//
// Main demo program for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2020 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

/*
  General information on directory structure and file handling.

  The "classic" autotools/make system creates executables in their source
  folders, i.e. fluid/fluid, test/demo and test/xyz, resp.. The menu file is
  in folder test/, as is the main demo(.exe) program. In the following text
  and directory lists all test and demo executables are represented by "demo"
  and the fluid executable by "fluid", no matter what OS (under Windows: *.exe).

  The CMake build system generates all executables in the build tree and copies
  the supporting test data files to the build tree as well. This structure is
  different and needs to be handled separately in this program.

  Additionally, different OS platforms create different types of files, for
  instance "app bundles" on macOS. All this needs to be considered.

  The overall structure, relative to the FLTK source dir (fltk) and the build
  tree (build):

  (1) Autotools / Make:

    fltk/fluid              fluid (../fluid/fluid)
    fltk/test               demo, demo.menu, working directory, data files
    fltk/documentation/src  images for help_dialog(.html)

  (2) CMake + make (e.g. Unix)

    build/bin               fluid, demo
    build/data              demo.menu, working directory, data files

  (3) CMake + Visual Studio (TYPE == build type: Debug, Release, ...)

    build/bin/TYPE          fluid, demo
    build/data              demo.menu, working directory, data files

  (4) macOS                 The setup is similar to Windows and Linux:
                            Makefiles: like (1) or (2)
                            Xcode: like (3), i.e. similar to VS layout

  The built executable 'demo' can also be executed with the menu filename
  as commandline argument. In this case all the support (data) files are
  expected to be in the same directory as the menu file or relative paths
  as needed by the test programs, for instance help_dialog which needs
  help_dialog.html and related image files.
*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

#if defined __APPLE__
#include <ApplicationServices/ApplicationServices.h>
#endif

#include <FL/Fl.H>
#include <FL/Fl_Double_Window.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Menu_Button.H> // right click popup menu
#include <FL/Fl_Choice.H>
#include <FL/Fl_Simple_Terminal.H> // tty
#include <FL/filename.H>
#include <FL/platform.H>
#include <FL/fl_ask.H> // fl_alert()
#include <FL/fl_utf8.h> // fl_getcwd()

#define FORM_W 350
#define FORM_H 440
#define TTY_W  int(FORM_W*2.5)
#define TTY_H  200

/* The form description */

void doexit(Fl_Widget *, void *);
void doback(Fl_Widget *, void *);
void dobut(Fl_Widget *, long);
void doscheme(Fl_Choice *c, void *) {
  Fl::scheme(c->text(c->value()));
}

Fl_Double_Window *form = 0;
Fl_Group *demogrp = 0;
Fl_Simple_Terminal *tty = 0;
Fl_Button *but[9];

// Allocate space to edit commands and arguments from demo.menu.
// We "trust demo.menu" that strings don't overflow

char cmdbuf[256];           // commandline w/o arguments
char params[256];           // commandline arguments

// Global path variables for all platforms and build systems
// to avoid duplication and dynamic allocation

char src_path   [FL_PATH_MAX];          // directory of this souce file
char app_path   [FL_PATH_MAX];          // directory of all demo binaries
char fluid_path [FL_PATH_MAX];          // binary directory of fluid
char data_path  [FL_PATH_MAX];          // working directory of all demos
char command    [2 * FL_PATH_MAX + 40]; // command to be executed

// platform specific suffix for executable files

#ifdef _WIN32
const char *suffix = ".exe";
#elif defined __APPLE__
const char *suffix = ".app";
#else
const char *suffix = "";
#endif

// debug output function
void debug_var(const char *varname, const char *value) {
  tty->printf("%-10s = '%s'\n", varname, value);
}

