subsurface/webservice.c

#include <libintl.h>
#include <glib/gi18n.h>
#include <libsoup/soup.h>
#include <libxml/tree.h>
#include <libxml/parser.h>
#include "dive.h"
#include "display-gtk.h"

enum {
	DD_STATUS_OK,
	DD_STATUS_ERROR_CONNECT,
	DD_STATUS_ERROR_ID,
	DD_STATUS_ERROR_PARSE,
};

static const gchar *download_dialog_status_text(const gint status)
{
	switch (status)	{
	case DD_STATUS_ERROR_CONNECT:
		return _("Connection Error: ");
	case DD_STATUS_ERROR_ID:
		return _("Invalid user identifier!");
	case DD_STATUS_ERROR_PARSE:
		return _("Cannot parse response!");
	}
	return _("Download Success!");
}

/* provides a state of the download dialog contents and the downloaded xml */
struct download_dialog_state {
	GtkWidget *uid;
	GtkWidget *status;
	GtkWidget *apply;
	gchar *xmldata;
};

/* this method uses libsoup as a backend. if there are some portability,
 * compatibility or speed issues, libcurl is a better choice. */
gboolean webservice_request_user_xml(const gchar *user_id,
	gchar **data,
	guint *len,
	guint *status_code)
{
	SoupMessage *msg;
	SoupSession *session;
	gboolean ret = FALSE;
	gchar url[80] = {0};

	session = soup_session_async_new();
	strcat(url, "http://api.hohndel.org/api/mydives/");
	strcat(url, user_id);
	strcat(url, "/xml");
	msg = soup_message_new("GET", url);
	soup_session_send_message(session, msg);
	if SOUP_STATUS_IS_SUCCESSFUL(msg->status_code) {
		*len = (guint)msg->response_body->length;
		*data = strdup((gchar *)msg->response_body->data);
		ret = TRUE;
	} else {
		*len = 0;
		*data = NULL;
	}
	*status_code = msg->status_code;
	soup_session_abort(session);
	g_object_unref(G_OBJECT(msg));
	g_object_unref(G_OBJECT(session));
	return ret;
}

/* requires that there is a <download> or <error> tag under the <root> tag */
static void download_dialog_traverse_xml(xmlNodePtr node, guint *download_status)
{
	xmlNodePtr cur_node;
	for (cur_node = node; cur_node; cur_node = cur_node->next) {
		if ((!strcmp(cur_node->name, (const gchar *)"download")) &&
			  (!strcmp(xmlNodeGetContent(cur_node), (const gchar *)"ok"))) {
			*download_status = DD_STATUS_OK;
			return;
		}	else if (!strcmp(cur_node->name, (const gchar *)"error")) {
			*download_status = DD_STATUS_ERROR_ID;
			return;
		}
	}
}

static guint download_dialog_parse_response(gchar *xmldata, guint len)
{
	xmlNodePtr root;
	xmlDocPtr doc = xmlParseMemory(xmldata, len);
	guint status = DD_STATUS_ERROR_PARSE;

	if (!doc)
		return DD_STATUS_ERROR_PARSE;
	root = xmlDocGetRootElement(doc);
	if (!root) {
		status = DD_STATUS_ERROR_PARSE;
		goto end;
	}
	if (root->children)
		download_dialog_traverse_xml(root->children, &status);
	end:
		xmlFreeDoc(doc);
		return status;
}

static void download_dialog_connect_cb(GtkWidget *w, gpointer data)
{
	struct download_dialog_state *state = (struct download_dialog_state *)data;
	const gchar *uid = gtk_entry_get_text(GTK_ENTRY(state->uid));
	guint len, status_connect, status_xml;
	gchar *xmldata;
	gboolean ret;
	gchar err[128] = {0};

