/*
 * This file is part of modulo.
 *
 * Copyright (C) 2020-2021 Federico Terzi
 *
 * modulo 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.
 *
 * modulo 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 modulo.  If not, see <https://www.gnu.org/licenses/>.
 */

// Mouse dragging mechanism greatly inspired by: https://developpaper.com/wxwidgets-implementing-the-drag-effect-of-titleless-bar-window/

#define _UNICODE

#include "../common/common.h"
#include "../interop/interop.h"

#include "wx/htmllbox.h"

#include <vector>
#include <memory>
#include <unordered_map>

// Platform-specific styles
#ifdef __WXMSW__
const int SEARCH_BAR_FONT_SIZE = 16;
const long DEFAULT_STYLE = wxSTAY_ON_TOP | wxFRAME_TOOL_WINDOW;
#endif
#ifdef __WXOSX__
const int SEARCH_BAR_FONT_SIZE = 20;
const long DEFAULT_STYLE = wxSTAY_ON_TOP | wxFRAME_TOOL_WINDOW | wxRESIZE_BORDER;
#endif
#ifdef __LINUX__
const int SEARCH_BAR_FONT_SIZE = 20;
const long DEFAULT_STYLE = wxSTAY_ON_TOP;
#endif

const int HELP_TEXT_FONT_SIZE = 10;

const wxColour SELECTION_LIGHT_BG = wxColour(164, 210, 253);
const wxColour SELECTION_DARK_BG = wxColour(49, 88, 126);

// https://docs.wxwidgets.org/stable/classwx_frame.html
const int MIN_WIDTH = 500;
const int MIN_HEIGHT = 80;

typedef void (*QueryCallback)(const char *query, void *app, void *data);
typedef void (*ResultCallback)(const char *id, void *data);

SearchMetadata *searchMetadata = nullptr;
QueryCallback queryCallback = nullptr;
ResultCallback resultCallback = nullptr;
void *data = nullptr;
void *resultData = nullptr;
wxArrayString wxItems;
wxArrayString wxTriggers;
wxArrayString wxIds;

// App Code

class SearchApp : public wxApp
{
public:
    virtual bool OnInit();
};

class ResultListBox : public wxHtmlListBox
{
public:
    ResultListBox() {}
    ResultListBox(wxWindow *parent, bool isDark, const wxWindowID id, const wxPoint &pos, const wxSize &size);

protected:
    // override this method to return data to be shown in the listbox (this is
    // mandatory)
    virtual wxString OnGetItem(size_t n) const;

    // change the appearance by overriding these functions (this is optional)
    virtual void OnDrawBackground(wxDC &dc, const wxRect &rect, size_t n) const;

    bool isDark;

public:
    wxDECLARE_NO_COPY_CLASS(ResultListBox);
    wxDECLARE_DYNAMIC_CLASS(ResultListBox);
};

wxIMPLEMENT_DYNAMIC_CLASS(ResultListBox, wxHtmlListBox);

ResultListBox::ResultListBox(wxWindow *parent, bool isDark, const wxWindowID id, const wxPoint &pos, const wxSize &size)
    : wxHtmlListBox(parent, id, pos, size, 0)
{
    this->isDark = isDark;
    SetMargins(5, 5);
    Refresh();
}

void ResultListBox::OnDrawBackground(wxDC &dc, const wxRect &rect, size_t n) const
{
    if (IsSelected(n))
    {
        if (isDark)
        {
            dc.SetBrush(wxBrush(SELECTION_DARK_BG));
        }
        else
        {
            dc.SetBrush(wxBrush(SELECTION_LIGHT_BG));
        }
    }
    else
    {
        dc.SetBrush(*wxTRANSPARENT_BRUSH);
    }
    dc.SetPen(*wxTRANSPARENT_PEN);
    dc.DrawRectangle(0, 0, rect.GetRight(), rect.GetBottom());
}

