/* GIO - GLib Input, Output and Streaming Library

 * 

 * Copyright (C) 2006-2007 Red Hat, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 *

 * Author: Alexander Larsson <alexl@redhat.com>

 */

#include "config.h"

#include <sys/types.h>

#include <sys/stat.h>

#include <string.h>

#include <errno.h>

#include <fcntl.h>

#include <stdlib.h>

#include "gdummyfile.h"

#include "gfile.h"

static void g_dummy_file_file_iface_init (GFileIface *iface);

typedef struct {

  char *scheme;

  char *userinfo;

  char *host;

  int port; /* -1 => not in uri */

  char *path;

  char *query;

  char *fragment;

} GDecodedUri;

struct _GDummyFile

{

  GObject parent_instance;

  GDecodedUri *decoded_uri;

  char *text_uri;

};

#define g_dummy_file_get_type _g_dummy_file_get_type

G_DEFINE_TYPE_WITH_CODE (GDummyFile, g_dummy_file, G_TYPE_OBJECT,

			 G_IMPLEMENT_INTERFACE (G_TYPE_FILE,

						g_dummy_file_file_iface_init))

#define SUB_DELIM_CHARS  "!$&'()*+,;="

static char *       _g_encode_uri       (GDecodedUri *decoded);

static void         _g_decoded_uri_free (GDecodedUri *decoded);

static GDecodedUri *_g_decode_uri       (const char  *uri);

static GDecodedUri *_g_decoded_uri_new  (void);

static char * unescape_string (const gchar *escaped_string,

			       const gchar *escaped_string_end,

			       const gchar *illegal_characters);

static void g_string_append_encoded (GString    *string, 

                                     const char *encoded,

				     const char *reserved_chars_allowed);

static void

g_dummy_file_finalize (GObject *object)

{

  GDummyFile *dummy;

  dummy = G_DUMMY_FILE (object);

  if (dummy->decoded_uri)

    _g_decoded_uri_free (dummy->decoded_uri);

  g_free (dummy->text_uri);

  G_OBJECT_CLASS (g_dummy_file_parent_class)->finalize (object);

}

static void

g_dummy_file_class_init (GDummyFileClass *klass)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->finalize = g_dummy_file_finalize;

}

static void

g_dummy_file_init (GDummyFile *dummy)

{

}

GFile *

_g_dummy_file_new (const char *uri)

{

  GDummyFile *dummy;

  g_return_val_if_fail (uri != NULL, NULL);

  dummy = g_object_new (G_TYPE_DUMMY_FILE, NULL);

  dummy->text_uri = g_strdup (uri);

  dummy->decoded_uri = _g_decode_uri (uri);

  return G_FILE (dummy);

}

static gboolean

g_dummy_file_is_native (GFile *file)

{

  return FALSE;

}

static char *

g_dummy_file_get_basename (GFile *file)

{

  GDummyFile *dummy = G_DUMMY_FILE (file);

  if (dummy->decoded_uri)

    return g_path_get_basename (dummy->decoded_uri->path);

  return g_strdup (dummy->text_uri);

}

static char *

g_dummy_file_get_path (GFile *file)

{

  return NULL;

}

static char *

g_dummy_file_get_uri (GFile *file)

{

  return g_strdup (G_DUMMY_FILE (file)->text_uri);

}

static char *

g_dummy_file_get_parse_name (GFile *file)

{

  return g_strdup (G_DUMMY_FILE (file)->text_uri);

}

static GFile *

g_dummy_file_get_parent (GFile *file)

{

  GDummyFile *dummy = G_DUMMY_FILE (file);

  GFile *parent;

  char *dirname;

  char *uri;

  GDecodedUri new_decoded_uri;

  if (dummy->decoded_uri == NULL ||

      g_strcmp0 (dummy->decoded_uri->path, "/") == 0)

    return NULL;

  dirname = g_path_get_dirname (dummy->decoded_uri->path);

  if (strcmp (dirname, ".") == 0)

    {

      g_free (dirname);

      return NULL;

    }

  new_decoded_uri = *dummy->decoded_uri;

  new_decoded_uri.path = dirname;

  uri = _g_encode_uri (&new_decoded_uri);

  g_free (dirname);

  parent = _g_dummy_file_new (uri);

  g_free (uri);

  return parent;

}

static GFile *

g_dummy_file_dup (GFile *file)

{

  GDummyFile *dummy = G_DUMMY_FILE (file);

  return _g_dummy_file_new (dummy->text_uri);

}

static guint

g_dummy_file_hash (GFile *file)

{

  GDummyFile *dummy = G_DUMMY_FILE (file);

  return g_str_hash (dummy->text_uri);

}

static gboolean

g_dummy_file_equal (GFile *file1,

		    GFile *file2)

