#include "journalwindow.hpp"

#include <set>
#include <stack>
#include <string>
#include <utility>

#include <MyGUI_TextBox.h>
#include <MyGUI_Button.h>
#include <MyGUI_InputManager.h>

#include <components/misc/stringops.hpp>
#include <components/widgets/imagebutton.hpp>
#include <components/widgets/list.hpp>

#include "../mwbase/environment.hpp"
#include "../mwbase/windowmanager.hpp"
#include "../mwbase/journal.hpp"

#include "bookpage.hpp"
#include "windowbase.hpp"
#include "journalviewmodel.hpp"
#include "journalbooks.hpp"

namespace
{
    static char const OptionsOverlay [] = "OptionsOverlay";
    static char const OptionsBTN [] = "OptionsBTN";
    static char const PrevPageBTN [] = "PrevPageBTN";
    static char const NextPageBTN [] = "NextPageBTN";
    static char const CloseBTN [] = "CloseBTN";
    static char const JournalBTN [] = "JournalBTN";
    static char const TopicsBTN [] = "TopicsBTN";
    static char const QuestsBTN [] = "QuestsBTN";
    static char const CancelBTN [] = "CancelBTN";
    static char const ShowAllBTN [] = "ShowAllBTN";
    static char const ShowActiveBTN [] = "ShowActiveBTN";
    static char const PageOneNum [] = "PageOneNum";
    static char const PageTwoNum [] = "PageTwoNum";
    static char const TopicsList [] = "TopicsList";
    static char const QuestsList [] = "QuestsList";
    static char const LeftBookPage [] = "LeftBookPage";
    static char const RightBookPage [] = "RightBookPage";
    static char const LeftTopicIndex [] = "LeftTopicIndex";
    static char const CenterTopicIndex [] = "CenterTopicIndex";
    static char const RightTopicIndex [] = "RightTopicIndex";

    struct JournalWindowImpl : MWGui::JournalBooks, MWGui::JournalWindow
    {
        struct DisplayState
        {
            unsigned int mPage;
            Book mBook;
        };

        typedef std::stack <DisplayState> DisplayStateStack;

        DisplayStateStack mStates;
        Book mTopicIndexBook;
        bool mQuestMode;
        bool mOptionsMode;
        bool mTopicsMode;
        bool mAllQuests;

        template <typename T>
        T * getWidget (char const * name)
        {
            T * widget;
            WindowBase::getWidget (widget, name);
            return widget;
        }

        template <typename value_type>
        void setText (char const * name, value_type const & value)
        {
            getWidget <MyGUI::TextBox> (name) ->
                setCaption (MyGUI::utility::toString (value));
        }

        void setVisible (char const * name, bool visible)
        {
            getWidget <MyGUI::Widget> (name) ->
                setVisible (visible);
        }

        void adviseButtonClick (char const * name, void (JournalWindowImpl::*Handler) (MyGUI::Widget* _sender))
        {
            getWidget <MyGUI::Widget> (name) ->
                eventMouseButtonClick += newDelegate(this, Handler);
        }

        void adviseKeyPress (char const * name, void (JournalWindowImpl::*Handler) (MyGUI::Widget* _sender, MyGUI::KeyCode key, MyGUI::Char character))
        {
            getWidget <MyGUI::Widget> (name) ->
                eventKeyButtonPressed += newDelegate(this, Handler);
        }

        MWGui::BookPage* getPage (char const * name)
        {
            return getWidget <MWGui::BookPage> (name);
        }

        JournalWindowImpl (MWGui::JournalViewModel::Ptr Model, bool questList, ToUTF8::FromType encoding)
            : JournalBooks (Model, encoding), JournalWindow()
        {
            center();

            adviseButtonClick (OptionsBTN,    &JournalWindowImpl::notifyOptions   );
            adviseButtonClick (PrevPageBTN,   &JournalWindowImpl::notifyPrevPage  );
            adviseButtonClick (NextPageBTN,   &JournalWindowImpl::notifyNextPage  );
            adviseButtonClick (CloseBTN,      &JournalWindowImpl::notifyClose     );
            adviseButtonClick (JournalBTN,    &JournalWindowImpl::notifyJournal   );

            adviseButtonClick (TopicsBTN,     &JournalWindowImpl::notifyTopics    );
            adviseButtonClick (QuestsBTN,     &JournalWindowImpl::notifyQuests    );
            adviseButtonClick (CancelBTN,     &JournalWindowImpl::notifyCancel    );

            adviseButtonClick (ShowAllBTN,    &JournalWindowImpl::notifyShowAll   );
            adviseButtonClick (ShowActiveBTN, &JournalWindowImpl::notifyShowActive);

            adviseKeyPress (OptionsBTN, &JournalWindowImpl::notifyKeyPress);
            adviseKeyPress (PrevPageBTN, &JournalWindowImpl::notifyKeyPress);
            adviseKeyPress (NextPageBTN, &JournalWindowImpl::notifyKeyPress);
            adviseKeyPress (CloseBTN, &JournalWindowImpl::notifyKeyPress);
            adviseKeyPress (JournalBTN, &JournalWindowImpl::notifyKeyPress);

