// -*- mode: c++; c-file-style: "linux"; c-basic-offset: 2; indent-tabs-mode:
// nil -*-
//
//  Copyright (C) 2006-2015 Andrej Vodopivec <andrej.vodopivec@gmail.com>
//  Copyright (C) 2015-2019 Gunter Königsmann <wxMaxima@physikbuch.de>
//
//  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 2 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, write to the Free Software
//  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//

//
// This class exists because the wxFileTipProvider does not translate tips.
// This is a bug in wxWidgets. This class can be removed after this bug is fixed
// and is common in wxWidgets libraries distributed all over.
//
//  SPDX-License-Identifier: GPL-2.0+

#include "TipOfTheDay.h"
#include "Image.h"
#include "SvgBitmap.h"
#include <cstdlib>
#include <wx/artprov.h>
#include <wx/config.h>
#include <wx/display.h>
#include <wx/mstream.h>
#include <wx/persist.h>
#include <wx/persist/toplevel.h>
#include <wx/txtstrm.h>
#include <wx/wfstream.h>
#include <wx/zstream.h>
#include <algorithm>


#define ICON_SCALE (0.35)

TipOfTheDay::TipOfTheDay(wxWindow *parent)
  : wxDialog(parent, -1, _("Tip of the day")) {
  m_tips.Add(_(
               "To start using wxMaxima right away, start typing your command. An input "
               "cell should appear. Then press Shift-Enter to evaluate your command."));
  m_tips.Add(
             _("By default, Shift-Enter is used to evaluate commands, while Enter is "
               "used for multiline input. This behaviour can be changed in "
               "'Edit->Configure' dialog by checking 'Enter evaluates cells'. This "
               "switches the roles of these two key commands."));
  m_tips.Add(
             _("Maxima uses ':' to assign values to a variable ('a : 3;'), not '=' as "
               "most programming languages do.\nThis allows, that a mathematical "
               "equation can be assigned to a variable, e.g.\n eq1:3*x=4;\nwhich may "
               "then be solved for x with\nsolve(eq1,x);"));
  m_tips.Add(_("Maxima uses ':=' to define functions, e.g.:\nf(x) := x^2;"));
  m_tips.Add(_("You can access the last output using the variable '%'. You can "
               "access the output of previous commands using variables '%on' "
               "where n is the number of output."));
  m_tips.Add(
             _("Maxima supports three types of numbers: exact fractions (which can be "
               "generated for example by typing 1/10), IEEE floating-point numbers "
               "(0.2) and arbitrary precision big floats (1b-1). Note that, owing to "
               "their nature as binary (not decimal) numbers, there is for example no "
               "way to generate an IEEE floating-point number that exactly equals "
               "0.1. If floating-point numbers are used instead of fractions, Maxima "
               "will therefore sometimes have to introduce a (very small) error and "
               "use things like 3602879701896397/36028797018963968 for 0.1."));
  m_tips.Add(_("If you type an operator (one of +*/^=,) as the first symbol in "
               "an input cell, % will be automatically inserted before the "
               "operator, as on a graphing calculator. You can disable this "
               "feature from the 'Edit->Configure' dialog."));
  m_tips.Add(
             _("You can insert different types of 'cells' in wxMaxima documents using "
               "the 'Cell' menu. Note that only 'input cells' can be evaluated, while "
               "others are used for commenting and structuring your calculations."));
  m_tips.Add(_("A new document format has been introduced in wxMaxima 0.8.2 "
               "that saves not only your input and text commentaries, but also "
               "the outputs of your calculations. When saving your document, "
               "select 'Whole document (*.wxmx)' format."));
  m_tips.Add(
             _("Title, section and subsection cells can be folded to hide their "
               "contents. To fold or unfold, click in the square next to the cell. If "
               "you shift-click, all sublevels of that cell will also fold/unfold."));
  m_tips.Add(_("You can hide output part of cells by clicking in the triangle "
               "on the left side of cells. This works on text cells also."));
  m_tips.Add(_(
               "There are many resources about Maxima and wxMaxima on the internet. "
               "Visit https://wxMaxima-developers.github.io/wxmaxima/help.html for more "
               "information and to find tutorials on using wxMaxima and Maxima."));
  m_tips.Add(_("You can get help on a Maxima function by selecting or clicking "
               "on the function name and pressing F1. wxMaxima will search the "
               "help index for the selection or the word under the cursor."));
  m_tips.Add(
             _("A 'horizontal cursor' was introduced in wxMaxima 0.8.0. It looks like "
               "a horizontal line between cells. It indicates where a new cell will "
               "appear if you type or paste text or execute a menu command."));
  m_tips.Add(_("Horizontal cursor works like a normal cursor, but it operates "