{

  GDummyFile *dummy1 = G_DUMMY_FILE (file1);

  GDummyFile *dummy2 = G_DUMMY_FILE (file2);

  return g_str_equal (dummy1->text_uri, dummy2->text_uri);

}

static int

safe_strcmp (const char *a, 

             const char *b)

{

  if (a == NULL)

    a = "";

  if (b == NULL)

    b = "";

  return strcmp (a, b);

}

static gboolean

uri_same_except_path (GDecodedUri *a,

		      GDecodedUri *b)

{

  if (safe_strcmp (a->scheme, b->scheme) != 0)

    return FALSE;

  if (safe_strcmp (a->userinfo, b->userinfo) != 0)

    return FALSE;

  if (safe_strcmp (a->host, b->host) != 0)

    return FALSE;

  if (a->port != b->port)

    return FALSE;

  return TRUE;

}

static const char *

match_prefix (const char *path, 

              const char *prefix)

{

  int prefix_len;

  prefix_len = strlen (prefix);

  if (strncmp (path, prefix, prefix_len) != 0)

    return NULL;

  return path + prefix_len;

}

static gboolean

g_dummy_file_prefix_matches (GFile *parent, GFile *descendant)

{

  GDummyFile *parent_dummy = G_DUMMY_FILE (parent);

  GDummyFile *descendant_dummy = G_DUMMY_FILE (descendant);

  const char *remainder;

  if (parent_dummy->decoded_uri != NULL &&

      descendant_dummy->decoded_uri != NULL)

    {

      if (uri_same_except_path (parent_dummy->decoded_uri,

				descendant_dummy->decoded_uri)) 

        {

	  remainder = match_prefix (descendant_dummy->decoded_uri->path,

                                    parent_dummy->decoded_uri->path);

          if (remainder != NULL && *remainder == '/')

	    {

	      while (*remainder == '/')

	        remainder++;

	      if (*remainder != 0)

	        return TRUE;

	    }

        }

    }

  else

    {

      remainder = match_prefix (descendant_dummy->text_uri,

				parent_dummy->text_uri);

      if (remainder != NULL && *remainder == '/')

	  {

	    while (*remainder == '/')

	      remainder++;

	    if (*remainder != 0)

	      return TRUE;

	  }

    }

  return FALSE;

}

static char *

g_dummy_file_get_relative_path (GFile *parent,

				GFile *descendant)

{

  GDummyFile *parent_dummy = G_DUMMY_FILE (parent);

  GDummyFile *descendant_dummy = G_DUMMY_FILE (descendant);

  const char *remainder;

  if (parent_dummy->decoded_uri != NULL &&

      descendant_dummy->decoded_uri != NULL)

    {

      if (uri_same_except_path (parent_dummy->decoded_uri,

				descendant_dummy->decoded_uri)) 

        {

          remainder = match_prefix (descendant_dummy->decoded_uri->path,

                                    parent_dummy->decoded_uri->path);

          if (remainder != NULL && *remainder == '/')

	    {

	      while (*remainder == '/')

	        remainder++;

	      if (*remainder != 0)

	        return g_strdup (remainder);

	    }

        }

    }

  else

    {

      remainder = match_prefix (descendant_dummy->text_uri,

				parent_dummy->text_uri);

      if (remainder != NULL && *remainder == '/')

	  {

	    while (*remainder == '/')

	      remainder++;

	    if (*remainder != 0)

	      return unescape_string (remainder, NULL, "/");

	  }

    }

  return NULL;

}

static GFile *

g_dummy_file_resolve_relative_path (GFile      *file,

				    const char *relative_path)

{

  GDummyFile *dummy = G_DUMMY_FILE (file);

  GFile *child;

  char *uri;

  GDecodedUri new_decoded_uri;

  GString *str;

  if (dummy->decoded_uri == NULL)

    {

      str = g_string_new (dummy->text_uri);

      g_string_append (str, "/");

      g_string_append_encoded (str, relative_path, SUB_DELIM_CHARS ":@/");

      child = _g_dummy_file_new (str->str);

      g_string_free (str, TRUE);

    }

  else

    {

      new_decoded_uri = *dummy->decoded_uri;

      if (g_path_is_absolute (relative_path))

	new_decoded_uri.path = g_strdup (relative_path);

      else

	new_decoded_uri.path = g_build_filename (new_decoded_uri.path, relative_path, NULL);

      uri = _g_encode_uri (&new_decoded_uri);

      g_free (new_decoded_uri.path);

      child = _g_dummy_file_new (uri);

      g_free (uri);

    }

  return child;

}

static GFile *

g_dummy_file_get_child_for_display_name (GFile        *file,

					 const char   *display_name,

					 GError      **error)

{

  return g_file_get_child (file, display_name);