wxString ResultListBox::OnGetItem(size_t n) const
{
    wxString textColor = isDark ? "white" : "";
    wxString shortcut = (n < 8) ? wxString::Format(wxT("Alt+%i"), (int)n + 1) : " ";
    return wxString::Format(wxT("<font color='%s'><table width='100%%'><tr><td>%s</td><td align='right'><b>%s</b> <font color='#636e72'> %s</font></td></tr></table></font>"), textColor, wxItems[n], wxTriggers[n], shortcut);
}

class SearchFrame : public wxFrame
{
public:
    SearchFrame(const wxString &title, const wxPoint &pos, const wxSize &size);

    wxPanel *panel;
    wxTextCtrl *searchBar;
    wxStaticBitmap *iconPanel;
    wxStaticText *helpText;
    ResultListBox *resultBox;
    void SetItems(SearchItem *items, int itemSize);

private:
    void OnCharEvent(wxKeyEvent &event);
    void OnQueryChange(wxCommandEvent &event);
    void OnItemClickEvent(wxCommandEvent &event);
    void OnActivate(wxActivateEvent &event);

    // Mouse events
    void OnMouseCaptureLost(wxMouseCaptureLostEvent &event);
    void OnMouseLeave(wxMouseEvent &event);
    void OnMouseMove(wxMouseEvent &event);
    void OnMouseLUp(wxMouseEvent &event);
    void OnMouseLDown(wxMouseEvent &event);
    wxPoint mLastPt;

    // Selection
    void SelectNext();
    void SelectPrevious();
    void Submit();
};

bool SearchApp::OnInit()
{
    SearchFrame *frame = new SearchFrame(wxString::FromUTF8(searchMetadata->windowTitle), wxPoint(50, 50), wxSize(450, 340));
    frame->Show(true);
    SetupWindowStyle(frame);
    Activate(frame);
    return true;
}
SearchFrame::SearchFrame(const wxString &title, const wxPoint &pos, const wxSize &size)
    : wxFrame(NULL, wxID_ANY, title, pos, size, DEFAULT_STYLE)
{
    wxInitAllImageHandlers();

#if wxCHECK_VERSION(3, 1, 3)
    bool isDark = wxSystemSettings::GetAppearance().IsDark();
#else
    // Workaround needed for previous versions of wxWidgets
    const wxColour bg = wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW);
    const wxColour fg = wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT);
    unsigned int bgSum = (bg.Red() + bg.Blue() + bg.Green());
    unsigned int fgSum = (fg.Red() + fg.Blue() + fg.Green());
    bool isDark = fgSum > bgSum;
#endif

    panel = new wxPanel(this, wxID_ANY);
    wxBoxSizer *vbox = new wxBoxSizer(wxVERTICAL);
    panel->SetSizer(vbox);

    wxBoxSizer *topBox = new wxBoxSizer(wxHORIZONTAL);

    int iconId = NewControlId();
    iconPanel = nullptr;
    if (searchMetadata->iconPath)
    {
        wxString iconPath = wxString::FromUTF8(searchMetadata->iconPath);
        if (wxFileExists(iconPath))
        {
            wxBitmap bitmap = wxBitmap(iconPath, wxBITMAP_TYPE_PNG);
            if (bitmap.IsOk())
            {
                wxImage image = bitmap.ConvertToImage();
                image.Rescale(32, 32, wxIMAGE_QUALITY_HIGH);
                wxBitmap resizedBitmap = wxBitmap(image, -1);
                iconPanel = new wxStaticBitmap(panel, iconId, resizedBitmap, wxDefaultPosition, wxSize(32, 32));
                topBox->Add(iconPanel, 0, wxEXPAND | wxLEFT | wxUP | wxDOWN, 10);
            }
        }
    }

    int textId = NewControlId();
    searchBar = new wxTextCtrl(panel, textId, "", wxDefaultPosition, wxDefaultSize);
    wxFont font = searchBar->GetFont();
    font.SetPointSize(SEARCH_BAR_FONT_SIZE);
    searchBar->SetFont(font);
    topBox->Add(searchBar, 1, wxEXPAND | wxALL, 10);

    vbox->Add(topBox, 1, wxEXPAND);

    if (searchMetadata->hintText) {
        helpText = new wxStaticText(panel, wxID_ANY, wxString::FromUTF8(searchMetadata->hintText));
        vbox->Add(helpText, 0, wxEXPAND | wxLEFT | wxRIGHT | wxBOTTOM, 10);
        wxFont helpFont = helpText->GetFont();
        helpFont.SetPointSize(HELP_TEXT_FONT_SIZE);
        helpText->SetFont(helpFont);
    }

    wxArrayString choices;
    int resultId = NewControlId();
    resultBox = new ResultListBox(panel, isDark, resultId, wxDefaultPosition, wxSize(MIN_WIDTH, MIN_HEIGHT));
    vbox->Add(resultBox, 5, wxEXPAND | wxALL, 0);

