#include "theme.h"
#include "imgui.h"
#include "json/value.h"
#include <cmath>
#include <exception>
#include <numbers>
#include <iostream>
#include <fstream>
#include <json/json.h>
#include <filesystem>

using namespace std::filesystem;
using namespace std::numbers;
const char* Theme::prefPath = NULL;
path Theme::themeDir = path();
std::set<path> Theme::availableThemes = std::set<path>();
bool Theme::ShowEditor(bool* open, Theme* &theme) {
    static ImGui::FileBrowser importDialog;
    static ImGui::FileBrowser exportDialog;
    static bool loadOpen = false;
    static bool saveAsOpen = false;
    ImGui::Begin("Theme Editor", open);
    ImGuiStyle& style = theme->style;
    ImGui::PushItemWidth(ImGui::GetWindowWidth() * 0.50f);
    ImVec2 buttonSize = ImVec2((ImGui::GetWindowWidth() * 0.50f) - (ImGui::GetStyle().WindowPadding.x) - (ImGui::GetStyle().ItemSpacing.x * 0.5f), 0);
    if (ImGui::Button("Create light", buttonSize)) {
        delete theme;
        theme = new Theme(false);

        ImGui::PopItemWidth();
        ImGui::End();
        return true;
    }
    ImGui::SameLine();
    if (ImGui::Button("Create dark", buttonSize)) {
        delete theme;
        theme = new Theme(true);

        ImGui::PopItemWidth();
        ImGui::End();
        return true;
    }
    if (ImGui::Button("Import...", buttonSize)) {
        importDialog.SetTitle("Import theme...");
        importDialog.SetTypeFilters({ ".json"});
        std::string userdir = std::getenv(
        #ifdef _WIN32
        "UserProfile"
        #else
        "HOME"
        #endif
        );
        importDialog.SetPwd(userdir);
        importDialog.Open();
    }
    ImGui::SameLine();
    if (ImGui::Button("Export...", buttonSize)) {
        exportDialog = ImGui::FileBrowser(ImGuiFileBrowserFlags_EnterNewFilename|ImGuiFileBrowserFlags_CreateNewDir);
        exportDialog.SetTitle("Export theme...");
        exportDialog.SetTypeFilters({ ".json"});
        std::string userdir = std::getenv(
        #ifdef _WIN32
        "UserProfile"
        #else
        "HOME"
        #endif
        );
        exportDialog.SetPwd(userdir);
        exportDialog.Open();
    }
    importDialog.Display();
    exportDialog.Display();
    if (!theme->file_path.empty()) {
        if (ImGui::Button("Revert", buttonSize)) {
            string file_path_backup = theme->file_path;
            delete theme;
            theme = new Theme(file_path_backup);
            ImGui::PopItemWidth();
            ImGui::End();
            return true;
        }
        ImGui::SameLine();
        if (ImGui::Button("Save", buttonSize)) {
            theme->Save(theme->file_path);
        }
    }
    if (ImGui::Button("Load...", buttonSize)) {
        loadOpen = true;
    }
    ImGui::SameLine();
    if (ImGui::Button("Save as...", buttonSize)) {
        saveAsOpen = true;
    }

    // Simplified Settings (expose floating-pointer border sizes as boolean representing 0.0f or 1.0f)
    if (ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f"))
        style.GrabRounding = style.FrameRounding; // Make GrabRounding always the same value as FrameRounding
    { bool border = (style.WindowBorderSize > 0.0f); if (ImGui::Checkbox("WindowBorder", &border)) { style.WindowBorderSize = border ? 1.0f : 0.0f; } }
    ImGui::SameLine();
    { bool border = (style.FrameBorderSize > 0.0f);  if (ImGui::Checkbox("FrameBorder",  &border)) { style.FrameBorderSize  = border ? 1.0f : 0.0f; } }
    ImGui::SameLine();
    { bool border = (style.PopupBorderSize > 0.0f);  if (ImGui::Checkbox("PopupBorder",  &border)) { style.PopupBorderSize  = border ? 1.0f : 0.0f; } }

    ImGui::Separator();

    if (ImGui::BeginTabBar("##tabs", ImGuiTabBarFlags_None))
    {
        if (ImGui::BeginTabItem("Sizes"))
        {

