//
// !!! THIS IS STILL A CONCEPT/PROTOTYPE. USE AT YOUR OWN RISK !!!
//
// Author:      Michal Idziorek <m.i@gmx.at>
//
// Last Update: 16th March 2018
//
// Last Tested: with surf commit 81f0452bc6c2a110239fa303ad1e72f11c33dc94
//              from htps://git.suckless.org/surf
//
// The following simple Webkit2GTK+ extension was hacked together
// in the sleepless night between 09th and 10th March 2018 (and later 
// refined).
//
// The DOM is manipulated,i.e: a <span> with a number added to every 
// link encountered.
// 
// Named FIFO pipes are used for communication with the ui process.
//
// TODO: g_free where appropriate !!
// TODO: allow focus on input boxes/forms 
// TODO: 1024 hardcoded doc references!. make dynamic and free unused.
// TODO: more todos directly in source
// TODO: implement New window in surf on msg receive
// TODO: fix hints positions!
//

#include <webkit2/webkit-web-extension.h>

#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>

#include "piper_webext.h"

#define CSS_CLASS_NAME "webext_piper_hint"
#define MAX_DOCS 1024

WebKitDOMHTMLDocument *my_doc[MAX_DOCS];
bool                  hints_active[MAX_DOCS];

void hide_hints(WebKitDOMHTMLDocument *doc,int skip)
{
    WebKitDOMNodeList *hints=webkit_dom_document_get_elements_by_class_name (doc,CSS_CLASS_NAME);
    gulong c=webkit_dom_node_list_get_length (hints);

    int s=0;
    for(gulong i=0;i<c;i++)
    {
	if(i==skip){s++;c--;}
	if(i==c)continue;
        WebKitDOMNode *node = webkit_dom_node_list_item (hints,s);
	WebKitDOMNode *parent = webkit_dom_node_get_parent_node (node);
	webkit_dom_node_remove_child (parent,node,NULL);
	
    }
}

void show_hints(WebKitDOMHTMLDocument *doc)
{
    WebKitDOMElement *body = webkit_dom_document_get_body(doc);
    WebKitDOMHTMLCollection *links = webkit_dom_document_get_links(doc);
    gulong c = webkit_dom_html_collection_get_length (links);

    for(gulong i=0;i<c;i++)
    {
	char buf[1024];
	WebKitDOMHTMLAnchorElement *node = webkit_dom_html_collection_item (links,i);
	WebKitDOMClientRect *rect=webkit_dom_element_get_bounding_client_rect (node);

	snprintf(buf,1024,"<span class='%s' style='"\

		"border:1px solid black;"\
		"font-weight:bold;"\
		"font-face:Arial;"\
		"font-size:10px;"\
		"color:rgba(255,255,255,1);"\
		"padding:3px;"\
		"background-color:rgba(255,0,0,0.5);"\
		"position:absolute;"\
		"z-index:100000;"\
		"left:%ipx;"\
		"top:%ipx;"\

		"'>%03d</span>",
		CSS_CLASS_NAME,(int)webkit_dom_element_get_scroll_left(body)+(int)webkit_dom_client_rect_get_left(rect),(int)webkit_dom_element_get_scroll_top(body)+(int)webkit_dom_client_rect_get_top(rect),i);
	webkit_dom_element_insert_adjacent_html (body,"beforeend",buf,NULL);
    }
}

void toggle_hints(int i)
{
    if(hints_active[i])
    {
	hide_hints(my_doc[i],-1);
	hints_active[i]=false;
	return;
    }

    show_hints(my_doc[i]);
    hints_active[i]=true;
}

void
document_loaded_callback (WebKitWebPage *web_page,
                          GPtrArray     *elements,
                          GVariant      *user_data)
{
    int id=webkit_web_page_get_id(web_page);
    g_print("Document Loaded Callback Called (page id:%i)\n",id); 
    hints_active[id]=false;
    my_doc[id] = webkit_web_page_get_dom_document(web_page);
}

void
page_created_callback (WebKitWebExtension *extension,
                       WebKitWebPage      *web_page,
                       GVariant           *user_data)
{
    g_print("Page Created Callback Called\n"); 

    g_signal_connect (web_page, "document-loaded", 
                      G_CALLBACK (document_loaded_callback), 
                      user_data);
}

static void follow_link(int id,int link_num,bool new_win)
{
    WebKitDOMHTMLCollection *links = webkit_dom_document_get_links(my_doc[id]);
    gulong c = webkit_dom_html_collection_get_length (links);
    if(link_num>=c)return;
    WebKitDOMHTMLAnchorElement *node = webkit_dom_html_collection_item (links,link_num);
    if(!new_win)
    {
	hide_hints(my_doc[id],link_num);
	hints_active[id]=false;
	webkit_dom_html_element_click(node);
	return;
    }
    char *href=webkit_dom_html_anchor_element_get_href (node);
    char buf[1024];
    snprintf(buf,1024,"%s\n",href);
    piper_send(buf);
}

void rcv(char *msg)
{
    static int num[3];
    static int l=0;
    static bool new=false;
    int id;
    int cmd;
    sscanf(msg,"%d %d",&id,&cmd);
    
    if(cmd<10)
    {
	num[l++]=cmd;
	if(l==3)
	{
	    int link_num=100*num[0]+10*num[1]+num[2];
	    g_printf("link_num: %i\n",link_num);
	    l=0;
	    follow_link(id,link_num,new);
	}
    }
    else
    {
	l=0;
	if(cmd==100)new=false;
	if(cmd==101)new=true;
	toggle_hints(id);
    }

}

G_MODULE_EXPORT void
webkit_web_extension_initialize_with_user_data (WebKitWebExtension *extension,
					        GVariant           *user_data)
{
    g_print("webext started [%i]\n",getpid());
    piper_init("surf-to-ext","ext-to-surf",rcv,NULL);
    
    g_signal_connect (extension, "page-created", 
                      G_CALLBACK (page_created_callback),
                      user_data );
    
}