//
// MainPage.xaml.cpp
// Implementation of the MainPage class.
//

#include "pch.h"
#include "MainPage.xaml.h"

#define LOOK_AHEAD 0 /* A +/- count on the pages to pre-render */
#define THUMB_PREADD 10
#define MIN_SCALE 0.5

#define SCALE_THUMB 0.1

#define BLANK_WIDTH 17
#define BLANK_HEIGHT 22

#define KEYBOARD_ZOOM_STEP 0.25
#define ZOOM_MAX 4
#define ZOOM_MIN 0.25

#define KEY_PLUS 0xbb
#define KEY_MINUS 0xbd
#define ZOOM_IN 0
#define ZOOM_OUT 1

static float screenScale = 1;

using namespace mupdf_cpp;
using namespace Windows::Foundation;
using namespace Windows::UI::Xaml;
using namespace Windows::UI::Xaml::Controls;
using namespace Windows::UI::Xaml::Controls::Primitives;
using namespace Windows::UI::Xaml::Data;
using namespace Windows::UI::Xaml::Media;
using namespace Windows::UI::Xaml::Navigation;
using namespace Windows::Graphics::Display;

//****************** Added *****************
using namespace Windows::Storage::Pickers;
using namespace Windows::Devices::Enumeration;
using namespace concurrency;
using namespace Windows::Graphics::Imaging;
//****************** End Add ****************

#ifndef NDEBUG
unsigned int _mainThreadId = 0U;

#ifdef  __cplusplus
extern "C" {
#endif

	// The IsMainThread function returns true if the current thread is the app's main thread and false otherwise.
	bool IsMainThread()
	{
		return (_mainThreadId == GetCurrentThreadId());
	}

	// The IsBackgroundThread function returns false if the current thread is the app's main thread and true otherwise.
	bool IsBackgroundThread()
	{
		return (_mainThreadId != GetCurrentThreadId());
	}

	// The RecordMainThread function registers the main thread ID for use by the IsMainThread and IsBackgroundThread functions.
	void RecordMainThread()
	{
		_mainThreadId = GetCurrentThreadId();
	}

#ifdef  __cplusplus
}
#endif

#endif /* not NDEBUG */

MainPage::MainPage()
{
	InitializeComponent();
	Application::Current->Suspending += 
		ref new SuspendingEventHandler(this, &MainPage::App_Suspending);
	m_textcolor="#402572AC";
	m_linkcolor="#40AC7225";
	mu_doc = nullptr;
	m_docPages = ref new Platform::Collections::Vector<DocumentPage^>();
	m_thumbnails = ref new Platform::Collections::Vector<DocumentPage^>();
	m_page_link_list = ref new Platform::Collections::Vector<IVector<RectList^>^>();
	m_text_list = ref new Platform::Collections::Vector<RectList^>();
	m_linkset = ref new Platform::Collections::Vector<int>();
	CleanUp();
	RecordMainThread();
}

/// <summary>
/// Invoked when this page is about to be displayed in a Frame.
/// </summary>
/// <param name="e">Event data that describes how this page was reached.  The Parameter
/// property is typically used to configure the page.</param>
void MainPage::OnNavigatedTo(NavigationEventArgs^ e)
{
	(void) e;	// Unused parameter
}

void mupdf_cpp::MainPage::App_Suspending(Object^ sender, SuspendingEventArgs^ e)
{

}

void mupdf_cpp::MainPage::ExitInvokedHandler(Windows::UI::Popups::IUICommand^ command)
{

}

void mupdf_cpp::MainPage::OKInvokedHandler(Windows::UI::Popups::IUICommand^ command)
{

}

void mupdf_cpp::MainPage::NotifyUser(String^ strMessage, NotifyType_t type)
{
	MessageDialog^ msg = ref new MessageDialog(strMessage);
	UICommand^ ExitCommand = nullptr;
	UICommand^  OKCommand = nullptr;

	switch (type)
	{
	case StatusMessage:
		OKCommand = ref new UICommand("OK",
			ref new UICommandInvokedHandler(this, &mupdf_cpp::MainPage::OKInvokedHandler));
		msg->Commands->Append(OKCommand);
		/// Set the command that will be invoked by default
		msg->DefaultCommandIndex = 0;
		// Set the command to be invoked when escape is pressed
		msg->CancelCommandIndex = 1;
		break;
	case ErrorMessage:
		ExitCommand = ref new UICommand("Exit",
			ref new UICommandInvokedHandler(this, &mupdf_cpp::MainPage::ExitInvokedHandler));
		msg->Commands->Append(ExitCommand);
		/// Set the command that will be invoked by default
		msg->DefaultCommandIndex = 0;
		// Set the command to be invoked when escape is pressed
		msg->CancelCommandIndex = 1;
		break;
	default:
		break;
	}
	// Show the message dialog
	msg->ShowAsync();
}

bool mupdf_cpp::MainPage::EnsureUnsnapped()
{
	// FilePicker APIs will not work if the application is in a snapped state.
	// If an app wants to show a FilePicker while snapped, it must attempt to unsnap first

	bool unsnapped = (ApplicationView::Value != ApplicationViewState::Snapped  ||
		ApplicationView::TryUnsnap());
	if (!unsnapped)
	{
		NotifyUser("Cannot unsnap the application", StatusMessage);
	}
	return unsnapped;
}

void mupdf_cpp::MainPage::Picker(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	if (!EnsureUnsnapped())
		return;

	FileOpenPicker^ openPicker = ref new FileOpenPicker();
	openPicker->ViewMode = PickerViewMode::List;
	openPicker->SuggestedStartLocation = PickerLocationId::DocumentsLibrary;
	openPicker->FileTypeFilter->Append(".pdf");
	openPicker->FileTypeFilter->Append(".xps");
	openPicker->FileTypeFilter->Append(".cbz");
	openPicker->FileTypeFilter->Append(".oxps");

	create_task(openPicker->PickSingleFileAsync()).then([this](StorageFile^ file)
	{
		if (file)
		{
			this->OpenDocumentPrep(file);
		}
		else
		{
			/* Nothing selected */
		}
	});
}

