/*******************************************************************/
/*                                                                 */
/*                 INTERFACE TO READLINE COMPLETION                */
/*                                                                 */
/*******************************************************************/
/* $Id: gp_rl.c,v 1.2 1999/09/20 16:39:33 karim Exp $ */
#include "pari.h"
#include "../language/anal.h"
#include "gp.h"

#ifdef READLINE
typedef char** (*CF)(char*, char* (*)()); /* completion function */
typedef char* (*GF)(char*, int); /* generator function */
typedef int (*RLCI)(int, int); /* rl_complete and rl_insert functions */

BEGINEXTERN
#ifdef HAS_RL_MESSAGE
#  define USE_VARARGS
#  define PREFER_STDARG
#endif
#ifdef READLINE_LIBRARY
#  include <readline.h>
#else
#  include <readline/readline.h>
#endif
#ifndef HAS_RL_MESSAGE
extern int rl_message (const char *, ...);
extern int rl_clear_message();
extern int rl_begin_undo_group(), rl_end_undo_group();
extern int rl_read_key();
extern int rl_stuff_char();
extern char *filename_completion_function(char *text,int state);
extern char *username_completion_function(char *text,int state);
#endif
char **pari_completion(char *text, int start, int end);
extern int rl_completion_query_items;
extern int rl_bind_key_in_map();
ENDEXTERN

void print_fun_list(char **matches, int nbli);
void aide(char *s, int flag);

extern default_type gp_default_list[];
extern char *keyword_list[];
static int add_help_keywords;
static entree *current_ep = NULL;

static int pari_rl_back;
extern RLCI rl_last_func;
static int do_args_complete = 1;
static int do_matched_insert = 0;
static int did_init_matched = 0;

#ifdef HAS_RL_SAVE_PROMPT
#  define SAVE_PROMPT() rl_save_prompt()
#  define RESTORE_PROMPT() rl_restore_prompt()
#else
#  ifdef HAS_UNDERSCORE_RL_SAVE_PROMPT
#    define SAVE_PROMPT() _rl_save_prompt()
#    define RESTORE_PROMPT() _rl_restore_prompt()
#  else
#    define SAVE_PROMPT()
#    define RESTORE_PROMPT()
#  endif
#endif

#define ELECTRIC_PAREN 1
#define ARGS_COMPLETE  2
static int
change_state(char *msg, int *opt, int count)
{
  int c;

  switch(count)
  {
    case  0: c = 0; break; /* off */
    case -1: c = 1; break; /* on  */
    case -2: c = 1 - *opt; /* toggle */
  }
  *opt = c;
  SAVE_PROMPT();
  rl_message("%s: %s.", (long)msg, (long)(c? "on": "off"));
  c = rl_read_key();
  RESTORE_PROMPT();
  rl_clear_message();
  rl_stuff_char(c); return 1;
}

/* Wrapper around rl_complete to allow insertion of () with a point in
   between. */
static int
pari_rl_complete(int count, int key)
{
  int ret;

  pari_rl_back = 0;
  if (count <= 0)
    return change_state("complete args", &do_args_complete, count);

  rl_begin_undo_group();
  if (rl_last_func == pari_rl_complete)
    rl_last_func = (RLCI) rl_complete; /* Make repeated TABs different */
  ret = ((RLCI)rl_complete)(count,key);
  if (pari_rl_back && (pari_rl_back <= rl_point))
    rl_point -= pari_rl_back;
  rl_end_undo_group(); return ret;
}

static const char paropen[] = "([{";
static const char parclose[] = ")]}";

