/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 2003 Free Software Foundation, Inc.

   GNU Mailutils 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, or (at your option)
   any later version.

   GNU Mailutils 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 GNU Mailutils; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301 USA */

#include <mh.h>

typedef int (*handler_fp) __PMT((struct mh_whatnow_env *wh,
				 int argc, char **argv,
				 int *status));

/* ********************* Auxiliary functions *********************** */
/* Auxiliary function for option comparisons */
static char
strnulcmp (const char *str, const char *pattern)
{
  return strncmp (str, pattern, strlen (str));
}

/* Dispatcher functions */

struct action_tab {
  char *name;
  handler_fp fp;
};

static handler_fp
func (struct action_tab *p, const char *name)
{
  int len;
  
  if (!name)
    return func (p, "help");

  len = strlen (name);
  for (; p->name; p++)
    {
      int min = strlen (p->name);
      if (min > len)
	min = len;
      if (strncmp (p->name, name, min) == 0)
	return p->fp;
    }

  mh_error (_("%s is unknown. Hit <CR> for help"), name);
  return NULL;
}

struct helpdata {
  char *name;
  char *descr;
};

/* Functions for printing help information */

#define OPT_DOC_COL  29		/* column in which option text starts */
#define RMARGIN      79		/* right margin used for wrapping */

static int
print_short (const char *str)
{
  int n;
  char *s;
  
  for (n = 0; *str; str++, n++)
    {
      switch (*str)
	{
	case '+':
	  putchar ('+');
	  s = _("FOLDER");
	  n += printf ("%s", s);
	  break;

	case '<':
	  switch (str[1]) 
	    {
	    case '>':
	      s = _("SWITCHES");
	      n += printf ("%s", s) - 1;
	      str++;
	      break;
	      
	    case 'e':
	      s = _("EDITOR");
	      n += printf ("%s", s) - 1;
	      str++;
	      break;

	    default:
	      putchar (*str);
	    }
	  break;

	default:
	  putchar (*str);
	}
    }
  return n;
}

static void
print_descr (int n, char *s)
{
  do
    {
      char *p;
      char *space = NULL;
      
      for (; n < OPT_DOC_COL; n++)
	putchar (' ');

      for (p = s; *p && p < s + (RMARGIN - OPT_DOC_COL); p++)
	if (isspace (*p))
	  space = p;
      
      if (!space || p < s + (RMARGIN - OPT_DOC_COL))
	{
	  printf ("%s", s);
	  s += strlen (s);
	}
      else
	{
	  for (; s < space; s++)
	    putchar (*s);
	  for (; *s && isspace (*s); s++)
	    ;
	}
      putchar ('\n');
      n = 1;
    }
  while (*s);
}

static int
_help (struct helpdata *helpdata, char *argname)
{
  struct helpdata *p;

  printf ("%s\n", _("Options are:"));
  if (argname == NULL || argname[0] == '?')
    {
      /* Short version */
      for (p = helpdata; p->name; p++)
	{
	  printf ("  ");
	  print_short (p->name);
	  putchar ('\n');
	}
    }
  else
    {
      for (p = helpdata; p->name; p++)
	{
	  int n;
	  
	  n = printf ("  ");
	  n += print_short (p->name);

	  print_descr (n+1, _(p->descr));
	}
    }
  return 0;
}

/* Display the contents of the given file on the terminal */
static void
display_file (const char *name)
{
  char *pager = mh_global_profile_get ("moreproc", getenv ("PAGER"));

  if (pager)
    mh_spawnp (pager, name);
  else
    {
      stream_t stream;
      int rc;
      size_t off = 0;
      size_t n;
      char buffer[512];
      
      rc = file_stream_create (&stream, name, MU_STREAM_READ);
      if (rc)
	{
	  mh_error ("file_stream_create: %s", mu_strerror (rc));
	  return;
	}
      rc = stream_open (stream);
      if (rc)
	{
	  mh_error ("stream_open: %s", mu_strerror (rc));
	  return;
	} 
      