}

static gboolean

g_dummy_file_has_uri_scheme (GFile *file,

			     const char *uri_scheme)

{

  GDummyFile *dummy = G_DUMMY_FILE (file);

  if (dummy->decoded_uri)

    return g_ascii_strcasecmp (uri_scheme, dummy->decoded_uri->scheme) == 0;

  return FALSE;

}

static char *

g_dummy_file_get_uri_scheme (GFile *file)

{

  GDummyFile *dummy = G_DUMMY_FILE (file);

  if (dummy->decoded_uri)

    return g_strdup (dummy->decoded_uri->scheme);

  return NULL;

}

static void

g_dummy_file_file_iface_init (GFileIface *iface)

{

  iface->dup = g_dummy_file_dup;

  iface->hash = g_dummy_file_hash;

  iface->equal = g_dummy_file_equal;

  iface->is_native = g_dummy_file_is_native;

  iface->has_uri_scheme = g_dummy_file_has_uri_scheme;

  iface->get_uri_scheme = g_dummy_file_get_uri_scheme;

  iface->get_basename = g_dummy_file_get_basename;

  iface->get_path = g_dummy_file_get_path;

  iface->get_uri = g_dummy_file_get_uri;

  iface->get_parse_name = g_dummy_file_get_parse_name;

  iface->get_parent = g_dummy_file_get_parent;

  iface->prefix_matches = g_dummy_file_prefix_matches;

  iface->get_relative_path = g_dummy_file_get_relative_path;

  iface->resolve_relative_path = g_dummy_file_resolve_relative_path;

  iface->get_child_for_display_name = g_dummy_file_get_child_for_display_name;

  iface->supports_thread_contexts = TRUE;

}

/* Uri handling helper functions: */

static int

unescape_character (const char *scanner)

{

  int first_digit;

  int second_digit;

  first_digit = g_ascii_xdigit_value (*scanner++);

  if (first_digit < 0)

    return -1;

  second_digit = g_ascii_xdigit_value (*scanner++);

  if (second_digit < 0)

    return -1;

  return (first_digit << 4) | second_digit;

}

static char *

unescape_string (const gchar *escaped_string,

		 const gchar *escaped_string_end,

		 const gchar *illegal_characters)

{

  const gchar *in;

  gchar *out, *result;

  gint character;

  if (escaped_string == NULL)

    return NULL;

  if (escaped_string_end == NULL)

    escaped_string_end = escaped_string + strlen (escaped_string);

  result = g_malloc (escaped_string_end - escaped_string + 1);

  out = result;

  for (in = escaped_string; in < escaped_string_end; in++) 

    {

      character = *in;

      if (*in == '%') 

        {

          in++;

          if (escaped_string_end - in < 2)

	    {

	      g_free (result);

	      return NULL;

	    }

          character = unescape_character (in);

          /* Check for an illegal character. We consider '\0' illegal here. */

          if (character <= 0 ||

	      (illegal_characters != NULL &&

	       strchr (illegal_characters, (char)character) != NULL))

	    {

	      g_free (result);

	      return NULL;

	    }

          in++; /* The other char will be eaten in the loop header */

        }

      *out++ = (char)character;

    }

  *out = '\0';

  g_warn_if_fail (out - result <= strlen (escaped_string));

  return result;

}

void

_g_decoded_uri_free (GDecodedUri *decoded)

{

  if (decoded == NULL)

    return;

  g_free (decoded->scheme);

  g_free (decoded->query);

  g_free (decoded->fragment);

  g_free (decoded->userinfo);

  g_free (decoded->host);

  g_free (decoded->path);

  g_free (decoded);

}

GDecodedUri *

_g_decoded_uri_new (void)

{

  GDecodedUri *uri;

  uri = g_new0 (GDecodedUri, 1);

  uri->port = -1;

  return uri;

}

GDecodedUri *

_g_decode_uri (const char *uri)

{

  GDecodedUri *decoded;

  const char *p, *in, *hier_part_start, *hier_part_end, *query_start, *fragment_start;

  char *out;

  char c;

  /* From RFC 3986 Decodes:

   * URI         = scheme ":" hier-part [ "?" query ] [ "#" fragment ]

   */ 

  p = uri;

  /* Decode scheme:

     scheme      = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )

  */

  if (!g_ascii_isalpha (*p))

    return NULL;

  while (1)

    {

      c = *p++;

      if (c == ':')

	break;

      if (!(g_ascii_isalnum(c) ||

	    c == '+' ||

	    c == '-' ||

	    c == '.'))

	return NULL;

    }

  decoded = _g_decoded_uri_new ();

  decoded->scheme = g_malloc (p - uri);

  out = decoded->scheme;

  for (in = uri; in < p - 1; in++)

    *out++ = g_ascii_tolower (*in);