/* To allow insertion of () with a point in between. */
static int
pari_rl_matched_insert(int count, int key)
{
  int i = 0, ret;

  if (count <= 0)
    return change_state("electric parens", &do_matched_insert, count);
  while (paropen[i] && paropen[i] != key) i++;
  if (!paropen[i] || !do_matched_insert || under_emacs)
    return ((RLCI)rl_insert)(count,key);
  rl_begin_undo_group();
  ((RLCI)rl_insert)(count,key);
  ret = ((RLCI)rl_insert)(count,parclose[i]);
  rl_point -= count;
  rl_end_undo_group(); return ret;
}

static int
pari_rl_default_matched_insert(int count, int key)
{
    if (!did_init_matched) {
	did_init_matched = 1;
	do_matched_insert = 1;
    }
    return pari_rl_matched_insert(count, key);
}

static int
pari_rl_forward_sexp(int count, int key)
{
  int deep = 0, dir = 1, move_point, lfail;

  if (count < 0)
  {
    count = -count; dir = -1;
    if (!rl_point) goto fail;
    rl_point--;
  }
  while (count || deep)
  {
    move_point = 1;	/* Need to move point if moving left. */
    lfail = 0;		/* Do not need to fail left movement yet. */
    while ( !is_keyword_char(rl_line_buffer[rl_point])
            && !strchr("\"([{}])",rl_line_buffer[rl_point])
            && !( (dir == 1)
                  ? (rl_point >= rl_end)
                  : (rl_point <= 0 && (lfail = 1))))
        rl_point += dir;
    if (lfail || !rl_line_buffer[rl_point]) goto fail;

    if (is_keyword_char(rl_line_buffer[rl_point]))
    {
      while ( is_keyword_char(rl_line_buffer[rl_point])
              && (!((dir == 1) ? (rl_point >= rl_end) : (rl_point <= 0))
                  || (move_point = 0)))
        rl_point += dir;
      if (!deep) count--;
    }
    else if (strchr(paropen,rl_line_buffer[rl_point]))
    {
      if (deep == 0 && dir == -1) goto fail; /* We are already out of pars. */
      rl_point += dir;
      deep++; if (!deep) count--;
    }
    else if (strchr(parclose,rl_line_buffer[rl_point]))
    {
      if (deep == 0 && dir == 1)
      {
        rl_point++; goto fail; /* Get out of pars. */
      }
      rl_point += dir;
      deep--; if (!deep) count--;
    }
    else if (rl_line_buffer[rl_point] == '\"')
    {
      int bad = 1;

      rl_point += dir;
      while ( ((rl_line_buffer[rl_point] != '\"') || (bad = 0))
              && (!((dir == 1) ? (rl_point >= rl_end) : (rl_point <= 0))
                  || (move_point = 0)) )
        rl_point += dir;
      if (bad) goto fail;
      rl_point += dir;	/* Skip the other delimiter */
      if (!deep) count--;
    }
    else
    {
      fail: ding(); return 1;
    }
  }
  if (dir != 1 && move_point) rl_point++;
  return 1;
}

static int
pari_rl_backward_sexp(int count, int key)
{
  return pari_rl_forward_sexp(-count, key);
}

/* do we add () at the end of completed word? (is it a function?) */
static int
add_paren(int end)
{
  entree *ep;
  char *s;

  if (end < 0 || rl_line_buffer[end] == '(')
    return 0; /* not from command_generator or already there */
  ep = do_alias(current_ep); /* current_ep set in command_generator */
  if (EpVALENCE(ep) < EpUSER)
  { /* is it a constant masked as a function (e.g Pi)? */
    s = ep->help; if (!s) return 1;
    while (is_keyword_char(*s)) s++;
    return (*s != '=');
  }
  switch(EpVALENCE(ep))
  {
    case EpUSER:
    case EpINSTALL: return 1;
  }
  return 0;
}

static void
match_concat(char **matches, char *s)
{
  int i = strlen(matches[0]) + 1;
  matches[0] = (char*) gprealloc(matches[0], i+strlen(s), i);
  strcat(matches[0],s);
}

static char **
matches_for_emacs(char *text, char **matches)
{
  if (!matches) printf("@");
  else
  {
    int i;
    printf("%s@", matches[0] + strlen(text));
    if (matches[1]) print_fun_list(matches+1,0);