/* Set the page with the new raster information */
void MainPage::UpdatePage(int page_num, InMemoryRandomAccessStream^ ras,
			  Point ras_size, Page_Content_t content_type)
{
	assert(IsMainThread());

	WriteableBitmap ^bmp = ref new WriteableBitmap(ras_size.X, ras_size.Y);
	bmp->SetSource(ras);

	DocumentPage^ doc_page = ref new DocumentPage();
	doc_page->Image = bmp;

	if (content_type == THUMBNAIL)
	{
		doc_page->Height = ras_size.Y / SCALE_THUMB;
		doc_page->Width = ras_size.X / SCALE_THUMB;
	}
	else
	{
		doc_page->Height = ras_size.Y;
		doc_page->Width = ras_size.X;
	}
	doc_page->Content = content_type;

	/* We do not want flipview change notification to occur for ourselves */
	m_page_update = true;
	this->m_docPages->SetAt(page_num, doc_page);
	m_page_update = false;
}

/* Set the page with the new raster information but only the image data */
void MainPage::ReplaceImage(int page_num, InMemoryRandomAccessStream^ ras,
				Point ras_size)
{
	assert(IsMainThread());

	WriteableBitmap ^bmp = ref new WriteableBitmap(ras_size.X, ras_size.Y);
	bmp->SetSource(ras);

	DocumentPage^ doc_page = this->m_docPages->GetAt(page_num);
	doc_page->Image = bmp;

	doc_page->Height = ras_size.Y;
	doc_page->Width = ras_size.X;
}

Point MainPage::ComputePageSize(spatial_info_t spatial_info, int page_num)
{
	Point screenSize;
	Point pageSize;
	Point size = mu_doc->GetPageSize(page_num);

	screenSize = spatial_info.size;
	screenSize.Y *= screenScale;
	screenSize.X *= screenScale;

	float hscale = screenSize.X / size.X;
	float vscale = screenSize.Y / size.Y;
	float scale = min(hscale, vscale);
	pageSize.X = size.X * scale * spatial_info.scale_factor;
	pageSize.Y = size.Y * scale * spatial_info.scale_factor;

	return pageSize;
}

static Point fitPageToScreen(Point page, Point screen)
{
	Point pageSize;

	float hscale = screen.X / page.X;
	float vscale = screen.Y / page.Y;
	float scale = min(hscale, vscale);
	pageSize.X = floorf(page.X * scale) / page.X;
	pageSize.Y = floorf(page.Y * scale) / page.Y;

	return pageSize;
}

spatial_info_t MainPage::InitSpatial(double scale)
{
	spatial_info_t value;

	value.size.Y = this->ActualHeight;
	value.size.X = this->ActualWidth;
	value.scale_factor = scale;

	return value;
}

void Prepare_bmp(int width, int height, DataWriter ^dw)
{
	int row_size = width * 4;
	int bmp_size = row_size * height + 54;

	dw->WriteString("BM");
	dw->ByteOrder = ByteOrder::LittleEndian;
	dw->WriteInt32(bmp_size);
	dw->WriteInt16(0);
	dw->WriteInt16(0);
	dw->WriteInt32(54);
	dw->WriteInt32(40);
	dw->WriteInt32(width);
	dw->WriteInt32(height);
	dw->WriteInt16(1);
	dw->WriteInt16(32);
	dw->WriteInt32(0);
	dw->WriteInt32(row_size * height);
	dw->WriteInt32(2835);
	dw->WriteInt32(2835);
	dw->WriteInt32(0);
	dw->WriteInt32(0);
}

void MainPage::ReleasePages(int old_page, int new_page)
{
	if (old_page == new_page) return;
	/* To keep from having memory issue reset the page back to
		the thumb if we are done rendering the thumbnails */
	for (int k = old_page - LOOK_AHEAD; k <= old_page + LOOK_AHEAD; k++)
	{
		if (k < new_page - LOOK_AHEAD || k > new_page + LOOK_AHEAD)
		{
			if (k >= 0 && k < this->m_num_pages)
			{
				SetThumb(k, true);
			}
		}
	}
}

/* Return this page from a full res image to the thumb image or only set
   to thumb if it has not already been set */
void MainPage::SetThumb(int page_num, bool replace)
{
	/* See what is there now */
	auto doc = this->m_docPages->GetAt(page_num);
	if (doc->Content == THUMBNAIL) return;
	if (doc->Content == FULL_RESOLUTION && replace == false) return;

	if (this->m_thumbnails->Size > page_num)
	{
		m_page_update = true;
		this->m_docPages->SetAt(page_num, this->m_thumbnails->GetAt(page_num));
		m_page_update = false;
	}
}

/* Create white image for us to use as place holder in large document for flip
   view filling instead of the thumbnail image  */
void MainPage::CreateBlank(int width, int height)
{
	Array<unsigned char>^ bmp_data = ref new Array<unsigned char>(height * 4 * width);
	/* Set up the memory stream */
	WriteableBitmap ^bmp = ref new WriteableBitmap(width, height);
	InMemoryRandomAccessStream ^ras = ref new InMemoryRandomAccessStream();
	DataWriter ^dw = ref new DataWriter(ras->GetOutputStreamAt(0));
	/* Go ahead and write our header data into the memory stream */
	Prepare_bmp(width, height, dw);

	/* Set the data to all white */
	memset(bmp_data->Data, 255, height * 4 * width);

	/* Write the data */
	dw->WriteBytes(bmp_data);

	DataWriterStoreOperation^ result = dw->StoreAsync();
	/* Block on the Async call */
	while(result->Status != AsyncStatus::Completed) {
	}
	/* And store in a the image brush */
	bmp->SetSource(ras);
	m_BlankBmp = bmp;
}

void mupdf_cpp::MainPage::SetFlipView()
{
	int height = this->ActualHeight;
	int width = this->ActualWidth;

	CreateBlank(BLANK_WIDTH, BLANK_HEIGHT);
	/* Set the current flip view mode */
	if (height > width)
		this->m_curr_flipView = xaml_vert_flipView;
	else
		this->m_curr_flipView = xaml_horiz_flipView;
}

