// MassBuilderSaveTool
// Copyright (C) 2021-2022 Guillaume Jacquemin
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

#include <Corrade/Utility/Format.h>

#include <Magnum/Math/Functions.h>

#include <imgui.h>

#include "../FontAwesome/IconsFontAwesome5.h"

#include "ToastQueue.h"

using namespace Containers::Literals;

constexpr UnsignedInt success_colour = 0xff67d23bu;
constexpr UnsignedInt info_colour    = 0xffcc832fu;
constexpr UnsignedInt warning_colour = 0xff2fcfc7u;
constexpr UnsignedInt error_colour   = 0xff3134cdu;

constexpr UnsignedInt fade_time = 150;
constexpr Float base_opacity = 1.0f;
constexpr Vector2 padding{20.0f, 20.0f};
constexpr Float toast_spacing = 10.0f;

Toast::Toast(Type type, Containers::StringView message, std::chrono::milliseconds timeout):
    _type{type}, _message{message}, _timeout{timeout}, _creationTime{std::chrono::steady_clock::now()}
{
    _phaseTrack = Animation::Track<UnsignedInt, Phase>{{
        {0,                           Phase::FadeIn},
        {fade_time,                   Phase::Wait},
        {fade_time + timeout.count(), Phase::FadeOut},
        {(fade_time * 2) + timeout.count(), Phase::TimedOut}
    }, Math::select, Animation::Extrapolation::Constant};
}

auto Toast::type() -> Type {
    return _type;
}

auto Toast::message() -> Containers::StringView {
    return _message;
}

auto Toast::timeout() -> std::chrono::milliseconds {
    return _timeout;
}

auto Toast::creationTime() -> std::chrono::steady_clock::time_point {
    return _creationTime;
}

auto Toast::elapsedTime() -> std::chrono::milliseconds {
    return std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now() - _creationTime);
}

auto Toast::phase() -> Phase {
    return _phaseTrack.at(elapsedTime().count());
}

auto Toast::opacity() -> Float {
    Phase phase = this->phase();
    Long elapsed_time = elapsedTime().count();

    if(phase == Phase::FadeIn) {
        return Float(elapsed_time) / Float(fade_time);
    }
    else if(phase == Phase::FadeOut) {
        return 1.0f - ((Float(elapsed_time) - Float(fade_time) - Float(_timeout.count())) / Float(fade_time));
    }

    return 1.0f;
}

void ToastQueue::addToast(Toast&& toast) {
    _toasts.push_back(std::move(toast));
}

void ToastQueue::addToast(Toast::Type type, Containers::StringView message, std::chrono::milliseconds timeout) {
    _toasts.emplace_back(type, message, timeout);
}

void ToastQueue::draw(Vector2i viewport_size) {
    Float height = 0.0f;

    for(UnsignedInt i = 0; i < _toasts.size(); i++) {
        Toast* current = &_toasts[i];

        if(current->phase() == Toast::Phase::TimedOut) {
            removeToast(i);
            continue;
        }

        Containers::String win_id = Utility::format("##Toast{}", i);

        Float opacity = base_opacity * current->opacity();

        ImGui::PushStyleVar(ImGuiStyleVar_Alpha, opacity);

        ImGui::SetNextWindowPos({viewport_size.x() - padding.x(), viewport_size.y() - padding.y() - height}, ImGuiCond_Always, {1.0f, 1.0f});
        if(ImGui::Begin(win_id.data(), nullptr,
                        ImGuiWindowFlags_AlwaysAutoResize|ImGuiWindowFlags_NoDecoration|
                        ImGuiWindowFlags_NoInputs|ImGuiWindowFlags_NoNav|ImGuiWindowFlags_NoFocusOnAppearing))
        {
            ImColor colour = 0xffffffff;

            switch(current->type()) {
                case Toast::Type::Default:
                    break;
                case Toast::Type::Success:
                    colour = success_colour;
                    ImGui::TextColored(colour, ICON_FA_CHECK_CIRCLE);
                    break;
                case Toast::Type::Info:
                    colour = info_colour;
                    ImGui::TextColored(colour, ICON_FA_INFO_CIRCLE);
                    break;
                case Toast::Type::Warning:
                    colour = warning_colour;
                    ImGui::TextColored(colour, ICON_FA_EXCLAMATION_TRIANGLE);
                    break;
                case Toast::Type::Error:
                    colour = error_colour;
                    ImGui::TextColored(colour, ICON_FA_TIMES_CIRCLE);
                    break;
            }

            if(current->type() != Toast::Type::Default) {
                ImGui::SameLine();
            }

            ImGui::PushTextWrapPos(500.0f);
            ImGui::TextColored(colour, current->message().data());
            ImGui::PopTextWrapPos();

            height += ImGui::GetWindowHeight() + toast_spacing;
        }
        ImGui::End();

        ImGui::PopStyleVar();
    }
}

void ToastQueue::removeToast(Long index) {
    _toasts.erase(_toasts.begin() + index);
}