#define _GNU_SOURCE
#include <stdio.h>
#include <stdarg.h>
#include <stdbool.h>
#include <string.h>
#include <stdarg.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/time.h>
#include <errno.h>
#include <assert.h>
#include <termio.h>
#include "memory.h"
#include "showmenu.h"
#include "tcp.h"

#define HOSTNAME "localhost"
#define PORT 1423

#define GAMENAME "regexbattle"


#define NUM_LEVELS (5)


typedef struct ConnectionData{
	int sock;
	i64 my_id;
} ConnectionData;


static char *die_message=NULL;

__attribute__((noreturn, format (printf,1,2)))
static void die(const char *format,...){
	va_list ap;
	va_start(ap,format);
	char *buf;
	int ret=vasprintf(&buf,format,ap);
	va_end(ap);
	if(ret<0){
		die_message=strdup("Double error roll");
	} else {
		die_message=buf;
	}
	exit(1);
}

static void exit_cleanup(void){
	endkeyboard();
	endscreen();
	if(die_message!=NULL){
		printf("%s\n",die_message);
	}
}

//-1: error; 0: timeout; >=1: fd ready for reading
static int wait_fds(const int *fds,i64 length,const struct timeval *timeout){
	if(fds==NULL||length<=0)return -1;
	struct timeval timeout2;
	if(timeout!=NULL)memcpy(&timeout2,timeout,sizeof(struct timeval));
	fd_set set;
	FD_ZERO(&set);
	int maxfd=-1;
	for(i64 i=0;i<length;i++){
		if(fds[i]>maxfd)maxfd=fds[i];
		FD_SET(fds[i],&set);
	}
	int ret=select(maxfd+1,&set,NULL,NULL,timeout==NULL?NULL:&timeout2);
	if(ret<0)return -1;
	if(ret==0)return 0;
	for(i64 i=0;i<length;i++){
		if(FD_ISSET(fds[i],&set))return fds[i];
	}
	return -1;
}

static char* show_prompt(int x,int y,int w,const char *title){
	Promptwidget *prw=prw_make(x,y,w,title);
	char *line=NULL;
	while(line==NULL){
		redraw();
		int key=tgetkey();
		if(key==KEY_ESC)break;
		line=prw_handlekey(prw,key);
	}
	prw_destroy(prw);
	return line;
}

typedef struct Level{
	i64 ngoods,nbads;
	char **goods,**bads;
} Level;

static char* random_string(void){
	static const char *alphabet="abcdefghijklmnopqrstuvwxyz -";
	i64 len=rand()%10+2;
	char *str=malloc(len+1,char);
	for(i64 i=0;i<len;i++){
		str[i]=alphabet[rand()%strlen(alphabet)];
	}
	str[len]='\0';
	return str;
}

static Level* generate_level(void){
	Level *level=malloc(1,Level);
	level->ngoods=10;
	level->nbads=10;
	level->goods=malloc(level->ngoods,char*);
	level->bads=malloc(level->nbads,char*);
	for(i64 i=0;i<level->ngoods;i++){
		level->goods[i]=random_string();
	}
	for(i64 i=0;i<level->nbads;i++){
		level->bads[i]=random_string();
	}
	return level;
}

static void destroy_level(Level *level){
	for(i64 i=0;i<level->ngoods;i++)free(level->goods[i]);
	for(i64 i=0;i<level->nbads;i++)free(level->bads[i]);
	free(level->goods);
	free(level->bads);
	free(level);
}

// "LEVEL 005 005 002 ka 002 as ..."
static char* serialise_level(const Level *level){
	i64 allocsize=13+(level->ngoods+level->nbads)*5;
	for(i64 i=0;i<level->ngoods;i++)allocsize+=strlen(level->goods[i]);
	for(i64 i=0;i<level->nbads;i++)allocsize+=strlen(level->bads[i]);

	char *str=malloc(allocsize+1,char);
	char *ptr=str;
#define WRITE(...) do {ptr+=sprintf(ptr,__VA_ARGS__);} while(0)

	WRITE("LEVEL %03" PRIi64 " %03" PRIi64,level->ngoods,level->nbads);
	for(i64 i=0;i<level->ngoods;i++)WRITE(" %lu %s",strlen(level->goods[i]),level->goods[i]);
	for(i64 i=0;i<level->nbads;i++)WRITE(" %lu %s",strlen(level->bads[i]),level->bads[i]);
	assert(ptr-str==allocsize);

