/*
 * Copyright © 2011  Google, Inc.
 *
 *  This is part of HarfBuzz, a text shaping library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Google Author(s): Behdad Esfahbod
 */

#ifndef OPTIONS_HH
#define OPTIONS_HH

#include "hb.hh"
#include "hb-map.hh"

#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <locale.h>
#include <errno.h>
#include <fcntl.h>
#if defined(_WIN32) || defined(__CYGWIN__)
#include <io.h> /* for setmode() under Windows */
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h> /* for isatty() */
#endif


#include <hb-features.h>
#include <hb.h>
#include <hb-ot.h>

#include <glib.h>
#include <glib/gprintf.h>


enum return_value_t
{
  RETURN_VALUE_SUCCESS = 0,
  RETURN_VALUE_OPTION_PARSING_FAILED = 1,
  RETURN_VALUE_FACE_LOAD_FAILED = 2,
  RETURN_VALUE_OPERATION_FAILED = 3,
  RETURN_VALUE_FONT_FUNCS_FAILED = 4,
} return_value = RETURN_VALUE_SUCCESS;

static inline void fail (hb_bool_t suggest_help, const char *format, ...) G_GNUC_NORETURN G_GNUC_PRINTF (2, 3);

static inline void
fail (hb_bool_t suggest_help, const char *format, ...)
{
  const char *msg;

  va_list vap;
  va_start (vap, format);
  msg = g_strdup_vprintf (format, vap);
  va_end (vap);
  const char *prgname = g_get_prgname ();
  g_printerr ("%s: %s\n", prgname, msg);
  if (suggest_help)
    g_printerr ("Try `%s --help' for more information.\n", prgname);

  if (return_value == RETURN_VALUE_SUCCESS)
    return_value = RETURN_VALUE_OPTION_PARSING_FAILED;

  exit (return_value);
}

struct option_parser_t
{
  option_parser_t (const char *parameter_string = nullptr)
  : context (g_option_context_new (parameter_string)),
    environs (g_ptr_array_new ()),
    exit_codes (g_ptr_array_new ()),
    to_free (g_ptr_array_new ())
  {}

  static void _g_free_g_func (void *p, void * G_GNUC_UNUSED) { g_free (p); }

  ~option_parser_t ()
  {
    g_ptr_array_free (exit_codes, TRUE);
    g_ptr_array_free (environs, TRUE);

    g_option_context_free (context);

    g_ptr_array_foreach (to_free, _g_free_g_func, nullptr);
    g_ptr_array_free (to_free, TRUE);
  }

  void add_options ();

  static void
  post_parse_ (void *thiz, GError **error) {}
  template <typename Type>
  static auto
  post_parse_ (Type *thiz, GError **error) -> decltype (thiz->post_parse (error))
  { thiz->post_parse (error); }
  template <typename Type>
  static gboolean
  post_parse (GOptionContext *context G_GNUC_UNUSED,
	      GOptionGroup *group G_GNUC_UNUSED,
	      gpointer data,
	      GError **error)
  {
    option_parser_t::post_parse_ (static_cast<Type *> (data), error);
    return !*error;
  }

  template <typename Type>
  void add_group (GOptionEntry   *entries,
		  const gchar    *name,
		  const gchar    *description,
		  const gchar    *help_description,
		  Type           *closure,
		  bool		  add_parse_hooks = true)
  {
    GOptionGroup *group = g_option_group_new (name, description, help_description,
					      static_cast<gpointer>(closure), nullptr);
    g_option_group_add_entries (group, entries);
    if (add_parse_hooks)
      g_option_group_set_parse_hooks (group, nullptr, post_parse<Type>);
    g_option_context_add_group (context, group);
  }

  template <typename Type>
  void add_main_group (GOptionEntry   *entries,
		       Type           *closure)
  {
    GOptionGroup *group = g_option_group_new (nullptr, nullptr, nullptr,
					      static_cast<gpointer>(closure), nullptr);
    g_option_group_add_entries (group, entries);
    /* https://gitlab.gnome.org/GNOME/glib/-/issues/2460 */
    //g_option_group_set_parse_hooks (group, nullptr, post_parse<Type>);
    g_option_context_set_main_group (context, group);
  }

  void set_summary (const char *summary)
  {
    g_option_context_set_summary (context, summary);
  }
  void set_description (const char *description_)
  {
    description = description_;
  }

  void set_full_description ()
  {
    GString *s = g_string_new (description);

    const char *env = getenv ("HB_UTIL_HELP_VERBOSE");
    bool verbose = env && atoi (env);
    if (verbose)
    {
      // Exit codes
      assert (exit_codes->len);
      g_string_append_printf (s, "\n\n*Exit Codes*\n");
      for (unsigned i = 0; i < exit_codes->len; i++)
	if (exit_codes->pdata[i])
	  g_string_append_printf (s, "\n  %u: %s\n", i, (const char *) exit_codes->pdata[i]);