            Gui::MWList* list = getWidget<Gui::MWList>(QuestsList);
            list->eventItemSelected += MyGUI::newDelegate(this, &JournalWindowImpl::notifyQuestClicked);

            Gui::MWList* topicsList = getWidget<Gui::MWList>(TopicsList);
            topicsList->eventItemSelected += MyGUI::newDelegate(this, &JournalWindowImpl::notifyTopicSelected);

            {
                MWGui::BookPage::ClickCallback callback;
                
                callback = std::bind (&JournalWindowImpl::notifyTopicClicked, this, std::placeholders::_1);

                getPage (LeftBookPage)->adviseLinkClicked (callback);
                getPage (RightBookPage)->adviseLinkClicked (callback);

                getPage (LeftBookPage)->eventMouseWheel += MyGUI::newDelegate(this, &JournalWindowImpl::notifyMouseWheel);
                getPage (RightBookPage)->eventMouseWheel += MyGUI::newDelegate(this, &JournalWindowImpl::notifyMouseWheel);
            }

            {
                MWGui::BookPage::ClickCallback callback;
                
                callback = std::bind(&JournalWindowImpl::notifyIndexLinkClicked, this, std::placeholders::_1);

                getPage (LeftTopicIndex)->adviseLinkClicked (callback);
                getPage (CenterTopicIndex)->adviseLinkClicked (callback);
                getPage (RightTopicIndex)->adviseLinkClicked (callback);
            }

            adjustButton(PrevPageBTN);
            float nextButtonScale = adjustButton(NextPageBTN);
            adjustButton(CloseBTN);
            adjustButton(CancelBTN);
            adjustButton(JournalBTN);

            Gui::ImageButton* optionsButton = getWidget<Gui::ImageButton>(OptionsBTN);
            Gui::ImageButton* showActiveButton = getWidget<Gui::ImageButton>(ShowActiveBTN);
            Gui::ImageButton* showAllButton = getWidget<Gui::ImageButton>(ShowAllBTN);
            Gui::ImageButton* questsButton = getWidget<Gui::ImageButton>(QuestsBTN);

            Gui::ImageButton* nextButton = getWidget<Gui::ImageButton>(NextPageBTN);
            if (nextButton->getSize().width == 64)
            {
                // english button has a 7 pixel wide strip of garbage on its right edge
                nextButton->setSize(64-7, nextButton->getSize().height);
                nextButton->setImageCoord(MyGUI::IntCoord(0,0,(64-7)*nextButtonScale,nextButton->getSize().height*nextButtonScale));
            }

            if (!questList)
            {
                // If tribunal is not installed (-> no options button), we still want the Topics button available,
                // so place it where the options button would have been
                Gui::ImageButton* topicsButton = getWidget<Gui::ImageButton>(TopicsBTN);
                topicsButton->detachFromWidget();
                topicsButton->attachToWidget(optionsButton->getParent());
                topicsButton->setPosition(optionsButton->getPosition());
                topicsButton->eventMouseButtonClick.clear();
                topicsButton->eventMouseButtonClick += MyGUI::newDelegate(this, &JournalWindowImpl::notifyOptions);

                optionsButton->setVisible(false);
                showActiveButton->setVisible(false);
                showAllButton->setVisible(false);
                questsButton->setVisible(false);

                adjustButton(TopicsBTN);
            }
            else
            {
                optionsButton->setImage("textures/tx_menubook_options.dds");
                showActiveButton->setImage("textures/tx_menubook_quests_active.dds");
                showAllButton->setImage("textures/tx_menubook_quests_all.dds");
                questsButton->setImage("textures/tx_menubook_quests.dds");

                adjustButton(ShowAllBTN);
                adjustButton(ShowActiveBTN);
                adjustButton(OptionsBTN);
                adjustButton(QuestsBTN);
                adjustButton(TopicsBTN);
                int topicsWidth = getWidget<MyGUI::Widget>(TopicsBTN)->getSize().width;
                int cancelLeft = getWidget<MyGUI::Widget>(CancelBTN)->getPosition().left;
                int cancelRight = getWidget<MyGUI::Widget>(CancelBTN)->getPosition().left + getWidget<MyGUI::Widget>(CancelBTN)->getSize().width;

                getWidget<MyGUI::Widget>(QuestsBTN)->setPosition(cancelRight, getWidget<MyGUI::Widget>(QuestsBTN)->getPosition().top);