      while (stream_read (stream, buffer, sizeof buffer - 1, off, &n) == 0
	     && n != 0)
	{
	  buffer[n] = '\0';
	  printf ("%s", buffer);
	  off += n;
	}
      stream_destroy (&stream, NULL);
    }
}      

static int
invoke (char *compname, char *defval, int argc, char **argv,
	char *extra0, char *extra1, int *status)
{
  int i, rc;
  char **xargv;
  char *progname;

  progname = mh_global_profile_get (compname, defval);
  if (!progname)
    return -1;
  
  xargv = calloc (argc+3, sizeof (*xargv));
  if (!xargv)
    {
      mh_err_memory (0);
      return -1;
    }

  xargv[0] = progname;
  for (i = 1; i < argc; i++)
    xargv[i] = argv[i];
  if (extra0)
    xargv[i++] = extra0;
  if (extra1)
    xargv[i++] = extra1;
  xargv[i++] = NULL;
  rc = mu_spawnvp (xargv[0], (const char **) xargv, status);
  free (xargv);
  return rc;
}


/* ************************ Shell Function ************************* */

static int
_whatnow (struct mh_whatnow_env *wh, struct action_tab *tab)
{
  int rc, status = 0;
  
  do
    {
      char *line = NULL;
      size_t size = 0;
      int argc;
      char **argv;
      handler_fp fun;
      
      printf ("%s ", wh->prompt);
      getline (&line, &size, stdin);
      if (!line)
	continue;
      rc = argcv_get (line, "", "#", &argc, &argv);
      free (line);
      if (rc)
	{
	  argcv_free (argc, argv);
	  break;
	}

      fun = func (tab, argv[0]);
      if (fun)
	rc = fun (wh, argc, argv, &status);
      else
	rc = 0;
      argcv_free (argc, argv);
    }
  while (rc == 0);
  return status;
}


/* ************************** Actions ****************************** */

/* Display action */
static int
display (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  if (!wh->msg)
    mh_error (_("no alternate message to display"));
  else
    display_file (wh->msg);
  return 0;
}

/* Edit action */
static int
edit (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  char *name;
  int rc;
  
  asprintf (&name, "%s-next", wh->editor);
  invoke (name, wh->editor, argc, argv, wh->file, NULL, &rc);
  free (name);
  
  return 0;
}

/* List action */
static int
list (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  if (!wh->file)
    mh_error (_("no draft file to display"));
  else
    display_file (wh->file);
  return 0;
}

/* Push action */
static int
push (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  int rc;
  invoke ("sendproc", MHBINDIR "/send", argc, argv, "-push", wh->file, &rc);
  return 0;
}

/* Quit action */
static int
quit (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  *status = 0;

  if (wh->draftfile)
    {
      if (argc == 2 && strnulcmp (argv[1], "-delete") == 0)
	unlink (wh->draftfile);
      else
	{
	  printf (_("draft left on \"%s\".\n"), wh->draftfile);
	  rename (wh->file, wh->draftfile);
	}
    }

  return 1;
}

/* Refile action */
static int
refile (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  int rc;
  invoke ("fileproc", MHBINDIR "/refile", argc, argv, "-file", wh->file, &rc);
  return 0;
}

/* Send action */
static int
send (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  int rc;
  invoke ("sendproc", MHBINDIR "/send", argc, argv, wh->file, NULL, &rc);
  return 0;
}

/* Whom action */
static int
whom (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  if (!wh->file)
    mh_error (_("no draft file to display"));
  else
    mh_whom (wh->file, (argc == 2
			&& (strcmp (argv[1], "-check") == 0
			    || strcmp (argv[1], "--check") == 0)));
  return 0;
}