// Show or hide the tty window
void show_tty(int val) {
  if ( val ) {
    form->size_range(FORM_W,FORM_H+TTY_H,0,0); // allow resizing
    form->size(TTY_W,FORM_H+TTY_H);         // demo + height for tty
    demogrp->size(FORM_W,FORM_H);
    tty->show();                               // show tty
    tty->resize(0, FORM_H, TTY_W, TTY_H);      // force tty position
  } else {
    form->size_range(FORM_W,FORM_H,FORM_W,FORM_H);  // no resizing
    tty->hide();                               // hide tty
    form->size(FORM_W, FORM_H);                // normal demo size
  }
  demogrp->size(FORM_W, FORM_H);
  form->init_sizes();
}

// Right click popup menu handler
void popup_menu_cb(Fl_Widget*, void *userdata) {
  const char *cmd = (const char*)userdata;
  if ( strcmp(cmd, "showtty")==0 ) { show_tty(1); }
  if ( strcmp(cmd, "hidetty")==0 ) { show_tty(0); }
}

void create_the_forms() {
  Fl_Widget *obj;
  Fl_Menu_Button *popup;
  form = new Fl_Double_Window(FORM_W,FORM_H);
  form->size_range(FORM_W,FORM_H,FORM_W+1,FORM_H+1); // XXX: +1 needed or window can't be made resizable later
  // Small terminal window parented to window, not demogrp
  tty = new Fl_Simple_Terminal(0, form->h(), form->w(), form->h());
  tty->history_lines(50);
  tty->ansi(true);
  tty->hide();
  tty->textsize(10);
  // Parent group for demo
  demogrp = new Fl_Group(0,0,FORM_W,FORM_H);
  demogrp->resizable(0);
  demogrp->begin();
  // Demo
  obj = new Fl_Box(FL_FRAME_BOX,10,15,330,40,"FLTK Demonstration");
  obj->color(FL_GRAY-4);
  obj->labelsize(24);
  obj->labelfont(FL_BOLD);
  obj->labeltype(FL_ENGRAVED_LABEL);
  obj = new Fl_Box(FL_FRAME_BOX,10,65,330,330,0);
  obj->color(FL_GRAY-8);
  obj = new Fl_Button(280,405,60,25,"Exit");
  obj->callback(doexit);
  Fl_Choice *choice = new Fl_Choice(75, 405, 100, 25, "Scheme:");
  choice->labelfont(FL_HELVETICA_BOLD);
  choice->add("none");
  choice->add("gtk+");
  choice->add("gleam");
  choice->add("plastic");
  choice->callback((Fl_Callback *)doscheme);
  Fl::scheme(NULL);
  if (!Fl::scheme()) choice->value(0);
  else if (!strcmp(Fl::scheme(), "gtk+")) choice->value(1);
  else if (!strcmp(Fl::scheme(), "gleam")) choice->value(2);
  else if (!strcmp(Fl::scheme(), "plastic")) choice->value(3);
  else choice->value(0);
  obj = new Fl_Button(10,15,330,380); obj->type(FL_HIDDEN_BUTTON);
  obj->callback(doback);
  obj = but[0] = new Fl_Button( 30, 85,90,90);
  obj = but[1] = new Fl_Button(130, 85,90,90);
  obj = but[2] = new Fl_Button(230, 85,90,90);
  obj = but[3] = new Fl_Button( 30,185,90,90);
  obj = but[4] = new Fl_Button(130,185,90,90);
  obj = but[5] = new Fl_Button(230,185,90,90);
  obj = but[6] = new Fl_Button( 30,285,90,90);
  obj = but[7] = new Fl_Button(130,285,90,90);
  obj = but[8] = new Fl_Button(230,285,90,90);
  for (int i=0; i<9; i++) {
    but[i]->align(FL_ALIGN_WRAP);
    but[i]->callback(dobut, i);
  }
  demogrp->end();
  // Right click popup menu
  popup = new Fl_Menu_Button(0,0,FORM_W,FORM_H);
  popup->box(FL_NO_BOX);
  popup->type(Fl_Menu_Button::POPUP3); // pop menu on right-click
  popup->add("Show debug terminal", 0, popup_menu_cb, (void*)"showtty");
  popup->add("Hide debug terminal", 0, popup_menu_cb, (void*)"hidetty");
  // End window
  form->end();
  form->resizable(tty);
}

