/*****************************************************************************
 * Eliot
 * Copyright (C) 1999-2006 Antoine Fraboulet
 * Authors: Antoine Fraboulet <antoine.fraboulet @@ free.fr>
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *****************************************************************************/

/**
 *  \file   regexp.c
 *  \brief  Regular Expression functions
 *  \author Antoine Fraboulet
 *  \date   2005
 */

#include "config.h"

#include <cstdio>
#include <cstdlib>
#include <cstring>
#ifdef HAVE_SYS_WAIT_H
#   include <sys/wait.h>
#endif
#include <unistd.h>

#include "dic.h"
#include "regexp.h"
#include "automaton.h"

#ifndef PDBG
#ifdef DEBUG_RE2
#define PDBG(x) x
#else
#define PDBG(x)
#endif
#endif


NODE* regexp_createNODE(int type, char v, NODE *fg, NODE *fd)
{
    NODE *x;
    x=(NODE *)malloc(sizeof(NODE));
    x->type      = type;
    x->var       = v;
    x->fd        = fd;
    x->fg        = fg;
    x->number    = 0;
    x->position  = 0;
    x->annulable = 0;
    x->PP        = 0;
    x->DP        = 0;
    return x;
}

void regexp_delete_tree(NODE *root)
{
    if (root == NULL)
        return;
    regexp_delete_tree(root->fg);
    regexp_delete_tree(root->fd);
    free(root);
}

#ifdef DEBUG_RE
static void print_node(FILE*, NODE *n, int detail);
#endif

/**
 * computes position, annulable, PP, DP attributes
 * @param r   = root
 * @param p   = current leaf position
 * @param n   = current node number
 * @param ptl = position to letter
 */

void regexp_parcours(NODE* r, int *p, int *n, int ptl[])
{
    if (r == NULL)
        return;

    regexp_parcours(r->fg, p, n, ptl);
    regexp_parcours(r->fd, p, n, ptl);

    switch (r->type)
    {
        case NODE_VAR:
            r->position = *p;
            ptl[*p] = r->var;
            *p = *p + 1;
            r->annulable = 0;
            r->PP = 1 << (r->position - 1);
            r->DP = 1 << (r->position - 1);
            break;
        case NODE_OR:
            r->position = 0;
            r->annulable = r->fg->annulable || r->fd->annulable;
            r->PP = r->fg->PP | r->fd->PP;
            r->DP = r->fg->DP | r->fd->DP;
            break;
        case NODE_AND:
            r->position = 0;
            r->annulable = r->fg->annulable && r->fd->annulable;
            r->PP = (r->fg->annulable) ? (r->fg->PP | r->fd->PP) : r->fg->PP;
            r->DP = (r->fd->annulable) ? (r->fg->DP | r->fd->DP) : r->fd->DP;
            break;
        case NODE_PLUS:
            r->position = 0;
            r->annulable = 0;
            r->PP = r->fg->PP;
            r->DP = r->fg->DP;
            break;
        case NODE_STAR:
            r->position = 0;
            r->annulable = 1;
            r->PP = r->fg->PP;
            r->DP = r->fg->DP;
            break;
    }

    r->number = *n;
    *n = *n + 1;
}

/**
 * computes possuivante
 * @param r   = root
 * @param PS  = next position
 */

void regexp_possuivante(NODE* r, int PS[])
{
    if (r == NULL)
        return;

    regexp_possuivante(r->fg, PS);
    regexp_possuivante(r->fd, PS);

    switch (r->type)
    {
        case NODE_AND:
            /************************************/
            /* \forall p \in DP(left)           */
            /*     PS[p] = PS[p] \cup PP(right) */
            /************************************/
            for (int pos = 1; pos <= PS[0]; pos++)
            {
                if (r->fg->DP & (1 << (pos-1)))
                    PS[pos] |= r->fd->PP;
            }
            break;
        case NODE_PLUS:
            /************************************/
            /* == same as START                 */
            /* \forall p \in DP(left)           */
            /*     PS[p] = PS[p] \cup PP(left)  */
            /************************************/
            for (int pos = 1; pos <= PS[0]; pos++)
            {
                if (r->DP & (1 << (pos-1)))
                    PS[pos] |= r->PP;
            }
            break;
        case NODE_STAR:
            /************************************/
            /* \forall p \in DP(left)           */
            /*     PS[p] = PS[p] \cup PP(left)  */
            /************************************/
            for (int pos = 1; pos <= PS[0]; pos++)
            {
                if (r->DP & (1 << (pos-1)))
                    PS[pos] |= r->PP;
            }
            break;
    }
}

/*////////////////////////////////////////////////
// DEBUG only fonctions
////////////////////////////////////////////////*/

#ifdef DEBUG_RE
void regexp_print_PS(int PS[])
{
    printf("** positions suivantes **\n");
    for (int i = 1; i <= PS[0]; i++)
    {
        printf("%02d: 0x%08x\n", i, PS[i]);
    }
}
#endif

/*////////////////////////////////////////////////
////////////////////////////////////////////////*/

