#include "client.h"

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

#include <endian.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <unistd.h>

#include "connection.h"
#include "event_loop.h"
#include "utils.h"

/*
 * Macros
 */
#define MAX_PENDING_CONNECTIONS         (100)

/*
 * Data
 */
static int _fds[MAX_PENDING_CONNECTIONS];


/*
 * Public API
 */
bool client_init() {
    for (int i = 0; i < MAX_PENDING_CONNECTIONS; ++i) {
        _fds[i] = -1;
    }
    return true;
}

void client_deinit() {
    for (int i = 0; i < MAX_PENDING_CONNECTIONS; ++i) {
        if (_fds[i] == -1) {
            continue;
        }
        shutdown(_fds[i], SHUT_RDWR);
        close(_fds[i]);
    }
}

bool client_connect(const char *host, uint16_t port) {
    int index = -1;
    for (int i = 0; i < MAX_PENDING_CONNECTIONS; ++i) {
        if (_fds[i] == -1) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        fprintf(stderr, "[!] no more space for new connect attempts\n");
        return false;
    }
    struct hostent *he = gethostbyname(host);
    if (!he) {
        fprintf(stderr, "[!] gethostbyname (%s) failed: %d (h_errno)\n", host,  h_errno);
        return false;
    }
    int fd = socket(
        AF_INET,
        SOCK_STREAM | SOCK_NONBLOCK,
        IPPROTO_TCP
    );
    if (fd == -1) {
        fprintf(stderr, "[!] socket failed: %d\n", errno);
        return false;
    }
    struct sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htobe16(port);
    memcpy(&addr.sin_addr, he->h_addr, he->h_length);
    int res = connect(fd, (const struct sockaddr *)&addr, sizeof(addr));
    if (res == -1) {
        if (errno != EINPROGRESS) {
            fprintf(stderr, "[!] connect failed: %d\n", errno);
            return false;
        }
        else {
            _fds[index] = fd;
            struct epoll_event ev;
            ev.data.fd = fd;
            ev.events = EPOLLOUT;
            loop_ctl(EPOLL_CTL_ADD, fd, &ev);
            return true;
        }
    }
    uint32_t id = connection_add(fd);
    if (id == 0) {
        shutdown(fd, SHUT_RDWR);
        close(fd);
        return false;
    }
    return true;
}

bool client_event(int fd, uint32_t events) {
    int index = -1;
    for (int i = 0; i < MAX_PENDING_CONNECTIONS; ++i) {
        if (_fds[i] == fd) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        return false;
    }
    if (events & (EPOLLERR | EPOLLHUP)) {
        shutdown(fd, SHUT_RDWR);
        close(fd);
        _fds[index] = -1;
        fprintf(stderr, "[!] connect failed\n");
        return true;
    }
    // check if socket has an error set
    int err = 0;
    socklen_t len = sizeof(err);
    if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &len) < 0 || err != 0) {
        shutdown(fd, SHUT_RDWR);
        close(fd);
        _fds[index] = -1;
        fprintf(stderr, "[!] connect failed: %d\n", err);
        return true;
    }
    // connected
    loop_ctl(EPOLL_CTL_DEL, fd, NULL);
    uint32_t id = connection_add(fd);
    if (id == 0) {
        shutdown(fd, SHUT_RDWR);
        close(fd);
    }
    _fds[index] = -1;
    return true;
}