#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include <assert.h>
#include "weechat-plugin.h"
#include "net.h"

WEECHAT_PLUGIN_NAME("tomsg")
WEECHAT_PLUGIN_DESCRIPTION("tomsg client plugin")
WEECHAT_PLUGIN_AUTHOR("Tom Smeding")
WEECHAT_PLUGIN_VERSION("0.1")
WEECHAT_PLUGIN_LICENSE("MIT")
WEECHAT_PLUGIN_PRIORITY(1000)


static const char *errpfx;


struct roomdata{
	char *name;
	struct t_gui_buffer *buffer;
	struct conndata *conn;  // do not free
};

struct conndata{
	int fd;
	struct t_hook *fd_hook;

	struct t_gui_buffer *buffer;

	int nrooms,roomscap;
	struct roomdata **rooms;

	char *username,*pending_username;

	i64 linebuf_sz,linebuf_len;
	char *linebuf;
};


FILE *debugf;

static struct t_weechat_plugin *weechat_plugin;

static struct t_hashtable *conntable;


static void close_room(struct roomdata *room){
	fprintf(debugf,"close_room(room=%p)\n",room);
	free(room->name);
	if(room->buffer)weechat_buffer_close(room->buffer);
	free(room);
}

static void message_net_callback(int fd,struct net_response res,void *payload){
	(void)payload;
	fprintf(debugf,"message_net_callback(fd=%d,res={.type=%d})\n",fd,res.type);
	struct conndata *conn=weechat_hashtable_get(conntable,&fd);
	assert(conn);
	if(res.type==NET_ERROR){
		weechat_printf(conn->buffer,"tomsg: send threw error: %s",res.error);
	} else if(res.type!=NET_OK){
		fprintf(debugf,"message_net_callback: res.type=%d\n",res.type);
	}
}

static int room_input_cb(const void *room_vp,void *_d,struct t_gui_buffer *buffer,const char *input){
	(void)_d; (void)buffer;
	struct roomdata *room=(struct roomdata*)room_vp;
	struct conndata *conn=room->conn;
	const char *tosend;
	const char *p=strchr(input,'\n');
	if(p!=NULL){
		fprintf(debugf,"room_input_cb: input contained newline <%s>\n",input);
		tosend=strdup(input);
		*strchr(tosend,'\n')='\0';
	} else {
		tosend=input;
	}

	net_sendf(conn->fd,message_net_callback,NULL,"send %s %s",room->name,tosend);
	weechat_printf(room->buffer,"%s\t%s",conn->username,tosend);

	if(tosend!=input){
		free((void*)tosend);
	}
	return WEECHAT_RC_OK;
}

static int room_close_cb(const void *room_vp,void *_d,struct t_gui_buffer *buffer){
	(void)_d; (void)buffer;
	struct roomdata *room=(struct roomdata*)room_vp;
	room->buffer=NULL;
	return WEECHAT_RC_OK;
}

static void push_net_callback(int fd,struct net_response res,void *payload){
	(void)payload;
	fprintf(debugf,"push_net_callback(fd=%d,res={.type=%d})\n",fd,res.type);
	struct conndata *conn=weechat_hashtable_get(conntable,&fd);
	assert(conn);
	if(res.type==NET_MESSAGE){
		i64 roomi;
		for(roomi=0;roomi<conn->nrooms;roomi++){
			if(strcmp(conn->rooms[roomi]->name,res.room)==0){
				break;
			}
		}
		if(roomi==conn->nrooms){
			fprintf(debugf,"push_net_callback: message to unknown room '%s'\n",res.room);
			return;
		}
		struct roomdata *room=conn->rooms[roomi];
		if(room->buffer==NULL){
			room->buffer=weechat_buffer_new(
				room->name,
				room_input_cb,room,NULL,
				room_close_cb,room,NULL);
		}
		weechat_printf_date_tags(
			room->buffer,res.timestamp/1000000LL,NULL,
			"%s\t%s",res.username,res.message);
	} else {
		fprintf(debugf,"push_net_callback: unknown response type %d\n",res.type);
	}
}

static void history_push_net_callback(int fd,struct net_response res,void *payload){
	push_net_callback(fd,res,payload);
}

static void history_net_callback(int fd,struct net_response res,void *payload){
	struct roomdata *room=(struct roomdata*)payload;
	assert(room);
	fprintf(debugf,"history_net_callback(fd=%d,res={.type=%d})\n",fd,res.type);
}