      // Environment variables if any
      if (environs->len)
      {
	g_string_append_printf (s, "\n\n*Environment*\n");
	for (unsigned i = 0; i < environs->len; i++)
	{
	  g_string_append_printf (s, "\n  %s\n", (char *)environs->pdata[i]);
	}
      }

      // See also
      g_string_append_printf (s, "\n\n*See also*\n");
      g_string_append_printf (s, "  hb-view(1), hb-shape(1), hb-subset(1), hb-info(1)");
    }

    // Footer
    g_string_append_printf (s, "\n\nFind more information or report bugs at <https://github.com/harfbuzz/harfbuzz>\n");

    g_option_context_set_description (context, s->str);
    g_string_free (s, TRUE);
  }

  void add_environ (const char *environment)
  {
    g_ptr_array_add (environs, (void *) environment);
  }

  void add_exit_code (unsigned code, const char *description)
  {
    while (exit_codes->len <= code)
      g_ptr_array_add (exit_codes, nullptr);
    exit_codes->pdata[code] = (void *) description;
  }

  void free_later (char *p) {
    g_ptr_array_add (to_free, p);
  }

  bool parse (int *argc, char ***argv, bool ignore_error = false);

  GOptionContext *context;
  protected:
  const char *description = nullptr;
  GPtrArray *environs;
  GPtrArray *exit_codes;
  GPtrArray *to_free;
};

static G_GNUC_NORETURN gboolean
show_version (const char *name G_GNUC_UNUSED,
	      const char *arg G_GNUC_UNUSED,
	      gpointer    data G_GNUC_UNUSED,
	      GError    **error G_GNUC_UNUSED)
{
  g_printf ("%s (%s) %s\n", g_get_prgname (), PACKAGE_NAME, PACKAGE_VERSION);

  if (strcmp (HB_VERSION_STRING, hb_version_string ()))
    g_printf ("Linked HarfBuzz library has a different version: %s\n", hb_version_string ());

  exit(0);
}

inline void
option_parser_t::add_options ()
{
  GOptionEntry entries[] =
  {
    {"version",		0, G_OPTION_FLAG_NO_ARG,
			      G_OPTION_ARG_CALLBACK,	(gpointer) &show_version,	"Show version numbers",			nullptr},
    {nullptr}
  };
  g_option_context_add_main_entries (context, entries, nullptr);
}

inline bool
option_parser_t::parse (int *argc, char ***argv, bool ignore_error)
{
  setlocale (LC_ALL, "");

  add_exit_code (RETURN_VALUE_SUCCESS, "Success.");
  add_exit_code (RETURN_VALUE_OPTION_PARSING_FAILED, "Option parsing failed.");

  set_full_description ();

  GError *parse_error = nullptr;
  if (!g_option_context_parse (context, argc, argv, &parse_error))
  {
    if (parse_error)
    {
      if (!ignore_error)
	fail (true, "%s", parse_error->message);
      g_error_free (parse_error);
    }
    else
    {
      if (!ignore_error)
	fail (true, "Option parse error");
    }
    return false;
  }
  return true;
}


/* fallback implementation for scalbn()/scalbnf() for pre-2013 MSVC */
#if defined (_MSC_VER) && (_MSC_VER < 1800)

#ifndef FLT_RADIX
#define FLT_RADIX 2
#endif

__inline long double scalbn (long double x, int exp)
{
  return x * (pow ((long double) FLT_RADIX, exp));
}

__inline float scalbnf (float x, int exp)
{
  return x * (pow ((float) FLT_RADIX, exp));
}
#endif

static inline bool
parse_color (const char *s,
	     unsigned &r,
	     unsigned &g,
	     unsigned &b,
	     unsigned &a)
{
  bool ret = false;

  while (*s == ' ') s++;
  if (*s == '#') s++;

  unsigned sr, sg, sb, sa;
  sa = 255;
  if (sscanf (s, "%2x%2x%2x%2x", &sr, &sg, &sb, &sa) <= 2)
  {
    if (sscanf (s, "%1x%1x%1x%1x", &sr, &sg, &sb, &sa) >= 3)
    {
      sr *= 17;
      sg *= 17;
      sb *= 17;
      sa *= 17;
      ret = true;
    }
  }
  else
    ret = true;

  if (ret)
  {
    r = sr;
    g = sg;
    b = sb;
    a = sa;
  }

  return ret;
}


#endif