path: root/server/server_data_processing.c

#include "server_data_processing.h"
#include "server.h"

#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>

enum {
    output_buffer_size  = 1024
};

static char output_buffer[output_buffer_size];

static int write_to_client(int fd, int length)
{
    return write(fd, output_buffer, length);
}

static int read_from_client(int fd, char *buffer, int max_buffer_size)
{
    int read_result;
    read_result = read(fd, buffer, max_buffer_size);
    if(read_result <= 0)
        return 0;
    /* buffer overflow */
    if(read_result >= max_buffer_size)
        return 0;
    return read_result;
}

int print_message_for_first_player(int fd)
{
    int data_size;

    data_size =  sprintf(output_buffer, "%u\n", first_player);
    return write_to_client(fd, data_size);
}

int print_connected_players(int fd, int number)
{
    int data_size;

    data_size = sprintf(output_buffer, "%u:%u\n", confirmation_waiting, number);
    return write_to_client(fd, data_size);
}

int send_disconnect_status(int fd)
{
    int data_size;

    data_size = sprintf(output_buffer, "%u\n", disconnect);
    return write_to_client(fd, data_size);
}

/*
 * 1 - ready
 * 0 - buffer overflow or player closed session
 * -1 - not ready
 */
int check_readiness(struct session *client)
{
    int read_result;
    read_result = read_from_client(client->fd, client->buffer, max_buffer_size);
    if(!read_result)
        return read_result;
    if(client->buffer[0] == '\n')
        return 1;
    else
        return -1;
}
/*
 * example: 10#\A^\7v'\n'
 * or:      10#\A^\7v:
 * or:      ='\n'
 * or:      =:
 */
static void copy_card_queue(int *offset, struct card_queue *cq)
{
    int length, i;
    struct card_queue_item *next_attack_card;

    next_attack_card = NULL;
    while((next_attack_card = get_next_card_from_queue(cq, next_attack_card))) {
        length = strlen(next_attack_card->str);
        for(i = 0; i < length; ++i, ++*offset)
            *(output_buffer + *offset) = (next_attack_card->str)[i];
        /* delimiter */
        *(output_buffer + *offset) = '\\';
        ++*offset;
    }
    *(output_buffer + *offset-1) = ':';
}

/*
 * example: 10#+\+Q#+A^+\+-+7v:
 * or       =:
 */
static void copy_cards_on_table(int *offset, struct cards_on_table cot)
{
    int i, j, length;
    for(i = 0; i <= cot.card_arr_idx; ++i) {
        length = strlen(cot.card_arr[i]);
        for(j = 0; j < length; ++j, ++*offset)
            *(output_buffer + *offset) = cot.card_arr[i][j];
        /* delimiter */
        *(output_buffer + *offset) = '+';
        ++*offset;
    }
    *(output_buffer + *offset-1) = ':';
}
/*
 * example: 10#\A^\7v:
 * or       10#\A^\7v'\n'
 * or       =:
 * or       ='\n'
 */
static void copy_own_deck(int *offset, player_cards deck)
{
    const char *card;
    int length, i;

    while(deck) {
        card = deck->str;
        length = strlen(card);
        for(i = 0; i < length; ++i, ++*offset)
            *(output_buffer + *offset) = card[i];
        *(output_buffer + *offset) = '\\';
        ++*offset;
        deck = deck->next;
    }
    *(output_buffer + *offset-1) = ':';
}

static void copy_base_info(int *free_pos, struct game_info *gi,
                           enum client_game_states state, player_cards deck,
                           int player_position)
{
    int i;

    *free_pos =
        sprintf(output_buffer, "%u:%u:%u:%u:%s:", state, gi->players_number,
                gi->shuffled_cards_left, player_position, gi->trump_card);
    /*
     * opponent's card count
     * example: 2\6\3:
     */
    for(i = 0; i < gi->players_number; ++i) {

        *free_pos += sprintf(output_buffer + *free_pos, "%u\\",
                            gi->card_quantity_arr[i]);
    }
    *(output_buffer + *free_pos-1) = ':';

    if(gi->cot->card_arr_idx != -1)
        copy_cards_on_table(free_pos, *gi->cot);
    else
        *free_pos += sprintf(output_buffer + *free_pos, "=:");

    if(!is_empty_stack(deck))
        copy_own_deck(free_pos, deck);
    else
        *free_pos += sprintf(output_buffer + *free_pos, "=:");
}

int print_game_part(const struct session *client,
                    enum server_states ss, struct game_info *gi)
{
    enum spectator_mode sp_mode;
    int free_pos;  /* free_pos == data length */

    copy_base_info(&free_pos, gi, client->state, client->deck,
                   client->player_position);

    switch(client->state) {
    case display_only_table:
    /* let the client print card tips and wait for input */
    case attack:
    case defense:
    /* other clents will be waiting particular player */
    case attack_expectation:
        free_pos += sprintf(output_buffer + free_pos, "%u:",
                            gi->position_whose_turn);
        *(output_buffer + free_pos-1) = '\n';
        break;
        /*
         * who haven't got tossing card (including defender) must wait
         * when other players make moves
         */
    case tossing_expectation:
    case tossing:
        /* instead of last ':' */
        *(output_buffer + free_pos-1) = '\n';
        break;
    case defense_expectation:
    case spectator:
        /* copying whose turn */
        free_pos += sprintf(output_buffer + free_pos, "%u:",
                            gi->position_whose_turn);
        /* copying card queue */
        if(is_empty_queue(gi->cq))
            free_pos += sprintf(output_buffer + free_pos, "=:");
        else
            copy_card_queue(&free_pos, gi->cq);
        if(client->state == spectator) {
            if(ss == attack_phase_out)
                sp_mode = spectator_attack;
            else if(ss == defense_phase_out)
                sp_mode = spectator_defense;
            else if(ss == tossing_phase_out)
                sp_mode = spectator_tossing;
            else
                sp_mode = spectator_table;
            free_pos += sprintf(output_buffer + free_pos, "%u:", sp_mode);
        }
        *(output_buffer + free_pos-1) = '\n';
    default:
        {}
    }
    return write_to_client(client->fd, free_pos);
}