static void roomlist_net_callback(int fd,struct net_response res,void *payload){
	(void)payload;
	fprintf(debugf,"roomlist_net_callback(fd=%d,res={.type=%d})\n",fd,res.type);
	struct conndata *conn=weechat_hashtable_get(conntable,&fd);
	assert(conn);
	if(res.type==NET_LIST){
		for(i64 i=0;i<conn->nrooms;i++){
			close_room(conn->rooms[i]);
		}
		if(conn->roomscap<res.nitems){
			conn->roomscap=res.nitems+1;
			conn->rooms=realloc(conn->rooms,conn->roomscap*sizeof(struct roomdata*));
			assert(conn->rooms);
		}
		conn->nrooms=res.nitems;
		for(i64 i=0;i<res.nitems;i++){
			conn->rooms[i]=malloc(sizeof(struct roomdata));
			conn->rooms[i]->name=strdup(res.items[i]);
			conn->rooms[i]->buffer=weechat_buffer_new(
				conn->rooms[i]->name,
				room_input_cb,conn->rooms[i],NULL,
				room_close_cb,conn->rooms[i],NULL);
			conn->rooms[i]->conn=conn;
			net_sendf(fd,history_net_callback,conn->rooms[i],"history %s 10",conn->rooms[i]->name);
		}
	} else {
		fprintf(debugf,"roomlist_net_callback: res.type=%d\n",res.type);
	}
}

static void login_net_callback(int fd,struct net_response res,void *payload){
	(void)payload;
	fprintf(debugf,"login_net_callback(fd=%d,res={.type=%d})\n",fd,res.type);
	struct conndata *conn=weechat_hashtable_get(conntable,&fd);
	assert(conn);
	if(res.type==NET_OK){
		if(conn->username)free(conn->username);
		conn->username=conn->pending_username;
		conn->pending_username=NULL;

		weechat_printf(conn->buffer,"Successfully logged in");
		net_sendf(conn->fd,roomlist_net_callback,NULL,"list_rooms");
	} else if(res.type==NET_ERROR){
		weechat_printf(conn->buffer,"Error logging in: %s",res.error);
	} else {
		fprintf(debugf,"login_net_callback: res.type=%d\n",res.type);
	}
}

static void conn_destroy(struct conndata *conn){
	fprintf(debugf,"conn_destroy(conn=%p (fd=%d))\n",conn,conn->fd);
	weechat_unhook(conn->fd_hook);
	if(conntable)weechat_hashtable_remove(conntable,&conn->fd);
	for(int i=0;i<conn->nrooms;i++){
		close_room(conn->rooms[i]);
	}
	if(conn->username)free(conn->username);
	if(conn->pending_username)free(conn->pending_username);
	free(conn->rooms);
	free(conn->linebuf);
	close(conn->fd);
	free(conn);
}

static int fd_hook_callback(const void *conn_vp,void *_d,int fd){
	(void)_d;
	struct conndata *conn=(struct conndata*)conn_vp;
	fprintf(debugf,"fd_hook_callback(conn=%p (fd=%d))\n",conn,fd);
	assert(fd==conn->fd);
	
	if(conn->linebuf_len>conn->linebuf_sz/2){
		conn->linebuf_sz*=2;
		conn->linebuf=realloc(conn->linebuf,conn->linebuf_sz);
		assert(conn->linebuf);
	}
	i64 nr=recv(fd,conn->linebuf+conn->linebuf_len,conn->linebuf_sz-conn->linebuf_len,0);
	if(nr<=0){
		fprintf(debugf,"fd_hook_callback: recv() <= 0\n");
		weechat_printf(NULL,"tomsg: Connection dropped");
		weechat_buffer_close(conn->buffer);
		return WEECHAT_RC_OK;
	}
	conn->linebuf_len+=nr;
	while(true){
		char *p=memchr(conn->linebuf,'\n',conn->linebuf_len);
		if(p==NULL)break;
		*p='\0';
		i64 lenp1=p-conn->linebuf+1;
		net_handle_recv(conn->fd,conn->linebuf);
		memmove(conn->linebuf,conn->linebuf+lenp1,conn->linebuf_len-lenp1);
		conn->linebuf_len-=lenp1;
	}
	return WEECHAT_RC_OK;
}

static int conn_input_cb(const void *conn_vp,void *_d,struct t_gui_buffer *buffer,const char *input){
	(void)_d;
	struct conndata *conn=(struct conndata*)conn_vp;
	fprintf(debugf,"conn_input_cb(conn=%p,buffer=%p,input=\"%s\")\n",conn,buffer,input);
	
	char *input2=strdup(input);
	assert(input2);
	char *cursor=input2;

	char *cmd=strsep(&cursor," ");
	if(cmd==NULL){
		free(input2);
		return WEECHAT_RC_OK;
	}
	if(strcmp(cmd,"login")==0){
		char *username=strsep(&cursor," ");
		char *password=cursor;
		if(conn->pending_username)free(conn->pending_username);
		conn->pending_username=strdup(username);
		net_sendf(conn->fd,login_net_callback,NULL,"login %s %s",username,password);
	} else {
		weechat_printf(conn->buffer,"Unknown command '%s'",cmd);
	}