                // Usually Topics, Quests, and Cancel buttons have the 64px width, so we can place the Topics left-up from the Cancel button, and the Quests right-up from the Cancel button.
                // But in some installations, e.g. German one, the Topics button has the 128px width, so we should place it exactly left from the Quests button.
                if (topicsWidth == 64)
                {
                    getWidget<MyGUI::Widget>(TopicsBTN)->setPosition(cancelLeft - topicsWidth, getWidget<MyGUI::Widget>(TopicsBTN)->getPosition().top);
                }
                else
                {
                    int questLeft = getWidget<MyGUI::Widget>(QuestsBTN)->getPosition().left;
                    getWidget<MyGUI::Widget>(TopicsBTN)->setPosition(questLeft - topicsWidth, getWidget<MyGUI::Widget>(TopicsBTN)->getPosition().top);
                }
            }

            mQuestMode = false;
            mAllQuests = false;
            mOptionsMode = false;
            mTopicsMode = false;
        }

        void onOpen() override
        {
            if (!MWBase::Environment::get().getWindowManager ()->getJournalAllowed ())
            {
                MWBase::Environment::get().getWindowManager()->popGuiMode ();
            }
            mModel->load ();

            setBookMode ();

            Book journalBook;
            if (mModel->isEmpty ())
                journalBook = createEmptyJournalBook ();
            else
                journalBook = createJournalBook ();

            pushBook (journalBook, 0);

            // fast forward to the last page
            if (!mStates.empty ())
            {
                unsigned int  & page = mStates.top ().mPage;
                page = mStates.top().mBook->pageCount()-1;
                if (page%2)
                    --page;
            }
            updateShowingPages();

            MWBase::Environment::get().getWindowManager()->setKeyFocusWidget(getWidget<MyGUI::Widget>(CloseBTN));
        }

        void onClose() override
        {
            mModel->unload ();

            getPage (LeftBookPage)->showPage (Book (), 0);
            getPage (RightBookPage)->showPage (Book (), 0);

            while (!mStates.empty ())
                mStates.pop ();

            mTopicIndexBook.reset ();
        }

        void setVisible (bool newValue) override
        {
            WindowBase::setVisible (newValue);
        }

        void setBookMode ()
        {
            mOptionsMode = false;
            mTopicsMode = false;
            setVisible (OptionsBTN, true);
            setVisible (OptionsOverlay, false);

            updateShowingPages ();
            updateCloseJournalButton ();
        }

        void setOptionsMode ()
        {
            mOptionsMode = true;
            mTopicsMode = false;

            setVisible (OptionsBTN, false);
            setVisible (OptionsOverlay, true);

            setVisible (PrevPageBTN, false);
            setVisible (NextPageBTN, false);
            setVisible (CloseBTN, false);
            setVisible (JournalBTN, false);

            setVisible (TopicsList, false);
            setVisible (QuestsList, mQuestMode);
            setVisible (LeftTopicIndex, !mQuestMode);
            setVisible (CenterTopicIndex, !mQuestMode);
            setVisible (RightTopicIndex, !mQuestMode);
            setVisible (ShowAllBTN, mQuestMode && !mAllQuests);
            setVisible (ShowActiveBTN, mQuestMode && mAllQuests);

            //TODO: figure out how to make "options" page overlay book page
            //      correctly, so that text may show underneath
            getPage (RightBookPage)->showPage (Book (), 0);

            // If in quest mode, ensure the quest list is updated
            if (mQuestMode)
                notifyQuests(getWidget<MyGUI::Widget>(QuestsList));
            else
                notifyTopics(getWidget<MyGUI::Widget>(TopicsList));
        }

        void pushBook (Book book, unsigned int page)
        {
            DisplayState bs;
            bs.mPage = page;
            bs.mBook = book;
            mStates.push (bs);
            updateShowingPages ();
            updateCloseJournalButton ();
        }

        void replaceBook (Book book, unsigned int page)
        {
            assert (!mStates.empty ());
            mStates.top ().mBook = book;
            mStates.top ().mPage = page;
            updateShowingPages ();
        }

        void popBook ()
        {
            mStates.pop ();
            updateShowingPages ();
            updateCloseJournalButton ();
        }

        void updateCloseJournalButton ()
        {
            setVisible (CloseBTN, mStates.size () < 2);
            setVisible (JournalBTN, mStates.size () >= 2);
        }

        void updateShowingPages ()
        {
            Book book;
            unsigned int page;
            unsigned int relPages;

            if (!mStates.empty ())
            {
                book = mStates.top ().mBook;
                page = mStates.top ().mPage;
                relPages = book->pageCount () - page;
            }
            else
            {
                page = 0;
                relPages = 0;
            }