/* Clean up everything as we are opening a new document after having another
   one open */
void mupdf_cpp::MainPage::CleanUp()
{
	m_init_done = false;
	/* Remove current pages in the flipviews */
	if (m_docPages != nullptr && m_docPages->Size > 0)
		m_docPages->Clear();
	if (m_thumbnails != nullptr && m_thumbnails->Size > 0)
		m_thumbnails->Clear();
	/* With the ref counting this should not leak */
	if (m_page_link_list != nullptr && m_page_link_list->Size > 0)
		m_page_link_list->Clear();
	if (m_text_list->Size > 0)
		m_text_list->Clear();
	if (m_linkset != nullptr && m_linkset->Size > 0)
		m_linkset->Clear();

	if (this->mu_doc != nullptr)
		mu_doc->CleanUp();

	mu_doc = ref new mudocument();
	if (mu_doc == nullptr)
		throw ref new FailureException("Document allocation failed!");

	this->m_curr_flipView = nullptr;
	m_currpage = -1;
	m_file_open = false;
	m_slider_min = 0;
	m_slider_max = 0;
	m_memory_use = 0;
	m_insearch = false;
	m_search_active = false;
	m_sliderchange = false;
	m_flip_from_searchlink = false;
	m_num_pages = -1;
	m_search_rect_count = 0;
	m_ren_status = REN_AVAILABLE;
	m_links_on = false;
	m_rectlist_page = -1;
	m_Progress = 0.0;

	this->xaml_PageSlider->Minimum = m_slider_min;
	this->xaml_PageSlider->Maximum = m_slider_max;
	this->xaml_PageSlider->IsEnabled = false;
}

/* Create the thumbnail images */
void mupdf_cpp::MainPage::RenderThumbs()
{
	spatial_info_t spatial_info = this->InitSpatial(1);
	int num_pages = this->m_num_pages;
	cancellation_token_source cts;
	auto token = cts.get_token();
	m_ThumbCancel = cts;
	auto ui = task_continuation_context::use_current();

	this->m_ren_status = REN_THUMBS;
	Vector<DocumentPage^>^ thumbnails = m_thumbnails;
	auto task_thumb = create_task([spatial_info, num_pages, thumbnails, this, ui, token]()-> int
	{
		spatial_info_t spatial_info_local = spatial_info;
		spatial_info_local.scale_factor = SCALE_THUMB;

		for (int k = 0; k < num_pages; k++)
		{
			Point ras_size = ComputePageSize(spatial_info_local, k);
			auto task2 = create_task(mu_doc->RenderPageAsync(k, ras_size.X, ras_size.Y, false));

			task2.then([this, k, thumbnails, ras_size](InMemoryRandomAccessStream^ ras)
			{
				assert(IsMainThread());
				WriteableBitmap ^bmp = ref new WriteableBitmap(ras_size.X, ras_size.Y);
				bmp->SetSource(ras);
				DocumentPage^ doc_page = ref new DocumentPage();
				doc_page->Image = bmp;
				doc_page->Height = ras_size.Y / SCALE_THUMB;
				doc_page->Width = ras_size.X / SCALE_THUMB;
				doc_page->Content = THUMBNAIL;
				doc_page->TextBox = nullptr;
				doc_page->LinkBox = nullptr;
				if (m_init_done)
				{
					m_thumbnails->SetAt(k, doc_page);  /* This avoids out of order returns from task */
					if (k < THUMB_PREADD) /* Flip view gets overwhelmed if I don't do this */
						SetThumb(k, false);
				}
			}, ui).then([this] (task<void> t)
				{
				try
				{
					t.get();
				}
				catch(Platform::InvalidArgumentException^ e)
				{
					//TODO handle error.
				}
			}, token); //end task chain */

			/* If cancelled then save the last one as the continuation will not
			   have occured.  */
			if (is_task_cancellation_requested())
			{
				cancel_current_task();
			}
		}
		return num_pages; /* all done with thumbnails! */
	}, token).then([this](task<int> the_task)
	{
		/* Finish adding them, but not if we were cancelled. */
		bool is_cancelled = false;
		try
		{
			the_task.get();
		}
		catch (const task_canceled& e)
		{
			(void) e;	// Unused parameter
			is_cancelled = true;
		}
		if (!is_cancelled)
		{
			for (int k = THUMB_PREADD; k < m_num_pages; k++)
				SetThumb(k, false);
		}
		this->m_ren_status = REN_AVAILABLE;
	}, task_continuation_context::use_current());

}

void mupdf_cpp::MainPage::OpenDocumentPrep(StorageFile^ file)
{
	if (this->m_num_pages != -1)
	{
		m_init_done = false;

		/* Set the index to the start of the document */
		this->xaml_vert_flipView->SelectedIndex = 0;
		this->xaml_horiz_flipView->SelectedIndex = 0;

		/* If the thumbnail thread is running then we need to end that first */
		RenderingStatus_t *ren_status = &m_ren_status;
		cancellation_token_source *ThumbCancel = &m_ThumbCancel;

		/* Create a task to wait until the renderer is available, then clean up then open */
		auto t = create_task([ren_status, ThumbCancel]()->int
		{
			if (*ren_status == REN_THUMBS)
				ThumbCancel->cancel();
			while (*ren_status != REN_AVAILABLE) {
			}
			return 0;
		}).then([this](task<int> the_task)
		{
			CleanUp();
			return 0;
		}, task_continuation_context::use_current()).then([this, file](task<int> the_task)
		{
			OpenDocument(file);
		}, task_continuation_context::use_current());
	}
	else
	{
		OpenDocument(file);
	}
}

void mupdf_cpp::MainPage::OpenDocument(StorageFile^ file)
{
	String^ path = file->Path;
	const wchar_t *w = path->Data();
	int cb = WideCharToMultiByte(CP_UTF8, 0, w, -1, nullptr, 0, nullptr, nullptr);
	char* name = new char[cb];

	WideCharToMultiByte(CP_UTF8, 0, w ,-1 ,name ,cb ,nullptr, nullptr);
	char *ext = strrchr(name, '.');

	this->SetFlipView();

