/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#include "cmCursesMainForm.h"

#include <algorithm>
#include <cstdio>
#include <cstring>
#include <utility>

#include <cm/memory>

#include "cmCursesCacheEntryComposite.h"
#include "cmCursesDummyWidget.h"
#include "cmCursesForm.h"
#include "cmCursesLabelWidget.h"
#include "cmCursesLongMessageForm.h"
#include "cmCursesStandardIncludes.h"
#include "cmCursesStringWidget.h"
#include "cmCursesWidget.h"
#include "cmState.h"
#include "cmStateTypes.h"
#include "cmStringAlgorithms.h"
#include "cmSystemTools.h"
#include "cmVersion.h"
#include "cmake.h"

inline int ctrl(int z)
{
  return (z & 037);
}

cmCursesMainForm::cmCursesMainForm(std::vector<std::string> args,
                                   int initWidth)
  : Args(std::move(args))
  , InitialWidth(initWidth)
{
  this->HasNonStatusOutputs = false;
  this->NumberOfPages = 0;
  this->AdvancedMode = false;
  this->NumberOfVisibleEntries = 0;
  this->OkToGenerate = false;
  this->HelpMessage.emplace_back(
    "Welcome to ccmake, curses based user interface for CMake.");
  this->HelpMessage.emplace_back();
  this->HelpMessage.emplace_back(s_ConstHelpMessage);
  this->CMakeInstance =
    cm::make_unique<cmake>(cmake::RoleProject, cmState::Project);
  this->CMakeInstance->SetCMakeEditCommand(
    cmSystemTools::GetCMakeCursesCommand());

  // create the arguments for the cmake object
  std::string whereCMake =
    cmStrCat(cmSystemTools::GetProgramPath(this->Args[0]), "/cmake");
  this->Args[0] = whereCMake;
  this->CMakeInstance->SetArgs(this->Args);
  this->SearchMode = false;
}

cmCursesMainForm::~cmCursesMainForm()
{
  if (this->Form) {
    unpost_form(this->Form);
    free_form(this->Form);
    this->Form = nullptr;
  }
}

// See if a cache entry is in the list of entries in the ui.
bool cmCursesMainForm::LookForCacheEntry(const std::string& key)
{
  return std::any_of(this->Entries.begin(), this->Entries.end(),
                     [&key](cmCursesCacheEntryComposite const& entry) {
                       return key == entry.Key;
                     });
}

// Create new cmCursesCacheEntryComposite entries from the cache
void cmCursesMainForm::InitializeUI()
{
  // Create a vector of cmCursesCacheEntryComposite's
  // which contain labels, entries and new entry markers
  std::vector<cmCursesCacheEntryComposite> newEntries;
  std::vector<std::string> cacheKeys =
    this->CMakeInstance->GetState()->GetCacheEntryKeys();
  newEntries.reserve(cacheKeys.size());

  // Count non-internal and non-static entries
  int count = 0;

  for (std::string const& key : cacheKeys) {
    cmStateEnums::CacheEntryType t =
      this->CMakeInstance->GetState()->GetCacheEntryType(key);
    if (t != cmStateEnums::INTERNAL && t != cmStateEnums::STATIC &&
        t != cmStateEnums::UNINITIALIZED) {
      ++count;
    }
  }

  int entrywidth = this->InitialWidth - 35;

  if (count == 0) {
    // If cache is empty, display a label saying so and a
    // dummy entry widget (does not respond to input)
    cmCursesCacheEntryComposite comp("EMPTY CACHE", 30, 30);
    comp.Entry = cm::make_unique<cmCursesDummyWidget>(1, 1, 1, 1);
    newEntries.emplace_back(std::move(comp));
  } else {
    // Create the composites.

    // First add entries which are new
    for (std::string const& key : cacheKeys) {
      cmStateEnums::CacheEntryType t =
        this->CMakeInstance->GetState()->GetCacheEntryType(key);
      if (t == cmStateEnums::INTERNAL || t == cmStateEnums::STATIC ||
          t == cmStateEnums::UNINITIALIZED) {
        continue;
      }

      if (!this->LookForCacheEntry(key)) {
        newEntries.emplace_back(key, this->CMakeInstance->GetState(), true, 30,
                                entrywidth);
        this->OkToGenerate = false;
      }
    }

    // then add entries which are old
    for (std::string const& key : cacheKeys) {
      cmStateEnums::CacheEntryType t =
        this->CMakeInstance->GetState()->GetCacheEntryType(key);
      if (t == cmStateEnums::INTERNAL || t == cmStateEnums::STATIC ||
          t == cmStateEnums::UNINITIALIZED) {
        continue;
      }

      if (this->LookForCacheEntry(key)) {
        newEntries.emplace_back(key, this->CMakeInstance->GetState(), false,
                                30, entrywidth);
      }
    }
  }