   /* we don't want readline to do anything, but insert some junk
    * which will be erased by emacs.
    */
    for (i=0; matches[i]; i++) free(matches[i]);
    free(matches);
  }
  matches = (char **) gpmalloc(2*sizeof(char *));
  matches[0] = gpmalloc(2); sprintf(matches[0],"_");
  matches[1] = NULL; printf("@E_N_D"); pariflush();
  return matches;
}

#define add_comma(x) (x==-2) /* from default_generator */

/* Attempt to complete on the contents of TEXT. END points to the end of the
 * word to complete. Return the array of matches, or NULL if there aren't any.
 */
static char **
get_matches(int end, char *text, char* f(char*,int))
{
  char **matches;

#ifdef HAS_COMPLETION_APPEND_CHAR
  rl_completion_append_character = ' ';
#endif
  current_ep = NULL;
  matches = ((CF) completion_matches)(text, (char *(*)())f);
  if (matches && !matches[1]) /* a single match */
  {
    if (add_paren(end))
    {
      match_concat(matches,"()");
      pari_rl_back = 1;
      if (rl_point == rl_end)
#ifdef HAS_COMPLETION_APPEND_CHAR
        rl_completion_append_character = '\0'; /* Do not append space. */
#else
        pari_rl_back = 2;
#endif
    }
    else if (add_comma(end))
      match_concat(matches,",");
  }
  if (under_emacs) matches = matches_for_emacs(text,matches);
  return matches;
}
#undef add_comma

static char *
add_junk(char *name, char *text, long junk)
{
  char *s = strncpy((char*) gpmalloc(strlen(name)+1+junk),text,junk);
  strcpy(s+junk,name); return s;
}

/* Generator function for command completion.  STATE lets us know whether
 * to start from scratch; without any state (i.e. STATE == 0), then we
 * start at the top of the list.
 */
static char *
hashtable_generator (char *text, int state, entree **hash)
{
  static int hashpos, len, junk, n;
  static entree* ep;
  static char *TEXT;

 /* If this is a new word to complete, initialize now:
  *  + indexes hashpos (GP hash list) and n (keywords specific to long help).
  *  + file completion and keyword completion use different word boundaries,
  *    have TEXT point to the keyword start.
  *  + save the length of TEXT for efficiency.
  */
  if (!state)
  {
    n = hashpos = 0; ep=hash[hashpos];
    len=strlen(text); junk=len-1;
    while (junk >= 0 && is_keyword_char(text[junk])) junk--;
    junk++; len -= junk; TEXT = text + junk;
  }

  /* First check the keywords list */
  if (add_help_keywords)
  {
    for ( ; keyword_list[n]; n++)
      if (!strncmp(keyword_list[n],TEXT,len))
      {
        text = add_junk(keyword_list[n],text,junk);
        n++; return text;
      }
  }

  /* Return the next name which partially matches from the command list. */
  for(;;)
    if (!ep)
    {
      if (++hashpos >= functions_tblsz) return NULL; /* no names matched */
      ep = hash[hashpos];
    }
    else if (strncmp(ep->name,TEXT,len))
      ep = ep->next;
    else
      break;
  current_ep = ep;
  text = add_junk(ep->name,text,junk);
  ep=ep->next; return text;
}

static char *
command_generator (char *text, int  state)
{
  return hashtable_generator(text,state, functions_hash);
}
static char *
member_generator (char *text, int  state)
{
  return hashtable_generator(text,state, members_hash);
}

#define DFLT 0
#define ENTREE 1

static char *
generator(void *list, char *text, int *nn, int len, int typ)
{
  char *def = NULL, *name;
  int n = *nn;

  /* Return the next name which partially matches from list.*/
  switch(typ)
  {
    case DFLT :
      do
	def = (((default_type *) list)[n++]).name;
      while (def && strncmp(def,text,len));
      break;

    case ENTREE :
      do
	def = (((entree *) list)[n++]).name;
      while (def && strncmp(def,text,len));
  }

