--- a
+++ b/R/get_graph_stats.R
@@ -0,0 +1,99 @@
+#' Get graph statistics
+#' 
+#' For a given igraph or list of igraph objects, this function summarize 
+#' the number of vertices/edges and other vertex attributes.
+#' 
+#' @param X an 'igraph' or 'list.igraph' object
+#' 
+#' @return 
+#' It returns a long data.frame with number of nodes/edges, 
+#' and the count of the different attributes 
+#' (if X is a list of graph, each row describes a graph)
+#' 
+#' @examples
+#' graph1 <- igraph::graph_from_data_frame(
+#'     list(from = c('A', 'B', 'A', 'D', 'C', 'A', 'C'),
+#'          to = c('B', 'C', 'D', 'E', 'D', 'F', 'G')), 
+#'     directed = FALSE)
+#' graph1 <- igraph::set_vertex_attr(graph = graph1, 
+#'                                   name = 'type', 
+#'                                   index = c('A','B','C'), 
+#'                                   value = '1')
+#' graph1 <- igraph::set_vertex_attr(graph = graph1, 
+#'                                   name = 'type', 
+#'                                   index = c('D','E'),
+#'                                   value = '2')
+#' graph1 <- igraph::set_vertex_attr(graph = graph1, 
+#'                                   name = 'type', 
+#'                                   index = c('F', 'G'),
+#'                                   value = '-1')
+#' 
+#' get_graph_stats(graph1)
+#' 
+#' graph1.list <- list(graph1 = graph1, 
+#'                     graph2 = graph1)
+#' get_graph_stats(graph1.list)
+#' 
+#' @importFrom minet build.mim aracne
+#' @importFrom magrittr %>%
+#' @importFrom dplyr select all_of
+#' @importFrom purrr imap_dfr
+#' @importFrom igraph set_vertex_attr graph_from_adjacency_matrix
+#' @export
+get_graph_stats <- function(X) {
+    
+    X <- check_graph(X)
+    
+    if (is(X, "list") |
+        is(X, "list.igraph")) {
+        as.data.frame(
+            lapply(X, function(x) .get_graph_stats_graph(x)),
+            check.names = FALSE
+        )
+        stats <- as.data.frame(
+            purrr::imap_dfr(X, ~.get_graph_stats_graph(.x)),
+            check.names = FALSE
+        )
+        rownames(stats) <- names(X)
+        
+    } else {
+        # X is not a list
+        stats <- .get_graph_stats_graph(X)
+    }
+    class(stats) <- c("stats", "data.frame")
+    return(stats)
+}
+
+
+#' @importFrom igraph degree ecount edge_density
+.get_graph_stats_graph <- function(X) {
+    node.c <- sum(igraph::degree(X) != 0)
+    node.i <- sum(igraph::degree(X) == 0)
+    edge <- igraph::ecount(X)
+    edge.density <- igraph::edge_density(graph = X)
+    res <- list(node.c = node.c, 
+                node.i = node.i, 
+                edge = edge, 
+                edge.density = edge.density)
+    
+    if (any(names(vertex_attr(X)) !="name")) {
+        item <- names(vertex_attr(X))[names(vertex_attr(X)) != "name"]
+        vertex.attr.res <- as.data.frame(
+            vertex_attr(X),
+            check.names = FALSE
+        ) %>%
+          # tidyselect deprecation was:
+            # dplyr::select(item)
+            # Now:
+            dplyr::select(dplyr::all_of(item))
+        for (i in item) {
+            tmp <- as.list(table(vertex.attr.res[[i]]))
+            for (j in names(tmp)) {
+                name_item <- paste(i, j, sep = ":")
+                res[[name_item]] <- tmp[[j]]
+            }
+        }
+    }
+    return(as.data.frame(res, check.names = FALSE))
+}
+