            MyGUI::Widget* nextPageBtn = getWidget<MyGUI::Widget>(NextPageBTN);
            MyGUI::Widget* prevPageBtn = getWidget<MyGUI::Widget>(PrevPageBTN);

            MyGUI::Widget* focus = MyGUI::InputManager::getInstance().getKeyFocusWidget();
            bool nextPageVisible = relPages > 2;
            nextPageBtn->setVisible(nextPageVisible);
            bool prevPageVisible = page > 0;
            prevPageBtn->setVisible(prevPageVisible);

            if (focus == nextPageBtn && !nextPageVisible && prevPageVisible)
                MWBase::Environment::get().getWindowManager()->setKeyFocusWidget(prevPageBtn);
            else if (focus == prevPageBtn && !prevPageVisible && nextPageVisible)
                MWBase::Environment::get().getWindowManager()->setKeyFocusWidget(nextPageBtn);

            setVisible (PageOneNum, relPages > 0);
            setVisible (PageTwoNum, relPages > 1);

            getPage (LeftBookPage)->showPage ((relPages > 0) ? book : Book (), page+0);
            getPage (RightBookPage)->showPage ((relPages > 0) ? book : Book (), page+1);

            setText (PageOneNum, page + 1);
            setText (PageTwoNum, page + 2);
        }

        void notifyKeyPress(MyGUI::Widget* sender, MyGUI::KeyCode key, MyGUI::Char character)
        {
            if (key == MyGUI::KeyCode::ArrowUp)
                notifyPrevPage(sender);
            else if (key == MyGUI::KeyCode::ArrowDown)
                notifyNextPage(sender);
        }

        void notifyTopicClicked (intptr_t linkId)
        {
            Book topicBook = createTopicBook (linkId);

            if (mStates.size () > 1)
                replaceBook (topicBook, 0);
            else
                pushBook (topicBook, 0);

            setVisible (OptionsOverlay, false);
            setVisible (OptionsBTN, true);
            setVisible (JournalBTN, true);

            mOptionsMode = false;
            mTopicsMode = false;

            MWBase::Environment::get().getWindowManager()->playSound("book page");
        }

        void notifyTopicSelected (const std::string& topic, int id)
        {
            const MWBase::Journal* journal = MWBase::Environment::get().getJournal();
            intptr_t topicId = 0; /// \todo get rid of intptr ids
            for(MWBase::Journal::TTopicIter i = journal->topicBegin(); i != journal->topicEnd (); ++i)
            {
                if (Misc::StringUtils::ciEqual(i->first, topic))
                    topicId = intptr_t (&i->second);
            }

            notifyTopicClicked(topicId);
        }

        void notifyQuestClicked (const std::string& name, int id)
        {
            Book book = createQuestBook (name);

            if (mStates.size () > 1)
                replaceBook (book, 0);
            else
                pushBook (book, 0);

            setVisible (OptionsOverlay, false);
            setVisible (OptionsBTN, true);
            setVisible (JournalBTN, true);

            mOptionsMode = false;

            MWBase::Environment::get().getWindowManager()->playSound("book page");
        }

        void notifyOptions(MyGUI::Widget* _sender)
        {
            setOptionsMode ();

            if (!mTopicIndexBook)
                mTopicIndexBook = createTopicIndexBook ();

            if (mIndexPagesCount == 3)
            {
                getPage (LeftTopicIndex)->showPage (mTopicIndexBook, 0);
                getPage (CenterTopicIndex)->showPage (mTopicIndexBook, 1);
                getPage (RightTopicIndex)->showPage (mTopicIndexBook, 2);
            }
            else
            {
                getPage (LeftTopicIndex)->showPage (mTopicIndexBook, 0);
                getPage (RightTopicIndex)->showPage (mTopicIndexBook, 1);
            }
        }

        void notifyJournal(MyGUI::Widget* _sender)
        {
            assert (mStates.size () > 1);
            popBook ();

            MWBase::Environment::get().getWindowManager()->playSound("book page");
        }

        void notifyIndexLinkClicked (MWGui::TypesetBook::InteractiveId index)
        {
            setVisible (LeftTopicIndex, false);
            setVisible (CenterTopicIndex, false);
            setVisible (RightTopicIndex, false);
            setVisible (TopicsList, true);

            mTopicsMode = true;

