/*
 * librest - RESTful web services access
 * Copyright (c) 2008, 2009, Intel Corporation.
 *
 * Authors: Rob Bradford <rob@linux.intel.com>
 *          Ross Burton <ross@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU Lesser General Public License,
 * version 2.1, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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 program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

/*
 * TODO:
 *
 * Convenience API for authentication so that the user doesn't have to parse the
 * XML themselves.
 *
 * Function to parse a payload and return either a xml document or a GError.
 */

#include <config.h>
#include <stdlib.h>
#include <string.h>
#include <rest/rest-proxy.h>
#include <libsoup/soup.h>
#include "flickr-proxy.h"
#include "flickr-proxy-private.h"
#include "flickr-proxy-call.h"

G_DEFINE_TYPE (FlickrProxy, flickr_proxy, REST_TYPE_PROXY)

enum {
  PROP_0,
  PROP_API_KEY,
  PROP_SHARED_SECRET,
  PROP_TOKEN,
};

GQuark
flickr_proxy_error_quark (void)
{
  return g_quark_from_static_string ("rest-flickr-proxy");
}

static RestProxyCall *
_new_call (RestProxy *proxy)
{
  RestProxyCall *call;

  call = g_object_new (FLICKR_TYPE_PROXY_CALL,
                       "proxy", proxy,
                       NULL);

  return call;
}

static void
flickr_proxy_get_property (GObject *object, guint property_id,
                              GValue *value, GParamSpec *pspec)
{
  FlickrProxyPrivate *priv = PROXY_GET_PRIVATE (object);

  switch (property_id) {
  case PROP_API_KEY:
    g_value_set_string (value, priv->api_key);
    break;
  case PROP_SHARED_SECRET:
    g_value_set_string (value, priv->shared_secret);
    break;
  case PROP_TOKEN:
    g_value_set_string (value, priv->token);
    break;
  default:
    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
  }
}

static void
flickr_proxy_set_property (GObject *object, guint property_id,
                              const GValue *value, GParamSpec *pspec)
{
  FlickrProxyPrivate *priv = PROXY_GET_PRIVATE (object);

  switch (property_id) {
  case PROP_API_KEY:
    if (priv->api_key)
      g_free (priv->api_key);
    priv->api_key = g_value_dup_string (value);
    break;
  case PROP_SHARED_SECRET:
    if (priv->shared_secret)
      g_free (priv->shared_secret);
    priv->shared_secret = g_value_dup_string (value);
    break;
  case PROP_TOKEN:
    if (priv->token)
      g_free (priv->token);
    priv->token = g_value_dup_string (value);
    break;
  default:
    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
  }
}

static void
flickr_proxy_finalize (GObject *object)
{
  FlickrProxyPrivate *priv = PROXY_GET_PRIVATE (object);

  g_free (priv->api_key);
  g_free (priv->shared_secret);
  g_free (priv->token);

  G_OBJECT_CLASS (flickr_proxy_parent_class)->finalize (object);
}

#ifndef G_PARAM_STATIC_STRINGS
#define G_PARAM_STATIC_STRINGS (G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB)
#endif

static void
flickr_proxy_class_init (FlickrProxyClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  RestProxyClass *proxy_class = REST_PROXY_CLASS (klass);
  GParamSpec *pspec;

  g_type_class_add_private (klass, sizeof (FlickrProxyPrivate));

  object_class->get_property = flickr_proxy_get_property;
  object_class->set_property = flickr_proxy_set_property;
  object_class->finalize = flickr_proxy_finalize;

  proxy_class->new_call = _new_call;

  pspec = g_param_spec_string ("api-key",  "api-key",
                               "The API key", NULL,
                               G_PARAM_READWRITE|G_PARAM_CONSTRUCT_ONLY|G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class,
                                   PROP_API_KEY,
                                   pspec);

  pspec = g_param_spec_string ("shared-secret",  "shared-secret",
                               "The shared secret", NULL,
                               G_PARAM_READWRITE|G_PARAM_CONSTRUCT_ONLY|G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class,
                                   PROP_SHARED_SECRET,
                                   pspec);

  pspec = g_param_spec_string ("token",  "token",
                               "The request or access token", NULL,
                               G_PARAM_READWRITE|G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class,
                                   PROP_TOKEN,
                                   pspec);
}

static void
flickr_proxy_init (FlickrProxy *self)
{
  self->priv = PROXY_GET_PRIVATE (self);
}

RestProxy *
flickr_proxy_new (const char *api_key,
                 const char *shared_secret)
{
  return flickr_proxy_new_with_token (api_key,
                                      shared_secret,
                                      NULL);
}

RestProxy *
flickr_proxy_new_with_token (const char *api_key,
                             const char *shared_secret,
                             const char *token)
{
  return g_object_new (FLICKR_TYPE_PROXY, 
                       "api-key", api_key,
                       "shared-secret", shared_secret,
                       "token", token,
                       "url-format", "http://api.flickr.com/services/rest/",
                       "binding-required", FALSE,
                       NULL);
}

/**
 * flickr_proxy_get_api_key:
 * @proxy: an #FlickrProxy
 *
 * Get the API key.
 *
 * Returns: the API key. This string is owned by #FlickrProxy and should not be
 * freed.
 */
const char *
flickr_proxy_get_api_key (FlickrProxy *proxy)
{
  FlickrProxyPrivate *priv = PROXY_GET_PRIVATE (proxy);
  return priv->api_key;
}