/* Maintaining and building up the menus. */

typedef struct {
  char name[64];
  int numb;
  char iname[9][64];
  char icommand[9][64];
} MENU;

#define MAXMENU 32

MENU menus[MAXMENU];
int mennumb = 0;

/* Return the number of a given menu name. */
int find_menu(const char* nnn) {
  int i;
  for (i=0; i<mennumb; i++)
    if (strcmp(menus[i].name,nnn) == 0) return i;
  return -1;
}

/* Create a new menu with name nnn */
void create_menu(const char* nnn) {
  if (mennumb == MAXMENU -1) return;
  strcpy(menus[mennumb].name,nnn);
  menus[mennumb].numb = 0;
  mennumb++;
}

/* Add an item to a menu */
void addto_menu(const char* men, const char* item, const char* comm) {
  int n = find_menu(men);
  if (n<0) { create_menu(men); n = find_menu(men); }
  if (menus[n].numb == 9) return;
  strcpy(menus[n].iname[menus[n].numb],item);
  strcpy(menus[n].icommand[menus[n].numb],comm);
  menus[n].numb++;
}

/* Button to Item conversion and back. */

int b2n[][9] = {
        { -1, -1, -1, -1,  0, -1, -1, -1, -1},
        { -1, -1, -1,  0, -1,  1, -1, -1, -1},
        {  0, -1, -1, -1,  1, -1, -1, -1,  2},
        {  0, -1,  1, -1, -1, -1,  2, -1,  3},
        {  0, -1,  1, -1,  2, -1,  3, -1,  4},
        {  0, -1,  1,  2, -1,  3,  4, -1,  5},
        {  0, -1,  1,  2,  3,  4,  5, -1,  6},
        {  0,  1,  2,  3, -1,  4,  5,  6,  7},
        {  0,  1,  2,  3,  4,  5,  6,  7,  8}
};
int n2b[][9] = {
        {  4, -1, -1, -1, -1, -1, -1, -1, -1},
        {  3,  5, -1, -1, -1, -1, -1, -1, -1},
        {  0,  4,  8, -1, -1, -1, -1, -1, -1},
        {  0,  2,  6,  8, -1, -1, -1, -1, -1},
        {  0,  2,  4,  6,  8, -1, -1, -1, -1},
        {  0,  2,  3,  5,  6,  8, -1, -1, -1},
        {  0,  2,  3,  4,  5,  6,  8, -1, -1},
        {  0,  1,  2,  3,  5,  6,  7,  8, -1},
        {  0,  1,  2,  3,  4,  5,  6,  7,  8}
};

/* Transform a button number to an item number when there are
  maxnumb items in total. -1 if the button should not exist. */
int but2numb(int bnumb, int maxnumb)
{ return b2n[maxnumb][bnumb]; }

/* Transform an item number to a button number when there are
  maxnumb items in total. -1 if the item should not exist. */
int numb2but(int inumb, int maxnumb)
{ return n2b[maxnumb][inumb]; }

/* Pushing and Popping menus */

char stack[64][32];
int stsize = 0;

/* Push a menu to be visible */
void push_menu(const char* nnn) {
  int n,i,bn;
  int men = find_menu(nnn);
  if (men < 0) return;
  n = menus[men].numb;
  for (i=0; i<9; i++) but[i]->hide();
  for (i=0; i<n; i++)
  {
    bn = numb2but(i,n-1);
    but[bn]->show();
    but[bn]->label(menus[men].iname[i]);
    if (menus[men].icommand[i][0] != '@') but[bn]->tooltip(menus[men].icommand[i]);
    else but[bn]->tooltip(0);
  }
  if (stack[stsize]!=nnn)
    strcpy(stack[stsize],nnn);
  stsize++;
}

/* Pop a menu */
void pop_menu() {
  if (stsize<=1) return;
  stsize -= 2;
  push_menu(stack[stsize]);
}