  // Replace old entries
  this->Entries = std::move(newEntries);

  // Compute fields from composites
  this->RePost();
}

void cmCursesMainForm::RePost()
{
  // Create the fields to be passed to the form.
  if (this->Form) {
    unpost_form(this->Form);
    free_form(this->Form);
    this->Form = nullptr;
  }
  this->Fields.clear();
  if (this->AdvancedMode) {
    this->NumberOfVisibleEntries = this->Entries.size();
  } else {
    // If normal mode, count only non-advanced entries
    this->NumberOfVisibleEntries = 0;
    for (cmCursesCacheEntryComposite& entry : this->Entries) {
      const char* existingValue =
        this->CMakeInstance->GetState()->GetCacheEntryValue(entry.GetValue());
      bool advanced =
        this->CMakeInstance->GetState()->GetCacheEntryPropertyAsBool(
          entry.GetValue(), "ADVANCED");
      if (!existingValue || (!this->AdvancedMode && advanced)) {
        continue;
      }
      this->NumberOfVisibleEntries++;
    }
  }
  // there is always one even if it is the dummy one
  if (this->NumberOfVisibleEntries == 0) {
    this->NumberOfVisibleEntries = 1;
  }
  // Assign the fields: 3 for each entry: label, new entry marker
  // ('*' or ' ') and entry widget
  this->Fields.reserve(3 * this->NumberOfVisibleEntries + 1);

  // Assign fields
  for (cmCursesCacheEntryComposite& entry : this->Entries) {
    const char* existingValue =
      this->CMakeInstance->GetState()->GetCacheEntryValue(entry.GetValue());
    bool advanced =
      this->CMakeInstance->GetState()->GetCacheEntryPropertyAsBool(
        entry.GetValue(), "ADVANCED");
    if (!existingValue || (!this->AdvancedMode && advanced)) {
      continue;
    }
    this->Fields.push_back(entry.Label->Field);
    this->Fields.push_back(entry.IsNewLabel->Field);
    this->Fields.push_back(entry.Entry->Field);
  }
  // if no cache entries there should still be one dummy field
  if (this->Fields.empty()) {
    const auto& front = this->Entries.front();
    this->Fields.push_back(front.Label->Field);
    this->Fields.push_back(front.IsNewLabel->Field);
    this->Fields.push_back(front.Entry->Field);
    this->NumberOfVisibleEntries = 1;
  }
  // Has to be null terminated.
  this->Fields.push_back(nullptr);
}

void cmCursesMainForm::Render(int left, int top, int width, int height)
{

  if (this->Form) {
    FIELD* currentField = current_field(this->Form);
    cmCursesWidget* cw =
      reinterpret_cast<cmCursesWidget*>(field_userptr(currentField));
    // If in edit mode, get out of it
    if (cw->GetType() == cmStateEnums::STRING ||
        cw->GetType() == cmStateEnums::PATH ||
        cw->GetType() == cmStateEnums::FILEPATH) {
      cmCursesStringWidget* sw = static_cast<cmCursesStringWidget*>(cw);
      sw->SetInEdit(false);
    }
    // Delete the previous form
    unpost_form(this->Form);
    free_form(this->Form);
    this->Form = nullptr;
  }

  // Wrong window size
  if (width < cmCursesMainForm::MIN_WIDTH || width < this->InitialWidth ||
      height < cmCursesMainForm::MIN_HEIGHT) {
    return;
  }

  // Leave room for toolbar
  height -= 7;

  if (this->AdvancedMode) {
    this->NumberOfVisibleEntries = this->Entries.size();
  } else {
    // If normal, display only non-advanced entries
    this->NumberOfVisibleEntries = 0;
    for (cmCursesCacheEntryComposite& entry : this->Entries) {
      const char* existingValue =
        this->CMakeInstance->GetState()->GetCacheEntryValue(entry.GetValue());
      bool advanced =
        this->CMakeInstance->GetState()->GetCacheEntryPropertyAsBool(
          entry.GetValue(), "ADVANCED");
      if (!existingValue || (!this->AdvancedMode && advanced)) {
        continue;
      }
      this->NumberOfVisibleEntries++;
    }
  }