  *out = 0;

  hier_part_start = p;

  query_start = strchr (p, '?');

  if (query_start)

    {

      hier_part_end = query_start++;

      fragment_start = strchr (query_start, '#');

      if (fragment_start)

	{

	  decoded->query = g_strndup (query_start, fragment_start - query_start);

	  decoded->fragment = g_strdup (fragment_start+1);

	}

      else

	{

	  decoded->query = g_strdup (query_start);

	  decoded->fragment = NULL;

	}

    }

  else

    {

      /* No query */

      decoded->query = NULL;

      fragment_start = strchr (p, '#');

      if (fragment_start)

	{

	  hier_part_end = fragment_start++;

	  decoded->fragment = g_strdup (fragment_start);

	}

      else

	{

	  hier_part_end = p + strlen (p);

	  decoded->fragment = NULL;

	}

    }

  /*  3:

      hier-part   = "//" authority path-abempty

                  / path-absolute

                  / path-rootless

                  / path-empty

  */

  if (hier_part_start[0] == '/' &&

      hier_part_start[1] == '/')

    {

      const char *authority_start, *authority_end;

      const char *userinfo_start, *userinfo_end;

      const char *host_start, *host_end;

      const char *port_start;

      authority_start = hier_part_start + 2;

      /* authority is always followed by / or nothing */

      authority_end = memchr (authority_start, '/', hier_part_end - authority_start);

      if (authority_end == NULL)

	authority_end = hier_part_end;

      /* 3.2:

	      authority   = [ userinfo "@" ] host [ ":" port ]

      */

      userinfo_end = memchr (authority_start, '@', authority_end - authority_start);

      if (userinfo_end)

	{

	  userinfo_start = authority_start;

	  decoded->userinfo = unescape_string (userinfo_start, userinfo_end, NULL);

	  if (decoded->userinfo == NULL)

	    {

	      _g_decoded_uri_free (decoded);

	      return NULL;

	    }

	  host_start = userinfo_end + 1;

	}

      else

	host_start = authority_start;

      port_start = memchr (host_start, ':', authority_end - host_start);

      if (port_start)

	{

	  host_end = port_start++;

	  decoded->port = atoi(port_start);

	}

      else

	{

	  host_end = authority_end;

	  decoded->port = -1;

	}

      decoded->host = g_strndup (host_start, host_end - host_start);

      hier_part_start = authority_end;

    }

  decoded->path = unescape_string (hier_part_start, hier_part_end, "/");

  if (decoded->path == NULL)

    {

      _g_decoded_uri_free (decoded);

      return NULL;

    }

  return decoded;

}

static gboolean

is_valid (char c, const char *reserved_chars_allowed)

{

  if (g_ascii_isalnum (c) ||

      c == '-' ||

      c == '.' ||

      c == '_' ||

      c == '~')

    return TRUE;

  if (reserved_chars_allowed &&

      strchr (reserved_chars_allowed, c) != NULL)

    return TRUE;

  return FALSE;

}

static void

g_string_append_encoded (GString    *string,

                         const char *encoded,

			 const char *reserved_chars_allowed)

{

  unsigned char c;

  static const gchar hex[16] = "0123456789ABCDEF";

  while ((c = *encoded) != 0)

    {

      if (is_valid (c, reserved_chars_allowed))

	{

	  g_string_append_c (string, c);

	  encoded++;

	}

      else

	{

	  g_string_append_c (string, '%');

	  g_string_append_c (string, hex[((guchar)c) >> 4]);

	  g_string_append_c (string, hex[((guchar)c) & 0xf]);

	  encoded++;

	}

    }

}

static char *

_g_encode_uri (GDecodedUri *decoded)

{

  GString *uri;

  uri = g_string_new (NULL);

  g_string_append (uri, decoded->scheme);

  g_string_append (uri, "://");

  if (decoded->host != NULL)

    {

      if (decoded->userinfo)

	{

	  /* userinfo    = *( unreserved / pct-encoded / sub-delims / ":" ) */

	  g_string_append_encoded (uri, decoded->userinfo, SUB_DELIM_CHARS ":");

	  g_string_append_c (uri, '@');

	}

      g_string_append (uri, decoded->host);

      if (decoded->port != -1)

	{

	  g_string_append_c (uri, ':');

	  g_string_append_printf (uri, "%d", decoded->port);

	}

    }

  g_string_append_encoded (uri, decoded->path, SUB_DELIM_CHARS ":@/");

  if (decoded->query)

    {

      g_string_append_c (uri, '?');

      g_string_append (uri, decoded->query);

    }

  if (decoded->fragment)

    {

      g_string_append_c (uri, '#');

      g_string_append (uri, decoded->fragment);

    }

  return g_string_free (uri, FALSE);

}