#include <stdio.h>
#include <gio/gio.h>
#include <gtk/gtk.h>

GHashTable* mime2icon_table;
GList* fileinfos;

gchar* clean_content_type(gchar* string);

int main (int argc, char **argv) {
    gtk_init(&argc, &argv);
    //g_thread_init (NULL);
    //g_type_init ();

    if (argc < 2)
        return -1;

    // set up datatypes
    mime2icon_table = g_hash_table_new(g_str_hash, g_str_equal);

    GError *error;
    GFile *file = g_file_new_for_path (argv[1]);

    if(!g_file_query_exists(file, NULL)) {
        printf("File %s does not exist!", argv[1]);
	return 1;
    }

    create_mappings(file);

    // so now we got:
    // mime2icon_table: A full mapping mime-type => base64 encoded PNG icon files
    // fileinfos An ordered list of files, better said, file info objects
    //           containing all information about the files.
    // we can start constructing.

    if(g_list_length(fileinfos)) // directory non-empty
	construct();
}

gboolean construct() {
	GHashTable* clean_mime = g_hash_table_new(g_str_hash, g_str_equal);

	// create CSS from mime2icon_table:
	GHashTableIter iter;
	gpointer key, value;
	g_hash_table_iter_init(&iter, mime2icon_table);
	while(g_hash_table_iter_next(&iter, &key, &value)) {
		// create a clean mime type mapping
		gchar* clean_key = g_strdup(key);
		g_hash_table_insert(clean_mime, key, 
			// g_strcanon modifies it argument, thus the duping (cloning)
			g_strcanon(clean_key, "-_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", '_'));
		// print out CSS
		printf(".%s { background-image: url('data:image/png;base64,%s'); }\n", clean_key, (char*)value);
	} // foreach mime2icon

	// Create File listing:
	GList *e = g_list_first(fileinfos);
	GFileInfo* finf;
	for(e = g_list_first(fileinfos); e; e = g_list_next(e)) {
		finf = (GFileInfo*) e->data;
		
		// example for fully featured table:
		/*
		GTimeVal lastmod_t; g_file_info_get_modification_time(finf, &lastmod_t);
		GDate *lastmod = g_date_new(); g_date_set_time_val(lastmod, &lastmod_t);
		gchar lastmod_str[50]; g_date_strftime(lastmod_str, 49, "%m,%d,%y", lastmod);
		printf("<tr><td><a href='%s' class='%s'>%s</a></td>"
			"<td>%d</td><td>%s</td><td>%s</td>\n",
			g_file_info_get_name(finf),
			(char*) g_hash_table_lookup(clean_mime, g_file_info_get_content_type(finf)),
			g_file_info_get_name(finf),
			(int) g_file_info_get_size(finf),
			lastmod_str,
			g_content_type_get_description(g_file_info_get_content_type(finf))
		);
		*/

		// simple lightweight, CSV format: mime;clean_mime;desc;filename
		fprintf(stderr, "%s;%s;%s;%s\n",
			g_file_info_get_content_type(finf),
			(char*) g_hash_table_lookup(clean_mime, g_file_info_get_content_type(finf)),
			g_content_type_get_description(g_file_info_get_content_type(finf)),
			g_file_info_get_name(finf)
		);	
	} // for files
} // construct()


gboolean create_mappings(GFile* file_or_directory) {
    GError* error;
    if(g_file_query_file_type(file_or_directory, 0, NULL) == G_FILE_TYPE_DIRECTORY) {
	GFileEnumerator* enumerate = g_file_enumerate_children(file_or_directory, "standard::*", G_FILE_QUERY_INFO_NONE, NULL, &error);
	GFileInfo* file_info;
	while(file_info = g_file_enumerator_next_file(enumerate, NULL, &error)) {
        	char* content_type = (char*) g_file_info_get_content_type(file_info);
		if(g_hash_table_lookup(mime2icon_table, content_type)) {
			// we already found out the icon for this mime-type
			// printf("Skipping %s\n", g_file_info_get_name(file_info));
			continue;
		} else get_icon(file_info);
		// put filename on list
		fileinfos = g_list_append(fileinfos, file_info);
	} // for directory
    } else {
        // do one single step
        GFileInfo* file_info = g_file_query_info(file_or_directory, "standard::*", 0, NULL, &error);
	fileinfos = g_list_append(fileinfos, file_info);
	get_icon(file_info);
    }
}

gboolean get_icon(GFileInfo* file_info) {
    GError* error;
    GIcon *icon = g_file_info_get_icon (file_info);
    GtkIconTheme* theme = gtk_icon_theme_get_default();
    GtkIconInfo* icon_info = gtk_icon_theme_lookup_by_gicon(theme, icon, 32,
	GTK_ICON_LOOKUP_GENERIC_FALLBACK || GTK_ICON_LOOKUP_FORCE_SIZE
	|| GTK_ICON_LOOKUP_USE_BUILTIN /* as optional fallback */);
    GdkPixbuf* pixbuf;

    if(!icon_info) {
       // no icon found. STDOUT comment for CSS
       printf("/* %s - no icon found */\n", g_file_info_get_content_type(file_info));
       // load some standard icon!
       pixbuf = gtk_icon_theme_load_icon(theme, "gtk-file", 32, GTK_ICON_LOOKUP_GENERIC_FALLBACK, &error);
    } else {
       // const gchar* filename = gtk_icon_info_get_filename(icon_info);
       pixbuf = gtk_icon_info_load_icon(icon_info, &error);
    }

    // render pixbuf with icon to PNG; perform base64 encoding.
    gchar* pngbuf;
    gsize pngbuf_len;
    gboolean ret = gdk_pixbuf_save_to_buffer(pixbuf, &pngbuf, &pngbuf_len, "png", &error, "compression", "9", NULL);
    gchar* pngencoding = g_base64_encode(pngbuf, pngbuf_len);

    // store pngencoding in hash table
    g_hash_table_insert(mime2icon_table, (char*) g_file_info_get_content_type(file_info), pngencoding);

    // debugging:
    //printf ("File: %s\nIcon Filename: %s\nBASE: %20.20s..\n",
    //        g_file_info_get_name(file_info), filename, pngencoding);

    return TRUE;
}