  // Re-adjust the fields according to their place
  this->NumberOfPages = 1;
  if (height > 0) {
    bool isNewPage;
    int i = 0;
    for (cmCursesCacheEntryComposite& entry : this->Entries) {
      const char* existingValue =
        this->CMakeInstance->GetState()->GetCacheEntryValue(entry.GetValue());
      bool advanced =
        this->CMakeInstance->GetState()->GetCacheEntryPropertyAsBool(
          entry.GetValue(), "ADVANCED");
      if (!existingValue || (!this->AdvancedMode && advanced)) {
        continue;
      }
      int row = (i % height) + 1;
      int page = (i / height) + 1;
      isNewPage = (page > 1) && (row == 1);

      if (isNewPage) {
        this->NumberOfPages++;
      }
      entry.Label->Move(left, top + row - 1, isNewPage);
      entry.IsNewLabel->Move(left + 32, top + row - 1, false);
      entry.Entry->Move(left + 33, top + row - 1, false);
      entry.Entry->SetPage(this->NumberOfPages);
      i++;
    }
  }

  // Post the form
  this->Form = new_form(this->Fields.data());
  post_form(this->Form);
  // Update toolbar
  this->UpdateStatusBar();
  this->PrintKeys();

  touchwin(stdscr);
  refresh();
}

void cmCursesMainForm::PrintKeys(int process /* = 0 */)
{
  int x;
  int y;
  getmaxyx(stdscr, y, x);
  if (x < cmCursesMainForm::MIN_WIDTH || x < this->InitialWidth ||
      y < cmCursesMainForm::MIN_HEIGHT) {
    return;
  }

  // Give the current widget (if it exists), a chance to print keys
  cmCursesWidget* cw = nullptr;
  if (this->Form) {
    FIELD* currentField = current_field(this->Form);
    cw = reinterpret_cast<cmCursesWidget*>(field_userptr(currentField));
  }

  char fmt_s[] = "%s";
  if (cw == nullptr || !cw->PrintKeys()) {
    char firstLine[512] = "";
    char secondLine[512] = "";
    char thirdLine[512] = "";
    if (process) {
      memset(firstLine, ' ', 68);
      memset(secondLine, ' ', 68);
      memset(thirdLine, ' ', 68);
    } else {
      if (this->OkToGenerate) {
        sprintf(firstLine,
                "      [l] Show log output   [c] Configure"
                "       [g] Generate        ");
      } else {
        sprintf(firstLine,
                "      [l] Show log output   [c] Configure"
                "                           ");
      }
      {
        const char* toggleKeyInstruction =
          "      [t] Toggle advanced mode (currently %s)";
        sprintf(thirdLine, toggleKeyInstruction,
                this->AdvancedMode ? "on" : "off");
      }
      sprintf(secondLine,
              "      [h] Help              [q] Quit without generating");
    }

    curses_move(y - 4, 0);
    char fmt[512] = "Keys: [enter] Edit an entry [d] Delete an entry";
    if (process) {
      memset(fmt, ' ', 57);
    }
    printw(fmt_s, fmt);
    curses_move(y - 3, 0);
    printw(fmt_s, firstLine);
    curses_move(y - 2, 0);
    printw(fmt_s, secondLine);
    curses_move(y - 1, 0);
    printw(fmt_s, thirdLine);
  }

  if (cw) {
    char pageLine[512] = "";
    sprintf(pageLine, "Page %d of %d", cw->GetPage(), this->NumberOfPages);
    curses_move(0, 65 - static_cast<unsigned int>(strlen(pageLine)) - 1);
    printw(fmt_s, pageLine);
  }

  pos_form_cursor(this->Form);
}

// Print the key of the current entry and the CMake version
// on the status bar. Designed for a width of 80 chars.
void cmCursesMainForm::UpdateStatusBar(cm::optional<std::string> message)
{
  int x;
  int y;
  getmaxyx(stdscr, y, x);
  // If window size is too small, display error and return
  if (x < cmCursesMainForm::MIN_WIDTH || x < this->InitialWidth ||
      y < cmCursesMainForm::MIN_HEIGHT) {
    curses_clear();
    curses_move(0, 0);
    char fmt[] = "Window is too small. A size of at least %dx%d is required.";
    printw(fmt,
           (cmCursesMainForm::MIN_WIDTH < this->InitialWidth
              ? this->InitialWidth
              : cmCursesMainForm::MIN_WIDTH),
           cmCursesMainForm::MIN_HEIGHT);
    touchwin(stdscr);
    wrefresh(stdscr);
    return;
  }

  // Find the current label index
  // Field are grouped by 3, the label should be 2 less than the current index
  using size_type = decltype(this->Fields)::size_type;
  size_type currentLabelIndex = field_index(current_field(this->Form)) - 2;

