#include <cmath>
#include <deque>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <memory>
#include <optional>
#include <unordered_set>
#include <vector>

#include <boost/program_options.hpp>

#include <components/esm/format.hpp>
#include <components/esm3/esmreader.hpp>
#include <components/esm3/esmwriter.hpp>
#include <components/files/configurationmanager.hpp>
#include <components/files/conversion.hpp>
#include <components/files/openfile.hpp>
#include <components/misc/strings/algorithm.hpp>

#include "arguments.hpp"
#include "labels.hpp"
#include "record.hpp"
#include "tes4.hpp"

namespace
{

    using namespace EsmTool;

    constexpr unsigned majorVersion = 1;
    constexpr unsigned minorVersion = 3;

    // Create a local alias for brevity
    namespace bpo = boost::program_options;

    struct ESMData
    {
        ESM::Header mHeader;
        std::deque<std::unique_ptr<EsmTool::RecordBase>> mRecords;
        // Value: (Reference, Deleted flag)
        std::map<ESM::Cell*, std::deque<std::pair<ESM::CellRef, bool>>> mCellRefs;
        std::map<int, int> mRecordStats;
    };

    bool parseOptions(int argc, char** argv, Arguments& info)
    {
        bpo::options_description desc(R"(Inspect and extract from Morrowind ES files (ESM, ESP, ESS)
Syntax: esmtool [options] mode infile [outfile]
Allowed modes:
  dump   Dumps all readable data from the input file.
  clone  Clones the input file to the output file.
  comp   Compares the given files.

Allowed options)");
        auto addOption = desc.add_options();
        addOption("help,h", "print help message.");
        addOption("version,v", "print version information and quit.");
        addOption("raw,r", bpo::value<std::string>(),
            "Show an unformatted list of all records and subrecords of given format:\n"
            "\n\tTES3"
            "\n\tTES4");
        // The intention is that this option would interact better
        // with other modes including clone, dump, and raw.
        addOption("type,t", bpo::value<std::vector<std::string>>(),
            "Show only records of this type (four character record code).  May "
            "be specified multiple times.  Only affects dump mode.");
        addOption("name,n", bpo::value<std::string>(), "Show only the record with this name.  Only affects dump mode.");
        addOption("plain,p",
            "Print contents of dialogs, books and scripts. "
            "(skipped by default) "
            "Only affects dump mode.");
        addOption("quiet,q", "Suppress all record information. Useful for speed tests.");
        addOption("loadcells,C", "Browse through contents of all cells.");

        addOption("encoding,e", bpo::value<std::string>(&(info.encoding))->default_value("win1252"),
            "Character encoding used in ESMTool:\n"
            "\n\twin1250 - Central and Eastern European such as Polish, Czech, Slovak, Hungarian, Slovene, Bosnian, "
            "Croatian, Serbian (Latin script), Romanian and Albanian languages\n"
            "\n\twin1251 - Cyrillic alphabet such as Russian, Bulgarian, Serbian Cyrillic and other languages\n"
            "\n\twin1252 - Western European (Latin) alphabet, used by default");

        std::string finalText
            = "\nIf no option is given, the default action is to parse all records in the archive\nand display "
              "diagnostic information.";

        // input-file is hidden and used as a positional argument
        bpo::options_description hidden("Hidden Options");
        auto addHiddenOption = hidden.add_options();
        addHiddenOption("mode,m", bpo::value<std::string>(), "esmtool mode");
        addHiddenOption("input-file,i", bpo::value<Files::MaybeQuotedPathContainer>(), "input file");

        bpo::positional_options_description p;
        p.add("mode", 1).add("input-file", 2);