	gtk_label_set_text(GTK_LABEL(state->status), _("Connecting..."));
	gtk_widget_set_sensitive(state->apply, FALSE);
	ret = webservice_request_user_xml(uid, &xmldata, &len, &status_connect);
	if (ret) {
		status_xml = download_dialog_parse_response(xmldata, len);
		gtk_label_set_text(GTK_LABEL(state->status), download_dialog_status_text(status_xml));
		if (status_xml != DD_STATUS_OK)
			ret = FALSE;
	} else {
		sprintf(err, "%s %u!", download_dialog_status_text(DD_STATUS_ERROR_CONNECT), status_connect);
		gtk_label_set_text(GTK_LABEL(state->status), err);
	}
	state->xmldata = xmldata;
	gtk_widget_set_sensitive(state->apply, ret);
}

static void download_dialog_release_xml(struct download_dialog_state *state)
{
	if (state->xmldata)
		free((void *)state->xmldata);
}

static void download_dialog_delete(GtkWidget *w, gpointer data)
{
	struct download_dialog_state *state = (struct download_dialog_state *)data;
	download_dialog_release_xml(state);
}

void webservice_download_dialog(void)
{
	const guint pad = 6;
	/* user entered value should be stored in the config */
	const gchar *current_uid = "41TFEC8ZMVD5DBE0JPBBU5JDDA2Y6T";
	GtkWidget *dialog, *vbox, *status, *info, *uid;
	GtkWidget *frame_uid, *frame_status, *download, *image, *apply;
	struct download_dialog_state state = {NULL};
	int result;

	dialog = gtk_dialog_new_with_buttons(_("Download From Web Service"),
		GTK_WINDOW(main_window),
		GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT,
		GTK_STOCK_APPLY,
		GTK_RESPONSE_ACCEPT,
		GTK_STOCK_CANCEL,
		GTK_RESPONSE_REJECT,
		NULL);

	apply = gtk_dialog_get_widget_for_response(GTK_DIALOG(dialog), GTK_RESPONSE_ACCEPT);
	gtk_widget_set_sensitive(apply, FALSE);

	vbox = gtk_dialog_get_content_area(GTK_DIALOG(dialog));
	info = gtk_label_new(_("Enter a user identifier and press 'Download'."
				 " Once the download is complete you can press 'Apply'"
				 " if you wish to apply the changes."));
	gtk_label_set_line_wrap(GTK_LABEL(info), TRUE);
	gtk_box_pack_start(GTK_BOX(vbox), info, FALSE, TRUE, 0);
	gtk_misc_set_padding(GTK_MISC(info), pad, pad);

	frame_uid = gtk_frame_new(_("User Identifier"));
	gtk_box_pack_start(GTK_BOX(vbox), frame_uid, FALSE, TRUE, pad);
	uid = gtk_entry_new();
	gtk_container_add(GTK_CONTAINER(frame_uid), uid);
	gtk_entry_set_max_length(GTK_ENTRY(uid), 30);
	gtk_entry_set_text(GTK_ENTRY(uid), current_uid);

	download = gtk_button_new_with_label(_(" Download"));
	image = gtk_image_new_from_stock(GTK_STOCK_CONNECT, GTK_ICON_SIZE_MENU);
	gtk_button_set_image(GTK_BUTTON(download), image);
	gtk_box_pack_start(GTK_BOX(vbox), download, FALSE, TRUE, pad);
	g_signal_connect(download, "clicked", G_CALLBACK(download_dialog_connect_cb), &state);

	frame_status = gtk_frame_new(_("Status"));
	status = gtk_label_new(_("Idle"));
	gtk_box_pack_start(GTK_BOX(vbox), frame_status, FALSE, TRUE, pad);
	gtk_container_add(GTK_CONTAINER(frame_status), status);
	gtk_misc_set_padding(GTK_MISC(status), pad, pad);

	state.uid = uid;
	state.status = status;
	state.apply = apply;

	gtk_widget_show_all(dialog);
	g_signal_connect(dialog, "delete-event", G_CALLBACK(download_dialog_delete), &state);
	result = gtk_dialog_run(GTK_DIALOG(dialog));
	if (result == GTK_RESPONSE_ACCEPT) {
		/* apply download */
		g_message("\napply download should happen here: \n\n %s", state.xmldata);
	}
	download_dialog_release_xml(&state);
	gtk_widget_destroy(dialog);
}