#ifdef DEBUG_RE
void regexp_print_ptl(int ptl[])
{
    printf("** pos -> lettre: ");
    for (int i = 1; i <= ptl[0]; i++)
    {
        printf("%d=%c ", i, ptl[i]);
    }
    printf("\n");
}
#endif

/*////////////////////////////////////////////////
////////////////////////////////////////////////*/

void regexp_print_letter(FILE* f, char l)
{
    switch (l)
    {
        case RE_EPSILON:    fprintf(f, "( &  [%d])", l); break;
        case RE_FINAL_TOK:  fprintf(f, "( #  [%d])", l);  break;
        case RE_ALL_MATCH:  fprintf(f, "( .  [%d])", l);  break;
        case RE_VOWL_MATCH: fprintf(f, "(:v: [%d])", l); break;
        case RE_CONS_MATCH: fprintf(f, "(:c: [%d])", l); break;
        case RE_USR1_MATCH: fprintf(f, "(:1: [%d])", l); break;
        case RE_USR2_MATCH: fprintf(f, "(:2: [%d])", l); break;
        default:
            if (l < RE_FINAL_TOK)
                fprintf(f, " (%c [%d]) ", l + 'a' - 1, l);
            else
                fprintf(f, " (liste %d)", l - RE_LIST_USER_END);
            break;
    }
}

/*////////////////////////////////////////////////
////////////////////////////////////////////////*/

void regexp_print_letter2(FILE* f, char l)
{
    switch (l)
    {
        case RE_EPSILON:    fprintf(f, "&"); break;
        case RE_FINAL_TOK:  fprintf(f, "#");  break;
        case RE_ALL_MATCH:  fprintf(f, ".");  break;
        case RE_VOWL_MATCH: fprintf(f, ":v:"); break;
        case RE_CONS_MATCH: fprintf(f, ":c:"); break;
        case RE_USR1_MATCH: fprintf(f, ":1:"); break;
        case RE_USR2_MATCH: fprintf(f, ":2:"); break;
        default:
            if (l < RE_FINAL_TOK)
                fprintf(f, "%c", l + 'a' - 1);
            else
                fprintf(f, "l%d", l - RE_LIST_USER_END);
            break;
    }
}

/*////////////////////////////////////////////////
////////////////////////////////////////////////*/

#ifdef DEBUG_RE
static void print_node(FILE* f, NODE *n, int detail)
{
    if (n == NULL)
        return;

    switch (n->type)
    {
        case NODE_VAR:
            regexp_print_letter(f, n->var);
            break;
        case NODE_OR:
            fprintf(f, "OR");
            break;
        case NODE_AND:
            fprintf(f, "AND");
            break;
        case NODE_PLUS:
            fprintf(f, "+");
            break;
        case NODE_STAR:
            fprintf(f, "*");
            break;
    }
    if (detail == 2)
    {
        fprintf(f, "\\n pos=%d\\n annul=%d\\n PP=0x%04x\\n DP=0x%04x",
                n->position, n->annulable, n->PP, n->DP);
    }
}
#endif

/*////////////////////////////////////////////////
////////////////////////////////////////////////*/

#ifdef DEBUG_RE
static void print_tree_nodes(FILE* f, NODE* n, int detail)
{
    if (n == NULL)
        return;

    print_tree_nodes(f, n->fg, detail);
    print_tree_nodes(f, n->fd, detail);

    fprintf(f, "%d [ label=\"", n->number);
    print_node(f, n, detail);
    fprintf(f, "\"];\n");
}
#endif

/*////////////////////////////////////////////////
////////////////////////////////////////////////*/

#ifdef DEBUG_RE
static void print_tree_edges(FILE *f, NODE *n)
{
    if (n == NULL)
        return;

    print_tree_edges(f, n->fg);
    print_tree_edges(f, n->fd);

    switch (n->type)
    {
        case NODE_OR:
            fprintf(f, "%d -> %d;", n->number, n->fg->number);
            fprintf(f, "%d -> %d;", n->number, n->fd->number);
            break;
        case NODE_AND:
            fprintf(f, "%d -> %d;", n->number, n->fg->number);
            fprintf(f, "%d -> %d;", n->number, n->fd->number);
            break;
        case NODE_PLUS:
        case NODE_STAR:
            fprintf(f, "%d -> %d;", n->number, n->fg->number);
            break;
    }
}
#endif

/*////////////////////////////////////////////////
////////////////////////////////////////////////*/

#ifdef DEBUG_RE
void regexp_print_tree(NODE* n, const string &iName, int detail)
{
    FILE *f = fopen(iName.c_str(), "w");
    if (f == NULL)
        return;
    fprintf(f, "digraph %s {\n", iName.c_str());
    print_tree_nodes(f, n, detail);
    print_tree_edges(f, n);
    fprintf(f, "fontsize=20;\n");
    fprintf(f, "}\n");
    fclose(f);

#ifdef HAVE_SYS_WAIT_H
    pid_t pid = fork();
    if (pid > 0)
    {
        wait(NULL);
    }
    else if (pid == 0)
    {
        execlp("dotty", "dotty", iName.c_str(), NULL);
        printf("exec dotty failed\n");
        exit(1);
    }
#endif
}
#endif


/// Local Variables:
/// mode: hs-minor
/// c-basic-offset: 2
/// End: