/* -*- mode: C; c-file-style: "gnu" -*- */
/* xdgmimeglob.c: Private file.  Datastructure for storing the globs.
 *
 * More info can be found at http://www.freedesktop.org/standards/
 *
 * Copyright (C) 2003  Red Hat, Inc.
 * Copyright (C) 2003  Jonathan Blandford <jrb@alum.mit.edu>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later or AFL-2.0
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "xdgmimeglob.h"
#include "xdgmimeint.h"
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <string.h>
#include <fnmatch.h>

#ifndef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif

#ifndef	FALSE
#define	FALSE	(0)
#endif

#ifndef	TRUE
#define	TRUE	(!FALSE)
#endif

typedef struct XdgGlobHashNode XdgGlobHashNode;
typedef struct XdgGlobList XdgGlobList;

struct XdgGlobHashNode
{
  xdg_unichar_t character;
  const char *mime_type;
  int weight;
  int case_sensitive;
  XdgGlobHashNode *next;
  XdgGlobHashNode *child;
};
struct XdgGlobList
{
  const char *data;
  const char *mime_type;
  int weight;
  int case_sensitive;
  XdgGlobList *next;
};

struct XdgGlobHash
{
  XdgGlobList *literal_list;
  XdgGlobHashNode *simple_node;
  XdgGlobList *full_list;
};


/* XdgGlobList
 */
static XdgGlobList *
_xdg_glob_list_new (void)
{
  XdgGlobList *new_element;

  new_element = calloc (1, sizeof (XdgGlobList));

  return new_element;
}

/* Frees glob_list and all of its children */
static void
_xdg_glob_list_free (XdgGlobList *glob_list)
{
  XdgGlobList *ptr, *next;

  ptr = glob_list;

  while (ptr != NULL)
    {
      next = ptr->next;

      if (ptr->data)
	free ((void *) ptr->data);
      if (ptr->mime_type)
	free ((void *) ptr->mime_type);
      free (ptr);

      ptr = next;
    }
}

static XdgGlobList *
_xdg_glob_list_append (XdgGlobList *glob_list,
		       const char  *data,
		       const char  *mime_type,
		       int          weight,
		       int          case_sensitive)
{
  XdgGlobList *new_element;
  XdgGlobList *tmp_element;

  tmp_element = glob_list;
  while (tmp_element != NULL)
    {
      if (strcmp (tmp_element->data, data) == 0 &&
	  strcmp (tmp_element->mime_type, mime_type) == 0)
	return glob_list;

      tmp_element = tmp_element->next;
    }

  new_element = _xdg_glob_list_new ();
  new_element->data = strdup (data);
  new_element->mime_type = strdup (mime_type);
  new_element->weight = weight;
  new_element->case_sensitive = case_sensitive;
  if (glob_list == NULL)
    return new_element;

  tmp_element = glob_list;
  while (tmp_element->next != NULL)
    tmp_element = tmp_element->next;

  tmp_element->next = new_element;

  return glob_list;
}

/* XdgGlobHashNode
 */

static XdgGlobHashNode *
_xdg_glob_hash_node_new (void)
{
  XdgGlobHashNode *glob_hash_node;

  glob_hash_node = calloc (1, sizeof (XdgGlobHashNode));

  return glob_hash_node;
}

static void
_xdg_glob_hash_node_dump (XdgGlobHashNode *glob_hash_node,
			  int depth)
{
  int i;
  for (i = 0; i < depth; i++)
    printf (" ");

  printf ("%c", (char)glob_hash_node->character);
  if (glob_hash_node->mime_type)
    printf (" - %s %d\n", glob_hash_node->mime_type, glob_hash_node->weight);
  else
    printf ("\n");
  if (glob_hash_node->child)
    _xdg_glob_hash_node_dump (glob_hash_node->child, depth + 1);
  if (glob_hash_node->next)
    _xdg_glob_hash_node_dump (glob_hash_node->next, depth);
}

static XdgGlobHashNode *
_xdg_glob_hash_insert_ucs4 (XdgGlobHashNode *glob_hash_node,
			    xdg_unichar_t   *text,
			    const char      *mime_type,
			    int              weight,
			    int              case_sensitive)
{
  XdgGlobHashNode *node;
  xdg_unichar_t character;

  character = text[0];

  if ((glob_hash_node == NULL) ||
      (character < glob_hash_node->character))
    {
      node = _xdg_glob_hash_node_new ();
      node->character = character;
      node->next = glob_hash_node;
      glob_hash_node = node;
    }
  else if (character == glob_hash_node->character)
    {
      node = glob_hash_node;
    }
  else
    {
      XdgGlobHashNode *prev_node;
      int found_node = FALSE;

      /* Look for the first character of text in glob_hash_node, and insert it if we
       * have to.*/
      prev_node = glob_hash_node;
      node = prev_node->next;

      while (node != NULL)
	{
	  if (character < node->character)
	    {
	      node = _xdg_glob_hash_node_new ();
	      node->character = character;
	      node->next = prev_node->next;
	      prev_node->next = node;

	      found_node = TRUE;
	      break;
	    }
	  else if (character == node->character)
	    {
	      found_node = TRUE;
	      break;
	    }
	  prev_node = node;
	  node = node->next;
	}

      if (! found_node)
	{
	  node = _xdg_glob_hash_node_new ();
	  node->character = character;
	  node->next = prev_node->next;
	  prev_node->next = node;
	}
    }

  text++;
  if (*text == 0)
    {
      if (node->mime_type)
	{
	  if (strcmp (node->mime_type, mime_type) != 0)
	    {
	      XdgGlobHashNode *child;
	      int found_node = FALSE;

	      child = node->child;
	      while (child && child->character == 0)
		{
		  if (strcmp (child->mime_type, mime_type) == 0)
		    {
		      found_node = TRUE;
		      break;
		    }
		  child = child->next;
		}

	      if (!found_node)
		{
		  child = _xdg_glob_hash_node_new ();
		  child->character = 0;
		  child->mime_type = strdup (mime_type);
		  child->weight = weight;
		  child->case_sensitive = case_sensitive;
		  child->child = NULL;
		  child->next = node->child;
		  node->child = child;
		}
	    }
	}
      else
	{
	  node->mime_type = strdup (mime_type);
	  node->weight = weight;
	  node->case_sensitive = case_sensitive;
	}
    }
  else
    {
      node->child = _xdg_glob_hash_insert_ucs4 (node->child, text, mime_type, weight, case_sensitive);
    }
  return glob_hash_node;
}

/* glob must be valid UTF-8 */
static XdgGlobHashNode *
_xdg_glob_hash_insert_text (XdgGlobHashNode *glob_hash_node,
			    const char      *text,
			    const char      *mime_type,
			    int              weight,
			    int              case_sensitive)
{
  XdgGlobHashNode *node;
  xdg_unichar_t *unitext;
  int len;

  unitext = _xdg_convert_to_ucs4 (text, &len);
  _xdg_reverse_ucs4 (unitext, len);
  node = _xdg_glob_hash_insert_ucs4 (glob_hash_node, unitext, mime_type, weight, case_sensitive);
  free (unitext);
  return node;
}

typedef struct {
  const char *mime;
  int weight;
} MimeWeight;

static int
_xdg_glob_hash_node_lookup_file_name (XdgGlobHashNode *glob_hash_node,
				      const char      *file_name,
				      int              len,
				      int              case_sensitive_check,
				      MimeWeight       mime_types[],
				      int              n_mime_types)
{
  int n;
  XdgGlobHashNode *node;
  xdg_unichar_t character;

  if (glob_hash_node == NULL)
    return 0;

  character = file_name[len - 1];

  for (node = glob_hash_node; node && character >= node->character; node = node->next)
    {
      if (character == node->character)
        {
          len--;
          n = 0;
          if (len > 0) 
	    {
	      n = _xdg_glob_hash_node_lookup_file_name (node->child,
							file_name,
							len,
							case_sensitive_check,
							mime_types,
							n_mime_types);
	    }
	  if (n == 0)
	    {
              if (node->mime_type &&
		  (case_sensitive_check ||
		   !node->case_sensitive))
                {
	          mime_types[n].mime = node->mime_type;
		  mime_types[n].weight = node->weight;
		  n++; 
                }
	      node = node->child;
	      while (n < n_mime_types && node && node->character == 0)
		{
                  if (node->mime_type &&
		      (case_sensitive_check ||
		       !node->case_sensitive))
		    {
		      mime_types[n].mime = node->mime_type;
		      mime_types[n].weight = node->weight;
		      n++;
		    }
		  node = node->next;
		}
	    }
	  return n;
	}
    }