  // Use the status message if any, otherwise join the key and help string
  std::string bar;
  if (message) {
    bar = *message;
  } else {
    // Get the key of the current entry
    cmCursesWidget* labelWidget = reinterpret_cast<cmCursesWidget*>(
      field_userptr(this->Fields[currentLabelIndex]));
    std::string labelValue = labelWidget->GetValue();
    bar = labelValue + ": ";

    // Get the help string of the current entry
    // and add it to the help string
    auto cmakeState = this->CMakeInstance->GetState();
    const char* existingValue = cmakeState->GetCacheEntryValue(labelValue);
    if (existingValue) {
      auto help = cmakeState->GetCacheEntryProperty(labelValue, "HELPSTRING");
      if (help) {
        bar += help;
      }
    }
  }
  // Pad with spaces to erase any previous text,
  // or truncate as necessary to fit the screen
  bar.resize(x, ' ');
  curses_move(y - 5, 0);
  attron(A_STANDOUT);
  char fmt_s[] = "%s";
  printw(fmt_s, bar.c_str());
  attroff(A_STANDOUT);

  // Highlight the current label, reset others
  // Fields are grouped by 3, the first one being the label
  // so start at 0 and move up by 3 avoiding the last null entry
  for (size_type index = 0; index < this->Fields.size() - 1; index += 3) {
    bool currentLabel = index == currentLabelIndex;
    set_field_fore(this->Fields[index], currentLabel ? A_STANDOUT : A_NORMAL);
  }

  // Display CMake version under the status bar
  // We want to display this on the right
  std::string version = "CMake Version ";
  version += cmVersion::GetCMakeVersion();
  version.resize(std::min<std::string::size_type>(x, version.size()));
  curses_move(y - 4, x - static_cast<int>(version.size()));
  printw(fmt_s, version.c_str());

  pos_form_cursor(this->Form);
}

void cmCursesMainForm::UpdateProgress(const std::string& msg, float prog)
{
  if (prog >= 0) {
    constexpr int progressBarWidth = 40;
    int progressBarCompleted = static_cast<int>(progressBarWidth * prog);
    int percentCompleted = static_cast<int>(100 * prog);
    this->LastProgress = (percentCompleted < 100 ? " " : "");
    this->LastProgress += (percentCompleted < 10 ? " " : "");
    this->LastProgress += std::to_string(percentCompleted) + "% [";
    this->LastProgress.append(progressBarCompleted, '#');
    this->LastProgress.append(progressBarWidth - progressBarCompleted, ' ');
    this->LastProgress += "] " + msg + "...";
  } else {
    this->Outputs.emplace_back(msg);
  }

  this->DisplayOutputs();
}

int cmCursesMainForm::Configure(int noconfigure)
{
  this->ResetOutputs();

  if (noconfigure == 0) {
    this->UpdateProgress("Configuring", 0);
    this->CMakeInstance->SetProgressCallback(
      [this](const std::string& msg, float prog) {
        this->UpdateProgress(msg, prog);
      });
  }

  // always save the current gui values to disk
  this->FillCacheManagerFromUI();
  this->CMakeInstance->SaveCache(
    this->CMakeInstance->GetHomeOutputDirectory());
  this->LoadCache(nullptr);

  // run the generate process
  this->OkToGenerate = true;
  int retVal;
  if (noconfigure) {
    retVal = this->CMakeInstance->DoPreConfigureChecks();
    this->OkToGenerate = false;
    if (retVal > 0) {
      retVal = 0;
    }
  } else {
    retVal = this->CMakeInstance->Configure();
  }
  this->CMakeInstance->SetProgressCallback(nullptr);

  keypad(stdscr, true); /* Use key symbols as KEY_DOWN */

  if (retVal != 0 || this->HasNonStatusOutputs) {
    // see if there was an error
    if (cmSystemTools::GetErrorOccuredFlag()) {
      this->OkToGenerate = false;
    }
    int xx;
    int yy;
    getmaxyx(stdscr, yy, xx);
    const char* title = "Configure produced the following output";
    if (cmSystemTools::GetErrorOccuredFlag()) {
      title = "Configure failed with the following output";
    }
    cmCursesLongMessageForm* msgs = new cmCursesLongMessageForm(
      this->Outputs, title,
      cmCursesLongMessageForm::ScrollBehavior::ScrollDown);
    // reset error condition
    cmSystemTools::ResetErrorOccuredFlag();
    CurrentForm = msgs;
    msgs->Render(1, 1, xx, yy);
    msgs->HandleInput();
    // If they typed the wrong source directory, we report
    // an error and exit
    if (retVal == -2) {
      return retVal;
    }
  }

  this->InitializeUI();
  CurrentForm = this;
  int xi;
  int yi;
  getmaxyx(stdscr, yi, xi);
  this->Render(1, 1, xi, yi);

  return 0;
}

int cmCursesMainForm::Generate()
{
  this->ResetOutputs();

  this->UpdateProgress("Generating", 0);
  this->CMakeInstance->SetProgressCallback(
    [this](const std::string& msg, float prog) {
      this->UpdateProgress(msg, prog);
    });