	/* Open document and when open, push on */
	auto open_task = create_task(mu_doc->OpenFileAsync(file));
	open_task.then([this](int code) -> int
	{
		assert(IsMainThread());
		if (code != S_ISOK)
		{
			return code;
		}
		/* We need to check if password is required */
		if (mu_doc->RequiresPassword())
		{
			xaml_PasswordStack->Visibility = Windows::UI::Xaml::Visibility::Visible;
			return E_NEEDPASSWORD;
		}
		else
		{
			xaml_PasswordStack->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
			return S_ISOK;
		}
	}).then([this](int code)->int
	{
		assert(IsMainThread());
		if (code == S_ISOK)
			InitialRender();
		return code;
	}, task_continuation_context::use_current()).then([this](int code)
	{
		if (code == S_ISOK)
			RenderThumbs();
		else
		{
			if (code != E_NEEDPASSWORD)
			{
				NotifyUser("Sorry, an issue was encountered in opening file", 
							StatusMessage);
			}
		}
	}, task_continuation_context::use_current());
}

void mupdf_cpp::MainPage::InitialRender()
{
	assert(IsMainThread());
	m_num_pages = mu_doc->GetNumPages();

	if ((m_currpage) >= m_num_pages)
	{
		m_currpage = m_num_pages - 1;
	}
	else if (m_currpage < 0)
	{
		m_currpage = 0;
	}

	/* Initialize all the flipvew items with blanks and the thumbnails. */
	for (int k = 0; k < m_num_pages; k++)
	{
		/* Blank pages */
		DocumentPage^ doc_page = ref new DocumentPage();
		doc_page->Image = m_BlankBmp;
		doc_page->Height = BLANK_HEIGHT;
		doc_page->Width = BLANK_WIDTH;
		doc_page->Content = DUMMY;
		doc_page->TextBox = nullptr;
		doc_page->LinkBox = nullptr;
		m_docPages->Append(doc_page);
		m_thumbnails->Append(doc_page);
		/* Create empty lists for our links and specify that they have
			not been computed for these pages */
		Vector<RectList^>^ temp_link = ref new Vector<RectList^>();
		m_page_link_list->Append(temp_link);
		m_linkset->Append(false);
	}

	this->xaml_horiz_flipView->ItemsSource = m_docPages;
	this->xaml_vert_flipView->ItemsSource = m_docPages;

	/* Do the first few pages, then start the thumbs */
	spatial_info_t spatial_info = InitSpatial(1);
	for (int k = 0; k < LOOK_AHEAD + 2; k++)
	{
		if (m_num_pages > k )
		{
			Point ras_size = ComputePageSize(spatial_info, k);

			auto render_task =
				create_task(mu_doc->RenderPageAsync(k, ras_size.X, ras_size.Y, true));

			render_task.then([this, k, ras_size] (InMemoryRandomAccessStream^ ras)
			{
				UpdatePage(k, ras, ras_size, FULL_RESOLUTION);
			}, task_continuation_context::use_current());
		}
	}

	/* Update the slider settings, if more than one page */
	if (m_num_pages > 1)
	{
		this->xaml_PageSlider->Maximum = m_num_pages;
		this->xaml_PageSlider->Minimum = 1;
		this->xaml_PageSlider->IsEnabled = true;
	}
	else
	{
		this->xaml_PageSlider->Maximum = 0;
		this->xaml_PageSlider->Minimum = 0;
		this->xaml_PageSlider->IsEnabled = false;
	}

	/* All done with initial pages */
	this->m_init_done = true;
}

void mupdf_cpp::MainPage::RenderRange(int curr_page)
{
	/* Render +/- the look ahead from where we are if blank page is present */
	spatial_info_t spatial_info = InitSpatial(1);
	bool curr_page_rendered = true;
	int range = LOOK_AHEAD;

	assert(IsMainThread());
	if (m_flip_from_searchlink)
		range = 0;
	for (int k = curr_page - LOOK_AHEAD; k <= curr_page + LOOK_AHEAD; k++)
	{
		if (k >= 0 && k < m_num_pages)
		{
			/* Check if page is already rendered */
			auto doc = this->m_docPages->GetAt(k);
			if (doc->Content != FULL_RESOLUTION)
			{
				Point ras_size = ComputePageSize(spatial_info, k);
				auto render_task =
					create_task(mu_doc->RenderPageAsync(k, ras_size.X, ras_size.Y, true));

				render_task.then([this, k, ras_size] (InMemoryRandomAccessStream^ ras)
				{
					UpdatePage(k, ras, ras_size, FULL_RESOLUTION);
				}, task_continuation_context::use_current()).then([this, k, curr_page]()
				{
					if (k == curr_page && this->m_links_on)
						AddLinkCanvas();
					if (k == curr_page && this->m_text_list->Size > 0 &&
						m_flip_from_searchlink)
					{
						AddTextCanvas();
						m_flip_from_searchlink = false;
					}
				},task_continuation_context::use_current());
			}
			else
			{
				/* We did not need to render the curr_page, so add links below if
				   needed.   Otherwise, we need to wait for the task above to
				   complete before we add the links. */
				if (k == curr_page)
					curr_page_rendered = false;
			}
		}
	}
	m_currpage = curr_page;
	if (this->m_links_on && !curr_page_rendered)
		AddLinkCanvas();
	if (this->m_text_list->Size > 0 && !curr_page_rendered && m_flip_from_searchlink)
	{
		AddTextCanvas();
		m_flip_from_searchlink = false;
	}
}

void mupdf_cpp::MainPage::Slider_ValueChanged(Platform::Object^ sender, Windows::UI::Xaml::Controls::Primitives::RangeBaseValueChangedEventArgs^ e)
{
	int newValue = (int) this->xaml_PageSlider->Value - 1;  /* zero based */

	if (IsNotStandardView())
		return;

	if (m_update_flip)
	{
		m_update_flip = false;
		return;
	}
	if (m_init_done && this->xaml_PageSlider->IsEnabled)
	{
		/* Make sure to clear any text search */
		auto doc_old = this->m_docPages->GetAt(m_currpage);
		doc_old->TextBox = nullptr;

		auto doc = this->m_docPages->GetAt(newValue);
		if (doc->Content != FULL_RESOLUTION)
		{
			spatial_info_t spatial_info = InitSpatial(1);
			Point ras_size = ComputePageSize(spatial_info, newValue);
			auto render_task =
				create_task(mu_doc->RenderPageAsync(newValue, ras_size.X, ras_size.Y, true));

