#include "content/views/view_find.hpp"

#include <hex/api/imhex_api.hpp>
#include <hex/providers/buffered_reader.hpp>

#include <array>
#include <regex>
#include <string>
#include <thread>
#include <utility>

#include <llvm/Demangle/Demangle.h>

namespace hex::plugin::builtin {

    ViewFind::ViewFind() : View("hex.builtin.view.find.name") {
        const static auto HighlightColor = [] { return (ImGui::GetCustomColorU32(ImGuiCustomCol_ToolbarPurple) & 0x00FFFFFF) | 0x70000000; };

        const static auto FindRegion = [this](u64 address) -> std::optional<Region> {
            auto &regions = this->m_foundRegions[ImHexApi::Provider::get()];

            auto it = std::upper_bound(regions.begin(), regions.end(), address, [](u64 address, Region &region) {
                return address < region.getStartAddress();
            });

            if (it != regions.begin())
                it--;

            if (it != regions.end() && it->getStartAddress() <= address && address <= it->getEndAddress())
                return *it;
            else
                return std::nullopt;
        };

        ImHexApi::HexEditor::addBackgroundHighlightingProvider([](u64 address, const u8* data, size_t size) -> std::optional<color_t> {
            hex::unused(data, size);

            if (FindRegion(address).has_value())
                return HighlightColor();
            else
                return std::nullopt;
        });

        ImHexApi::HexEditor::addTooltipProvider([this](u64 address, const u8* data, size_t size) {
            hex::unused(data, size);

            auto region = FindRegion(address);
            if (!region.has_value())
                return;

            ImGui::BeginTooltip();

            ImGui::PushID(&region);
            if (ImGui::BeginTable("##tooltips", 1, ImGuiTableFlags_RowBg | ImGuiTableFlags_NoClip)) {
                ImGui::TableNextRow();
                ImGui::TableNextColumn();

                {
                    const auto value = this->decodeValue(ImHexApi::Provider::get(), region.value());

                    ImGui::ColorButton("##color", ImColor(HighlightColor()));
                    ImGui::SameLine(0, 10);
                    ImGui::TextFormatted("{}", value);

                    if (ImGui::GetIO().KeyShift) {
                        ImGui::Indent();
                        if (ImGui::BeginTable("##extra_info", 2, ImGuiTableFlags_RowBg | ImGuiTableFlags_NoClip)) {

                            ImGui::TableNextRow();
                            ImGui::TableNextColumn();
                            ImGui::TextFormatted("{}: ", "hex.builtin.common.region"_lang.get());
                            ImGui::TableNextColumn();
                            ImGui::TextFormatted("[ 0x{:08X} - 0x{:08X} ]", region->getStartAddress(), region->getEndAddress());

                            auto demangledValue = llvm::demangle(value);

                            if (value != demangledValue) {
                                ImGui::TableNextRow();
                                ImGui::TableNextColumn();
                                ImGui::TextFormatted("{}: ", "hex.builtin.view.find.demangled"_lang.get());
                                ImGui::TableNextColumn();
                                ImGui::TextFormatted("{}", demangledValue);
                            }

                            ImGui::EndTable();
                        }
                        ImGui::Unindent();
                    }
                }


                ImGui::PushStyleColor(ImGuiCol_TableRowBg, HighlightColor());
                ImGui::PushStyleColor(ImGuiCol_TableRowBgAlt, HighlightColor());
                ImGui::EndTable();
                ImGui::PopStyleColor(2);
            }
            ImGui::PopID();

            ImGui::EndTooltip();
        });
    }

    std::vector<Region> ViewFind::searchStrings(prv::Provider *provider, hex::Region searchRegion, SearchSettings::Strings settings) {
        std::vector<Region> results;

        auto reader = prv::BufferedReader(provider);
        reader.seek(searchRegion.getStartAddress());
        reader.setEndAddress(searchRegion.getEndAddress());

        size_t countedCharacters = 0;
        u64 startAddress = reader.begin().getAddress();
        for (u8 byte : reader) {
            bool validChar =
                (settings.m_lowerCaseLetters    && std::islower(byte))  ||
                (settings.m_upperCaseLetters    && std::isupper(byte))  ||
                (settings.m_numbers             && std::isdigit(byte))  ||
                (settings.m_spaces              && std::isspace(byte))  ||
                (settings.m_underscores         && byte == '_')             ||
                (settings.m_symbols             && std::ispunct(byte))  ||
                (settings.m_lineFeeds           && byte == '\n');

