Add --show-changelog flag to flatpak-info

This shows the latest changelog entry from the appstream data for
a given app.

app/flatpak-builtins-info.c

@@ -47,6 +47,7 @@ static gboolean opt_show_sdk;
 static gboolean opt_show_permissions;
 static gboolean opt_show_extensions;
 static gboolean opt_show_location;
+static gboolean opt_show_changelog;
 static char *opt_arch;
 static char **opt_installations;
 static char *opt_file_access;
@@ -67,6 +68,7 @@ static GOptionEntry options[] = {
  { "file-access", 0, 0, G_OPTION_ARG_FILENAME, &opt_file_access, N_("Query file access"), N_("PATH") },
  { "show-extensions", 'e', 0, G_OPTION_ARG_NONE, &opt_show_extensions, N_("Show extensions"), NULL },
  { "show-location", 'l', 0, G_OPTION_ARG_NONE, &opt_show_location, N_("Show location"), NULL },
+ { "show-changelog", 0, 0, G_OPTION_ARG_NONE, &opt_show_changelog, N_("Show changelog"), NULL },
  { NULL }
 };
 
@@ -166,7 +168,7 @@ flatpak_builtin_info (int argc, char **argv, GCancellable *cancellable, GError *
  metakey = flatpak_deploy_get_metadata (deploy);
 
  if (opt_show_ref || opt_show_origin || opt_show_commit || opt_show_size || opt_show_metadata || opt_show_permissions ||
- opt_file_access || opt_show_location || opt_show_runtime || opt_show_sdk)
+ opt_file_access || opt_show_location || opt_show_runtime || opt_show_sdk || opt_show_changelog)
  friendly = FALSE;
 
  if (friendly)
@@ -443,6 +445,38 @@ flatpak_builtin_info (int argc, char **argv, GCancellable *cancellable, GError *
  g_print ("read-write\n");
  }
  }
+
+ if (opt_show_changelog)
+ {
+#if AS_CHECK_VERSION(1, 0, 0)
+ g_autoptr(AsMetadata) mdata = as_metadata_new ();
+ g_autofree char *remote = g_strdup ("flathub"); // FIXME: Returns NULL: flatpak_decomposed_dup_remote(ref);
+ g_autofree char *arch = flatpak_decomposed_dup_arch (ref);
+ g_autoptr(GError) appstream_error = NULL;
+ g_autoptr(GPtrArray) dirs = g_ptr_array_new ();
+ AsComponent *component;
+
+ g_ptr_array_add(dirs, dir);
+
+ update_appstream (dirs, remote, arch, FLATPAK_APPSTREAM_TTL, TRUE, cancellable, NULL);
+ flatpak_dir_load_appstream_data (dir, remote, arch, mdata, cancellable, &appstream_error);
+
+ component = metadata_find_component (mdata, flatpak_decomposed_get_ref(ref));
+ if (component)
+ {
+ AsReleaseList *releases = as_component_get_releases_plain(component);
+ AsRelease *release = as_release_list_index_safe (releases, 0);
+ if (releases)
+ flatpak_print_appstream_release_description_markup (as_release_get_description (release));
+ else
+ g_print ("No changelog\n");
+ }
+ else
+ g_print ("Failed to find app, missing appstream data?\n");
+#else
+ g_warning ("Listing changelogs is not supported with this version of libappstream"); 
+#endif
+ }
  }
 
  if (opt_show_extensions)

app/flatpak-tty-utils-private.h

@@ -83,3 +83,5 @@ void flatpak_format_choices (const char **choices,
 
 void flatpak_print_escaped_string (const char *s,
  FlatpakEscapeFlags flags);
+
+void flatpak_print_appstream_release_description_markup (const char *s);

app/flatpak-tty-utils.c

@@ -521,3 +521,119 @@ flatpak_print_escaped_string (const char *s,
  g_autofree char *escaped = flatpak_escape_string (s, flags);
  g_print ("%s", escaped);
 }
+
+/* Markup format documented here: https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-description */
+typedef struct {
+ GString *formatted;
+ guint current_list_index;
+ gboolean in_list;
+ gboolean in_paragraph;
+} DescriptionParserData;
+
+static void
+start_element (GMarkupParseContext *context,
+ const char *element_name,
+ const char **attribute_names,
+ const char **attribute_values,
+ gpointer user_data,
+ GError **error)
+{
+ DescriptionParserData *data = user_data;
+
+ if (g_str_equal (element_name, "p"))
+ {
+ if (data->formatted->len != 0)
+ g_string_append_c (data->formatted, '\n');
+ data->in_paragraph = TRUE;
+ }
+ else if (!data->in_list && g_str_equal (element_name, "ol"))
+ {
+ data->in_list = TRUE;
+ data->current_list_index = 1;
+ }
+ else if (!data->in_list && g_str_equal (element_name, "ul"))
+ {
+ data->in_list = TRUE;
+ }
+ else if (data->in_list && g_str_equal (element_name, "li"))
+ {
+ if (data->formatted->len != 0)
+ g_string_append_c (data->formatted, '\n');
+
+ if (data->current_list_index)
+ g_string_append_printf(data->formatted, " %u. ", data->current_list_index++);
+ else
+ g_string_append(data->formatted, " - ");
+ }
+ else if ((data->in_list || data->in_paragraph) && g_str_equal (element_name, "em"))
+ {
+ g_string_append (data->formatted, "\033[3m");
+ }
+}
+
+static void
+end_element (GMarkupParseContext *context,
+ const char *element_name,
+ gpointer user_data,
+ GError **error)
+{
+ DescriptionParserData *data = user_data;
+
+ if (g_str_equal (element_name, "p"))
+ {
+ data->in_paragraph = FALSE;
+ }
+ else if (data->in_list && g_str_equal (element_name, "ol"))
+ {
+ data->in_list = FALSE;
+ data->current_list_index = 0; 
+ }
+ else if (data->in_list && g_str_equal (element_name, "ul"))
+ {
+ data->in_list = FALSE;
+ }
+ else if ((data->in_list || data->in_paragraph) && g_str_equal (element_name, "em"))
+ {
+ g_string_append (data->formatted, "\e[0m");
+ }
+}
+
+static void
+text (GMarkupParseContext *context,
+ const char *text,
+ gsize text_len,
+ gpointer user_data,
+ GError **error)
+{
+ DescriptionParserData *data = user_data;
+
+ g_string_append_len (data->formatted, text, text_len);
+}
+
+void
+flatpak_print_appstream_release_description_markup (const char *s)
+{
+ g_autoptr(GString) formatted = g_string_new_len(NULL, strlen (s));
+ g_autoptr(GError) error = NULL;
+ g_autoptr(GMarkupParseContext) context = NULL;
+ GMarkupParser parser = {
+ start_element,
+ end_element,
+ text,
+ NULL,
+ NULL
+ };
+
+ g_autofree DescriptionParserData *data = g_new0 (DescriptionParserData, 1);
+ data->formatted = formatted;
+
+ context = g_markup_parse_context_new (&parser, G_MARKUP_TREAT_CDATA_AS_TEXT, data, NULL);
+ if (!g_markup_parse_context_parse (context, s, -1, &error))
+ {
+ g_warning ("Failed to release description: %s", error->message);
+ return;
+ }
+
+ g_string_append_c (formatted, '\n');
+ g_print ("%s", formatted->str);
+}