#include <assert.h>
#include <SDL2/SDL_net.h>

#include "game.h"
#include "server.h"
#include "network.h"
#include "protocol.h"

#define MAX_NAMESIZE 32

typedef struct Client {
	bool      connected;
	IPaddress address;
	char      name[MAX_NAMESIZE];
} Client;

static Uint32 lastTime;
static Uint32 currTime;

static UDPsocket sock;
static Client    client[MAX_PLAYERS];
static char      name[MAX_NAMESIZE] = "netwar! server"; 
static int       clientlimit        = 0;

static inline float randf() {
	return (float) rand() / (float) RAND_MAX;
}

static inline float randfm() {
	return (rand() % 2) ? (-randf()) : (+randf());
}

static inline bool cmpaddr(IPaddress a, IPaddress b) {
	return (a.host == b.host) && (a.port == b.port);
}

static int sv_find_client(IPaddress address) {
	for(int i = 0; i < clientlimit; i++)
		if(client[i].connected && cmpaddr(client[i].address, address))
			return i;
	return -1;
}

static void sv_sync_client(int id, bool full) {
	assert(id >= 0);
	assert(client[id].connected);

	for(int i = 0; i < clientlimit; i++)
		if(full || g_player[i].updated)
			SendMessage(sock, client[id].address, sv_splr(i, g_player[i].live, g_player[i].x, g_player[i].y, g_player[i].r, g_player[i].vx, g_player[i].vy, g_player[i].vr));
}

static void sv_kill_player(int id, bool send, const char * msg) {
	assert(id >= 0);
	assert(client[id].connected);

	if(send)
		SendMessage(sock, client[id].address, sv_kill(msg));

	client[id].connected = false;
	g_player_set(id, false, 0, 0, 0, 0, 0, 0);
	SDL_Log("Player %s (%i) disconnected: %s", client[id].name, id, msg);
}

static void sv_move_player(int id, ProtocolMessage m) {
	assert(id >= 0);
	assert(client[id].connected);

	g_player_does(id, m.cl.does.code);
}

static void sv_register_player(IPaddress address, ProtocolMessage m) {
	if(m.cl.info.version != PROTOCOL_VERSION)
		SendMessage(sock, address, sv_kill("Uncompatible version"));

	int i = 0;
	while((i < clientlimit) && (client[i].connected))
		++i;

	int namesize = sizeof(m.cl.info.name);
	if(i >= clientlimit) {
		SDL_Log("Too may clints, player %.*s disconnected", namesize, m.cl.info.name);
		SendMessage(sock, address, sv_kill("Too many clients"));
		return;
	}

	client[i].connected = true;
	client[i].address   = address;
	strncpy(client[i].name, (char*) m.cl.info.name, MAX_NAMESIZE);
	client[i].name[MAX_NAMESIZE - 1] = 0;

	SDL_Log("Player %s (%i) connected", client[i].name, i);
	SendMessage(sock, address, sv_info(name, i, clientlimit));

	g_player_set(i, true, randfm(), randfm(), randfm(), 0, 0, 0);
	sv_sync_client(i, true);
}

static void sv_recv() {
	IPaddress address;
	ProtocolMessage m;
	if(!RecvMessage(sock, &address, &m))
		return;

	switch(m.type) {
	case CL_INFO: sv_register_player(address, m); break;
	case CL_KILL: sv_kill_player(sv_find_client(address), false, ""); break;
	case CL_DOES: sv_move_player(sv_find_client(address), m); break;
	default:      SDL_Log("invalid message %i", m.type);
	}
}

static void sv_send() {
	for(int i = 0; i < clientlimit; i++)
		if(client[i].connected)
			sv_sync_client(i, false);
	
	for(int i = 0; i < clientlimit; i++)
		g_player[i].updated = false;
}

void sv_start(uint16_t port) {
	sock = OpenPort(port);
	lastTime = SDL_GetTicks();
	currTime = SDL_GetTicks();
}

void sv_stop() {
	for(int i = 0; i < clientlimit; i++)
		if(client[i].connected)
			sv_kill_player(i, true, "Server shutdown");
	ClosePort(sock);
}

void sv_setclientlimit(unsigned int maxclients) {
	// TODO disconnect clients
	clientlimit = (maxclients > MAX_PLAYERS) ? (MAX_PLAYERS) : (maxclients);
}

void sv_handle() {
	if(currTime - lastTime >= TICK_DELAY) {
		sv_recv();
		g_update();
		sv_send();
		lastTime = SDL_GetTicks();
	}
	currTime = SDL_GetTicks();
}