            ImGui::SeparatorText("Borders");
            ImGui::SliderFloat("WindowBorderSize", &style.WindowBorderSize, 0.0f, 1.0f, "%.0f");
            ImGui::SliderFloat("ChildBorderSize", &style.ChildBorderSize, 0.0f, 1.0f, "%.0f");
            ImGui::SliderFloat("PopupBorderSize", &style.PopupBorderSize, 0.0f, 1.0f, "%.0f");
            ImGui::SliderFloat("FrameBorderSize", &style.FrameBorderSize, 0.0f, 1.0f, "%.0f");
            ImGui::SliderFloat("TabBorderSize", &style.TabBorderSize, 0.0f, 1.0f, "%.0f");

            ImGui::SeparatorText("Rounding");
            ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 12.0f, "%.0f");
            ImGui::SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 12.0f, "%.0f");
            ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f");
            ImGui::SliderFloat("PopupRounding", &style.PopupRounding, 0.0f, 12.0f, "%.0f");
            ImGui::SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 12.0f, "%.0f");
            ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 12.0f, "%.0f");
            ImGui::SliderFloat("TabRounding", &style.TabRounding, 0.0f, 12.0f, "%.0f");

            ImGui::EndTabItem();
        }

        if (ImGui::BeginTabItem("Colors"))
        {

            static ImGuiTextFilter filter;
            filter.Draw("Filter colors", ImGui::GetFontSize() * 16);

            static ImGuiColorEditFlags alpha_flags = 0;
            if (ImGui::RadioButton("Opaque", alpha_flags == ImGuiColorEditFlags_None))             { alpha_flags = ImGuiColorEditFlags_None; } ImGui::SameLine();
            if (ImGui::RadioButton("Alpha",  alpha_flags == ImGuiColorEditFlags_AlphaPreview))     { alpha_flags = ImGuiColorEditFlags_AlphaPreview; } ImGui::SameLine();
            if (ImGui::RadioButton("Both",   alpha_flags == ImGuiColorEditFlags_AlphaPreviewHalf)) { alpha_flags = ImGuiColorEditFlags_AlphaPreviewHalf; }

            ImGui::BeginChild("##colors", ImVec2(0, 0), true, ImGuiWindowFlags_AlwaysVerticalScrollbar | ImGuiWindowFlags_AlwaysHorizontalScrollbar | ImGuiWindowFlags_NavFlattened);
            ImGui::PushItemWidth(-160);
            for (int i = 0; i < ImGuiCol_COUNT; i++)
            {
                const char* name = ImGui::GetStyleColorName(i);
                if (!filter.PassFilter(name))
                    continue;
                ImGui::PushID(i);
                ImGui::ColorEdit4("##color", (float*)&style.Colors[i], ImGuiColorEditFlags_AlphaBar | alpha_flags | ImGuiColorEditFlags_DisplayHSV);
                ImGui::SameLine(0.0f, style.ItemInnerSpacing.x);
                ImGui::TextUnformatted(name);
                bool hueEnabled = theme->HueEnabledColors.contains(i);
                if (ImGui::Checkbox("Match accent color hue", &hueEnabled)) {
                    if (hueEnabled) {
                        theme->HueEnabledColors.insert(i);
                    } else {
                        theme->HueEnabledColors.erase(i);
                    }
                }
                ImGui::PopID();
            }
            ImGui::PopItemWidth();
            ImGui::EndChild();