    Bind(wxEVT_CHAR_HOOK, &SearchFrame::OnCharEvent, this, wxID_ANY);
    searchBar->Bind(wxEVT_CHAR, &SearchFrame::OnCharEvent, this, wxID_ANY);
    Bind(wxEVT_TEXT, &SearchFrame::OnQueryChange, this, textId);
    Bind(wxEVT_LISTBOX_DCLICK, &SearchFrame::OnItemClickEvent, this, resultId);
    Bind(wxEVT_ACTIVATE, &SearchFrame::OnActivate, this, wxID_ANY);

    // Events to handle the mouse drag
    if (iconPanel)
    {
        iconPanel->Bind(wxEVT_LEFT_UP, &SearchFrame::OnMouseLUp, this);
        iconPanel->Bind(wxEVT_LEFT_DOWN, &SearchFrame::OnMouseLDown, this);
        Bind(wxEVT_MOTION, &SearchFrame::OnMouseMove, this);
        Bind(wxEVT_LEFT_UP, &SearchFrame::OnMouseLUp, this);
        Bind(wxEVT_LEFT_DOWN, &SearchFrame::OnMouseLDown, this);
        Bind(wxEVT_MOUSE_CAPTURE_LOST, &SearchFrame::OnMouseCaptureLost, this);
        Bind(wxEVT_LEAVE_WINDOW, &SearchFrame::OnMouseLeave, this);
    }

    this->SetClientSize(panel->GetBestSize());
    this->CentreOnScreen();

    // Trigger the first data update
    queryCallback("", (void *)this, data);
}

void SearchFrame::OnCharEvent(wxKeyEvent &event)
{
    if (event.GetKeyCode() == WXK_ESCAPE)
    {
        Close(true);
    }
    else if (event.GetKeyCode() == WXK_TAB)
    {
        if (wxGetKeyState(WXK_SHIFT))
        {
            SelectPrevious();
        }
        else
        {
            SelectNext();
        }
    }
    else if (event.GetUnicodeKey() >= '1' && event.GetUnicodeKey() <= '9')
    { // Alt + num shortcut
        int index = event.GetUnicodeKey() - '1';
        if (wxGetKeyState(WXK_ALT))
        {
            if (resultBox->GetItemCount() > index)
            {
                resultBox->SetSelection(index);
                Submit();
            }
        } else {
            event.Skip();
        }
    }
    else if (event.GetKeyCode() == WXK_DOWN)
    {
        SelectNext();
    }
    else if (event.GetKeyCode() == WXK_UP)
    {
        SelectPrevious();
    }
    else if (event.GetKeyCode() == WXK_RETURN)
    {
        Submit();
    }
    else
    {
        event.Skip();
    }
}

void SearchFrame::OnQueryChange(wxCommandEvent &event)
{
    if (helpText != nullptr) {
        helpText->Destroy();
        panel->Layout();
        helpText = nullptr;
    }
    
    wxString queryString = searchBar->GetValue();
    const char *query = queryString.ToUTF8();
    queryCallback(query, (void *)this, data);
}

void SearchFrame::OnItemClickEvent(wxCommandEvent &event)
{
    resultBox->SetSelection(event.GetInt());
    Submit();
}

void SearchFrame::OnActivate(wxActivateEvent &event)
{
    if (!event.GetActive())
    {
        Close(true);
    }
    event.Skip();
}

void SearchFrame::OnMouseMove(wxMouseEvent &event)
{
    if (event.LeftIsDown() && event.Dragging())
    {
        wxPoint pt = event.GetPosition();
        wxPoint wndLeftTopPt = GetPosition();
        int distanceX = pt.x - mLastPt.x;
        int distanceY = pt.y - mLastPt.y;