/* The callback Routines */

/* Handle a button push */
void dobut(Fl_Widget *, long arg) {
  int men = find_menu(stack[stsize-1]);
  int n = menus[men].numb;
  int bn = but2numb( (int) arg, n-1);

  // menu ?

  if (menus[men].icommand[bn][0] == '@') {
    push_menu(menus[men].icommand[bn]);
    return;
  }

  // not a menu: run test/demo/fluid executable
  // find and separate "command" and "params"

  // skip leading spaces in command
  char *start_command = menus[men].icommand[bn];
  while (*start_command == ' ') ++start_command;

  strcpy(cmdbuf, start_command); // here still full command w/params

  // find the space between the command and parameters if one exists
  char *start_params = strchr(cmdbuf, ' ');
  if (start_params) {
    *start_params = '\0';         // terminate command
    start_params++;               // skip space
    strcpy(params, start_params); // copy parameters
  } else {
    params[0] = '\0';             // empty string
  }

  // select application path: either app_path or fluid_path

  const char *path = app_path;
  if (!strncmp(cmdbuf, "fluid", 5))
    path = fluid_path;

  // format commandline with optional parameters

#if defined(__APPLE__) // macOS

  if (params[0]) {
    // we assume that we have only one argument which is a filename in 'data_path'
    sprintf(command, "open '%s/%s%s' --args '%s/%s'", path, cmdbuf, suffix, data_path, params);
  } else {
    sprintf(command, "open '%s/%s%s'", path, cmdbuf, suffix);
  }

#else // other platforms

  if (params[0])
    sprintf(command, "%s/%s%s %s", path, cmdbuf, suffix, params);
  else
    sprintf(command, "%s/%s%s", path, cmdbuf, suffix);

#endif

  // finally, execute program (the system specific part)

#ifdef _WIN32

  STARTUPINFO         suInfo;         // Process startup information
  PROCESS_INFORMATION prInfo;         // Process information

  memset(&suInfo, 0, sizeof(suInfo));
  suInfo.cb = sizeof(suInfo);

  debug_var("Command", command);

  BOOL stat = CreateProcess(NULL, command, NULL, NULL, FALSE,
                            NORMAL_PRIORITY_CLASS, NULL,
                            NULL, &suInfo, &prInfo);
  if (!stat) {
    DWORD err = GetLastError();
    fl_alert("Error starting process, error #%d\n'%s'", err, command);
  }

#elif defined __APPLE__

  debug_var("Command", command);

  system(command);

#else // other platforms (Unix, Linux)

  strcat(command, " &"); // run in background

  debug_var("Command", command);

  if (system(command) == -1) {
    fl_alert("Could not start program, errno = %d\n'%s'", errno, command);
  }

#endif // _WIN32

}

void doback(Fl_Widget *, void *) {pop_menu();}

void doexit(Fl_Widget *, void *) {exit(0);}

/*
  Load the menu file. Returns whether successful.
*/
int load_the_menu(char *menu) {
  FILE *fin = 0;
  char line[256], mname[64],iname[64],cname[64];
  int i, j;

  fin = fl_fopen(menu, "r");

  if (fin == NULL)
    return 0;

  for (;;) {
    if (fgets(line,256,fin) == NULL) break;
    // remove all carriage returns that Cygwin may have inserted
    char *s = line, *d = line;
    for (;;++d) {
      while (*s=='\r') s++;
      *d = *s++;
      if (!*d) break;
    }
    // interpret the line
    j = 0; i = 0;
    while (line[i] == ' ' || line[i] == '\t') i++;
    if (line[i] == '\n') continue;
    if (line[i] == '#') continue;
    while (line[i] != ':' && line[i] != '\n') mname[j++] = line[i++];
    mname[j] = '\0';
    if (line[i] == ':') i++;
    j = 0;
    while (line[i] != ':' && line[i] != '\n') {
      if (line[i] == '\\') {
        i++;
        if (line[i] == 'n') iname[j++] = '\n';
        else iname[j++] = line[i];
        i++;
      } else
        iname[j++] = line[i++];
    }
    iname[j] = '\0';
    if (line[i] == ':') i++;
    j = 0;
    while (line[i] != ':' && line[i] != '\n') cname[j++] = line[i++];
    cname[j] = '\0';
    addto_menu(mname,iname,cname);
  }
  fclose(fin);
  return 1;
}

