/*

 * caps.c       -- Entity Capabilities Cache for mcabber

 *

 * Copyright (C) 2008-2010 Frank Zschockelt <mcabber@freakysoft.de>

 *

 * 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, see <http://www.gnu.org/licenses/>.

 */

#include <glib.h>

#include <string.h>

#include <sys/stat.h>

#include <unistd.h>

#include <fcntl.h>

#include "settings.h"

#include "utils.h"

typedef struct {

  char *category;

  char *type;

  char *name;

typedef struct {

  GHashTable *fields;

typedef struct {

  GHashTable *identities;

  GHashTable *features;

  GHashTable *forms;

static GHashTable *caps_cache = NULL;

void caps_destroy(gpointer data)

{

  g_hash_table_destroy(c->identities);

  g_hash_table_destroy(c->features);

  g_hash_table_destroy(c->forms);

  g_free(c);

}

void identity_destroy(gpointer data)

{

  g_free(i->category);

  g_free(i->type);

  g_free(i->name);

  g_free(i);

}

void form_destroy(gpointer data)

{

  g_hash_table_destroy(f->fields);

  g_free(f);

}

void field_destroy(gpointer data)

{

  GList *v = data;

  g_list_foreach (v, (GFunc) g_free, NULL);

  g_list_free (v);

}

void caps_init(void)

{

  if (!caps_cache)

    caps_cache = g_hash_table_new_full(g_str_hash, g_str_equal,

                                       g_free, caps_destroy);

}

void caps_free(void)

{

  if (caps_cache) {

    g_hash_table_destroy(caps_cache);

    caps_cache = NULL;

  }

}

void caps_add(const char *hash)

{

  if (!hash)

    return;

  c->features = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);

  c->identities = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, identity_destroy);

  c->forms = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, form_destroy);

  g_hash_table_replace(caps_cache, g_strdup(hash), c);

}

void caps_remove(const char *hash)

{

  if (!hash)

    return;

  g_hash_table_remove(caps_cache, hash);

}

/* if hash is not verified, this will bind capabilities set only with bare jid */

void caps_move_to_local(char *hash, char *bjid)

{

  char *orig_hash;

  if (!hash || !bjid)

    return;

  g_hash_table_lookup_extended(caps_cache, hash, (gpointer*)&orig_hash, (gpointer*)&c);

  if (c) {

    g_hash_table_steal(caps_cache, hash);

    g_free(orig_hash);

    g_hash_table_replace(caps_cache, g_strdup_printf("%s/#%s", bjid, hash), c);

    // solidus is guaranteed to never appear in bare jid

    // hash will not appear in base64 encoded hash

    // sequence "/#" is deterministic separator, and allows to identify local cache entry

  }

}

/*if bjid is NULL, it will check only verified hashes */

int caps_has_hash(const char *hash, const char *bjid)

{

  if (!hash)

    return 0;

  c = g_hash_table_lookup(caps_cache, hash);

  if (!c && bjid) {

    char *key = g_strdup_printf("%s/#%s", bjid, hash);

    c = g_hash_table_lookup(caps_cache, key);

    g_free(key);

  }

  return (c != NULL);

}

void caps_add_identity(const char *hash,

                       const char *category,

                       const char *name,

                       const char *type,

                       const char *lang)

{

  if (!hash || !category || !type)

    return;

  if (!lang)

    lang = "";

  c = g_hash_table_lookup(caps_cache, hash);

  if (c) {

    i->category = g_strdup(category);

    i->name = g_strdup(name);

    i->type = g_strdup(type);

    g_hash_table_replace(c->identities, g_strdup(lang), i);

  }

}

void caps_set_identity(char *hash,

                       const char *category,

                       const char *name,

                       const char *type)

{

  caps_add_identity(hash, category, name, type, NULL);

}

void caps_add_dataform(const char *hash, const char *formtype)

{

  if (!formtype)

    return;

  c = g_hash_table_lookup(caps_cache, hash);

  if (c) {

    char *f = g_strdup(formtype);

    d->fields = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, field_destroy);

    g_hash_table_replace(c->forms, f, d);

  }

}

gint _strcmp_sort(gconstpointer a, gconstpointer b)

{

  return g_strcmp0(a, b);

}

void caps_add_dataform_field(const char *hash, const char *formtype,

                             const char *field, const char *value)

{

  if (!formtype || !field || !value)

    return;

  c = g_hash_table_lookup(caps_cache, hash);

  if (c) {

    d = g_hash_table_lookup(c->forms, formtype);

    if (d) {

      gpointer key, val;

      char *f;

      GList *v = NULL;

      if (g_hash_table_lookup_extended(d->fields, field, &key, &val)) {

        g_hash_table_steal(d->fields, field);

        g_free(key);

        v = val;

      }

      f = g_strdup(field);

      v = g_list_insert_sorted(v, g_strdup(value), _strcmp_sort);

      g_hash_table_replace(d->fields, f, v);

    }

  }

}

void caps_add_feature(const char *hash, const char *feature)

{

  if (!hash || !feature)

    return;

  c = g_hash_table_lookup(caps_cache, hash);

  if (c) {

    char *f = g_strdup(feature);

    g_hash_table_replace(c->features, f, f);

  }

}

/* If hash is verified, then bare jid is ignored.