               "on cells: press up or down arrow to move it, holding down "
               "Shift while moving will select cells, pressing backspace or "
               "delete twice will delete a cell next to it."));
  m_tips.Add(_("Selecting a part of an output and right-clicking on the "
               "selection will bring up a menu with convenient functions that "
               "will operate on the selection."));
  m_tips.Add(_("You can select multiple cells either with a mouse - "
               "click'n'drag from between cells or from a cell bracket on the "
               "left - or with a keyboard - hold down Shift while moving the "
               "horizontal cursor - and then operate on selection. This comes "
               "in handy when you want to delete or evaluate multiple cells."));
  m_tips.Add(
             _("You can evaluate your whole document by using 'Cell->Evaluate All "
               "Cells' menu command or the appropriate key shortcut. The cells will "
               "be evaluated in the order they appear in the document."));
  m_tips.Add(
             _("If your calculation is taking too long to evaluate, you can try "
               "'Maxima->Interrupt' or 'Maxima->Restart Maxima' menu commands."));
  m_tips.Add(_("To plot in polar coordinates, select 'set polar' in the "
               "Options entry for Plot2d dialog. You can also plot in "
               "spherical and cylindrical coordinates in 3D."));
  m_tips.Add(_("wxMaxima dialogs set default values for inputs entries, one of "
               "which is '%'. If you have made a selection in your document, "
               "the selection will be used instead of '%'."));
  m_tips.Add(
             _("To put parentheses around an expression, select it, and press '(' or "
               "')' depending on where you want the cursor to appear afterwards."));
  m_tips.Add(
             _("When applying functions with one argument from menus, the default "
               "argument is '%'. To apply the function to some other value, select it "
               "in the document before executing a menu command."));
  m_tips.Add(_("To save the size and position of wxMaxima windows between "
               "session, use 'Edit->Configure' dialog."));
  m_tips.Add(_("Since wxMaxima 0.8.2 you can also insert images into your "
               "documents. Use 'Cell->Insert Image...' menu command."));
  m_tips.Add(_("Besides the global undo functionality that is active when the "
               "cursor is between cells, wxMaxima has a per-cell undo function "
               "that is active if the cursor is inside a cell. Pressing Ctrl+Z "
               "inside a cell can therefore been used for a fine-pitch undo "
               "that doesn't affect latter changes made in other cells."));
  m_tips.Add(_("Pressing Ctrl+Space or Ctrl+Tab starts an autocomplete "
               "function that can not only complete all functions that are "
               "integrated into the Maxima core and their parameters: It also "
               "knows about parameters from currently loaded packages and from "
               "functions that are defined in the current file."));
  m_tips.Add(
             _("It is possible to define reusable Maxima libraries with wxMaxima that "
               "can be later loaded by using the load() function. All that has to be "
               "done is to export a file in the .mac or to save it in the .wxm "
               "format. Note, though, that a few special characters like the \"not "
               "equal\" symbol for \"#\" are handled by wxMaxima, not by Maxima and "
               "therefore cannot be recognized on load()."));
  m_tips.Add(
             _("wxMaxima can be made to execute commands at every start-up by placing "
               "them in a text file with the name wxmaxima.rc in the user directory. "
               "This directory can be found by typing maxima_userdir;"));
  m_tips.Add(
             _("Libraries can be accessed by any wxMaxima process regardless of which "
               "directory it runs in, if they are placed in the user directory. This "
               "directory can be found by typing maxima_userdir;"));
  m_tips.Add(_("The load() command of Maxima versions >5.38 is able to load "
               ".wxm files as library of Maxima's commands."));
  m_tips.Add(_("A plot to be embedded into the work sheet by preceding its "
               "name with a \"wx\". \"draw\" can be replaced by \"wxdraw\", "
               "plot by \"wxplot\" etc."));
  m_tips.Add(
             _("wxMaxima provides the \"table_form\" command that shows lists in an "
               "alternative form. One example would be:\n\ntable_form([1,2,3,4,5]);"));
  m_tips.Add(
             _("In order to visualize how a parameter affects an equation wxMaxima "
               "provides commands that start with \"with_slider_\" and that create "
               "animations. One example would be:\n\n    with_slider_draw(\n        "
               "a,[-16,-9,-4,-2,0,1,2,3,4,5,6,7],\n        title=concat(\"a=\",a),\n  "