// Fix '\' in Windows paths (convert to '/') and cut off filename (optional, default)
void fix_path(char *path, int strip_filename = 1) {
  if (!path[0])
    return;
#ifdef _WIN32 // convert '\' to '/'
  char *p = path;
  while (*p) {
    if (*p == '\\')
      *p = '/';
    p++;
  }
#endif // _WIN32
  if (strip_filename) {
    char *pos = strrchr(path, '/');
    if (pos)
      *pos = 0;
  }
}

int main(int argc, char **argv) {

  fl_putenv("FLTK_DOCDIR=../documentation/html"); // not sure if this is needed

  char menu[FL_PATH_MAX];

  // construct app_path for all executable files

  fl_filename_absolute(app_path, sizeof(app_path), argv[0]);
#ifdef __APPLE__
    char *q = strstr(app_path, "/Contents/MacOS/");
    if (q) *q = 0;
#endif
  fix_path(app_path);

  // construct src_path in case we want to use it (macOS ?)

#if defined(GENERATED_BY_CMAKE)
  strcpy(src_path, CMAKE_SOURCE_PATH);
#else
  strcpy(src_path, app_path);
#endif
  fix_path(src_path, 0);

  // fluid's path is the same for CMake builds but not for autoconf/make

  strcpy(fluid_path, app_path);

#if !defined(GENERATED_BY_CMAKE)
  fix_path(fluid_path); // removes folder name (test)
  strcat(fluid_path, "/fluid");
#endif

  // construct data_path for the menu file and all resources (data files)
  // CMake: replace "/bin/*"" with "/data"
  // autotools: use app_path directly

  strcpy(data_path, app_path);

#if defined(GENERATED_BY_CMAKE)
  {
    char *pos = strstr(data_path, "/bin");
    if (pos)
      strcpy(pos, "/data");
  }
#endif

  // construct the menu file name, optionally overridden by command args
  // CMake: use data_path instead of app_path

  const char *fn = fl_filename_name(argv[0]);

#if defined(GENERATED_BY_CMAKE)
  strcpy(menu, data_path);
#else
  strcpy(menu, app_path);
#endif

  // append "/<exe-file-name>.menu"
  strcat(menu, "/");
  strcat(menu, fn);
  fl_filename_setext(menu, sizeof(menu), ".menu");

  // parse commandline

  int i = 0;
  if (!Fl::args(argc,argv,i) || i < argc-1)
    Fl::fatal("Usage: %s <switches> <menufile>\n%s", argv[0], Fl::help);
  if (i < argc) {
    // override menu file *and* data path !
    fl_filename_absolute(menu, sizeof(menu), (const char *)argv[i]);
    strcpy(data_path, menu);
    fix_path(data_path);
  }

  // set current work directory to 'app_path'

  if (fl_chdir(data_path) == -1) { /* ignore */ }

  // Create forms first
  //    tty needs to exist before we can print debug msgs
  //
  create_the_forms();

  {
    char cwd[1024];
    debug_var("src_path",   src_path);
    debug_var("app_path",   app_path);
    debug_var("fluid_path", fluid_path);
    debug_var("data_path",  data_path);
    debug_var("Menu file",  menu);
    debug_var("Cwd",        fl_getcwd(cwd,sizeof(cwd)));
    tty->printf("\n");
  }

  // note: load_the_menu() *may* change the `menu` buffer contents !
  if (!load_the_menu(menu))
    Fl::fatal("Can't open %s", menu);

  push_menu("@main");
  form->show(argc,argv);
  Fl::run();
  return 0;
}