/* Help table for whatnow */
static struct helpdata whatnow_helptab[] = {
  { "display [<>]",
    N_("List the message being distributed/replied-to on the terminal.") },
  { "edit [<e <>]",
    N_("Edit the message. If EDITOR is omitted use the one that was used on"
       " the preceeding round unless the profile entry \"LASTEDITOR-next\""
       " names an alternate editor.") },
  { "list [<>]",
    N_("List the draft on the terminal.") },
  { "push [<>]",
    N_("Send the message in the background.") },
  { "quit [-delete]",
    N_("Terminate the session. Preserve the draft, unless -delete flag is given.") },
  { "refile [<>] +",
    N_("Refile the draft into the given FOLDER.") },
  { "send [-watch] [<>]",
    N_("Send the message. The -watch flag causes the delivery process to be "
       "monitored. SWITCHES are passed to send program verbatim.") },
  { "whom [-check] [<>]",
    N_("List the addresses and verify that they are acceptable to the "
       "transport service.") },
  { NULL },
};

/* Help action for whatnow shell */
static int
whatnow_help (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  return _help (whatnow_helptab, argv[0]);
}

/* Actions specific for the ``disposition'' shell */

/* Help table for ``disposition'' shell */
static struct helpdata disposition_helptab[] = {
  { "quit",           N_("Terminate the session. Preserve the draft.") },
  { "replace",        N_("Replace the draft with the newly created one") },
  { "use",            N_("Use this draft") },
  { "list",           N_("List the draft on the terminal.") },
  { "refile [<>] +",  N_("Refile the draft into the given FOLDER.") },
  { NULL },
};

/* Help action */
static int
disp_help (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  return _help (disposition_helptab, argv[0]);
}

/* Use action */
static int
use (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  *status = DISP_USE;
  return 1;
}

/* Replace action */
static int
replace (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  *status = DISP_REPLACE;
  return 1;
}


/* *********************** Interfaces ****************************** */

/* Whatnow shell */
static struct action_tab whatnow_tab[] = {
  { "help", whatnow_help },
  { "?", whatnow_help },
  { "display", display },
  { "edit", edit },
  { "list", list },
  { "push", push },
  { "quit", quit },
  { "refile", refile },
  { "send", send },
  { "whom", whom },
  { NULL }
};

int
mh_whatnow (struct mh_whatnow_env *wh, int initial_edit)
{
  if (!wh->editor)
    wh->editor = mh_global_profile_get ("Editor", "prompter");
  
  if (initial_edit)
    mh_spawnp (wh->editor, wh->file);

  if (!wh->prompt)
    wh->prompt = _("What now?");
  
  return _whatnow (wh, whatnow_tab);
}

/* Disposition shell */
static struct action_tab disp_tab[] = {
  { "help", disp_help },
  { "?", disp_help },
  { "quit", quit },
  { "replace", replace },
  { "use", use },
  { "list", list },
  { "refile",  refile },
  { NULL }
};
    
int
mh_disposition (const char *filename)
{
  struct mh_whatnow_env wh;

  memset (&wh, 0, sizeof (wh));
  wh.file = filename;
  wh.prompt = _("Disposition?");
  return _whatnow (&wh, disp_tab);
}

/* Use draft shell */

/* Help table for ``use draft'' shell */
static struct helpdata usedraft_helptab[] = {
  { "no",             N_("Don't use the draft.") },
  { "yes",            N_("Use the draft.") },
  { "list",           N_("List the draft on the terminal.") },
  { NULL },
};

static int
usedraft_help (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  return _help (usedraft_helptab, argv[0]);
}

static int
yes (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  *status = 1;
  return 1;
}

static int
no (struct mh_whatnow_env *wh, int argc, char **argv, int *status)
{
  *status = 0;
  return 1;
}

static struct action_tab usedraft_tab[] = {
  { "help", usedraft_help },
  { "?", usedraft_help },
  { "yes", yes },
  { "no", no },
  { "list", list },
  { NULL }
};

int
mh_usedraft (const char *filename)
{
  struct mh_whatnow_env wh;
  int rc;
  
  memset (&wh, 0, sizeof (wh));
  wh.file = filename;
  asprintf (&wh.prompt, _("Use \"%s\"?"), filename);
  rc = _whatnow (&wh, usedraft_tab);
  free (wh.prompt);
  return rc;
}