/**
 * flickr_proxy_get_shared_secret:
 * @proxy: an #FlickrProxy
 *
 * Get the shared secret for authentication.
 *
 * Returns: the shared secret. This string is owned by #FlickrProxy and should not be
 * freed.
 */
const char *
flickr_proxy_get_shared_secret (FlickrProxy *proxy)
{
  FlickrProxyPrivate *priv = PROXY_GET_PRIVATE (proxy);
  return priv->shared_secret;
}

/**
 * flickr_proxy_get_token:
 * @proxy: an #FlickrProxy
 *
 * Get the current token.
 *
 * Returns: the token, or %NULL if there is no token yet.  This string is owned
 * by #FlickrProxy and should not be freed.
 */
const char *
flickr_proxy_get_token (FlickrProxy *proxy)
{
  FlickrProxyPrivate *priv = PROXY_GET_PRIVATE (proxy);
  return priv->token;
}

/**
 * flickr_proxy_set_token:
 * @proxy: an #FlickrProxy
 * @token: the access token
 *
 * Set the token.
 */
void
flickr_proxy_set_token (FlickrProxy *proxy, const char *token)
{
  FlickrProxyPrivate *priv;

  g_return_if_fail (FLICKR_IS_PROXY (proxy));
  priv = PROXY_GET_PRIVATE (proxy);

  if (priv->token)
    g_free (priv->token);

  priv->token = g_strdup (token);
}

char *
flickr_proxy_sign (FlickrProxy *proxy, GHashTable *params)
{
  FlickrProxyPrivate *priv;
  GString *s;
  GList *keys;
  char *md5;

  g_return_val_if_fail (FLICKR_IS_PROXY (proxy), NULL);
  g_return_val_if_fail (params, NULL);

  priv = PROXY_GET_PRIVATE (proxy);

  s = g_string_new (priv->shared_secret);

  keys = g_hash_table_get_keys (params);
  keys = g_list_sort (keys, (GCompareFunc)strcmp);

  while (keys) {
    const char *key;
    const char *value;

    key = keys->data;
    value = g_hash_table_lookup (params, key);

    g_string_append_printf (s, "%s%s", key, value);

    keys = g_list_delete_link (keys, keys);
  }

  md5 = g_compute_checksum_for_string (G_CHECKSUM_MD5, s->str, s->len);

  g_string_free (s, TRUE);

  return md5;
}

char *
flickr_proxy_build_login_url (FlickrProxy *proxy, const char *frob)
{
  SoupURI *uri;
  GHashTable *params;
  char *sig, *s;

  g_return_val_if_fail (FLICKR_IS_PROXY (proxy), NULL);

  uri = soup_uri_new ("http://flickr.com/services/auth/");
  params = g_hash_table_new (g_str_hash, g_str_equal);

  g_hash_table_insert (params, "api_key", proxy->priv->api_key);
  /* TODO: parameter */
  g_hash_table_insert (params, "perms", "read");
  if (frob)
    g_hash_table_insert (params, "frob", (gpointer)frob);

  sig = flickr_proxy_sign (proxy, params);
  g_hash_table_insert (params, "api_sig", sig);

  soup_uri_set_query_from_form (uri, params);

  s = soup_uri_to_string (uri, FALSE);

  g_free (sig);
  g_hash_table_destroy (params);
  soup_uri_free (uri);

  return s;
}

/**
 * flickr_proxy_is_successful:
 * @root: The root node of a parsed Flickr response
 * @error: #GError to set if the response was an error
 *
 * Examines the Flickr response and if it not a successful reply, set @error and
 * return FALSE.
 *
 * Returns: %TRUE if this response is successful, %FALSE otherwise.
 */
gboolean
flickr_proxy_is_successful (RestXmlNode *root, GError **error)
{
  RestXmlNode *node;

  g_return_val_if_fail (root, FALSE);

  if (strcmp (root->name, "rsp") != 0) {
    g_set_error (error, FLICKR_PROXY_ERROR, 0,
                 "Unexpected response from Flickr (root node %s)",
                 root->name);
    return FALSE;
  }

  if (strcmp (rest_xml_node_get_attr (root, "stat"), "ok") != 0) {
    node = rest_xml_node_find (root, "err");
    g_set_error_literal (error,FLICKR_PROXY_ERROR,
                         atoi (rest_xml_node_get_attr (node, "code")),
                         rest_xml_node_get_attr (node, "msg"));
    return FALSE;
  }

  return TRUE;
}

#if BUILD_TESTS
void
test_flickr_error (void)
{
  RestXmlParser *parser;
  RestXmlNode *root;
  GError *error;
  const char test_1[] = "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
    "<rsp stat=\"ok\"><auth></auth></rsp>";
  const char test_2[] = "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
    "<foobar/>";
  const char test_3[] = "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
    "<rsp stat=\"fail\"><err code=\"108\" msg=\"Invalid frob\" /></rsp>";

  parser = rest_xml_parser_new ();

  root = rest_xml_parser_parse_from_data (parser, test_1, sizeof (test_1) - 1);
  error = NULL;
  flickr_proxy_is_successful (root, &error);
  g_assert_no_error (error);
  rest_xml_node_unref (root);

  error = NULL;
  root = rest_xml_parser_parse_from_data (parser, test_2, sizeof (test_2) - 1);
  flickr_proxy_is_successful (root, &error);
  g_assert_error (error, FLICKR_PROXY_ERROR, 0);
  g_error_free (error);
  rest_xml_node_unref (root);

  error = NULL;
  root = rest_xml_parser_parse_from_data (parser, test_3, sizeof (test_3) - 1);
  flickr_proxy_is_successful (root, &error);
  g_assert_error (error, FLICKR_PROXY_ERROR, 108);
  g_error_free (error);
  rest_xml_node_unref (root);
}
#endif