            if (settings.type == SearchSettings::Strings::Type::UTF16LE) {
                // Check if second byte of UTF-16 encoded string is 0x00
                if (countedCharacters % 2 == 1)
                    validChar =  byte == 0x00;
            } else if (settings.type == SearchSettings::Strings::Type::UTF16BE) {
                // Check if first byte of UTF-16 encoded string is 0x00
                if (countedCharacters % 2 == 0)
                    validChar =  byte == 0x00;
            }

            if (validChar)
                countedCharacters++;
            else {
                if (countedCharacters >= size_t(settings.minLength)) {
                    if (!(settings.nullTermination && byte != 0x00)) {
                        results.push_back(Region { startAddress, countedCharacters });
                    }
                }

                startAddress += countedCharacters + 1;
                countedCharacters = 0;
            }
        }

        return results;
    }

    std::vector<Region> ViewFind::searchSequence(prv::Provider *provider, hex::Region searchRegion, SearchSettings::Bytes settings) {
        std::vector<Region> results;

        auto reader = prv::BufferedReader(provider);
        reader.seek(searchRegion.getStartAddress());
        reader.setEndAddress(searchRegion.getEndAddress());

        auto sequence = hex::decodeByteString(settings.sequence);
        auto occurrence = reader.begin();
        while (true) {
            occurrence = std::search(reader.begin(), reader.end(), std::boyer_moore_horspool_searcher(sequence.begin(), sequence.end()));
            if (occurrence == reader.end())
                break;

            reader.seek(occurrence.getAddress() + sequence.size());
            results.push_back(Region { occurrence.getAddress(), sequence.size() });
        }

        return results;
    }

    std::vector<Region> ViewFind::searchRegex(prv::Provider *provider, hex::Region searchRegion, SearchSettings::Regex settings) {
        auto stringRegions = searchStrings(provider, searchRegion, SearchSettings::Strings {
            .minLength          = 1,
            .type               = SearchSettings::Strings::Type::ASCII,
            .m_lowerCaseLetters = true,
            .m_upperCaseLetters = true,
            .m_numbers          = true,
            .m_underscores      = true,
            .m_symbols          = true,
            .m_spaces           = true,
            .m_lineFeeds        = true
        });

        std::vector<Region> result;
        std::regex regex(settings.pattern);
        for (const auto &region : stringRegions) {
            std::string string(region.getSize(), '\x00');
            provider->read(region.getStartAddress(), string.data(), region.getSize());

            if (std::regex_match(string, regex))
                result.push_back(region);
        }

        return result;
    }

    void ViewFind::runSearch() {
        Region searchRegion = [this]{
            if (this->m_searchSettings.range == 0 || !ImHexApi::HexEditor::isSelectionValid()) {
                auto provider = ImHexApi::Provider::get();
                return Region { provider->getBaseAddress(), provider->getActualSize() };
            } else {
                return ImHexApi::HexEditor::getSelection().value();
            }
        }();

        this->m_searchRunning = true;
        std::thread([this, settings = this->m_searchSettings, searchRegion]{
            auto task = ImHexApi::Tasks::createTask("hex.builtin.view.find.searching", 0);
            auto provider = ImHexApi::Provider::get();

            switch (settings.mode) {
                using enum SearchSettings::Mode;
                case Strings:
                    this->m_foundRegions[provider] = searchStrings(provider, searchRegion, settings.strings);
                    break;
                case Sequence:
                    this->m_foundRegions[provider] = searchSequence(provider, searchRegion, settings.bytes);
                    break;
                case Regex:
                    this->m_foundRegions[provider] = searchRegex(provider, searchRegion, settings.regex);
                    break;
            }

            this->m_sortedRegions = this->m_foundRegions;
            this->m_searchRunning = false;
        }).detach();
    }

    std::string ViewFind::decodeValue(prv::Provider *provider, hex::Region region) {
        std::vector<u8> bytes(std::min<size_t>(region.getSize(), 128));
        provider->read(region.getStartAddress(), bytes.data(), bytes.size());

        std::string result;
        switch (this->m_decodeSettings.mode) {
            using enum SearchSettings::Mode;

            case Strings:
            {
                auto &settings = this->m_decodeSettings.strings;

                switch (settings.type) {
                    using enum SearchSettings::Strings::Type;
                    case ASCII:
                        result = hex::encodeByteString(bytes);
                        break;
                    case UTF16LE:
                        for (size_t i = 0; i < bytes.size(); i += 2)
                            result += hex::encodeByteString({ bytes[i] });
                        break;
                    case UTF16BE:
                        for (size_t i = 1; i < bytes.size(); i += 2)
                            result += hex::encodeByteString({ bytes[i] });
                        break;
                }
            }
                break;
            case Sequence:
            case Regex:
                result = hex::encodeByteString(bytes);
                break;
        }