			render_task.then([this, newValue, ras_size] (InMemoryRandomAccessStream^ ras)
			{
				UpdatePage(newValue, ras, ras_size, FULL_RESOLUTION);
				this->m_currpage = newValue;
				m_sliderchange = true;
				this->m_curr_flipView->SelectedIndex = newValue;
			}, task_continuation_context::use_current());
		}
	}
}

void mupdf_cpp::MainPage::FlipView_SelectionChanged(Object^ sender, SelectionChangedEventArgs^ e)
{
	if (m_init_done && !m_page_update)
	{
		int pos = this->m_curr_flipView->SelectedIndex;

		if (pos >= 0)
		{
			m_update_flip = true;
			if (xaml_PageSlider->IsEnabled)
			{
				xaml_PageSlider->Value = pos;
			}
			if (m_sliderchange)
			{
				m_sliderchange = false;
				return;
			}
			else
			{
				 /* Make sure to clear any text search */
				auto doc_old = this->m_docPages->GetAt(m_currpage);
				doc_old->TextBox = nullptr;
			}
			/* Get the current page */
			int curr_page = this->m_currpage;
			this->RenderRange(pos);
			this->ReleasePages(curr_page, pos);
		}
	}
}

/* Search Related Code */
void mupdf_cpp::MainPage::Searcher(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	ShowSearchBox();
	UpdateAppBarButtonViewState();
}

void mupdf_cpp::MainPage::ShowSearchBox()
{
	/* Update the app bar so that we can do the search */
	StackPanel^ leftPanel = (StackPanel^) this->TopAppBar->FindName("LeftPanel");

	if (leftPanel != nullptr && m_insearch)
	{
		m_insearch = false;
		FindBox->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
		PrevSearch->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
		NextSearch->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
	}
	else if (leftPanel != nullptr && !m_insearch)
	{
		/* Search is not going to work in snapped view for now to simplify UI
		   in this cramped case.  So see if we can get out of snapped mode. */
		if (!EnsureUnsnapped())
			return;

		m_insearch = true;
		FindBox->Visibility = Windows::UI::Xaml::Visibility::Visible;
		PrevSearch->Visibility = Windows::UI::Xaml::Visibility::Visible;
		NextSearch->Visibility = Windows::UI::Xaml::Visibility::Visible;
	}
}

void mupdf_cpp::MainPage::ClearTextSearch()
{
	/* Clear out any old search result */
	if (m_text_list->Size > 0)
		m_text_list->Clear();
}

void mupdf_cpp::MainPage::ShowSearchResults(int page_num, int box_count)
{
	int old_page = this->m_currpage;
	int new_page = page_num;

	ClearTextSearch();

	/* Compute any scalings */
	Point screenSize;
	Point pageSize;
	Point scale;

	screenSize.Y = this->ActualHeight;
	screenSize.X = this->ActualWidth;
	screenSize.X *= screenScale;
	screenSize.Y *= screenScale;
	pageSize = mu_doc->GetPageSize(m_currpage);
	scale = fitPageToScreen(pageSize, screenSize);
	auto doc_page = this->m_docPages->GetAt(old_page);

	/* Construct our list of rectangles */
	for (int k = 0; k < box_count; k++)
	{
		RectList^ rect_item = ref new RectList();
		auto curr_box = mu_doc->GetTextSearch(k);

		rect_item->Color = m_textcolor;
		rect_item->Height = curr_box->LowerRight.Y - curr_box->UpperLeft.Y;
		rect_item->Width = curr_box->LowerRight.X - curr_box->UpperLeft.X;
		rect_item->X = curr_box->UpperLeft.X * scale.X;
		rect_item->Y = curr_box->UpperLeft.Y * scale.Y;
		rect_item->Width *= (scale.X * doc_page->Zoom);
		rect_item->Height *= (scale.Y * doc_page->Zoom);
		rect_item->Index = k.ToString();
		m_text_list->Append(rect_item);
	}
	/* Make sure the current page has its text results cleared */
	doc_page->TextBox = nullptr;

	/* Go ahead and set our doc item to this in the vertical and horizontal view */
	m_searchpage = new_page;
	m_flip_from_searchlink = true;

	if (old_page == new_page)
	{
		FlipView_SelectionChanged(nullptr, nullptr);
	}
	else
	{
		this->m_curr_flipView->SelectedIndex = new_page;
	}
	return;
}

void mupdf_cpp::MainPage::SearchNext(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	if (IsNotStandardView())
		return;

	StackPanel^ leftPanel = (StackPanel^) this->TopAppBar->FindName("LeftPanel");
	TextBox^ findBox = (TextBox^) leftPanel->FindName("FindBox");
	String^ textToFind = findBox->Text;

	if (this->m_search_active == false && textToFind != nullptr)
		SearchInDirection(1, textToFind);
}

void mupdf_cpp::MainPage::SearchPrev(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	if (IsNotStandardView())
		return;

	StackPanel^ leftPanel = (StackPanel^) this->TopAppBar->FindName("LeftPanel");
	TextBox^ findBox = (TextBox^) leftPanel->FindName("FindBox");
	String^ textToFind = findBox->Text;

	if (this->m_search_active == false && textToFind != nullptr)
		SearchInDirection(-1, textToFind);
}

void mupdf_cpp::MainPage::CancelSearch(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	m_searchcts.cancel();
	xaml_ProgressStack->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
	this->m_search_active = false;
}

void mupdf_cpp::MainPage::AddTextCanvas()
{
	/* Go ahead and set our doc item to this in the vertical and horizontal view */
	auto doc_page = this->m_docPages->GetAt(m_currpage);
	assert(doc_page->Content == FULL_RESOLUTION);
	if (doc_page->Content == FULL_RESOLUTION)  // We should not be doing links for thumbnails
	{
		doc_page->TextBox = m_text_list;
	}
	this->m_search_active = false;
}

void mupdf_cpp::MainPage::SearchProgress(IAsyncOperationWithProgress<int, double>^ operation, double status)
{
	xaml_Progress->Value = status;
}

void mupdf_cpp::MainPage::SearchInDirection(int dir, String^ textToFind)
{
	cancellation_token_source cts;
	auto token = cts.get_token();
	m_searchcts = cts;
	int pos = m_currpage;
	int start;

	if (m_searchpage == pos)
		start = pos + dir;
	else
		start = pos;

	if (start < 0)
		return;
	if (start > this->m_num_pages - 1)
		return;
	this->m_search_active = true;