            ImGui::EndTabItem();
        }

        ImGui::EndTabBar();
    }

    ImGui::PopItemWidth();
    ImGui::End();
    if (importDialog.HasSelected()) {
        path selected_path = importDialog.GetSelected();
        path filename = selected_path.filename();
        copy_file(selected_path, theme->themeDir / filename);
        theme->availableThemes.insert(filename);
    }
    if (exportDialog.HasSelected()) {
        path selected_path = importDialog.GetSelected();
        theme->Save(selected_path);
    }
    if (loadOpen) {
        ImGui::OpenPopup("Load...");
    }
    if (ImGui::BeginPopupModal("Load...", &loadOpen)) {
        static path selectedThemePath;
        static char filter[1024] = {0};
        ImGui::Text("Filter:"); ImGui::SameLine();
        ImGui::SetNextItemWidth(ImGui::GetWindowWidth() - ImGui::GetCursorPosX() - ImGui::GetStyle().WindowPadding.x);
        ImGui::InputText("##FilterInput", filter, 1024);
        ImGui::Text("Available themes...");
        if (ImGui::BeginListBox("##Themes", ImVec2(ImGui::GetWindowWidth() - (ImGui::GetStyle().WindowPadding.x * 2.0f), -ImGui::GetTextLineHeightWithSpacing() - ImGui::GetStyle().WindowPadding.y))) {
            for (auto themePath : Theme::availableThemes) {
                if (themePath.stem().string().starts_with(filter)) {
                    const bool is_selected = themePath == selectedThemePath;
                    if (ImGui::Selectable(themePath.stem().c_str(), is_selected)) {
                        selectedThemePath = themePath;
                    }
                    if (is_selected) {
                        ImGui::SetItemDefaultFocus();
                    }
                }
            }
            ImGui::EndListBox();
        }
        if (ImGui::Button("Load")) {
            if (!selectedThemePath.empty()) {
                filter[0] = '\0';
                loadOpen = false;
                delete theme;
                theme = new Theme(selectedThemePath);
                selectedThemePath = path();
                ImGui::EndPopup();
                return true;
            }
        }
        ImGui::SameLine();
        if (ImGui::Button("Cancel")) {
            selectedThemePath = path();
            filter[0] = '\0';
            loadOpen = false;
        }
        ImGui::EndPopup();
    }
    if (saveAsOpen) {
        ImGui::OpenPopup("Save as...");
    }
    if (ImGui::BeginPopupModal("Save as...", &saveAsOpen)) {
        static char selectedThemeName[1024] = {0};
        static char filter[1024] = {0};
        ImGui::Text("Filter:"); ImGui::SameLine();
        ImGui::SetNextItemWidth(ImGui::GetWindowWidth() - ImGui::GetCursorPosX() - ImGui::GetStyle().WindowPadding.x);
        ImGui::InputText("##FilterInput", filter, 1024);
        ImGui::Text("Available themes...");
        if (ImGui::BeginListBox("##Themes", ImVec2(ImGui::GetWindowWidth() - (ImGui::GetStyle().WindowPadding.x * 2.0f), -ImGui::GetFrameHeightWithSpacing() - ImGui::GetTextLineHeightWithSpacing() - ImGui::GetStyle().WindowPadding.y))) {
            for (auto themePath : Theme::availableThemes) {
                if (themePath.stem().string().starts_with(filter)) {
                    const bool is_selected = strcmp(themePath.stem().c_str(), selectedThemeName) == 0;
                    if (ImGui::Selectable(themePath.stem().c_str(), is_selected)) {
                        strncpy(selectedThemeName, themePath.stem().c_str(), 1024);
                    }
                    if (is_selected) {
                        ImGui::SetItemDefaultFocus();
                    }
                }
            }
            ImGui::EndListBox();
        }
        ImGui::SetNextItemWidth(ImGui::GetWindowWidth() - (ImGui::GetStyle().WindowPadding.x * 2.0f));
        ImGui::InputText("Theme name: ", selectedThemeName, 1024);
        if (ImGui::Button("Save")) {
            path selectedThemePath(selectedThemeName);
            if (!selectedThemePath.empty() && !selectedThemePath.is_absolute()) {
                selectedThemeName[0] = '\0'; // This empties the string by taking advantage of C strings.
                filter[0] = '\0';
                saveAsOpen = false;
                theme->Save(Theme::themeDir / selectedThemePath.replace_extension(".json"));
                theme->file_path = selectedThemePath;
            }
        }
        ImGui::SameLine();
        if (ImGui::Button("Cancel")) {
            selectedThemeName[0] = '\0'; // Same as above
            filter[0] = '\0';
            saveAsOpen = false;
        }
        ImGui::EndPopup();
    }
    return false;
}
ImVec4 change_accent_color(ImVec4 in, float hue) {
    if (in.x == in.y && in.y == in.z) {
        return in;
    }
    ImVec4 hsv = in;
    ImVec4 out = in;
    ImGui::ColorConvertRGBtoHSV(in.x, in.y, in.z, hsv.x, hsv.y, hsv.z);
    hsv.x = hue / 360.0f;
    ImGui::ColorConvertHSVtoRGB(hsv.x, hsv.y, hsv.z, out.x, out.y, out.z);
    return out;
}
void Theme::Apply(float hue) {
    ImGuiStyle& actual_style = ImGui::GetStyle();
    actual_style = style;
    for (int i = 0; i < ImGuiCol_COUNT; i++)
    {
        if (HueEnabledColors.contains(i)) {
            actual_style.Colors[i] = change_accent_color(style.Colors[i], hue);
        }
    }
    ImGuiIO& io = ImGui::GetIO();
    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
    {
        actual_style.WindowRounding = 0.0f;
        actual_style.Colors[ImGuiCol_WindowBg].w = 1.0f;
    }
}
void Theme::Save(string path) {
    {
        Json::Value config;
        std::ofstream stream;
        stream.open(path);
        {
            Json::Value rounding;
            rounding["Frame"] = style.FrameRounding;
            rounding["Window"] = style.WindowRounding;
            rounding["Child"] = style.ChildRounding;
            rounding["Popup"] = style.PopupRounding;
            rounding["Scrollbar"] = style.ScrollbarRounding;
            rounding["Grab"] = style.GrabRounding;
            rounding["Tab"] = style.TabRounding;
            config["rounding"] = rounding;
        }
        {
            Json::Value borders;
            borders["Frame"] = style.FrameBorderSize;
            borders["Window"] = style.WindowBorderSize;
            borders["Child"] = style.ChildBorderSize;
            borders["Popup"] = style.PopupBorderSize;
            borders["Tab"] = style.TabBorderSize;
            config["borders"] = borders;
        }
        {
            Json::Value colors;
            for (int i = 0; i < ImGuiCol_COUNT; i++)
            {
                const char* name = ImGui::GetStyleColorName(i);
                ImVec4 color = style.Colors[i];
                Json::Value colorValue;
                colorValue["r"] = color.x;
                colorValue["g"] = color.y;
                colorValue["b"] = color.z;
                colorValue["a"] = color.w;
                colorValue["ConvertToAccent"] = HueEnabledColors.contains(i);
                colors[name] = colorValue;
            }
            config["colors"] = colors;
        }
        stream << config;
        stream.close();
    }
    updateAvailableThemes();
}
void Theme::updateAvailableThemes() {
    themeDir = path(prefPath) / path("themes");
    create_directories(themeDir);
    availableThemes.clear();
    for (auto const& dir_entry : directory_iterator(themeDir)) {
        if (dir_entry.is_regular_file()) {
            if (dir_entry.path().extension().string() == ".json") {
                availableThemes.insert(dir_entry.path());
            }
        }
    }
}
Theme::Theme() {
    if (prefPath == NULL) {
        throw std::exception();
    }
    updateAvailableThemes();
}