        // there might be a better way to do this
        bpo::options_description all;
        all.add(desc).add(hidden);
        bpo::variables_map variables;

        try
        {
            bpo::parsed_options valid_opts = bpo::command_line_parser(argc, argv).options(all).positional(p).run();

            bpo::store(valid_opts, variables);
        }
        catch (std::exception& e)
        {
            std::cout << "ERROR parsing arguments: " << e.what() << std::endl;
            return false;
        }

        bpo::notify(variables);

        if (variables.count("help"))
        {
            std::cout << desc << finalText << std::endl;
            return false;
        }
        if (variables.count("version"))
        {
            std::cout << "ESMTool version " << majorVersion << '.' << minorVersion << std::endl;
            return false;
        }
        if (!variables.count("mode"))
        {
            std::cout << "No mode specified!\n\n" << desc << finalText << std::endl;
            return false;
        }

        if (variables.count("type") > 0)
            info.types = variables["type"].as<std::vector<std::string>>();
        if (variables.count("name") > 0)
            info.name = variables["name"].as<std::string>();

        info.mode = variables["mode"].as<std::string>();
        if (!(info.mode == "dump" || info.mode == "clone" || info.mode == "comp"))
        {
            std::cout << "\nERROR: invalid mode \"" << info.mode << "\"\n\n" << desc << finalText << std::endl;
            return false;
        }

        if (!variables.count("input-file"))
        {
            std::cout << "\nERROR: missing ES file\n\n";
            std::cout << desc << finalText << std::endl;
            return false;
        }

        // handling gracefully the user adding multiple files
        /*    if (variables["input-file"].as< std::vector<std::string> >().size() > 1)
              {
              std::cout << "\nERROR: more than one ES file specified\n\n";
              std::cout << desc << finalText << std::endl;
              return false;
              }*/

        const auto& inputFiles = variables["input-file"].as<Files::MaybeQuotedPathContainer>();
        info.filename = inputFiles[0].u8string(); // This call to u8string is redundant, but required to build on
                                                  // MSVC 14.26 due to implementation bugs.
        if (inputFiles.size() > 1)
            info.outname = inputFiles[1].u8string(); // This call to u8string is redundant, but required to build on
                                                     // MSVC 14.26 due to implementation bugs.

        if (const auto it = variables.find("raw"); it != variables.end())
            info.mRawFormat = ESM::parseFormat(it->second.as<std::string>());

        info.quiet_given = variables.count("quiet") != 0;
        info.loadcells_given = variables.count("loadcells") != 0;
        info.plain_given = variables.count("plain") != 0;

        // Font encoding settings
        info.encoding = variables["encoding"].as<std::string>();
        if (info.encoding != "win1250" && info.encoding != "win1251" && info.encoding != "win1252")
        {
            std::cout << info.encoding << " is not a valid encoding option.\n";
            info.encoding = "win1252";
        }
        std::cout << ToUTF8::encodingUsingMessage(info.encoding) << std::endl;

        return true;
    }

    void loadCell(const Arguments& info, ESM::Cell& cell, ESM::ESMReader& esm, ESMData* data);

    int load(const Arguments& info, ESMData* data);
    int clone(const Arguments& info);
    int comp(const Arguments& info);

}

int main(int argc, char** argv)
{
    try
    {
        Arguments info;
        if (!parseOptions(argc, argv, info))
            return 1;

        if (info.mode == "dump")
            return load(info, nullptr);
        else if (info.mode == "clone")
            return clone(info);
        else if (info.mode == "comp")
            return comp(info);
        else
        {
            std::cout << "Invalid or no mode specified, dying horribly. Have a nice day." << std::endl;
            return 1;
        }
    }
    catch (std::exception& e)
    {
        std::cerr << "ERROR: " << e.what() << std::endl;
        return 1;
    }

    return 0;
}

namespace
{

    void loadCell(const Arguments& info, ESM::Cell& cell, ESM::ESMReader& esm, ESMData* data)
    {
        bool quiet = (info.quiet_given || info.mode == "clone");
        bool save = (info.mode == "clone");

        // Skip back to the beginning of the reference list
        // FIXME: Changes to the references backend required to support multiple plugins have
        //  almost certainly broken this following line. I'll leave it as is for now, so that
        //  the compiler does not complain.
        cell.restore(esm, 0);