/*
 * example: 7v\2#\A^\'\n'
 */
int get_cards_from_attacker(struct session *client,
                            const struct cards_on_table *cot,
                            const player_cards defense_deck,
                            struct card_queue *cq)
{
    int read_result, i, j;
    int card_return_status = 0, all_cards_received_status = 1;
    int data_length;
    char given_card[4];
    const char *stack_card = NULL;

    read_result = read_from_client(client->fd, client->buffer, max_buffer_size);

#if DEBUG
    printf("%d\n", read_result);
    for(i = 0; i < read_result; ++i)
        putchar(client->buffer[i]);
    putchar('\n');
#endif

    if(!read_result)
        return read_result;
    for(i = 0, j = 0; i < read_result; ++i) {
        if(client->buffer[i] == '\\') {
            given_card[j] = '\0';
            j = 0;
            if(card_return_status) {
                all_cards_received_status = 0;
                break;
            }
            stack_card = remove_card_from_stack(&client->deck, given_card);
            push_queue(cq, stack_card);
            if(is_receiving_cards_limit(cot, defense_deck, cq))
                card_return_status = 1;
            continue;
        }
        given_card[j] = client->buffer[i];
        ++j;
    }
    data_length = sprintf(output_buffer, "%d:%s\n", card_acceptance_status,
                          all_cards_received_status ? "all" : "not all");
    write_to_client(client->fd, data_length);
    sleep(2);
    return read_result;
}

/*
 * 0 - error
 * 1 - card was bited, not bited, or
 *     defender didn't want to continue defense phase
 *
 * example: 5v'\n'
 * or: '\n'
 */
int get_card_from_defender(struct session *client, struct cards_on_table *cot,
                           const char * trump_suit)
{
    int read_result, i;
    char given_card[4];
    const char *stack_card = NULL;

    read_result = read_from_client(client->fd, client->buffer, max_buffer_size);

#if DEBUG
    printf("%d\n", read_result);
    for(i = 0; i < read_result; ++i)
        putchar(client->buffer[i]);
    putchar('\n');
#endif

    if(!read_result)
        return read_result;
    if(client->buffer[0] == '\n') {
        /* the client sees “accepting cards” at the same time */
        sleep(2);
        return 1;
    }
    for(i = 0; i < read_result && client->buffer[i] != '\n'; ++i)
        given_card[i] = client->buffer[i];
    given_card[i] = '\0';
    if(is_card_beat(cot->card_arr[cot->card_arr_idx-2], given_card, trump_suit)){
        stack_card = remove_card_from_stack(&client->deck, given_card);
        put_defender_card_on_table(cot, stack_card);
        return 1;
    } else
        return 0;
}

/*
 * 0 - buffer overflow or client closed connection
 * 1 - some number of cards added to card queue (answer_got)
 * 2 - card toss limit was reached when accepting cards from this player
 *                                                (anwer_got_with_limit)
 * 3 - player refused to toss the card (cancel)
 *
 * example: 10#\A^\7v\'\n'
 * or: '\n'
 */
int get_cards_from_tossing_player(struct session *client,
                                  const player_cards defense_deck,
                                  struct cards_on_table *cot,
                                  struct card_queue *cq)
{
    int read_result, i, j;
    int card_return_status = 0, all_cards_received_status = 1;
    int data_length;
    char given_card[4];
    const char *stack_card = NULL;

    read_result = read_from_client(client->fd, client->buffer, max_buffer_size);

#if DEBUG
    printf("%d\n", read_result);
    for(i = 0; i < read_result; ++i)
        putchar(client->buffer[i]);
    putchar('\n');
#endif

    if(!read_result)
        return read_result;

    /* cancellation */
    if(client->buffer[0] == '\n') {
        /* the client sees “skipping the card toss” at the same time */
        sleep(2);
        return cancel;
    }

    for(i = 0, j = 0; i < read_result; ++i) {
        if(client->buffer[i] == '\\') {
            /* tossing limit was set */
            if(client->tm == cancel) {
                /* it's impossible to accept cards due to tossing limit */
                data_length =
                    sprintf(output_buffer, "%d\n", tossing_limit_status);
                write_to_client(client->fd, data_length);
                return cancel;
            }
            given_card[j] = '\0';
            j = 0;
            if(card_return_status) {
                all_cards_received_status = 0;
            } else if(is_correct_tossing_card(given_card, cot)) {
                stack_card = remove_card_from_stack(&client->deck, given_card);
                push_queue(cq, stack_card);
                if(is_receiving_cards_limit(cot, defense_deck, cq))
                {
                    card_return_status = 1;
                }
            }
            continue;
        }
        given_card[j] = client->buffer[i];
        ++j;
    }

    data_length = sprintf(output_buffer, "%d:%s\n", card_acceptance_status,
                          all_cards_received_status ? "all" : "not all");
    write_to_client(client->fd, data_length);
    sleep(2);
    if(!card_return_status)
        return answer_got;
    else
        return answer_got_with_limit;
}

void print_game_result(const struct session *client, int durak_position)
{
    int data_size;

    data_size =
        sprintf(output_buffer, "%u:%u\n", client->state, durak_position);
    write_to_client(client->fd, data_size);
}