  *nn = n;
  if (def)
  {
    name = strcpy((char*) gpmalloc(strlen(def)+1), def);
    return name;
  }
  return NULL; /* no names matched */
}

static char *
old_generator(char *text,int state)
{
  static int n,len;
  static char *res;

  if (!state) { res = "a"; n=0; len=strlen(text); }
  if (res)
  {
    res = generator((void *)oldfonctions,text,&n,len,ENTREE);
    if (res) return res;
    n=0;
  }
  return generator((void *)functions_oldgp,text,&n,len,ENTREE);
}

static char *
default_generator(char *text,int state)
{
  static int n,len;

  if (!state) { n=0; len=strlen(text); }
  return generator(gp_default_list,text,&n,len,DFLT);
}

char **
pari_completion(char *text, int start, int end)
{
  int i, first=0;

/* If the line does not begin by a backslash, then it is:
 * . an old command ( if preceded by "whatnow(" ).
 * . a default ( if preceded by "default(" ).
 * . a member function ( if preceded by "." within 4 letters )
 * . a file name (in current directory) ( if preceded by "read(" )
 * . a command
 */
  if (start >=1 && rl_line_buffer[start] != '~') start--;
  while (start && is_keyword_char(rl_line_buffer[start])) start--;
  if (rl_line_buffer[start] == '~')
  {
    for(i=start+1;i<=end;i++)
      if (rl_line_buffer[i] == '/')
	return get_matches(-1,text,(GF)filename_completion_function);
    return get_matches(-1,text,(GF)username_completion_function);
  }

  while (rl_line_buffer[first] && isspace((int)rl_line_buffer[first])) first++;
  switch (rl_line_buffer[first])
  {
    case '\\':
      if (first == start) text = rl_line_buffer+start+1;
      return get_matches(-1,text,(GF)filename_completion_function);
    case '?':
      if (rl_line_buffer[first+1] == '?') add_help_keywords = 1;
      return get_matches(-1,text,command_generator);
  }

  while (start && rl_line_buffer[start] != '('
               && rl_line_buffer[start] != ',') start--;
  if (rl_line_buffer[start] == '(' && start)
  {
#define MAX_KEYWORD 200
    int iend, j;
    entree *ep;
    char buf[MAX_KEYWORD];

    i = start;

    while (i && isspace((int)rl_line_buffer[i-1])) i--;
    iend = i;
    while (i && is_keyword_char(rl_line_buffer[i-1])) i--;

    if (iend - i == 7)
    {
      if (strncmp(rl_line_buffer + i,"default",7) == 0)
	return get_matches(-2,text,default_generator);
      if (strncmp(rl_line_buffer + i,"whatnow",7) == 0)
	return get_matches(-1,text,old_generator);
    }
    if (iend - i >= 4)
    {
      if (strncmp(rl_line_buffer + i,"read",4) == 0)
	return get_matches(-1,text,(GF)filename_completion_function);
    }

    j = start + 1;
    while (j && isspace((int)rl_line_buffer[j])) j++;
    /* If we are in empty parens, insert arguments for the function: */
    if ( (rl_line_buffer[j] == ')' || !rl_line_buffer[j] )
	 && do_args_complete
	 && (iend - i < MAX_KEYWORD)
	 && ( strncpy(buf, rl_line_buffer + i, iend - i),
	      buf[iend - i] = 0, 1)
	 && (ep = is_entry(buf)) && ep->help)
     {
      char *s = ep->help;