#undef WRITE

	return str;
}

static Level* deserialise_level(const char *str){
	if(memcmp(str,"LEVEL ",6)!=0)die("Argument to deserialise_level not a level");
	Level *level=malloc(1,Level);
	level->ngoods=strtoll(str+6,NULL,10);
	level->nbads=strtoll(str+10,NULL,10);
	level->goods=malloc(level->ngoods,char*);
	level->bads=malloc(level->nbads,char*);
	i64 offset=14;
	for(i64 i=0;i<level->ngoods;i++){
		i64 len=strtoll(str+offset,NULL,10);
		offset+=4;
		level->goods[i]=memdup(str+offset,len);
		offset+=len+1;
	}
	for(i64 i=0;i<level->nbads;i++){
		i64 len=strtoll(str+offset,NULL,10);
		offset+=4;
		level->bads[i]=memdup(str+offset,len);
		offset+=len+1;
	}
	return level;
}

static void game_start(ConnectionData cd,const char *roomname,i64 other_id,bool host){
	if(host){
		tcp_send_line_f(cd.sock,"room_message " GAMENAME " %s %" PRIi64 " 9",roomname,other_id);
		tcp_send_str(cd.sock,"regexping");
	} else {
		TcpResponse *res=tcp_read_response(cd.sock,"");
		if(res==NULL)die("Protocol error");
		if(res->type==TCP_PUSH_LEAVE){
			tcp_response_destroy(res);
			moveto(1,7);
			tprintf("Other player left game.");
			return;
		}
		if(res->type!=TCP_PUSH_MESSAGE)die("Protocol error: push expected");
		if(strcmp(res->mval.message,"regexping")!=0)die("Protocol error: regexping message expected");
		tcp_response_destroy(res);
	}

	if(host){
		TcpResponse *res=tcp_read_response(cd.sock,"");
		if(res==NULL)die("Protocol error");
		if(res->type==TCP_PUSH_LEAVE){
			tcp_response_destroy(res);
			moveto(1,7);
			tprintf("Other player left game.");
			return;
		}
		if(res->type!=TCP_PUSH_MESSAGE)die("Protocol error: push expected");
		if(strcmp(res->mval.message,"regexpong")!=0)die("Protocol error: regexpong message expected");
		tcp_response_destroy(res);
	} else {
		tcp_send_line_f(cd.sock,"room_message " GAMENAME " %s %" PRIi64 " 9",roomname,other_id);
		tcp_send_str(cd.sock,"regexpong");
	}


	for(i64 lvidx=0;lvidx<NUM_LEVELS;lvidx++){
		Level *level;
		if(host){
			level=generate_level();
			char *ser=serialise_level(level);
			tcp_send_line_f(cd.sock,"room_message " GAMENAME " %s %" PRIi64 " %lu",roomname,other_id,strlen(ser));
			tcp_send_str(cd.sock,ser);
			free(ser);
		} else {
			TcpResponse *res=tcp_read_response(cd.sock,"");
			if(res==NULL)die("Protocol error");
			if(res->type==TCP_PUSH_LEAVE){
				tcp_response_destroy(res);
				moveto(1,7);
				tprintf("Other player left game.");
				return;
			}
			if(res->type!=TCP_PUSH_MESSAGE)die("Protocol error: message push expected");
			level=deserialise_level(res->mval.message);
			tcp_response_destroy(res);
			if(level==NULL)die("Protocol error: invalid serialised level received");
		}

		//TODO: present level

		destroy_level(level);
	}

	//TODO: end game properly
}

static void room_create(ConnectionData cd,const char *name){
	tcp_send_line_f(cd.sock,"room_create " GAMENAME " %s 1 2",name);
	TcpResponse *res=tcp_read_response(cd.sock,"room_create");
	if(res==NULL)die("Protocol error");
	if(res->type==TCP_ERROR){
		moveto(1,7);
		tprintf("Error: %s",res->eval);
		tcp_response_destroy(res);
		return;
	}
	if(res->type!=TCP_OK)die("Protocol error: ok or error expected on room_create");
	tcp_response_destroy(res);

	moveto(1,7);
	tprintf("Waiting for other player to enter room '%s'...\n"
	        "Press <escape> to cancel.",name);
	redraw();
	int fds[2]={1,cd.sock};
	i64 other_id;
	while(true){
		int fd=wait_fds(fds,2,NULL);
		if(fd<=0)die("select: %s",strerror(errno));
		if(fd==1){
			int key=tgetkey();
			if(key==KEY_ESC){
				clearscreen();
				return;
			}
			bel();
		} else if(fd==cd.sock){
			TcpResponse *res=tcp_read_response(cd.sock,"");
			if(res==NULL||res->type!=TCP_PUSH_JOIN)die("Protocol error: unexpected not-push-join %d",res->type);
			other_id=res->jval.id;
			tcp_response_destroy(res);
			break;
		} else assert(false);
	}

	game_start(cd,name,other_id,true);