        // Loop through all the references
        ESM::CellRef ref;
        if (!quiet)
            std::cout << "  References:\n";

        bool deleted = false;
        ESM::MovedCellRef movedCellRef;
        bool moved = false;
        while (cell.getNextRef(esm, ref, deleted, movedCellRef, moved))
        {
            if (data != nullptr && save)
                data->mCellRefs[&cell].push_back(std::make_pair(ref, deleted));

            if (quiet)
                continue;

            std::cout << "  - Refnum: " << ref.mRefNum.mIndex << '\n';
            std::cout << "    ID: " << ref.mRefID << '\n';
            std::cout << "    Position: (" << ref.mPos.pos[0] << ", " << ref.mPos.pos[1] << ", " << ref.mPos.pos[2]
                      << ")\n";
            if (ref.mScale != 1.f)
                std::cout << "    Scale: " << ref.mScale << '\n';
            if (!ref.mOwner.empty())
                std::cout << "    Owner: " << ref.mOwner << '\n';
            if (!ref.mGlobalVariable.empty())
                std::cout << "    Global: " << ref.mGlobalVariable << '\n';
            if (!ref.mFaction.empty())
                std::cout << "    Faction: " << ref.mFaction << '\n';
            if (!ref.mFaction.empty() || ref.mFactionRank != -2)
                std::cout << "    Faction rank: " << ref.mFactionRank << '\n';
            std::cout << "    Enchantment charge: " << ref.mEnchantmentCharge << '\n';
            std::cout << "    Uses/health: " << ref.mChargeInt << '\n';
            std::cout << "    Count: " << ref.mCount << '\n';
            std::cout << "    Blocked: " << static_cast<int>(ref.mReferenceBlocked) << '\n';
            std::cout << "    Deleted: " << deleted << '\n';
            if (!ref.mKey.empty())
                std::cout << "    Key: " << ref.mKey << '\n';
            std::cout << "    Lock level: " << ref.mLockLevel << '\n';
            if (!ref.mTrap.empty())
                std::cout << "    Trap: " << ref.mTrap << '\n';
            if (!ref.mSoul.empty())
                std::cout << "    Soul: " << ref.mSoul << '\n';
            if (ref.mTeleport)
            {
                std::cout << "    Destination position: (" << ref.mDoorDest.pos[0] << ", " << ref.mDoorDest.pos[1]
                          << ", " << ref.mDoorDest.pos[2] << ")\n";
                if (!ref.mDestCell.empty())
                    std::cout << "    Destination cell: " << ref.mDestCell << '\n';
            }
            std::cout << "    Moved: " << std::boolalpha << moved << std::noboolalpha << '\n';
            if (moved)
            {
                std::cout << "    Moved refnum: " << movedCellRef.mRefNum.mIndex << '\n';
                std::cout << "    Moved content file: " << movedCellRef.mRefNum.mContentFile << '\n';
                std::cout << "    Target: " << movedCellRef.mTarget[0] << ", " << movedCellRef.mTarget[1] << '\n';
            }
        }
    }

    void printRawTes3(const std::filesystem::path& path)
    {
        std::cout << "TES3 RAW file listing: " << Files::pathToUnicodeString(path) << '\n';
        ESM::ESMReader esm;
        esm.openRaw(path);
        while (esm.hasMoreRecs())
        {
            ESM::NAME n = esm.getRecName();
            std::cout << "Record: " << n.toStringView() << '\n';
            esm.getRecHeader();
            while (esm.hasMoreSubs())
            {
                size_t offs = esm.getFileOffset();
                esm.getSubName();
                esm.skipHSub();
                n = esm.retSubName();
                std::ios::fmtflags f(std::cout.flags());
                std::cout << "    " << n.toStringView() << " - " << esm.getSubSize() << " bytes @ 0x" << std::hex
                          << offs << '\n';
                std::cout.flags(f);
            }
        }
    }

    int loadTes3(const Arguments& info, std::unique_ptr<std::ifstream>&& stream, ESMData* data)
    {
        std::cout << "Loading TES3 file: " << info.filename << '\n';