	ProgressBar^ my_xaml_Progress = (ProgressBar^) (this->FindName("xaml_Progress"));
	xaml_ProgressStack->Visibility = Windows::UI::Xaml::Visibility::Visible;
	auto temp = mu_doc->SearchDocumentWithProgressAsync(textToFind, dir, start);
	temp->Progress = ref new AsyncOperationProgressHandler<int, double>(this, &MainPage::SearchProgress);

	auto search_task = create_task(temp, token);

	/* Do the continuation on the ui thread */
	auto con_task = search_task.then([this, textToFind](int page_num)
	{
		xaml_ProgressStack->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
		if (page_num == TEXT_NOT_FOUND)
		{
			auto str1 = "\"" + textToFind + "\" Was Not Found In The Search";
			NotifyUser(str1, StatusMessage);
			this->m_search_active = false;
		}
		else
		{
			int box_count = mu_doc->TextSearchCount();

			if (box_count > 0)
			{
				this->ShowSearchResults(page_num, box_count);
			}
		}
	}, task_continuation_context::use_current());
}

/* This is here to handle when we rotate or go into the snapview mode  */
void mupdf_cpp::MainPage::GridSizeChanged()
{
	int height = this->ActualHeight;
	int width = this->ActualWidth;
	FlipView^ old_flip = m_curr_flipView;

	if (TopAppBar1->IsOpen)
	{
		UpdateAppBarButtonViewState();
	}

	if (height > width)
	{
		m_curr_flipView = this->xaml_vert_flipView;
		this->xaml_zoomCanvas->Height = height;
		this->xaml_zoomCanvas->Width = width;
		this->m_curr_flipView->Height = height;
		this->m_curr_flipView->Width = width;

		xaml_vert_flipView->IsEnabled = true;
		xaml_vert_flipView->Opacity = 1;
		xaml_horiz_flipView->IsEnabled = false;
		xaml_horiz_flipView->Opacity = 0;	
	}
	else
	{
		m_curr_flipView = this->xaml_horiz_flipView;
		this->xaml_zoomCanvas->Height = height;
		this->xaml_zoomCanvas->Width = width;
		this->m_curr_flipView->Height = height;
		this->m_curr_flipView->Width = width;

		xaml_horiz_flipView->IsEnabled = true;
		xaml_horiz_flipView->Opacity = 1;
		xaml_vert_flipView->IsEnabled = false;
		xaml_vert_flipView->Opacity = 0;
	}

	if (xaml_WebView->Visibility == Windows::UI::Xaml::Visibility::Visible)
	{
		int height = xaml_OutsideGrid->ActualHeight;
		int height_app = TopAppBar1->ActualHeight;

		xaml_WebView->Height = height - height_app;
	}

	UpDatePageSizes();

	if (m_num_pages > 0 && old_flip != m_curr_flipView && old_flip != nullptr)
	{
		/* If links are on or off, we need to invalidate */
		ClearLinks();
		InvalidateLinks();
		auto doc = this->m_docPages->GetAt(m_currpage);
		doc->Content = OLD_RESOLUTION; /* To force a rerender */
		this->m_curr_flipView->SelectedIndex = this->m_currpage;
		FlipView_SelectionChanged(nullptr, nullptr);
	}
}

void mupdf_cpp::MainPage::UpDatePageSizes()
{
	/* Reset the thumb view scaling value */
	if (m_num_pages > 0)
	{
		int num_items = m_thumbnails->Size;
		for (int i = 0; i < num_items; i++)
		{
			DocumentPage ^thumb_page = m_thumbnails->GetAt(i);
			if (thumb_page != nullptr && thumb_page->Image != nullptr)
			{
				int curr_height = thumb_page->Height;
				int curr_width = thumb_page->Width;

				double scale_x = (double) curr_height / (double) this->xaml_zoomCanvas->Height;
				double scale_y = (double) curr_width / (double) this->xaml_zoomCanvas->Width;

				double min_scale = max(scale_x, scale_y);
				thumb_page->Height = curr_height / min_scale;
				thumb_page->Width = curr_width / min_scale;
			}
		}
	}
};

/* Link related code */
void mupdf_cpp::MainPage::Linker(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	m_links_on = !m_links_on;

	if (!m_init_done || IsNotStandardView())
		return;
	if (m_links_on)
		AddLinkCanvas();
	else
		ClearLinks();
}

void mupdf_cpp::MainPage::ClearLinks()
{
	/* Make sure surrounding render pages lose their links */
	for (int k = m_currpage - LOOK_AHEAD; k <= m_currpage + LOOK_AHEAD; k++)
	{
		if (k >= 0 && k < m_num_pages)
		{
			auto doc_page = this->m_docPages->GetAt(k);
			if (doc_page->Content == FULL_RESOLUTION)
			{
				doc_page->LinkBox = nullptr;
			}
		}
	}
}

void mupdf_cpp::MainPage::InvalidateLinks()
{
	for (int k = 0; k < m_num_pages; k++)
		m_linkset->SetAt(k, false);
}

/* Add in the link rects.  If we have not already computed them then do that now */
void mupdf_cpp::MainPage::AddLinkCanvas()
{
	/* See if the link object for this page has already been computed */
	int link_page = m_linkset->GetAt(m_currpage);
	auto doc_page = this->m_docPages->GetAt(m_currpage);

	if (!link_page)
	{
		m_linkset->SetAt(m_currpage, true);
		int num_links = mu_doc->ComputeLinks(m_currpage);
		if (num_links == 0) return;

		Point screenSize;
		Point pageSize;
		Point scale;

		screenSize.Y = this->ActualHeight;
		screenSize.X = this->ActualWidth;
		screenSize.X *= screenScale;
		screenSize.Y *= screenScale;
		pageSize = mu_doc->GetPageSize(m_currpage);
		scale = fitPageToScreen(pageSize, screenSize);