	return WEECHAT_RC_OK;
}

static int conn_close_cb(const void *conn_vp,void *_d,struct t_gui_buffer *buffer){
	(void)_d; (void)buffer;
	struct conndata *conn=(struct conndata*)conn_vp;
	fprintf(debugf,"conn_close_cb(conn=%p,buffer=%p)  fd=%d\n",conn,buffer,conn->fd);
	conn_destroy(conn);
	return WEECHAT_RC_OK;
}

static int connect_cb(const void *_p,void *hostname,int status,int _g,int fd,const char *err,const char *_i){
	(void)_p; (void)_g; (void)_i;
	switch(status){
		case WEECHAT_HOOK_CONNECT_OK: {
			struct conndata *conn=malloc(sizeof(struct conndata));
			assert(conn);
			conn->fd=fd;
			conn->fd_hook=weechat_hook_fd(fd,1,0,0,fd_hook_callback,conn,NULL);
			conn->buffer=weechat_buffer_new((char*)hostname,conn_input_cb,conn,NULL,conn_close_cb,conn,NULL);
			conn->nrooms=0;
			conn->roomscap=2;
			conn->rooms=malloc(conn->roomscap*sizeof(struct roomdata));
			assert(conn->rooms);
			conn->username=NULL;
			conn->pending_username=NULL;
			conn->linebuf_sz=512;
			conn->linebuf_len=0;
			conn->linebuf=malloc(conn->linebuf_sz);
			assert(conn->linebuf);

			weechat_printf(conn->buffer,"Connected!");

			weechat_hashtable_set(conntable,&fd,conn);

			return WEECHAT_RC_OK;
		}

		default:
			weechat_printf(NULL,"%stomsg: Could not connect to %s: %s",errpfx,(char*)hostname,err);
			return WEECHAT_RC_ERROR;
	}
}

static int cmd_tomsg_cb(const void *_p,void *_d,struct t_gui_buffer *buffer,int argc,char **argv,char **_a){
	(void)_p; (void)_d; (void)_a;
	if(argc<2){
		weechat_printf(buffer,"%stomsg: Invalid number of arguments to /tomsg",errpfx);
		return WEECHAT_RC_ERROR;
	}
	if(strcmp(argv[1],"connect")==0){
		if(argc<3||argc>4){
			weechat_printf(buffer,"%stomsg: Invalid number of arguments to /tomsg connect",errpfx);
			return WEECHAT_RC_ERROR;
		}

		char *hostname=argv[2];
		char *endp;
		int port;
		if(argc==4){
			port=strtol(argv[3],&endp,10);
			if(argv[3][0]=='\0'||*endp!='\0'||port<=0||port>=65536){
				weechat_printf(buffer,"%sInvalid port number",errpfx);
				return WEECHAT_RC_ERROR;
			}
		} else {
			port=29536;
		}
		if(strlen(hostname)==0){
			weechat_printf(buffer,"%stomsg: Invalid hostname",errpfx);
			return WEECHAT_RC_ERROR;
		}

		fprintf(debugf,"Connecting to %s:%d\n",hostname,port);
		char *hostname_copy=strdup(hostname);
		weechat_hook_connect(
			NULL,
			hostname,port,1,0,
			NULL,NULL,0,NULL,
			NULL,
			connect_cb,NULL,hostname_copy);
	} else {
		weechat_printf(buffer,"%stomsg: Unknown command \"%s\" to /tomsg",errpfx,argv[1]);
		return WEECHAT_RC_ERROR;
	}

	return WEECHAT_RC_OK;
}

int weechat_plugin_init(struct t_weechat_plugin *plugin,int argc,char **argv){
	(void)argc; (void)argv;
	weechat_plugin=plugin;

	char *fname;
	asprintf(&fname,"%s/Desktop/debugf.txt",getenv("HOME"));
	debugf=fopen(fname,"w");
	free(fname);
	setvbuf(debugf,NULL,_IONBF,0);

	fprintf(debugf,"------\n");

	errpfx=weechat_prefix("error");

	weechat_hook_command(
		"tomsg",
		"Execute commands related to tomsg.",
		"connect <hostname> [port]",
		"  connect: Connect to a tomsg server",
		NULL,
		cmd_tomsg_cb,NULL,NULL);

	net_set_push_callback(push_net_callback);
	net_set_history_callback(history_push_net_callback);

	conntable=weechat_hashtable_new(
		16,WEECHAT_HASHTABLE_INTEGER,WEECHAT_HASHTABLE_POINTER,NULL,NULL);

	return WEECHAT_RC_OK;
}

int weechat_plugin_end(struct t_weechat_plugin *plugin){
	(void)plugin;
	weechat_hashtable_free(conntable);
	conntable=NULL;
	fclose(debugf);
	return WEECHAT_RC_OK;
}