  // run the generate process
  int retVal = this->CMakeInstance->Generate();

  this->CMakeInstance->SetProgressCallback(nullptr);
  keypad(stdscr, true); /* Use key symbols as KEY_DOWN */

  if (retVal != 0 || this->HasNonStatusOutputs) {
    // see if there was an error
    if (cmSystemTools::GetErrorOccuredFlag()) {
      this->OkToGenerate = false;
    }
    // reset error condition
    cmSystemTools::ResetErrorOccuredFlag();
    int xx;
    int yy;
    getmaxyx(stdscr, yy, xx);
    const char* title = "Generate produced the following output";
    if (cmSystemTools::GetErrorOccuredFlag()) {
      title = "Generate failed with the following output";
    }
    cmCursesLongMessageForm* msgs = new cmCursesLongMessageForm(
      this->Outputs, title,
      cmCursesLongMessageForm::ScrollBehavior::ScrollDown);
    CurrentForm = msgs;
    msgs->Render(1, 1, xx, yy);
    msgs->HandleInput();
    // If they typed the wrong source directory, we report
    // an error and exit
    if (retVal == -2) {
      return retVal;
    }
  }

  this->InitializeUI();
  CurrentForm = this;
  int xi;
  int yi;
  getmaxyx(stdscr, yi, xi);
  this->Render(1, 1, xi, yi);

  return 0;
}

void cmCursesMainForm::AddError(const std::string& message,
                                const char* /*unused*/)
{
  this->Outputs.emplace_back(message);
  this->HasNonStatusOutputs = true;
  this->DisplayOutputs();
}

void cmCursesMainForm::RemoveEntry(const char* value)
{
  if (!value) {
    return;
  }

  auto removeIt =
    std::find_if(this->Entries.begin(), this->Entries.end(),
                 [value](cmCursesCacheEntryComposite& entry) -> bool {
                   const char* val = entry.GetValue();
                   return val != nullptr && !strcmp(value, val);
                 });

  if (removeIt != this->Entries.end()) {
    this->CMakeInstance->UnwatchUnusedCli(value);
    this->Entries.erase(removeIt);
  }
}

// copy from the list box to the cache manager
void cmCursesMainForm::FillCacheManagerFromUI()
{
  for (cmCursesCacheEntryComposite& entry : this->Entries) {
    const std::string& cacheKey = entry.Key;
    const char* existingValue =
      this->CMakeInstance->GetState()->GetCacheEntryValue(cacheKey);
    if (existingValue) {
      std::string oldValue = existingValue;
      std::string newValue = entry.Entry->GetValue();
      std::string fixedOldValue;
      std::string fixedNewValue;
      cmStateEnums::CacheEntryType t =
        this->CMakeInstance->GetState()->GetCacheEntryType(cacheKey);
      this->FixValue(t, oldValue, fixedOldValue);
      this->FixValue(t, newValue, fixedNewValue);

      if (!(fixedOldValue == fixedNewValue)) {
        // The user has changed the value.  Mark it as modified.
        this->CMakeInstance->GetState()->SetCacheEntryBoolProperty(
          cacheKey, "MODIFIED", true);
        this->CMakeInstance->GetState()->SetCacheEntryValue(cacheKey,
                                                            fixedNewValue);
      }
    }
  }
}

void cmCursesMainForm::FixValue(cmStateEnums::CacheEntryType type,
                                const std::string& in, std::string& out) const
{
  out = in.substr(0, in.find_last_not_of(' ') + 1);
  if (type == cmStateEnums::PATH || type == cmStateEnums::FILEPATH) {
    cmSystemTools::ConvertToUnixSlashes(out);
  }
  if (type == cmStateEnums::BOOL) {
    if (cmIsOff(out)) {
      out = "OFF";
    } else {
      out = "ON";
    }
  }
}

void cmCursesMainForm::HandleInput()
{
  int x = 0;
  int y = 0;

  if (!this->Form) {
    return;
  }

  FIELD* currentField;
  cmCursesWidget* currentWidget;

  char debugMessage[128];

  for (;;) {
    this->UpdateStatusBar();
    this->PrintKeys();
    if (this->SearchMode) {
      std::string searchstr = "Search: " + this->SearchString;
      this->UpdateStatusBar(searchstr);
      this->PrintKeys(1);
      curses_move(y - 5, static_cast<unsigned int>(searchstr.size()));
      // curses_move(1,1);
      touchwin(stdscr);
      refresh();
    }
    int key = getch();