	tcp_send_line_f(cd.sock,"room_leave " GAMENAME " %s",name);
	if(tcp_read_ok(cd.sock,"room_leave")==-1)die("Protocol error: ok expected after room_leave");

	clearscreen();
}

static void room_join(ConnectionData cd,const char *name){
	tcp_send_line_f(cd.sock,"room_join " GAMENAME " %s",name);
	TcpResponse *res=tcp_read_response(cd.sock,"room_join");
	if(res==NULL)die("Protocol error");
	if(res->type==TCP_ERROR){
		moveto(1,7);
		tprintf("Error: %s",res->eval);
		tcp_response_destroy(res);
		return;
	}
	if(res->type!=TCP_OK)die("Protocol error: expecting ok or error on room_join");
	tcp_response_destroy(res);

	tcp_send_line_f(cd.sock,"room_player_list " GAMENAME " %s",name);
	res=tcp_read_response(cd.sock,"room_player_list");
	if(res==NULL)die("Protocol error");
	if(res->type==TCP_ERROR){
		moveto(1,7);
		tprintf("Error: %s",res->eval);
		tcp_response_destroy(res);
		return;
	}
	if(res->type==TCP_PUSH_LEAVE){
		tcp_response_destroy(res);
		moveto(1,7);
		tprintf("Other player already left the game.");
		return;
	}
	if(res->type!=TCP_LIST)die("Protocol error: expecting error or list on room_player_list");

	i64 other_id=-1;
	for(i64 i=0;i<res->lval->nitems;i++){
		i64 id=strtoll(res->lval->items[i],NULL,10);
		if(id!=cd.my_id){
			other_id=id;
			break;
		}
	}
	tcp_response_destroy(res);
	if(other_id==-1)die("Protocol error: self not found in own room list");

	game_start(cd,name,other_id,false);

	tcp_send_line_f(cd.sock,"room_leave " GAMENAME " %s",name);
	if(tcp_read_ok(cd.sock,"room_leave")==-1)die("Protocol error: ok expected after room_leave");

	clearscreen();
}

int main(void){
	struct timeval tv;
	gettimeofday(&tv,NULL);
	srand((unsigned)(tv.tv_sec*1000000L+tv.tv_usec));

	int sock=tcp_connect(HOSTNAME,PORT);
	if(sock==-1){
		printf("Could not connect to %s:%d\n",HOSTNAME,PORT);
		return 1;
	}
	char *recvbuf=NULL;
	i64 recvbufsz=0;
	tcp_send_line(sock,"ping");
	tcp_read_line(sock,&recvbuf,&recvbufsz);
	if(strcmp(recvbuf,"pong")!=0){
		printf("Protocol error; different server running on %s:%d?\n",HOSTNAME,PORT);
		return 1;
	}

	ConnectionData cdata;
	cdata.sock=sock;

	tcp_send_line(sock,"id");
	TcpResponse *resp=tcp_read_response(sock,"id");
	if(resp==NULL||resp->type!=TCP_INT){
		printf("Protocol error; different server running on %s:%d?\n",HOSTNAME,PORT);
		return 1;
	} else {
		cdata.my_id=resp->ival;
	}
	tcp_response_destroy(resp);

	initscreen();
	initkeyboard(false);
	installCLhandler(true);
	atexit(exit_cleanup);

	clearscreen();

	while(true){
		i64 sel=showmenu("REGEXBATTLE",
			"List open public games","Create a new game","Join an open game",
			"Quit",NULL);
		Size termsize=gettermsize();
		fillrect(0,7,termsize.w,termsize.h-7,' ');
		switch(sel){
			case 0: {
				tcp_send_line(sock,"room_list " GAMENAME);
				TcpList *list=tcp_read_list(sock,"room_list");
				if(list==NULL)die("Protocol error: receiving list");
				Size termsize=gettermsize();
				fillrect(0,7,termsize.w,termsize.h-7,' ');
				moveto(0,7);
				for(i64 i=0;i<list->nitems&&i+7<termsize.h;i++){
					tprintf("Public games: %s\n",list->items[i]);
				}
				tcp_list_destroy(list);
				break;
			}

			case 1: {
				char *line=show_prompt(2,8,20,"Game name to create");
				Size termsize=gettermsize();
				fillrect(0,7,termsize.w,termsize.h-7,' ');
				if(line!=NULL){
					room_create(cdata,line);
					free(line);
				}
				break;
			}

			case 2: {
				char *line=show_prompt(2,8,20,"Game name to join");
				Size termsize=gettermsize();
				fillrect(0,7,termsize.w,termsize.h-7,' ');
				if(line!=NULL){
					room_join(cdata,line);
					free(line);
				}
				break;
			}

			case 3: return 0;
		}
	}
}