        ESM::ESMReader esm;
        ToUTF8::Utf8Encoder encoder(ToUTF8::calculateEncoding(info.encoding));
        esm.setEncoder(&encoder);

        std::unordered_set<uint32_t> skipped;

        try
        {
            bool quiet = (info.quiet_given || info.mode == "clone");
            bool loadCells = (info.loadcells_given || info.mode == "clone");
            bool save = (info.mode == "clone");

            esm.open(std::move(stream), info.filename);

            if (data != nullptr)
                data->mHeader = esm.getHeader();

            if (!quiet)
            {
                std::cout << "Author: " << esm.getAuthor() << '\n'
                          << "Description: " << esm.getDesc() << '\n'
                          << "File format version: " << esm.esmVersionF() << '\n';
                std::vector<ESM::Header::MasterData> masterData = esm.getGameFiles();
                if (!masterData.empty())
                {
                    std::cout << "Masters:" << '\n';
                    for (const auto& master : masterData)
                        std::cout << "  " << master.name << ", " << master.size << " bytes\n";
                }
            }

            // Loop through all records
            while (esm.hasMoreRecs())
            {
                const ESM::NAME n = esm.getRecName();
                uint32_t flags;
                esm.getRecHeader(flags);

                auto record = EsmTool::RecordBase::create(n);
                if (record == nullptr)
                {
                    if (!quiet && skipped.count(n.toInt()) == 0)
                    {
                        std::cout << "Skipping " << n.toStringView() << " records.\n";
                        skipped.emplace(n.toInt());
                    }

                    esm.skipRecord();
                    if (quiet)
                        break;
                    std::cout << "  Skipping\n";

                    continue;
                }

                record->setFlags(static_cast<int>(flags));
                record->setPrintPlain(info.plain_given);
                record->load(esm);

                // Is the user interested in this record type?
                bool interested = true;
                if (!info.types.empty()
                    && std::find(info.types.begin(), info.types.end(), n.toStringView()) == info.types.end())
                    interested = false;

                if (!info.name.empty() && !Misc::StringUtils::ciEqual(info.name, record->getId()))
                    interested = false;

                if (!quiet && interested)
                {
                    std::cout << "\nRecord: " << n.toStringView() << " " << record->getId() << "\n"
                              << "Record flags: " << recordFlags(record->getFlags()) << '\n';
                    record->print();
                }

                if (record->getType().toInt() == ESM::REC_CELL && loadCells && interested)
                {
                    loadCell(info, record->cast<ESM::Cell>()->get(), esm, data);
                }

                if (data != nullptr)
                {
                    if (save)
                        data->mRecords.push_back(std::move(record));
                    ++data->mRecordStats[n.toInt()];
                }
            }
        }
        catch (const std::exception& e)
        {
            std::cout << "\nERROR:\n\n  " << e.what() << std::endl;
            if (data != nullptr)
                data->mRecords.clear();
            return 1;
        }

        return 0;
    }

    int load(const Arguments& info, ESMData* data)
    {
        if (info.mRawFormat.has_value() && info.mode == "dump")
        {
            switch (*info.mRawFormat)
            {
                case ESM::Format::Tes3:
                    printRawTes3(info.filename);
                    break;
                case ESM::Format::Tes4:
                    std::cout << "Printing raw TES4 file is not supported: "
                              << Files::pathToUnicodeString(info.filename) << "\n";
                    break;
            }
            return 0;
        }

        auto stream = Files::openBinaryInputFileStream(info.filename);
        if (!stream->is_open())
        {
            std::cout << "Failed to open file " << info.filename << ": " << std::generic_category().message(errno)
                      << '\n';
            return -1;
        }

        const ESM::Format format = ESM::readFormat(*stream);
        stream->seekg(0);

        switch (format)
        {
            case ESM::Format::Tes3:
                return loadTes3(info, std::move(stream), data);
            case ESM::Format::Tes4:
                if (data != nullptr)
                {
                    std::cout << "Collecting data from esm file is not supported for TES4\n";
                    return -1;
                }
                return loadTes4(info, std::move(stream));
        }

        std::cout << "Unsupported ESM format: " << ESM::NAME(format).toStringView() << '\n';

        return -1;
    }

    int clone(const Arguments& info)
    {
        if (info.outname.empty())
        {
            std::cout << "You need to specify an output name" << std::endl;
            return 1;
        }