Theme::Theme(bool dark) : Theme() {
    if (dark) {
        ImGui::StyleColorsDark(&style);
    } else {
        ImGui::StyleColorsLight(&style);
        style.FrameBorderSize = 1;
    }
    for (int i = 0; i < ImGuiCol_COUNT; i++)
    {
        HueEnabledColors.insert(i);
    }
    style.FrameRounding = 12;
    style.GrabRounding = 12;
    style.WindowRounding = 12;
}
Theme::Theme(string path) : Theme() {
    Json::Value config;
    std::ifstream stream;
    stream.open(path);
    if (stream.is_open()) {
        stream >> config;
        if (config.isMember("rounding")) {
            Json::Value rounding = config["rounding"];
            style.FrameRounding = rounding["Frame"].asFloat();
            style.WindowRounding = rounding["Window"].asFloat();
            style.ChildRounding = rounding["Child"].asFloat();
            style.PopupRounding = rounding["Popup"].asFloat();
            style.ScrollbarRounding = rounding["Scrollbar"].asFloat();
            style.GrabRounding = rounding["Grab"].asFloat();
            style.TabRounding = rounding["Tab"].asFloat();
        }
        if (config.isMember("borders")) {
            Json::Value borders = config["borders"];
            style.FrameBorderSize = borders["Frame"].asFloat();
            style.WindowBorderSize = borders["Window"].asFloat();
            style.ChildBorderSize = borders["Child"].asFloat();
            style.PopupBorderSize = borders["Popup"].asFloat();
            style.TabBorderSize = borders["Tab"].asFloat();
        }
        if (config.isMember("colors")) {
            Json::Value colors = config["colors"];
            for (int i = 0; i < ImGuiCol_COUNT; i++)
            {
                const char* name = ImGui::GetStyleColorName(i);
                if (colors.isMember(name)) {
                    Json::Value colorValue = colors[name];
                    ImVec4 color = ImVec4(colorValue["r"].asFloat(), colorValue["g"].asFloat(), colorValue["b"].asFloat(), colorValue["a"].asFloat());
                    bool hueShifted = colorValue["ConvertToAccent"].asBool();
                    style.Colors[i] = color;
                    if (hueShifted) {
                        HueEnabledColors.insert(i);
                    }
                }
            }
        }
        stream.close();
    }
    file_path = path;
}