/* This is dvipdfmx, an eXtended version of dvipdfm by Mark A. Wicks.

    Copyright (C) 2002-2016 by Jin-Hwan Cho and Shunsaku Hirata,
    the dvipdfmx project team.

    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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/

#include "dpx-otl_opt.h"

#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>

#include "dpx-error.h"
#include "dpx-mem.h"

struct bt_node {
  int    flag;

  struct bt_node *left;
  struct bt_node *right;

  char data[4];
};

#define FLAG_NOT (1 << 0)
#define FLAG_AND (1 << 1)

static int match_expr (struct bt_node *expr, const char *key);
static int
match_expr (struct bt_node *expr, const char *key)
{
  int retval = 1;
  int i;

  if (expr) {
    if (!expr->left && !expr->right) {
      for (i = 0; i < 4; i++) {
        if (expr->data[i] != '?' &&
            expr->data[i] != key[i]) {
          retval = 0;
          break;
        }
      }
    } else {
      if (expr->left) {
        retval  = match_expr(expr->left, key);
      }
      if (expr->right) {
        if (retval && (expr->flag & FLAG_AND)) /* and */
          retval &= match_expr(expr->right, key);
        else if (!retval && !(expr->flag & FLAG_AND)) /* or */
          retval  = match_expr(expr->right, key);
      }
    }
    if (expr->flag & FLAG_NOT) /* not */
      retval = retval ? 0 : 1;

  }

  return retval;
}

static struct bt_node *
bt_new_tree (void)
{
  struct bt_node *expr;

  expr = NEW(1, struct bt_node);
  expr->flag  = 0;
  expr->left  = NULL;
  expr->right = NULL;
  memset(expr->data, 0, 4);

  return expr;
}

static void bt_release_tree (struct bt_node *tree);

static void
bt_release_tree (struct bt_node *tree)
{
  if (tree) {
    if (tree->left)
      bt_release_tree(tree->left);
    if (tree->right)
      bt_release_tree(tree->right);
    free(tree);
  }
}

static struct bt_node *
parse_expr (const char **pp, const char *endptr)
{
  struct bt_node *root, *curr;

  if (*pp >= endptr)
    return NULL;

  root = curr = bt_new_tree();
  while (*pp < endptr) {
    switch (**pp) {
    case '!':
      if (curr->flag & 2)
        curr->flag &= ~FLAG_NOT;
      else
        curr->flag |=  FLAG_NOT;
      (*pp)++;
      break;
    case '(':
      (*pp)++;
      if (*pp < endptr) {
        struct bt_node *expr;

        expr = parse_expr(pp, endptr);
        if (!expr) {
            dpx_warning("Syntax error: %s\n", *pp);
            return NULL;
        }
        if (**pp != ')') {
            dpx_warning("Syntax error: Unbalanced ()\n");
            return NULL;
           }
        curr->left  = expr->left;
        curr->right = expr->right;
        memcpy(curr->data, expr->data, 4);

        free(expr);
      } else {
        dpx_warning("Syntax error: Unbalanced ()\n");
        bt_release_tree(root);
        return NULL;
      }
      (*pp)++;
      break;
    case ')':
      return root;
    case '|': case '&':
      if (*pp >= endptr) {
        dpx_warning("Syntax error: %s\n", *pp);
        bt_release_tree(root);
        return NULL;
      } else {
        struct bt_node *tmp;

        tmp        = bt_new_tree();
        tmp->left  = root;
        tmp->right = curr = bt_new_tree();
        if (**pp == '&')
          tmp->flag = 1;
        else
          tmp->flag = 0;
        root = tmp;
      }
      (*pp)++;
      break;
    case '*':
      memset(curr->data, '?', 4);
      (*pp)++;
      break;
    default:
      if (*pp + 4 <= endptr) {
        int i;

        for (i = 0; i < 4; i++) {
            if (**pp == ' '   || **pp == '?' ||
                isalpha((unsigned char)**pp) || isdigit((unsigned char)**pp))
                curr->data[i] = **pp;
            else if (**pp == '_')
                curr->data[i] = ' ';
            else {
                dpx_warning("Invalid char in tag: %c\n", **pp);
                bt_release_tree(root);
                return NULL;
            }
            (*pp)++;
        }
      } else {
        dpx_warning("Syntax error: %s\n", *pp);
        bt_release_tree(root);
        return NULL;
      }
      break;
    }
  }

  return root;
}


struct otl_opt
{
  struct bt_node *rule;
};

otl_opt *
otl_new_opt (void)
{
  struct otl_opt *opt;

  opt = NEW(1, struct otl_opt);
  opt->rule = NULL;

  return (otl_opt *) opt;
}


void
otl_release_opt (otl_opt *opt)
{
  if (opt->rule) {
    bt_release_tree(opt->rule);
  }
  opt->rule = NULL;
  free(opt);
}

int
otl_parse_optstring (otl_opt *opt, const char *optstr)
{
  const char *p, *endptr;

  assert(opt);

  if (optstr) {
    p      = optstr;
    endptr = p + strlen(optstr);
    opt->rule = parse_expr(&p, endptr);
  }

  return 0;
}

int
otl_match_optrule (otl_opt *opt, const char *tag)
{
  assert(tag);

  if (!opt || !opt->rule)
    return 1;

  return match_expr(opt->rule, tag);
}