    getmaxyx(stdscr, y, x);
    // If window too small, handle 'q' only
    if (x < cmCursesMainForm::MIN_WIDTH || y < cmCursesMainForm::MIN_HEIGHT) {
      // quit
      if (key == 'q') {
        break;
      }
      continue;
    }

    currentField = current_field(this->Form);
    currentWidget =
      reinterpret_cast<cmCursesWidget*>(field_userptr(currentField));

    bool widgetHandled = false;

    if (this->SearchMode) {
      if (key == 10 || key == KEY_ENTER) {
        this->SearchMode = false;
        if (!this->SearchString.empty()) {
          this->JumpToCacheEntry(this->SearchString.c_str());
          this->OldSearchString = this->SearchString;
        }
        this->SearchString.clear();
      }
      /*
      else if ( key == KEY_ESCAPE )
        {
        this->SearchMode = false;
        }
      */
      else if ((key >= 'a' && key <= 'z') || (key >= 'A' && key <= 'Z') ||
               (key >= '0' && key <= '9') || (key == '_')) {
        if (this->SearchString.size() <
            static_cast<std::string::size_type>(x - 10)) {
          this->SearchString += static_cast<char>(key);
        }
      } else if (key == ctrl('h') || key == KEY_BACKSPACE || key == KEY_DC) {
        if (!this->SearchString.empty()) {
          this->SearchString.pop_back();
        }
      }
    } else if (currentWidget && !this->SearchMode) {
      // Ask the current widget if it wants to handle input
      widgetHandled = currentWidget->HandleInput(key, this, stdscr);
      if (widgetHandled) {
        this->OkToGenerate = false;
        this->UpdateStatusBar();
        this->PrintKeys();
      }
    }
    if ((!currentWidget || !widgetHandled) && !this->SearchMode) {
      // If the current widget does not want to handle input,
      // we handle it.
      sprintf(debugMessage, "Main form handling input, key: %d", key);
      cmCursesForm::LogMessage(debugMessage);
      // quit
      if (key == 'q') {
        break;
      }
      // if not end of page, next field otherwise next page
      // each entry consists of fields: label, isnew, value
      // therefore, the label field for the prev. entry is index-5
      // and the label field for the next entry is index+1
      // (index always corresponds to the value field)
      // scroll down with arrow down, ctrl+n (emacs binding), or j (vim
      // binding)
      if (key == KEY_DOWN || key == ctrl('n') || key == 'j') {
        FIELD* cur = current_field(this->Form);
        size_t findex = field_index(cur);
        if (findex == 3 * this->NumberOfVisibleEntries - 1) {
          continue;
        }
        if (new_page(this->Fields[findex + 1])) {
          form_driver(this->Form, REQ_NEXT_PAGE);
        } else {
          form_driver(this->Form, REQ_NEXT_FIELD);
        }
      }
      // if not beginning of page, previous field, otherwise previous page
      // each entry consists of fields: label, isnew, value
      // therefore, the label field for the prev. entry is index-5
      // and the label field for the next entry is index+1
      // (index always corresponds to the value field)
      // scroll down with arrow up, ctrl+p (emacs binding), or k (vim binding)
      else if (key == KEY_UP || key == ctrl('p') || key == 'k') {
        FIELD* cur = current_field(this->Form);
        int findex = field_index(cur);
        if (findex == 2) {
          continue;
        }
        if (new_page(this->Fields[findex - 2])) {
          form_driver(this->Form, REQ_PREV_PAGE);
          set_current_field(this->Form, this->Fields[findex - 3]);
        } else {
          form_driver(this->Form, REQ_PREV_FIELD);
        }
      }
      // pg down
      else if (key == KEY_NPAGE || key == ctrl('d')) {
        form_driver(this->Form, REQ_NEXT_PAGE);
      }
      // pg up
      else if (key == KEY_PPAGE || key == ctrl('u')) {
        form_driver(this->Form, REQ_PREV_PAGE);
      }
      // configure
      else if (key == 'c') {
        this->Configure();
      }
      // display help
      else if (key == 'h') {
        getmaxyx(stdscr, y, x);

        FIELD* cur = current_field(this->Form);
        int findex = field_index(cur);
        cmCursesWidget* lbl = reinterpret_cast<cmCursesWidget*>(
          field_userptr(this->Fields[findex - 2]));
        const char* curField = lbl->GetValue();
        const char* helpString = nullptr;

        const char* existingValue =
          this->CMakeInstance->GetState()->GetCacheEntryValue(curField);
        if (existingValue) {
          helpString = this->CMakeInstance->GetState()->GetCacheEntryProperty(
            curField, "HELPSTRING");
        }
        if (helpString) {
          this->HelpMessage[1] =
            cmStrCat("Current option is: ", curField, '\n',
                     "Help string for this option is: ", helpString, '\n');
        } else {
          this->HelpMessage[1] = "";
        }

        cmCursesLongMessageForm* msgs = new cmCursesLongMessageForm(
          this->HelpMessage, "Help",
          cmCursesLongMessageForm::ScrollBehavior::NoScroll);
        CurrentForm = msgs;
        msgs->Render(1, 1, x, y);
        msgs->HandleInput();
        CurrentForm = this;
        this->Render(1, 1, x, y);
        set_current_field(this->Form, cur);
      }
      // display last errors
      else if (key == 'l') {
        getmaxyx(stdscr, y, x);
        cmCursesLongMessageForm* msgs = new cmCursesLongMessageForm(
          this->Outputs, "CMake produced the following output",
          cmCursesLongMessageForm::ScrollBehavior::NoScroll);
        CurrentForm = msgs;
        msgs->Render(1, 1, x, y);
        msgs->HandleInput();
        CurrentForm = this;
        this->Render(1, 1, x, y);
      } else if (key == '/') {
        this->SearchMode = true;
        this->UpdateStatusBar("Search");
        this->PrintKeys(1);
        touchwin(stdscr);
        refresh();
      } else if (key == 'n') {
        if (!this->OldSearchString.empty()) {
          this->JumpToCacheEntry(this->OldSearchString.c_str());
        }
      }
      // switch advanced on/off
      else if (key == 't') {
        if (this->AdvancedMode) {
          this->AdvancedMode = false;
        } else {
          this->AdvancedMode = true;
        }
        getmaxyx(stdscr, y, x);
        this->RePost();
        this->Render(1, 1, x, y);
      }
      // generate and exit
      else if (key == 'g') {
        if (this->OkToGenerate) {
          this->Generate();
          break;
        }
      }
      // delete cache entry
      else if (key == 'd' && this->NumberOfVisibleEntries) {
        this->OkToGenerate = false;
        FIELD* cur = current_field(this->Form);
        size_t findex = field_index(cur);

        // make the next or prev. current field after deletion
        // each entry consists of fields: label, isnew, value
        // therefore, the label field for the prev. entry is findex-5
        // and the label field for the next entry is findex+1
        // (findex always corresponds to the value field)
        FIELD* nextCur;
        if (findex == 2) {
          nextCur = nullptr;
        } else if (findex == 3 * this->NumberOfVisibleEntries - 1) {
          nextCur = this->Fields[findex - 5];
        } else {
          nextCur = this->Fields[findex + 1];
        }

        // Get the label widget
        // each entry consists of fields: label, isnew, value
        // therefore, the label field for the is findex-2
        // (findex always corresponds to the value field)
        cmCursesWidget* lbl = reinterpret_cast<cmCursesWidget*>(
          field_userptr(this->Fields[findex - 2]));
        if (lbl) {
          this->CMakeInstance->GetState()->RemoveCacheEntry(lbl->GetValue());

          std::string nextVal;
          if (nextCur) {
            nextVal =
              (reinterpret_cast<cmCursesWidget*>(field_userptr(nextCur))
                 ->GetValue());
          }

          getmaxyx(stdscr, y, x);
          this->RemoveEntry(lbl->GetValue());
          this->RePost();
          this->Render(1, 1, x, y);

          if (nextCur) {
            // make the next or prev. current field after deletion
            auto nextEntryIt = std::find_if(
              this->Entries.begin(), this->Entries.end(),
              [&nextVal](cmCursesCacheEntryComposite const& entry) {
                return nextVal == entry.Key;
              });

            if (nextEntryIt != this->Entries.end()) {
              set_current_field(this->Form, nextEntryIt->Entry->Field);
            }
          }
        }
      }
    }

    touchwin(stdscr);
    wrefresh(stdscr);
  }
}

int cmCursesMainForm::LoadCache(const char* /*unused*/)