 * If there is no globally verified hash, and bare jid is not null,

 * then local storage for that jid will be checked */

int caps_has_feature(const char *hash, char *feature, char *bjid)

{

  if (!hash || !feature)

    return 0;

  c = g_hash_table_lookup(caps_cache, hash);

  if (!c && bjid) {

    char *key = g_strdup_printf("%s/#%s", bjid, hash);

    c = g_hash_table_lookup(caps_cache, key);

    g_free(key);

  }

  if (c)

    return (g_hash_table_lookup(c->features, feature) != NULL);

  return 0;

}

static GFunc _foreach_function;

void _caps_foreach_helper(gpointer key, gpointer value, gpointer user_data)

{

  // GFunc func = (GFunc)user_data;

  _foreach_function(value, user_data);

}

void caps_foreach_feature(const char *hash, GFunc func, gpointer user_data)

{

  if (!hash)

    return;

  c = g_hash_table_lookup(caps_cache, hash);

  if (!c)

    return;

  _foreach_function = func;

  g_hash_table_foreach(c->features, _caps_foreach_helper, user_data);

}

// Generates the sha1 hash for the special capability "" and returns it

const char *caps_generate(void)

{

  GList *features, *langs;

  GChecksum *sha1;

  guint8 digest[20];

  gsize digest_size = 20;

  gchar *hash, *old_hash = NULL;

  gpointer key;

  if (!g_hash_table_lookup_extended(caps_cache, "", &key, (gpointer *)&c))

    return NULL;

  g_hash_table_steal(caps_cache, "");

  g_free(key);

  sha1 = g_checksum_new(G_CHECKSUM_SHA1);

  langs = g_hash_table_get_keys(c->identities);

  langs = g_list_sort(langs, _strcmp_sort);

  {

    GList *lang;

    char *identity_S;

    for (lang=langs; lang; lang=lang->next) {

      i = g_hash_table_lookup(c->identities, lang->data);

      identity_S = g_strdup_printf("%s/%s/%s/%s<", i->category, i->type,

                                   (char *)lang->data, i->name ? i->name : "");

      g_checksum_update(sha1, (guchar *)identity_S, -1);

      g_free(identity_S);

    }

  }

  g_list_free(langs);

  features = g_hash_table_get_values(c->features);

  features = g_list_sort(features, _strcmp_sort);

  {

    GList *feature;

    for (feature=features; feature; feature=feature->next) {

      g_checksum_update(sha1, feature->data, -1);

      g_checksum_update(sha1, (guchar *)"<", -1);

    }

  }

  g_list_free(features);

  g_checksum_get_digest(sha1, digest, &digest_size);

  hash = g_base64_encode(digest, digest_size);

  g_checksum_free(sha1);

  g_hash_table_lookup_extended(caps_cache, hash,

                               (gpointer *)&old_hash, (gpointer *)&old_caps);

  g_hash_table_insert(caps_cache, hash, c);

  if (old_hash)

    return old_hash;

  else

    return hash;

}

gboolean caps_verify(const char *hash, char *function)

{

  GList *features, *langs, *forms;

  GChecksum *checksum;

  guint8 digest[20];

  gsize digest_size = 20;

  gchar *local_hash;

  gboolean match = FALSE;

  if (!g_strcmp0(function, "sha-1")) {

    checksum = g_checksum_new(G_CHECKSUM_SHA1);

  } else if (!g_strcmp0(function, "md5")) {

    checksum = g_checksum_new(G_CHECKSUM_MD5);

    digest_size = 16;

  } else

    return FALSE;

  langs = g_hash_table_get_keys(c->identities);

  langs = g_list_sort(langs, _strcmp_sort);

  {

    GList *lang;

    char *identity_S;

    for (lang=langs; lang; lang=lang->next) {

      i = g_hash_table_lookup(c->identities, lang->data);

      identity_S = g_strdup_printf("%s/%s/%s/%s<", i->category, i->type,

                                   (char *)lang->data, i->name ? i->name : "");

      g_checksum_update(checksum, (guchar *)identity_S, -1);

      g_free(identity_S);

    }

  }

  g_list_free(langs);

  features = g_hash_table_get_values(c->features);

  features = g_list_sort(features, _strcmp_sort);

  {

    GList *feature;

    for (feature=features; feature; feature=feature->next) {

      g_checksum_update(checksum, feature->data, -1);

      g_checksum_update(checksum, (guchar *)"<", -1);

    }

  }

  g_list_free(features);

  forms = g_hash_table_get_keys(c->forms);

  forms = g_list_sort(forms, _strcmp_sort);

  {

    GList *form, *fields;

    for (form=forms; form; form=form->next) {

      d = g_hash_table_lookup(c->forms, form->data);

      g_checksum_update(checksum, form->data, -1);