        wxPoint desPt;
        desPt.x = distanceX + wndLeftTopPt.x - 24;
        desPt.y = distanceY + wndLeftTopPt.y - 24;
        this->Move(desPt);
    }

    if (event.LeftDown())
    {
        this->CaptureMouse();
        mLastPt = event.GetPosition();
    }
}

void SearchFrame::OnMouseLeave(wxMouseEvent &event)
{
    if (event.LeftIsDown() && event.Dragging())
    {
        wxPoint pt = event.GetPosition();
        wxPoint wndLeftTopPt = GetPosition();
        int distanceX = pt.x - mLastPt.x;
        int distanceY = pt.y - mLastPt.y;

        wxPoint desPt;
        desPt.x = distanceX + wndLeftTopPt.x - 24;
        desPt.y = distanceY + wndLeftTopPt.y - 24;
        this->Move(desPt);
    }
}

void SearchFrame::OnMouseLDown(wxMouseEvent &event)
{
    if (!HasCapture())
        this->CaptureMouse();
}

void SearchFrame::OnMouseLUp(wxMouseEvent &event)
{
    if (HasCapture())
        ReleaseMouse();
}

void SearchFrame::OnMouseCaptureLost(wxMouseCaptureLostEvent &event)
{
    if (HasCapture())
        ReleaseMouse();
}

void SearchFrame::SetItems(SearchItem *items, int itemSize)
{
    wxItems.Clear();
    wxIds.Clear();
    wxTriggers.Clear();

    for (int i = 0; i < itemSize; i++)
    {
        wxString item = wxString::FromUTF8(items[i].label);
        wxItems.Add(item);

        wxString id = wxString::FromUTF8(items[i].id);
        wxIds.Add(id);

        wxString trigger = wxString::FromUTF8(items[i].trigger);
        wxTriggers.Add(trigger);
    }

    resultBox->SetItemCount(itemSize);

    if (itemSize > 0)
    {
        resultBox->SetSelection(0);
    }
    resultBox->RefreshAll();
    resultBox->Refresh();
}

void SearchFrame::SelectNext()
{
    if (resultBox->GetItemCount() > 0 && resultBox->GetSelection() != wxNOT_FOUND)
    {
        int newSelected = 0;
        if (resultBox->GetSelection() < (resultBox->GetItemCount() - 1))
        {
            newSelected = resultBox->GetSelection() + 1;
        }

        resultBox->SetSelection(newSelected);
    }
}

void SearchFrame::SelectPrevious()
{
    if (resultBox->GetItemCount() > 0 && resultBox->GetSelection() != wxNOT_FOUND)
    {
        int newSelected = resultBox->GetItemCount() - 1;
        if (resultBox->GetSelection() > 0)
        {
            newSelected = resultBox->GetSelection() - 1;
        }

        resultBox->SetSelection(newSelected);
    }
}

void SearchFrame::Submit()
{
    if (resultBox->GetItemCount() > 0 && resultBox->GetSelection() != wxNOT_FOUND)
    {
        long index = resultBox->GetSelection();
        wxString id = wxIds[index];
        if (resultCallback)
        {
            resultCallback(id.ToUTF8(), resultData);
        }

        Close(true);
    }
}

extern "C" void interop_show_search(SearchMetadata *_metadata, QueryCallback _queryCallback, void *_data, ResultCallback _resultCallback, void *_resultData)
{
// Setup high DPI support on Windows
#ifdef __WXMSW__
    SetProcessDPIAware();
#endif

    searchMetadata = _metadata;
    queryCallback = _queryCallback;
    resultCallback = _resultCallback;
    data = _data;
    resultData = _resultData;

    wxApp::SetInstance(new SearchApp());
    int argc = 0;
    wxEntry(argc, (char **)nullptr);
}

extern "C" void update_items(void *app, SearchItem *items, int itemSize)
{
    SearchFrame *frame = (SearchFrame *)app;
    frame->SetItems(items, itemSize);
}