               "      grid=true,\n        explicit(\n            x^2-a*x,\n           "
               " x,-10,10\n        )\n    );"));
  m_tips.Add(_("If the \"Autosave\" functionality is enabled in the "
               "configuration dialogue wxMaxima acts like mobile apps that "
               "backup the file every few minutes and save it on closing."));
  m_tips.Add(_(
               "It is possible to add custom symbols to the \"symbols\" sidebar by "
               "copying them into the respective field in the configuration dialogue."));
  m_tips.Add(
             _("Maxima's strengths are manipulating equations and in symbolic "
               "calculations. It therefore makes sense to use functions (as opposed "
               "to equations with labels) sparingly and to keep the actual values of "
               "variables in a list, instead of directly assigning them values. An "
               "example session that does do so would be:\n\n/* We keep the actual "
               "values in a list so we can use them later on */\n    "
               "Values:[a=10,c=100];\n    Pyth:a^2+b^2=c^2;\n    solve(%,b);\n    "
               "result:%[2];\n    at(result,Values);\n    float(%);"));
  m_tips.Add(_("Equations have several advantages over functions. For example "
               "they can be manipulated with factor(), expand() and similar "
               "functions. They can easily be introduced one into another. "
               "Also they are always printed out as 2D maths."));
  m_tips.Add(
             _("Maxima's \"at\" function allows to access to arbitrary variables in a "
               "list of results:\n\n    g1:a*x+y=0;\n    g2:b*y+x*x=1;\n    "
               "solve([g1,g2],[a,b]);\n    %[1];\n    result_b:b=at(b,%);"));
  m_tips.Add(
             _("The \"at\" function allows to introduce one equation into "
               "another:\n\n    ohm:U=R*I;\n    r_parallel:R=R_1*R_2/(R_1+R_2);\n    "
               "result:at(ohm,r_parallel);"));
  m_tips.Add(
             _("The rhs() (\"right hand side\") command allows to retrieve the result "
               "of an equation in exactly the format a function would have:\n\n    "
               "Values:[\n        /* m=1.2 tons */\n        m=1.2*10^3,\n        /* "
               "100 km/h*/\n        v=100*10^3/(60*60)\n    ];\n    "
               "Energy:W=1/2*m*v^2;\n    at(Energy,Values);\n    W_mech:rhs(%);"));
  m_tips.Add(_("In text cells bullet lists can be created by beginning a line "
               "with \" * \". The number of spaces in front of the \"*\" "
               "determines the indentation level; Indentation can be continued "
               "in the next line by indenting the line using spaces."));
  m_tips.Add(
             _("Text cells can hold citations that as marked as such by beginning a "
               "line with \" > \". The number of spaces in front of the \">\" "
               "determines the indentation level, as it does with bullet lists."));
  m_tips.Add(
             _("The key combination Shift+Space results in a non-breakable space."));
  m_tips.Add(_("wxMaxima needs more translators. We do not speak every "
               "language. Help us to translate wxMaxima and the manual to your "
               "language. Join the wxMaxima development at: "
               "https://github.com/wxMaxima-developers/wxmaxima"));
  m_tips.Add(_("wxMaxima needs more developers. It is an open source project "
               "where you can contribute. Join the wxMaxima development at: "
               "https://github.com/wxMaxima-developers/wxmaxima"));
  m_tips.Add(
             _("You found a bug in wxMaxima? Please report it at "
               "https://github.com/wxMaxima-developers/wxmaxima/issues\nA "
               "mathematical bug is maybe a bug in Maxima (the backend), which can be "
               "reported at https://sourceforge.net/p/maxima/bugs/\nPlease check, "
               "before, if the bug was not already reported."));
  m_tips.Add(_(
               "You got an idea for an improvement of wxMaxima? Great! Please submit "
               "your idea at https://github.com/wxMaxima-developers/wxmaxima/issues. "));
  m_tips.Add(_("wxMaxima is programmed in C++ using the wxWidgets toolkit and "
               "uses CMake as build system. You can contribute to wxMaxima, if "
               "you have some knowledge with this environment."));
  m_tips.Add(_("While wxMaxima is programmed mostly in C++, it also uses some "
               "Lisp code. You can help to improve wxMaxima, if you have "
               "knowledge of Common Lisp."));
  m_tips.Add(
             _("If you have ideas, how to improve the design or functionality of "
               "wxMaxima, please share your ideas at the issue list or discussion "
               "forum at https://github.com/wxMaxima-developers/wxmaxima/."));
  m_tips.Add(
             _("There is a discussion forum for wxMaxima at "
               "https://github.com/wxMaxima-developers/wxmaxima/discussions.\nYou can "
               "ask questions there - and please help other users, by answering their "
               "questions, if you know an answer."));