            Gui::MWList* list = getWidget<Gui::MWList>(TopicsList);
            list->clear();

            AddNamesToList add(list);

            mModel->visitTopicNamesStartingWith(index, add);

            list->adjustSize();

            MWBase::Environment::get().getWindowManager()->playSound("book page");
        }

        void notifyTopics(MyGUI::Widget* _sender)
        {
            mQuestMode = false;
            mTopicsMode = false;
            setVisible (LeftTopicIndex, true);
            setVisible (CenterTopicIndex, true);
            setVisible (RightTopicIndex, true);
            setVisible (TopicsList, false);
            setVisible (QuestsList, false);
            setVisible (ShowAllBTN, false);
            setVisible (ShowActiveBTN, false);

            MWBase::Environment::get().getWindowManager()->playSound("book page");
        }

        struct AddNamesToList
        {
            AddNamesToList(Gui::MWList* list) : mList(list) {}

            Gui::MWList* mList;
            void operator () (const std::string& name, bool finished=false)
            {
                mList->addItem(name);
            }
        };
        struct SetNamesInactive
        {
            SetNamesInactive(Gui::MWList* list) : mList(list) {}

            Gui::MWList* mList;
            void operator () (const std::string& name, bool finished)
            {
                if (finished)
                {
                    mList->getItemWidget(name)->setStateSelected(true);
                }
            }
        };

        void notifyQuests(MyGUI::Widget* _sender)
        {
            mQuestMode = true;

            setVisible (LeftTopicIndex, false);
            setVisible (CenterTopicIndex, false);
            setVisible (RightTopicIndex, false);
            setVisible (TopicsList, false);
            setVisible (QuestsList, true);
            setVisible (ShowAllBTN, !mAllQuests);
            setVisible (ShowActiveBTN, mAllQuests);

            Gui::MWList* list = getWidget<Gui::MWList>(QuestsList);
            list->clear();

            AddNamesToList add(list);

            mModel->visitQuestNames(!mAllQuests, add);

            list->adjustSize();

            if (mAllQuests)
            {
                SetNamesInactive setInactive(list);
                mModel->visitQuestNames(false, setInactive);
            }

            MWBase::Environment::get().getWindowManager()->playSound("book page");
        }

        void notifyShowAll(MyGUI::Widget* _sender)
        {
            mAllQuests = true;
            notifyQuests(_sender);
        }

        void notifyShowActive(MyGUI::Widget* _sender)
        {
            mAllQuests = false;
            notifyQuests(_sender);
        }

        void notifyCancel(MyGUI::Widget* _sender)
        {
            if (mTopicsMode)
            {
                notifyTopics(_sender);
            }
            else
            {
                setBookMode();
                MWBase::Environment::get().getWindowManager()->playSound("book page");
            }

        }

        void notifyClose(MyGUI::Widget* _sender)
        {
            MWBase::WindowManager *winMgr = MWBase::Environment::get().getWindowManager();
            winMgr->playSound("book close");
            winMgr->popGuiMode();
        }

        void notifyMouseWheel(MyGUI::Widget* sender, int rel)
        {
            if (rel < 0)
                notifyNextPage(sender);
            else
                notifyPrevPage(sender);
        }

        void notifyNextPage(MyGUI::Widget* _sender)
        {
            if (mOptionsMode)
                return;
            if (!mStates.empty ())
            {
                unsigned int  & page = mStates.top ().mPage;
                Book   book = mStates.top ().mBook;

                if (page+2 < book->pageCount())
                {
                    MWBase::Environment::get().getWindowManager()->playSound("book page");

                    page += 2;
                    updateShowingPages ();
                }
            }
        }

        void notifyPrevPage(MyGUI::Widget* _sender)
        {
            if (mOptionsMode)
                return;
            if (!mStates.empty ())
            {
                unsigned int & page = mStates.top ().mPage;

                if(page >= 2)
                {
                    MWBase::Environment::get().getWindowManager()->playSound("book page");

                    page -= 2;
                    updateShowingPages ();
                }
            }
        }
    };
}

// glue the implementation to the interface
MWGui::JournalWindow * MWGui::JournalWindow::create (JournalViewModel::Ptr Model, bool questList, ToUTF8::FromType encoding)
{
    return new JournalWindowImpl (Model, questList, encoding);
}

MWGui::JournalWindow::JournalWindow()
    : BookWindowBase("openmw_journal.layout")
{

}