15ai_client_c

main.c

#include <netdb.h> 
#include <netinet/in.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>

const char *team_name = "test-c-client";

#define PORT 25252

#define MSG_TEAM_LENGTH 24
#define BOARD_WIDTH 25
#define BOARD_HEIGHT 13
#define NUM_SLIMES 5

#define MSG_STATE_SIZE (2 + BOARD_WIDTH * BOARD_HEIGHT + NUM_SLIMES * 4)
#define MSG_MOVE_SIZE (2 + NUM_SLIMES)

#define DIR_RIGHT 0
#define DIR_TOP 1
#define DIR_LEFT 2
#define DIR_DOWN 3

#define TEAM_RED 0
#define TEAM_BLUE 1

struct position {
    uint8_t x, y;
};

struct game_state {
    int team;
    int turn;
    uint8_t board[BOARD_WIDTH * BOARD_HEIGHT];
    struct position slime_positions[NUM_SLIMES * 2];
};

struct action {
    uint8_t slime_directions[NUM_SLIMES];
};

static void
make_move(struct game_state *state, struct action *action) {
    // XXX: fill here
    for(int i = 0; i < 5; i++) {
        struct position pos = state->slime_positions[i + state->team*NUM_SLIMES];
        fprintf(stderr, "%i: %d %d\n", i, pos.x, pos.y);

        if(state->team == TEAM_RED) {
            action->slime_directions[i] = DIR_RIGHT;
        } else {
            action->slime_directions[i] = DIR_LEFT;
        }
    }
}

static void
exitf(const char *format, ...) {
    va_list args;
    va_start(args, format);
    fprintf(stderr, "error: ");
    vfprintf(stderr, format, args);
    va_end(args);
    exit(EXIT_FAILURE);
}

static int
connect_server(const char *addr, int port) {
    int sockfd;
    struct sockaddr_in serv_addr;
    struct hostent *server;

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        exitf("socket\n");
    }
    server = gethostbyname(addr);
    if (server == NULL) {
        exitf("gethostbyname\n");
    }
    bzero((char *) &serv_addr, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    bcopy((char *)server->h_addr, 
         (char *)&serv_addr.sin_addr.s_addr,
         server->h_length);
    serv_addr.sin_port = htons(port);
    if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) {
        exitf("connect\n");
    }

    return sockfd;
}

static int
handshake(int fd, const char *team_name, int team) {
    char out[MSG_TEAM_LENGTH];
    memset(out, 0, MSG_TEAM_LENGTH);
    snprintf(out, MSG_TEAM_LENGTH, "%c%s", team, team_name);

    ssize_t len = send(fd, out, MSG_TEAM_LENGTH, 0);
    if(len != MSG_TEAM_LENGTH) {
        exitf("short send: %d != %d\n", len, MSG_TEAM_LENGTH);
    }

    char in[1];
    len = recv(fd, in, 1, MSG_WAITALL);
    if(len != 1) {
        exitf("short recv: %d != %d\n", len, 1);
    }
    fprintf(stderr, "team %d\n", in[0]);
    return in[0];
}

static void
loop(int fd, int team) {
    ssize_t len;
    char in[MSG_STATE_SIZE];
    char out[MSG_MOVE_SIZE];

    if((len = recv(fd, in, MSG_STATE_SIZE, MSG_WAITALL)) != MSG_STATE_SIZE) {
        exitf("short recv on loop: %d != %d\n", len, MSG_STATE_SIZE);
    }

    // turn nubmer is in big endian
    uint16_t turn = (in[0] << 8) + in[1];
    fprintf(stderr, "turn %d\n", turn);

    struct game_state state;
    state.turn = turn;
    state.team = team;
    memcpy(&state.board, in+2, MSG_STATE_SIZE-2);

    struct action action;

    make_move(&state, &action);

    memcpy(out, in, 2);
    memcpy(out+2, &action, sizeof(action));
    if((len = send(fd, out, MSG_MOVE_SIZE, 0)) != MSG_MOVE_SIZE) {
        exitf("short send on loop: %d != %d\n", len, MSG_MOVE_SIZE);
    }
}

int main(int argc, char ** argv) {
    if(argc < 2) {
        exitf("usage: %s hostname\n", argv[0]);
    }

    int fd = connect_server(argv[1], PORT);
    int team = handshake(fd, team_name, 0);

    for(;;) {
        loop(fd, team);
    }

    return 0;
}

Makefile

CFLAGS=-Wall -Werror -Wextra -g -ggdb

main: main.c
	gcc $(CFLAGS) $< -o $@