		/* Create a new RectList collection */
		auto link_list = ref new Platform::Collections::Vector<RectList^>();

		/* Now add the rects */
		for (int k = 0; k < num_links; k++)
		{
			auto curr_link = mu_doc->GetLink(k);
			if (curr_link->Type != NOT_SET)
			{
				RectList^ rect_item = ref new RectList();
				rect_item->Color = m_linkcolor;
				rect_item->Height = curr_link->LowerRight.Y - curr_link->UpperLeft.Y;
				rect_item->Width = curr_link->LowerRight.X - curr_link->UpperLeft.X;
				rect_item->X = curr_link->UpperLeft.X * scale.X;
				rect_item->Y = curr_link->UpperLeft.Y * scale.Y;
				rect_item->Width *= (scale.X * doc_page->Zoom);
				rect_item->Height *= (scale.Y * doc_page->Zoom);
				rect_item->Type = curr_link->Type;
				rect_item->Urilink = curr_link->Uri;
				rect_item->PageNum = curr_link->PageNum;
				rect_item->Index = k.ToString();
				link_list->Append(rect_item);
			}
		}
		/* Now set it in our list of links */
		m_page_link_list->SetAt(m_currpage, link_list);
	}
	/* Go ahead and set our doc item to this in the vertical and horizontal view */
	if (doc_page->LinkBox == nullptr)
	{
		if (doc_page->Content == FULL_RESOLUTION)  // We should not be doing links for thumbnails
		{
			doc_page->LinkBox = m_page_link_list->GetAt(m_currpage);
		}
	}
}

/* A link was tapped */
void mupdf_cpp::MainPage::LinkTapped(Platform::Object^ sender, Windows::UI::Xaml::Input::TappedRoutedEventArgs^ e)
{
	Rectangle^ rect = safe_cast<Rectangle^>(e->OriginalSource);
	String^ str_index = safe_cast<String^>(rect->Tag);
	int index = _wtof(str_index->Data());

	if (index >= 0 && index < m_num_pages)
	{
		auto link_list = m_page_link_list->GetAt(m_currpage);
		auto link = link_list->GetAt(index);

		if (link->Type == LINK_GOTO)
		{
			this->m_curr_flipView->SelectedIndex = link->PageNum;
		}
		else if (link->Type == LINK_URI)
		{
			// Set the option to show a warning
			auto launchOptions = ref new Windows::System::LauncherOptions();
			launchOptions->TreatAsUntrusted = true;

			// Launch the URI with a warning prompt
			concurrency::task<bool> launchUriOperation(Windows::System::Launcher::LaunchUriAsync(link->Urilink, launchOptions));
			launchUriOperation.then([](bool success)
			{
				if (success)
				{
					// URI launched
				}
				else
				{
					// URI launch failed
				}
			});
		}
	}
}

/* Bring up the contents */
void mupdf_cpp::MainPage::ContentDisplay(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	if (this->m_num_pages < 0)
		return;

	if (IsNotStandardView() && !this->xaml_ListView->IsEnabled)
		return;

	if (this->xaml_ListView->IsEnabled)
	{
		this->xaml_ListView->Opacity = 0.0;
		this->xaml_ListView->IsEnabled = false;
		this->m_curr_flipView->Opacity = 1.0;
		this->m_curr_flipView->IsEnabled = true;
		this->xaml_PageSlider->IsEnabled = true;
	}
	else
	{
		if (xaml_ListView->Items->Size == 0)
		{
			int size_content = mu_doc->ComputeContents();
			/* Bring up the content now */
			for (int k = 0; k < size_content; k++)
			{
				ContentItem^ item = mu_doc->GetContent(k);
				this->xaml_ListView->Items->Append(item);
			}
			if (size_content > 0)
			{
				this->xaml_ListView->Opacity = 1.0;
				this->xaml_ListView->IsEnabled = true;
				this->m_curr_flipView->Opacity = 0.0;
				this->m_curr_flipView->IsEnabled = false;
				this->xaml_PageSlider->IsEnabled = false;
			}
		}
		else
		{
			this->xaml_ListView->Opacity = 1.0;
			this->xaml_ListView->IsEnabled = true;
			this->m_curr_flipView->Opacity = 0.0;
			this->m_curr_flipView->IsEnabled = false;
			this->xaml_PageSlider->IsEnabled = false;
		}
	}
}

void mupdf_cpp::MainPage::ContentSelected(Platform::Object^ sender, Windows::UI::Xaml::Controls::ItemClickEventArgs^ e)
{
	ContentItem^ b = safe_cast<ContentItem^>(e->ClickedItem);
	int newpage = b->Page;

	if (newpage > -1 && newpage < this->m_num_pages)
	{
		this->xaml_ListView->Opacity = 0.0;
		this->xaml_ListView->IsEnabled = false;
		this->m_curr_flipView->Opacity = 1.0;
		this->m_curr_flipView->IsEnabled = true;
		this->xaml_PageSlider->IsEnabled = true;

		int old_page = this->m_currpage;
		this->m_curr_flipView->SelectedIndex = newpage;
		this->m_currpage = newpage;
	}
}

void mupdf_cpp::MainPage::Reflower(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	if (this->m_num_pages < 0) return;

	if (xaml_WebView->Visibility == Windows::UI::Xaml::Visibility::Visible)
	{
		/* Go back to flip view */
		xaml_WebView->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
		this->xaml_MainGrid->Opacity = 1.0;
		this->m_curr_flipView->IsEnabled = true;
		this->xaml_PageSlider->IsEnabled = true;
		xaml_WebView->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
		xaml_WebView->Opacity = 0.0;

	}
	else if (this->m_curr_flipView->IsEnabled)
	{
		String^ html_string = mu_doc->ComputeHTML(this->m_currpage);
		xaml_WebView->Visibility = Windows::UI::Xaml::Visibility::Visible;
		this->xaml_MainGrid->Opacity = 0.0;
		this->m_curr_flipView->IsEnabled = false;
		this->xaml_PageSlider->IsEnabled = false;
		this->xaml_WebView->NavigateToString(html_string);
		this->xaml_WebView->Height = this->ActualHeight - 2 * this->BottomAppBar->ActualHeight;
		/* Check if thumb rendering is done.  If not then restart */
	}
}