      while (is_keyword_char(*s)) s++;
      if (*s++ == '(')
      { /* Function, print arguments! */
        char *endh = s;
        while (*endh && *endh != ')' && *endh != '(') endh++;
        if (*endh == ')')
        { /* Well-formed help.  */
          char *str = strncpy((char*) gpmalloc(endh-s + 1), s, endh-s);
          char **ret = (char**)gpmalloc(sizeof(char*)*2);
          str[endh-s] = 0;
          ret[0] = str; ret[1] = NULL;
          if (under_emacs) ret = matches_for_emacs("",ret);
          return ret;
        }
      }
    }
  }
  for(i=end-1;i>=start;i--)
    if (!is_keyword_char(rl_line_buffer[i]))
    {
      if (rl_line_buffer[i] == '.')
        return get_matches(-1,text,member_generator);
      break;
    }
  add_help_keywords = 0;
  return get_matches(end,text,command_generator);
}

static int
rl_short_help(int count, int key)
{
  int p=rl_point, off=p, e = rl_end;
  FILE *save = pari_outfile;
  long flag = h_RL;

  while (off && is_keyword_char(rl_line_buffer[off-1])) off--;
  rl_point = 0; rl_end = 0; pari_outfile = rl_outstream;
  if (count < 0) flag |= h_LONG; /* long help */
  SAVE_PROMPT();
  rl_message("",0,0);
  aide(rl_line_buffer + off, flag);
  RESTORE_PROMPT();
  rl_point = p; rl_end = e; pari_outfile = save;
  rl_clear_message();
#ifdef RL_REFRESH_LINE_OLDPROTO
  rl_refresh_line();
#else
  rl_refresh_line(count,key);
#endif
  return 0;
}

static int
rl_long_help(int count, int key)
{
  return rl_short_help(-1,key);
}

void
init_readline()
{
  /* Allow conditional parsing of the ~/.inputrc file. */
  rl_readline_name = "Pari-GP";

  /* added ~, ? and , */
  rl_basic_word_break_characters = " \t\n\"\\'`@$><=;|&{(?,~";
  rl_special_prefixes = "~";

  /* custom completer */
#ifndef CPPFunction_defined
#  define CPPFunction Function
#endif
  rl_attempted_completion_function = (CPPFunction *) pari_completion;

  /* we always want the whole list of completions under emacs */
  if (under_emacs) rl_completion_query_items = 0x8fff;

#define Bind ((void(*)(int,Function*,Keymap)) rl_bind_key_in_map)
#define Defun ((void(*)(const char*,Function*,int)) rl_add_defun)

  Defun("short-help", (Function*) rl_short_help, -1);
  Defun("long-help", (Function*) rl_long_help, -1);
  Defun("pari-complete", (Function*) pari_rl_complete, '\t');
  Defun("pari-matched-insert", (Function*) pari_rl_default_matched_insert, -1);
  Defun("pari-forward-sexp", (Function*) pari_rl_forward_sexp, -1);
  Defun("pari-backward-sexp", (Function*) pari_rl_backward_sexp, -1);

  Bind('h', (Function*) rl_short_help, emacs_meta_keymap);
  Bind('H', (Function*) rl_long_help,  emacs_meta_keymap);
  Bind('h', (Function*) rl_short_help, vi_movement_keymap);
  Bind('H', (Function*) rl_long_help,  vi_movement_keymap);
  Bind('(', (Function*) pari_rl_matched_insert, emacs_standard_keymap);
  Bind('[', (Function*) pari_rl_matched_insert, emacs_standard_keymap);
  Bind(6, (Function*) pari_rl_forward_sexp,  emacs_meta_keymap); /* M-C-f */
  Bind(2, (Function*) pari_rl_backward_sexp, emacs_meta_keymap); /* M-C-b */

#ifdef EMACS_DOS_KEYMAP
  Bind(';', (Function*) rl_short_help, emacs_dos_keymap); /* F1 */
  Bind('T', (Function*) rl_long_help,  emacs_dos_keymap); /* Shift-F1 */
  Bind(155, (Function*) pari_rl_backward_sexp, emacs_dos_keymap); /* Alt-Left */
  Bind(157, (Function*) pari_rl_forward_sexp,  emacs_dos_keymap); /* Alt-Right*/
#endif
}
#endif