to do.");
        LOG(DEBUG) << "Modifying fragmentation journal";
        BinaryData data(4);
        ReadData(data, 4, fragmentation_journal_offset + 8 * fragmentation_journal_size);
        LOG(INFO) << "FREE_SIZE BLOCK = " << data.ToNumber<4>(0);

        long long free_size = data.ToNumber<4>(0);
        long long free_offset = file_size;

        BinaryData nulldata = BinaryData(unsigned(free_size));
        WriteData(nulldata, nulldata.size(), file_size);
        file_size += nulldata.size();

        WriteData(BinaryData::FromNumber<4>(free_size), 4,
                  fragmentation_journal_offset + 8 * fragmentation_journal_size);
        WriteData(BinaryData::FromNumber<4>(free_offset), 4,
                  fragmentation_journal_offset + 8 * fragmentation_journal_size + 4);

        //nulldata = BinaryData(8);
        //WriteData(nulldata, nulldata.size(), fragmentation_journal_offset + 16);
        LOG(DEBUG) << "Finished modifying fragmentation journal";
        return DatOperationResult<>(SUCCESS, "Fragmentation journal patched successfully!");
    }

    DatOperationResult<> DatIO::UpdateHeader() {
        LOG(DEBUG) << "Updating header";
        WriteData(BinaryData::FromNumber<4>(constant1), 4, 0x100);
        WriteData(BinaryData::FromNumber<4>(constant2), 4, 0x140);
        //WriteData(BinaryData::FromNumber<4>(    0     ), 4, 0x144);
        WriteData(BinaryData::FromNumber<4>(file_size), 4, 0x148);
        WriteData(BinaryData::FromNumber<4>(version1), 4, 0x14C);
        WriteData(BinaryData::FromNumber<4>(version2), 4, 0x150);
        WriteData(BinaryData::FromNumber<4>(fragmentation_journal_offset), 4, 0x154);
        WriteData(BinaryData::FromNumber<4>(fragmentation_journal_end), 4, 0x158);
        WriteData(BinaryData::FromNumber<4>(fragmentation_journal_size), 4, 0x15C);
        WriteData(BinaryData::FromNumber<4>(root_directory_offset), 4, 0x160);
        WriteData(BinaryData::FromNumber<4>(free_dat_size), 4, 0x19C);
        LOG(DEBUG) << "Finished updating header";
        return DatOperationResult<>(SUCCESS, "File header patched successfully");;
    }

    DatOperationResult<long long> DatIO::GetActualDatSize() {
        return DatOperationResult<long long>(actual_dat_size_, SUCCESS);
    }

    DatOperationResult<std::string> DatIO::GetFilename() {
        return DatOperationResult<std::string>(filename_, SUCCESS);
    }
}
}