        ESMData data;
        if (load(info, &data) != 0)
        {
            std::cout << "Failed to load, aborting." << std::endl;
            return 1;
        }

        size_t recordCount = data.mRecords.size();

        int digitCount = 1; // For a nicer output
        if (recordCount > 0)
            digitCount = (int)std::log10(recordCount) + 1;

        std::cout << "Loaded " << recordCount << " records:\n\n";

        int i = 0;
        for (std::pair<int, int> stat : data.mRecordStats)
        {
            ESM::NAME name;
            name = stat.first;
            int amount = stat.second;
            std::cout << std::setw(digitCount) << amount << " " << name.toStringView() << "  ";
            if (++i % 3 == 0)
                std::cout << '\n';
        }

        if (i % 3 != 0)
            std::cout << '\n';

        std::cout << "\nSaving records to: " << Files::pathToUnicodeString(info.outname) << "...\n";

        ESM::ESMWriter esm;
        ToUTF8::Utf8Encoder encoder(ToUTF8::calculateEncoding(info.encoding));
        esm.setEncoder(&encoder);
        esm.setHeader(data.mHeader);
        esm.setVersion(ESM::VER_130);
        esm.setRecordCount(recordCount);

        std::fstream save(info.outname, std::fstream::out | std::fstream::binary);
        esm.save(save);

        int saved = 0;
        for (auto& record : data.mRecords)
        {
            if (i <= 0)
                break;

            const ESM::NAME typeName = record->getType();

            esm.startRecord(typeName, record->getFlags());

            record->save(esm);
            if (typeName.toInt() == ESM::REC_CELL)
            {
                ESM::Cell* ptr = &record->cast<ESM::Cell>()->get();
                if (!data.mCellRefs[ptr].empty())
                {
                    for (std::pair<ESM::CellRef, bool>& ref : data.mCellRefs[ptr])
                        ref.first.save(esm, ref.second);
                }
            }

            esm.endRecord(typeName);

            saved++;
            int perc = recordCount == 0 ? 100 : (int)((saved / (float)recordCount) * 100);
            if (perc % 10 == 0)
            {
                std::cerr << "\r" << perc << "%";
            }
        }

        std::cout << "\rDone!" << std::endl;

        esm.close();
        save.close();

        return 0;
    }

    int comp(const Arguments& info)
    {
        if (info.filename.empty() || info.outname.empty())
        {
            std::cout << "You need to specify two input files" << std::endl;
            return 1;
        }

        Arguments fileOne;
        Arguments fileTwo;

        fileOne.mode = "clone";
        fileTwo.mode = "clone";

        fileOne.encoding = info.encoding;
        fileTwo.encoding = info.encoding;

        fileOne.filename = info.filename;
        fileTwo.filename = info.outname;

        ESMData dataOne;
        if (load(fileOne, &dataOne) != 0)
        {
            std::cout << "Failed to load " << Files::pathToUnicodeString(info.filename) << ", aborting comparison."
                      << std::endl;
            return 1;
        }

        ESMData dataTwo;
        if (load(fileTwo, &dataTwo) != 0)
        {
            std::cout << "Failed to load " << Files::pathToUnicodeString(info.outname) << ", aborting comparison."
                      << std::endl;
            return 1;
        }

        if (dataOne.mRecords.size() != dataTwo.mRecords.size())
        {
            std::cout << "Not equal, different amount of records." << std::endl;
            return 1;
        }

        return 0;
    }

}