/* Need to handle resizing of app bar to make sure everything fits */
void mupdf_cpp::MainPage::topAppBar_Loaded(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	/* Remove search box in snapped view as we don't have the room for it */
	if (ApplicationView::Value == ApplicationViewState::Snapped && m_insearch)
		ShowSearchBox();
	UpdateAppBarButtonViewState();
}

void mupdf_cpp::MainPage::UpdateAppBarButtonViewState()
{
	String ^viewState = Windows::UI::ViewManagement::ApplicationView::Value.ToString();
	VisualStateManager::GoToState(Search, viewState, true);
	VisualStateManager::GoToState(Contents, viewState, true);
	VisualStateManager::GoToState(Links, viewState, true);
	VisualStateManager::GoToState(Reflow, viewState, true);
	VisualStateManager::GoToState(ZoomIn, viewState, true);
	VisualStateManager::GoToState(ZoomOut, viewState, true);
	VisualStateManager::GoToState(PrevSearch, viewState, true);
	VisualStateManager::GoToState(NextSearch, viewState, true);
}

/* Manipulation zooming with touch input */
void mupdf_cpp::MainPage::ScrollChanged(Platform::Object^ sender,
					Windows::UI::Xaml::Controls::ScrollViewerViewChangedEventArgs^ e)
{
	ScrollViewer^ scrollviewer = safe_cast<ScrollViewer^> (sender);
	auto doc_page = this->m_docPages->GetAt(m_currpage);

	if (scrollviewer->ZoomFactor == doc_page->Zoom)
		return;

	if (!e->IsIntermediate)
	{
		doc_page->Zoom = scrollviewer->ZoomFactor;
		int page = m_currpage;

		/* Render at new resolution */
		spatial_info_t spatial_info = InitSpatial(doc_page->Zoom);
		Point ras_size = ComputePageSize(spatial_info, page);

		/* Go ahead and create display list if we dont have one for this page */
		auto render_task =
			create_task(mu_doc->RenderPageAsync(page, ras_size.X, ras_size.Y, true));
		render_task.then([this, page, ras_size] (InMemoryRandomAccessStream^ ras)
		{
			ReplaceImage(page, ras, ras_size);
		}, task_continuation_context::use_current());
	}
}

/* Needed to find scrollviewer child from template of flipview item */
Windows::UI::Xaml::FrameworkElement^ FindVisualChildByName(DependencyObject^ obj, String^ name)
{
	FrameworkElement^ ret;
	if (obj == nullptr) return nullptr;

	int numChildren = VisualTreeHelper::GetChildrenCount(obj);

	for (int i = 0; i < numChildren; i++)
	{
		auto objChild = VisualTreeHelper::GetChild(obj, i);
		auto child = safe_cast<FrameworkElement^>(objChild);
		if (child != nullptr && child->Name == name)
		{
			return child;
		}
		ret = FindVisualChildByName(objChild, name);
		if (ret != nullptr)
			break;
	}
	return ret;
}

void mupdf_cpp::MainPage::ZoomInPress(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	if (!m_init_done || IsNotStandardView()) return;
	NonTouchZoom(ZOOM_IN);
}

void mupdf_cpp::MainPage::ZoomOutPress(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	if (!m_init_done || IsNotStandardView()) return;
	NonTouchZoom(ZOOM_OUT);
}

void MainPage::NonTouchZoom(int zoom)
{
	ScrollViewer^ scrollviewer;
	FlipViewItem^ item = safe_cast<FlipViewItem^> 
		(m_curr_flipView->ItemContainerGenerator->ContainerFromIndex(m_currpage));
	auto item2 = m_curr_flipView->ItemContainerGenerator->ContainerFromIndex(m_currpage);

	/* We don't know which one so check for both */
	ScrollViewer^ t1 = 
		safe_cast<ScrollViewer^> (FindVisualChildByName(item2, "xaml_ScrollView_v"));
	ScrollViewer^ t2 = 
		safe_cast<ScrollViewer^> (FindVisualChildByName(item2, "xaml_ScrollView_h"));

	if (t1 != nullptr)
		scrollviewer = t1;
	else
		scrollviewer = t2;

	if (scrollviewer == nullptr) 
		return;

	double curr_zoom = scrollviewer->ZoomFactor;
	if (zoom == ZOOM_IN)
	{
		curr_zoom = curr_zoom + KEYBOARD_ZOOM_STEP;
		if (curr_zoom > ZOOM_MAX) curr_zoom = ZOOM_MAX;
	}
	else if (zoom == ZOOM_OUT)
	{
		curr_zoom = curr_zoom - KEYBOARD_ZOOM_STEP;
		if (curr_zoom < ZOOM_MIN) curr_zoom = ZOOM_MIN;
	} else
		return;

	scrollviewer->ZoomToFactor(curr_zoom);
}

/* Zoom in and out for keyboard only case. */
void MainPage::OnKeyDown(KeyRoutedEventArgs^ e)
{
	if (!m_init_done || IsNotStandardView()) return;

	long val = (long) (e->Key);

	if (val == KEY_PLUS)
		NonTouchZoom(ZOOM_IN);
	else if (val == KEY_MINUS)
		NonTouchZoom(ZOOM_OUT);
	else
		return;
}

void mupdf_cpp::MainPage::PasswordOK(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
	/* If password checks out then go ahead and start rendering */
	if (mu_doc->ApplyPassword(xaml_password->Password))
	{
		xaml_password->Password = nullptr;
		xaml_PasswordStack->Visibility = Windows::UI::Xaml::Visibility::Collapsed;
		InitialRender();
		RenderThumbs();
	}
	else
		NotifyUser("Incorrect Password", StatusMessage);
}

/* So that we know if we are in a standard view case and not in reflow, or
 * content type */
bool mupdf_cpp::MainPage::IsNotStandardView()
{
	return (this->xaml_ListView->Opacity == 1.0 ||
			xaml_WebView->Visibility == Windows::UI::Xaml::Visibility::Visible);
}