  return 0;
}

static int compare_mime_weight (const void *a, const void *b)
{
  const MimeWeight *aa = (const MimeWeight *)a;
  const MimeWeight *bb = (const MimeWeight *)b;

  return bb->weight - aa->weight;
}

#define ISUPPER(c)		((c) >= 'A' && (c) <= 'Z')
static char *
ascii_tolower (const char *str)
{
  char *p, *lower;

  lower = strdup (str);
  p = lower;
  while (*p != 0)
    {
      char c = *p;
      *p++ = ISUPPER (c) ? c - 'A' + 'a' : c;
    }
  return lower;
}

static int
filter_out_dupes (MimeWeight mimes[], int n_mimes)
{
  int last;
  int i, j;

  last = n_mimes;

  for (i = 0; i < last; i++)
    {
      j = i + 1;
      while (j < last)
        {
          if (strcmp (mimes[i].mime, mimes[j].mime) == 0)
            {
              mimes[i].weight = MAX (mimes[i].weight, mimes[j].weight);
              last--;
              mimes[j].mime = mimes[last].mime;
              mimes[j].weight = mimes[last].weight;
            }
          else
            j++;
        }
    }

  return last;
}

int
_xdg_glob_hash_lookup_file_name (XdgGlobHash *glob_hash,
				 const char  *file_name,
				 const char  *mime_types[],
				 int          n_mime_types)
{
  XdgGlobList *list;
  int i, n;
  MimeWeight mimes[10];
  int n_mimes = 10;
  int len;
  char *lower_case;

  /* First, check the literals */

  assert (file_name != NULL && n_mime_types > 0);

  n = 0;

  lower_case = ascii_tolower (file_name);

  for (list = glob_hash->literal_list; list; list = list->next)
    {
      if (strcmp ((const char *)list->data, file_name) == 0)
	{
	  mime_types[0] = list->mime_type;
	  free (lower_case);
	  return 1;
	}
    }

  for (list = glob_hash->literal_list; list; list = list->next)
    {
      if (!list->case_sensitive &&
	  strcmp ((const char *)list->data, lower_case) == 0)
	{
	  mime_types[0] = list->mime_type;
	  free (lower_case);
	  return 1;
	}
    }


  len = strlen (file_name);
  n = _xdg_glob_hash_node_lookup_file_name (glob_hash->simple_node, lower_case, len, FALSE,
					    mimes, n_mimes);
  if (n < 2)
    n += _xdg_glob_hash_node_lookup_file_name (glob_hash->simple_node, file_name, len, TRUE,
					       mimes + n, n_mimes - n);

  if (n < 2)
    {
      for (list = glob_hash->full_list; list && n < n_mime_types; list = list->next)
        {
          if (fnmatch ((const char *)list->data, file_name, 0) == 0)
	    {
	      mimes[n].mime = list->mime_type;
	      mimes[n].weight = list->weight;
	      n++;
	    }
        }
    }
  free (lower_case);

  n = filter_out_dupes (mimes, n);

  qsort (mimes, n, sizeof (MimeWeight), compare_mime_weight);

  if (n_mime_types < n)
    n = n_mime_types;

  for (i = 0; i < n; i++)
    mime_types[i] = mimes[i].mime;

  return n;
}



/* XdgGlobHash
 */

XdgGlobHash *
_xdg_glob_hash_new (void)
{
  XdgGlobHash *glob_hash;

  glob_hash = calloc (1, sizeof (XdgGlobHash));

  return glob_hash;
}


static void
_xdg_glob_hash_free_nodes (XdgGlobHashNode *node)
{
  if (node)
    {
      if (node->child)
       _xdg_glob_hash_free_nodes (node->child);
      if (node->next)
       _xdg_glob_hash_free_nodes (node->next);
      if (node->mime_type)
	free ((void *) node->mime_type);
      free (node);
    }
}

void
_xdg_glob_hash_free (XdgGlobHash *glob_hash)
{
  _xdg_glob_list_free (glob_hash->literal_list);
  _xdg_glob_list_free (glob_hash->full_list);
  _xdg_glob_hash_free_nodes (glob_hash->simple_node);
  free (glob_hash);
}