        return result;
    }

    static void drawContextMenu(const std::string &value) {
        if (ImGui::IsMouseClicked(ImGuiMouseButton_Right) && ImGui::IsItemHovered()) {
            ImGui::OpenPopup("FindContextMenu");
        }

        if (ImGui::BeginPopup("FindContextMenu")) {
            if (ImGui::MenuItem("hex.builtin.view.find.context.copy"_lang))
                ImGui::SetClipboardText(value.c_str());
            if (ImGui::MenuItem("hex.builtin.view.find.context.copy_demangle"_lang))
                ImGui::SetClipboardText(llvm::demangle(value).c_str());

            ImGui::EndPopup();
        }
    }

    void ViewFind::drawContent() {
        if (ImGui::Begin(View::toWindowName("hex.builtin.view.find.name").c_str(), &this->getWindowOpenState())) {

            ImGui::BeginDisabled(this->m_searchRunning);
            {
                ImGui::Header("hex.builtin.view.find.range"_lang, true);
                ImGui::RadioButton("hex.builtin.view.find.range.entire_data"_lang, &this->m_searchSettings.range, 0);
                ImGui::RadioButton("hex.builtin.view.find.range.selection"_lang, &this->m_searchSettings.range, 1);

                ImGui::NewLine();

                if (ImGui::BeginTabBar("SearchMethods")) {
                    auto &mode = this->m_searchSettings.mode;
                    if (ImGui::BeginTabItem("hex.builtin.view.find.strings"_lang)) {
                        auto &settings = this->m_searchSettings.strings;
                        mode = SearchSettings::Mode::Strings;

                        ImGui::InputInt("hex.builtin.view.find.strings.min_length"_lang, &settings.minLength, 1, 1);
                        if (settings.minLength < 1)
                            settings.minLength = 1;

                        const std::array<std::string, 3> StringTypes = { "hex.builtin.common.encoding.ascii"_lang,"hex.builtin.common.encoding.utf16le"_lang, "hex.builtin.common.encoding.utf16be"_lang };
                        if (ImGui::BeginCombo("hex.builtin.common.type"_lang, StringTypes[std::to_underlying(settings.type)].c_str())) {
                            for (size_t i = 0; i < StringTypes.size(); i++) {
                                auto type = static_cast<SearchSettings::Strings::Type>(i);

                                if (ImGui::Selectable(StringTypes[i].c_str(), type == settings.type))
                                    settings.type = type;
                            }
                            ImGui::EndCombo();
                        }

                        if (ImGui::CollapsingHeader("hex.builtin.view.find.strings.match_settings"_lang)) {
                            ImGui::Checkbox("hex.builtin.view.find.strings.null_term"_lang, &settings.nullTermination);

                            ImGui::Header("hex.builtin.view.find.strings.chars"_lang);
                            ImGui::Checkbox(hex::format("{} [a-z]", "hex.builtin.view.find.strings.lower_case"_lang.get()).c_str(), &settings.m_lowerCaseLetters);
                            ImGui::Checkbox(hex::format("{} [A-Z]", "hex.builtin.view.find.strings.upper_case"_lang.get()).c_str(), &settings.m_upperCaseLetters);
                            ImGui::Checkbox(hex::format("{} [0-9]", "hex.builtin.view.find.strings.numbers"_lang.get()).c_str(), &settings.m_numbers);
                            ImGui::Checkbox(hex::format("{} [_]", "hex.builtin.view.find.strings.underscores"_lang.get()).c_str(), &settings.m_underscores);
                            ImGui::Checkbox(hex::format("{} [!\"#$%...]", "hex.builtin.view.find.strings.symbols"_lang.get()).c_str(), &settings.m_symbols);
                            ImGui::Checkbox(hex::format("{} [ ]", "hex.builtin.view.find.strings.spaces"_lang.get()).c_str(), &settings.m_spaces);
                            ImGui::Checkbox(hex::format("{} [\\n]", "hex.builtin.view.find.strings.line_feeds"_lang.get()).c_str(), &settings.m_lineFeeds);
                        }

                        this->m_settingsValid = true;

                        ImGui::EndTabItem();
                    }
                    if (ImGui::BeginTabItem("hex.builtin.view.find.sequences"_lang)) {
                        auto &settings = this->m_searchSettings.bytes;

                        mode = SearchSettings::Mode::Sequence;

                        ImGui::InputText("hex.builtin.common.value"_lang, settings.sequence);

                        this->m_settingsValid = !settings.sequence.empty();

                        ImGui::EndTabItem();
                    }
                    if (ImGui::BeginTabItem("hex.builtin.view.find.regex"_lang)) {
                        auto &settings = this->m_searchSettings.regex;

                        mode = SearchSettings::Mode::Regex;

                        ImGui::InputText("hex.builtin.view.find.regex"_lang, settings.pattern);

                        try {
                            std::regex regex(settings.pattern);
                            this->m_settingsValid = true;
                        } catch (std::regex_error &e) {
                            this->m_settingsValid = false;
                        }

                        if (settings.pattern.empty())
                            this->m_settingsValid = false;

                        ImGui::EndTabItem();
                    }

                    ImGui::EndTabBar();
                }

                ImGui::NewLine();

                ImGui::BeginDisabled(!this->m_settingsValid);
                {
                    if (ImGui::Button("hex.builtin.view.find.search"_lang)) {
                        this->runSearch();

                        this->m_decodeSettings = this->m_searchSettings;
                    }
                }
                ImGui::EndDisabled();

            }
            ImGui::EndDisabled();


            ImGui::Separator();
            ImGui::NewLine();

            if (ImGui::BeginTable("##entries", 3, ImGuiTableFlags_Borders | ImGuiTableFlags_Resizable | ImGuiTableFlags_Sortable | ImGuiTableFlags_Reorderable | ImGuiTableFlags_RowBg | ImGuiTableFlags_ScrollY)) {
                ImGui::TableSetupScrollFreeze(0, 1);
                ImGui::TableSetupColumn("hex.builtin.common.offset"_lang, 0, -1, ImGui::GetID("offset"));
                ImGui::TableSetupColumn("hex.builtin.common.size"_lang, 0, -1, ImGui::GetID("size"));
                ImGui::TableSetupColumn("hex.builtin.common.value"_lang, 0, -1, ImGui::GetID("value"));

                auto provider = ImHexApi::Provider::get();
                auto &regions = this->m_sortedRegions[provider];

                auto sortSpecs = ImGui::TableGetSortSpecs();

                if (sortSpecs->SpecsDirty) {
                    std::sort(regions.begin(), regions.end(), [this, &sortSpecs, provider](Region &left, Region &right) -> bool {
                        if (sortSpecs->Specs->ColumnUserID == ImGui::GetID("offset")) {
                            if (sortSpecs->Specs->SortDirection == ImGuiSortDirection_Ascending)
                                return left.getStartAddress() > right.getStartAddress();
                            else
                                return left.getStartAddress() < right.getStartAddress();
                        } else if (sortSpecs->Specs->ColumnUserID == ImGui::GetID("size")) {
                            if (sortSpecs->Specs->SortDirection == ImGuiSortDirection_Ascending)
                                return left.getSize() > right.getSize();
                            else
                                return left.getSize() < right.getSize();
                        } else if (sortSpecs->Specs->ColumnUserID == ImGui::GetID("value")) {
                            if (sortSpecs->Specs->SortDirection == ImGuiSortDirection_Ascending)
                                return this->decodeValue(provider, left) > this->decodeValue(provider, right);
                            else
                                return this->decodeValue(provider, left) < this->decodeValue(provider, right);
                        }

                        return false;
                    });

                    sortSpecs->SpecsDirty = false;
                }

                ImGui::TableHeadersRow();

                ImGuiListClipper clipper;
                clipper.Begin(regions.size());

                while (clipper.Step()) {
                    for (int i = clipper.DisplayStart; i < clipper.DisplayEnd; i++) {
                        auto &foundItem = regions[i];

                        ImGui::TableNextRow();
                        ImGui::TableNextColumn();

                        ImGui::TextFormatted("0x{:08X}", foundItem.getStartAddress());
                        ImGui::TableNextColumn();
                        ImGui::TextFormatted("{}", hex::toByteString(foundItem.getSize()));
                        ImGui::TableNextColumn();

                        ImGui::PushID(i);

                        auto value = this->decodeValue(provider, foundItem);
                        ImGui::TextFormatted("{}", value);
                        ImGui::SameLine();
                        if (ImGui::Selectable("##line", false, ImGuiSelectableFlags_SpanAllColumns))
                            ImHexApi::HexEditor::setSelection(foundItem.getStartAddress(), foundItem.getSize());
                        drawContextMenu(value);

                        ImGui::PopID();
                    }
                }
                clipper.End();

                ImGui::EndTable();
            }

        }
        ImGui::End();
    }

}