#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <glib-2.0/glib.h>
#include <gtk-4.0/gtk/gtk.h>

// Simplified TreeNode structure for demonstration purposes
struct TreeNode_t
{
    gchar *text;
    struct TreeNode_t *child;
    struct TreeNode_t *next;
};

struct TreeNode_t *root = NULL;


// Function to create a new TreeNode instance
struct TreeNode_t *create_tree_node (const gchar* text)
{
    struct TreeNode_t *node = g_malloc0 (sizeof(struct TreeNode_t));
    node->text = g_strdup(text);
    node->child = NULL;
    return node;
}

// Function to add a child node to a parent node
void add_child_node (struct TreeNode_t *parent, struct TreeNode_t *child)
{
    struct TreeNode_t *cur;

    if (parent->child) {
        cur = parent->child;
        while (cur && cur->next) {
            cur = cur->next;
        }
        cur->next = child;
    } else {
        parent->child = child;
    }
}

// Recursive function to free a TreeNode and its children
void free_tree_node (struct TreeNode_t *node)
{
    struct TreeNode_t *cur;
    struct TreeNode_t *tmp;

    if (!node) return;
    
    // free siblings
    cur = node;
    while (cur) {
        tmp = cur->next;
        g_free(cur);
        cur = tmp;
    }
    
    // recursive free
    free_tree_node(node->child);
    g_free(node->text);
    g_free(node);
}

// Function to simulate getting a GListModel of children for a given TreeNode
GListModel* get_children_model (struct TreeNode_t *parent)
{
    struct TreeNode_t *child;

    GtkStringList *list = NULL;
    
    if (parent) {
        printf("[get_children_model] here is %s content : ", parent->text);

        child = parent->child;

        if (child) {
            list = gtk_string_list_new(NULL);
        }
        while(child) {
             gtk_string_list_append(list, child->text);
             printf("%s ", child->text);
             child = child->next;
        }
    }
    printf("\n");

    return G_LIST_MODEL(list);
}

// GtkTreeListModelCreateModelFunc callback implementation
GListModel* create_model_func(GObject *item, gpointer user_data)
{
    struct TreeNode_t *cur = root;
    struct TreeNode_t *parent = NULL;
    struct TreeNode_t *res = NULL;

    gchar *string =  gtk_string_object_get_string(GTK_STRING_OBJECT(item));
    
    parent = root;
    while (cur) {
        if (strcmp(string, cur->text) == NULL) {
            res = cur;
            break;
        }

        cur = cur->next;
        if (cur == NULL) {
            cur = parent->child;
            parent = cur;
        }
    }

    printf("[create_model_func] here is %s item\n", string);

    return get_children_model(cur);
}

void on_expander_toggled(GtkExpander *expander, gpointer user_data) {
    // This is a conceptual callback for when an expander is toggled
    GtkTreeListRow *row = GTK_TREE_LIST_ROW(user_data);
    gboolean is_expanded = gtk_tree_list_row_get_expanded(row);
    gtk_tree_list_row_set_expanded(row, !is_expanded);
    // Assuming you have a way to update your model's is_expanded property
    // Update your model here based on the new state
}

void on_setup_factory (GtkListItemFactory *factory, GtkListItem *list_item, gpointer user_data)
{
    GtkWidget* expander = gtk_expander_new (NULL);
    gtk_list_item_set_child (list_item, expander);
    printf("[on_setup_factory] here is an expander\n");
}

void on_bind_factory (GtkListItemFactory *factory, GtkListItem *list_item, gpointer user_data)
{
    GObject *item;
    const gchar *text;
    GtkTreeListRow *row = gtk_list_item_get_item(list_item);

    if (row != NULL) {
        text = gtk_string_object_get_string(GTK_STRING_OBJECT(gtk_tree_list_row_get_item(row)));
        GtkWidget *expander = gtk_list_item_get_child(list_item);
        gtk_expander_set_label(GTK_EXPANDER(expander), text);

        // Disconnect previous signal handlers to avoid stacking them
        g_signal_handlers_disconnect_by_func(expander, G_CALLBACK(on_expander_toggled), row);

        // Connect the signal handler
        g_signal_connect(expander, "activate", G_CALLBACK(on_expander_toggled), row);

        gtk_widget_set_margin_start(expander, gtk_tree_list_row_get_depth(row)*20);
        gboolean is_expanded = gtk_tree_list_row_get_expanded(row);
        //gtk_tree_list_row_set_expanded(row, !is_expanded);
    } else {
        printf("[on_bind_factory] here is NON %s content\n", text);
    }
}

// Application activation callback
void app_activate (GApplication *app, gpointer user_data)
{
    GtkWidget *window = gtk_application_window_new(GTK_APPLICATION(app));
    gtk_window_set_title(GTK_WINDOW(window), "GTK4 Tree Example");
    gtk_window_set_default_size(GTK_WINDOW(window), 400, 300);

    GtkStringList *model = gtk_string_list_new(NULL);
    gtk_string_list_append(model, root->text);

    // Create and setup the list view and item factory
    GtkListItemFactory *factory = gtk_signal_list_item_factory_new ();
    g_signal_connect (factory, "setup", G_CALLBACK(on_setup_factory), NULL);
    g_signal_connect (factory, "bind", G_CALLBACK(on_bind_factory), NULL);

    // Create a GtkTreeListModel
    GtkTreeListModel *tree_model = gtk_tree_list_model_new(
        G_LIST_MODEL(model),
        FALSE, // Passthrough - False in actual usage with dynamic children retrieval
        FALSE, // autoexpand
        (GtkTreeListModelCreateModelFunc)create_model_func,
        NULL,
        (GDestroyNotify)g_object_unref //(GDestroyNotify)free_tree_node
    );

    GtkNoSelection *selection_model = gtk_no_selection_new (
                                            G_LIST_MODEL (tree_model));

    GtkWidget *list_view = gtk_list_view_new (selection_model, factory);

    gtk_window_set_child(GTK_WINDOW(window), list_view);

    gtk_widget_set_visible(window, TRUE);
}

int main (int argc, char **argv)
{
    // Create a simple tree structure
    root = create_tree_node("Root");
    struct TreeNode_t *A = create_tree_node("A");
    struct TreeNode_t *B = create_tree_node("B");
    struct TreeNode_t *C = create_tree_node("C");
    struct TreeNode_t *D = create_tree_node("D");
    struct TreeNode_t *E = create_tree_node("E");
    struct TreeNode_t *F = create_tree_node("F");
    struct TreeNode_t *G = create_tree_node("G");
    add_child_node(root, A);
    add_child_node(A, B);
    add_child_node(B, C);
    add_child_node(C, D);
    add_child_node(E, F);
    add_child_node(F, G);

    GtkApplication *app = gtk_application_new("org.gtk.example", G_APPLICATION_FLAGS_NONE);
    g_signal_connect(app, "activate", G_CALLBACK(app_activate), NULL);
    int status = g_application_run(G_APPLICATION(app), argc, argv);
    g_object_unref(app);
    free_tree_node(root); // Ensure to free the tree structure after the app has finished
    return status;
}