{
  int r = this->CMakeInstance->LoadCache();
  if (r < 0) {
    return r;
  }
  this->CMakeInstance->SetCacheArgs(this->Args);
  this->CMakeInstance->PreLoadCMakeFiles();
  return r;
}

void cmCursesMainForm::JumpToCacheEntry(const char* astr)
{
  std::string str;
  if (astr) {
    str = cmSystemTools::LowerCase(astr);
  }

  if (str.empty()) {
    return;
  }
  FIELD* cur = current_field(this->Form);
  int start_index = field_index(cur);
  int findex = start_index;
  for (;;) {
    if (!str.empty()) {
      cmCursesWidget* lbl = nullptr;
      if (findex >= 0) {
        lbl = reinterpret_cast<cmCursesWidget*>(
          field_userptr(this->Fields[findex - 2]));
      }
      if (lbl) {
        const char* curField = lbl->GetValue();
        if (curField) {
          std::string cfld = cmSystemTools::LowerCase(curField);
          if (cfld.find(str) != std::string::npos && findex != start_index) {
            break;
          }
        }
      }
    }
    if (size_t(findex) >= 3 * this->NumberOfVisibleEntries - 1) {
      set_current_field(this->Form, this->Fields[2]);
    } else if (new_page(this->Fields[findex + 1])) {
      form_driver(this->Form, REQ_NEXT_PAGE);
    } else {
      form_driver(this->Form, REQ_NEXT_FIELD);
    }
    cur = current_field(this->Form);
    findex = field_index(cur);
    if (findex == start_index) {
      break;
    }
  }
}

void cmCursesMainForm::ResetOutputs()
{
  this->LogForm.reset();
  this->Outputs.clear();
  this->HasNonStatusOutputs = false;
  this->LastProgress.clear();
}

void cmCursesMainForm::DisplayOutputs()
{
  int xi;
  int yi;
  getmaxyx(stdscr, yi, xi);

  auto newLogForm = new cmCursesLongMessageForm(
    this->Outputs, this->LastProgress.c_str(),
    cmCursesLongMessageForm::ScrollBehavior::ScrollDown);
  CurrentForm = newLogForm;
  this->LogForm.reset(newLogForm);
  this->LogForm->Render(1, 1, xi, yi);
}

const char* cmCursesMainForm::s_ConstHelpMessage =
  "CMake is used to configure and generate build files for software projects. "
  "The basic steps for configuring a project with ccmake are as follows:\n\n"
  "1. Run ccmake in the directory where you want the object and executable "
  "files to be placed (build directory). If the source directory is not the "
  "same as this build directory, you have to specify it as an argument on the "
  "command line.\n\n"
  "2. When ccmake is run, it will read the configuration files and display "
  "the current build options. "
  "If you have run CMake before and have updated the configuration files "
  "since then, any new entries will be displayed on top and will be marked "
  "with a *. "
  "On the other hand, the first time you run ccmake, all build options will "
  "be new and will be marked as such. "
  "At this point, you can modify any options (see keys below) you want to "
  "change. "
  "When you are satisfied with your changes, press 'c' to have CMake process "
  "the configuration files. "
  "Please note that changing some options may cause new ones to appear. These "
  "will be shown on top and will be marked with *. "
  "Repeat this procedure until you are satisfied with all the options and "
  "there are no new entries. "
  "At this point, a new command will appear: G)enerate and Exit. You can now "
  "hit 'g' to have CMake generate all the build files (i.e. makefiles or "
  "project files) and exit. "
  "At any point during the process, you can exit ccmake with 'q'. However, "
  "this will not generate/change any build files.\n\n"
  "ccmake KEYS:\n\n"
  "Navigation: "
  "You can use the arrow keys and page up, down to navigate the options. "
  "Alternatively, you can use the following keys: \n"
  " C-n or j : next option\n"
  " C-p or k : previous options\n"
  " C-d : down one page\n"
  " C-u : up one page\n\n"
  "Editing options: "
  "To change an option  press enter or return. If the current options is a "
  "boolean, this will toggle its value. "
  "Otherwise, ccmake will enter edit mode. Alternatively, you can toggle "
  "a bool variable by pressing space, and enter edit mode with i."
  "In this mode you can edit an option using arrow keys and backspace. "
  "Alternatively, you can use the following keys:\n"
  " C-b : back one character\n"
  " C-f : forward one character\n"
  " C-a : go to the beginning of the field\n"
  " C-e : go to the end of the field\n"
  " C-d : delete previous character\n"
  " C-k : kill the rest of the field\n"
  " Esc : Restore field (discard last changes)\n"
  " Enter : Leave edit mode\n"
  "Commands:\n"
  " q : quit ccmake without generating build files\n"
  " h : help, shows this screen\n"
  " c : process the configuration files with the current options\n"
  " g : generate build files and exit, only available when there are no "
  "new options and no errors have been detected during last configuration.\n"
  " l : shows cmake output\n"
  " d : delete an option\n"
  " t : toggles advanced mode. In normal mode, only the most important "
  "options are shown. In advanced mode, all options are shown. We recommend "
  "using normal mode unless you are an expert.\n"
  " / : search for a variable name.\n";