XdgGlobType
_xdg_glob_determine_type (const char *glob)
{
  const char *ptr;
  int maybe_in_simple_glob = FALSE;
  int first_char = TRUE;

  ptr = glob;

  while (*ptr != '\0')
    {
      if (*ptr == '*' && first_char)
	maybe_in_simple_glob = TRUE;
      else if (*ptr == '\\' || *ptr == '[' || *ptr == '?' || *ptr == '*')
	  return XDG_GLOB_FULL;

      first_char = FALSE;
      ptr = _xdg_utf8_next_char (ptr);
    }
  if (maybe_in_simple_glob)
    return XDG_GLOB_SIMPLE;
  else
    return XDG_GLOB_LITERAL;
}

/* glob must be valid UTF-8 */
void
_xdg_glob_hash_append_glob (XdgGlobHash *glob_hash,
			    const char  *glob,
			    const char  *mime_type,
			    int          weight,
			    int          case_sensitive)
{
  XdgGlobType type;

  assert (glob_hash != NULL);
  assert (glob != NULL);

  type = _xdg_glob_determine_type (glob);

  switch (type)
    {
    case XDG_GLOB_LITERAL:
      glob_hash->literal_list = _xdg_glob_list_append (glob_hash->literal_list, glob, mime_type, weight, case_sensitive);
      break;
    case XDG_GLOB_SIMPLE:
      glob_hash->simple_node = _xdg_glob_hash_insert_text (glob_hash->simple_node, glob + 1, mime_type, weight, case_sensitive);
      break;
    case XDG_GLOB_FULL:
      glob_hash->full_list = _xdg_glob_list_append (glob_hash->full_list, glob, mime_type, weight, case_sensitive);
      break;
    }
}

void
_xdg_glob_hash_dump (XdgGlobHash *glob_hash)
{
  XdgGlobList *list;
  printf ("LITERAL STRINGS\n");
  if (!glob_hash || glob_hash->literal_list == NULL)
    {
      printf ("    None\n");
    }
  else
    {
      for (list = glob_hash->literal_list; list; list = list->next)
	printf ("    %s - %s %d\n", (char *)list->data, list->mime_type, list->weight);
    }
  printf ("\nSIMPLE GLOBS\n");
  if (!glob_hash || glob_hash->simple_node == NULL)
    {
      printf ("    None\n");
    }
  else
    {
      _xdg_glob_hash_node_dump (glob_hash->simple_node, 4);
    }

  printf ("\nFULL GLOBS\n");
  if (!glob_hash || glob_hash->full_list == NULL)
    {
      printf ("    None\n");
    }
  else
    {
      for (list = glob_hash->full_list; list; list = list->next)
	printf ("    %s - %s %d\n", (char *)list->data, list->mime_type, list->weight);
    }
}


void
_xdg_mime_glob_read_from_file (XdgGlobHash *glob_hash,
			       const char  *file_name,
			       int          version_two)
{
  FILE *glob_file;
  char line[255];
  char *p;

  glob_file = fopen (file_name, "r");

  if (glob_file == NULL)
    return;

  /* FIXME: Not UTF-8 safe.  Doesn't work if lines are greater than 255 chars.
   * Blah */
  while (fgets (line, 255, glob_file) != NULL)
    {
      char *colon;
      char *mimetype, *glob, *end;
      int weight;
      int case_sensitive;

      if (line[0] == '#' || line[0] == 0)
	continue;

      end = line + strlen(line) - 1;
      if (*end == '\n')
	*end = 0;

      p = line;
      if (version_two)
	{
	  colon = strchr (p, ':');
	  if (colon == NULL)
	    continue;
	  *colon = 0;
          weight = atoi (p);
	  p = colon + 1;
	}
      else
	weight = 50;

      colon = strchr (p, ':');
      if (colon == NULL)
	continue;
      *colon = 0;

      mimetype = p;
      p = colon + 1;
      glob = p;
      case_sensitive = FALSE;

      colon = strchr (p, ':');
      if (version_two && colon != NULL)
	{
	  char *flag;

	  /* We got flags */
	  *colon = 0;
	  p = colon + 1;

	  /* Flags end at next colon */
	  colon = strchr (p, ':');
	  if (colon != NULL)
	    *colon = 0;

	  flag = strstr (p, "cs");
	  if (flag != NULL &&
	      /* Start or after comma */
	      (flag == p ||
	       flag[-1] == ',') &&
	      /* ends with comma or end of string */
	      (flag[2] == 0 ||
	       flag[2] == ','))
	    case_sensitive = TRUE;
	}

      _xdg_glob_hash_append_glob (glob_hash, glob, mimetype, weight, case_sensitive);
    }

  fclose (glob_file);
}