  m_num = 0;
  wxConfigBase *config = wxConfig::Get();

  // If nm is negative, the if will make it positive.
  long nm;
  config->Read(wxS("tipNum"), &nm);
  m_num = nm;
  if (m_num >= m_tips.GetCount())
    m_num = 0;

  SetName("TipOfTheDay");
  SetTitle(_("Tip of the day"));
  wxBoxSizer *vbox = new wxBoxSizer(wxVERTICAL);
  wxBoxSizer *hbox = new wxBoxSizer(wxHORIZONTAL);
  wxButton *backButton = new wxButton(this, wxID_BACKWARD);
  backButton->Connect(wxEVT_BUTTON,
                      wxCommandEventHandler(TipOfTheDay::OnPreviousButton),
                      NULL, this);
  hbox->Add(backButton, wxSizerFlags().Expand());
  hbox->Add(new wxStaticText(this, -1, _(" Did you know? "), wxDefaultPosition,
                             wxDefaultSize, wxALIGN_CENTRE_HORIZONTAL),
            wxSizerFlags().Proportion(10).Center());
  wxButton *forwardButton = new wxButton(this, wxID_FORWARD);
  forwardButton->Connect(wxEVT_BUTTON,
                         wxCommandEventHandler(TipOfTheDay::OnNextButton), NULL,
                         this);
  hbox->Add(forwardButton, wxSizerFlags().Expand());
  vbox->Add(hbox, wxSizerFlags().Expand());
  Connect(wxEVT_TEXT_URL, wxTextUrlEventHandler(TipOfTheDay::OnTextURLEvent),
          NULL, this);

  m_tip = new wxTextCtrl(this, -1, m_tips[m_num], wxDefaultPosition,
                         wxDefaultSize, wxTE_READONLY | wxTE_MULTILINE | wxTE_AUTO_URL);
  vbox->Add(m_tip, wxSizerFlags().Expand().Proportion(10));

  wxBoxSizer *buttonSizer = new wxBoxSizer(wxHORIZONTAL);

  m_showAtStartup = new wxCheckBox(this, -1, _("Show tips at Startup"));
  bool showTip = true;
  config->Read(wxS("ShowTips"), &showTip);
  m_showAtStartup->SetValue(showTip);
  buttonSizer->Add(m_showAtStartup, wxSizerFlags().Expand());
  buttonSizer->AddStretchSpacer(5);

  wxButton *okButton = new wxButton(this, wxID_OK, _("OK"));
  okButton->Connect(wxEVT_BUTTON,
                    wxCommandEventHandler(TipOfTheDay::OnOkButton), NULL, this);

  buttonSizer->Add(okButton);
  okButton->SetDefault();
  vbox->Add(buttonSizer, wxSizerFlags().Expand().Proportion(1));

  wxPersistenceManager::Get().RegisterAndRestore(this);
  config->Write(wxS("tipNum"), m_num + 1);
  SetSizerAndFit(vbox);
}

TipOfTheDay::~TipOfTheDay() {
  wxConfigBase *config = wxConfig::Get();
  config->Write(wxS("ShowTips"), m_showAtStartup->GetValue());
  config->Write(wxS("tipNum"), m_num + 1);
}

wxImage TipOfTheDay::GetImage(unsigned char *data, std::size_t len) {
  int ppi;
#if wxCHECK_VERSION(3, 1, 1)
  wxDisplay display;

  int display_idx = wxDisplay::GetFromWindow(GetParent());
  if (display_idx < 0)
    ppi = 72;
  else
    ppi = wxDisplay(display_idx).GetPPI().x;
#else
  ppi = wxGetDisplayPPI().x;
#endif
  if (ppi <= 10)
    ppi = 72;

  int targetSize = std::max(ppi, 75) * ICON_SCALE;

  int sizeA = 128 << 4;
  while (sizeA * 3 / 2 > targetSize && sizeA >= 32) {
    sizeA >>= 1;
  };

  int sizeB = 192 << 4;
  while (sizeB * 4 / 3 > targetSize && sizeB >= 32) {
    sizeB >>= 1;
  }

  if (std::abs(targetSize - sizeA) < std::abs(targetSize - sizeB)) {
    targetSize = sizeA;
  } else {
    targetSize = sizeB;
  }

  wxImage img =
    SvgBitmap(this, data, len, targetSize, targetSize).ConvertToImage();

#if defined __WXMSW__
#if wxCHECK_VERSION(3, 1, 1)
  // MSW is notorious for having problems with transparent black pixels.
  // Let's see if we can avoid these problems by converting the alpha
  // channel to a mask even if that means we cannot antialias a transparent
  // and a colored pixel to a half-transparent one any more.
  img.ConvertAlphaToMask();
#endif
#endif

  img.Rescale(targetSize, targetSize, wxIMAGE_QUALITY_HIGH);
  return img;
}

void TipOfTheDay::OnNextButton(wxCommandEvent &WXUNUSED(dummy)) {
  m_num++;
  if (m_num >= m_tips.GetCount())
    m_num = 0;
  m_tip->SetValue(m_tips[m_num]);
}

void TipOfTheDay::OnPreviousButton(wxCommandEvent &WXUNUSED(dummy)) {
  if (m_num > 0)
    m_num--;
  else
    m_num = m_tips.GetCount() - 1;
  m_tip->SetValue(m_tips[m_num]);
}

void TipOfTheDay::OnOkButton(wxCommandEvent &WXUNUSED(dummy)) {
  wxConfigBase *config = wxConfig::Get();
  config->Write(wxS("ShowTips"), m_showAtStartup->GetValue());
  config->Write(wxS("tipNum"), m_num + 1);
  Destroy();
}

void TipOfTheDay::OnTextURLEvent(wxTextUrlEvent &event) {
  if (event.GetMouseEvent().LeftUp()) {
    wxTextCtrl *pTextCtrl = static_cast<wxTextCtrl *>(event.GetEventObject());
    wxLaunchDefaultBrowser(pTextCtrl->GetRange(event.GetURLStart(), event.GetURLEnd()));
  }
}
