#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <ecp/core.h>
#include <ecp/vconn/vconn.h>
#include <ecp/dir/dir.h>

#include <util.h>

#include "dir.h"
#include "vlink.h"
#include "ht.h"
#include "acl.h"
#include "sig.h"

#include "server.h"

static SRVConfig srv_config;
static int proc_forked = 0;
static FILE *log_file = NULL;
static const char *log_level_str[] = {
    "DEBUG",
    "INFO",
    "ERROR"
};

SRVConfig *srv_get_config(void) {
    return &srv_config;
}

static void handle_err(ECPConnection *conn, unsigned char mtype, int err) {
    LOG(LOG_ERR, "handle_err: ctype:%d mtype:%d err:%d\n", conn->type, mtype, err);
}

static ECPConnection *conn_new(ECPSocket *sock, ECPConnection *parent, unsigned char ctype) {
    ECPConnection *conn = NULL;

    switch (ctype) {
        case CTYPE_DIR: {
            if (!(srv_config.roles & ECP_ROLE_DIR)) return NULL;

            conn = malloc(sizeof(ECPConnection));
            if (conn) {
                ecp_conn_init(conn, sock, ctype);
                ecp_conn_set_flags(conn, ECP_CONN_FLAG_VBOX);
            }
            break;
        }

        case ECP_CTYPE_DIR: {
            if (!(srv_config.roles & ECP_ROLE_DIR)) return NULL;

            conn = malloc(sizeof(ECPConnection));
            if (conn) ecp_conn_init(conn, sock, ctype);
            break;
        }

        case ECP_CTYPE_VCONN: {
            ECPVConnInb *_conn;

            if (!(srv_config.roles & ECP_ROLE_VCONN)) return NULL;

            _conn = malloc(sizeof(ECPVConnInb));
            if (_conn) {
                ecp_vconn_init_inb(_conn, sock);
                conn = &_conn->b;
            }
            break;
        }

        case ECP_CTYPE_VLINK: {
            if (!(srv_config.roles & ECP_ROLE_VCONN)) return NULL;

            conn = malloc(sizeof(ECPConnection));
            if (conn) ecp_vlink_init(conn, sock);
            break;
        }
    }

    if (conn) ecp_conn_set_flags(conn, ECP_CONN_FLAG_GC);
    return conn;
}

static void conn_free(ECPConnection *conn) {
    free(conn);
}

static int conn_auth(ECPSocket *sock, ECPConnection *parent, unsigned char ctype, ecp_ecdh_public_t *public) {
    switch (ctype) {
        case CTYPE_DIR: {
            if (public == NULL) return 0;
            return acl_inlist(public);
        }

        case ECP_CTYPE_VLINK: {
            if (public == NULL) return 0;
            if (parent == NULL) return acl_inlist(public);
            return 1;
        }

        case ECP_CTYPE_DIR:
        case ECP_CTYPE_VCONN:
            return 1;

        default:
            return 0;
    }
}

int ecp_init(ECPContext *ctx, ECPConnHandler *vconn_handler, ECPConnHandler *vlink_handler) {
    int rv;

    rv = ecp_ctx_init(ctx, conn_auth, conn_new, conn_free, handle_err);
    if (rv) return rv;

    rv = ecp_vconn_handler_init(ctx, vconn_handler);
    if (rv) return rv;

    rv = ecp_vlink_handler_init(ctx, vlink_handler);
    if (rv) return rv;

    return ECP_OK;
}

void log_vfprintf(int level, FILE *file, char *format, va_list ap) {
    time_t t;
    char t_buf[26];
    char s_buf[256];

    if (level >= (sizeof(log_level_str) / sizeof(char *))) return;

    t = time(NULL);
    ctime_r(&t, t_buf);
    /* terminate before newline */
    t_buf[24] = '\0';

    vsnprintf(s_buf, sizeof(s_buf), format, ap);

    fprintf(file, "%s [%s]: %s", t_buf, log_level_str[level], s_buf);
    fflush(file);
}

void log_printf(int level, char *format, ...) {
    va_list ap;
    FILE *file = log_file ? log_file : stderr;

    va_start(ap, format);
    log_vfprintf(level, file, format, ap);
    va_end(ap);
}

static void fail(char *format, ...) {
    va_list ap;
    FILE *file;

    va_start(ap, format);
    if (proc_forked) {
        file = log_file ? log_file : stderr;
        log_vfprintf(LOG_ERR, file, format, ap);
    } else {
        file = stderr;
        vfprintf(file, format, ap);
    }
    va_end(ap);
    fflush(file);
    exit(1);
}

static void usage(char *arg) {
    fprintf(stderr, "Usage: %s [options] <region> <roles> <private key> <addr> [ <dir acl> <vconn acl> ] [ <public key> <addr> ]\n", arg);
    fprintf(stderr, "Options:\n");

    fprintf(stderr, "\t-d\n");
    fprintf(stderr, "\t\tdetach\n");

    fprintf(stderr, "\t-l <log file>\n");
    fprintf(stderr, "\t\twrite optput to <log file>\n");

    fprintf(stderr, "\t-u <uid>\n");
    fprintf(stderr, "\t\trun as user <uid>\n");

    fprintf(stderr, "\t-g <gid>\n");
    fprintf(stderr, "\t\trun as group <gid>\n");
    exit(1);
}

static void daemonize(void) {
    pid_t pid;
    int null_rd, null_wr;
    int rv;

    pid = fork();
    if (pid < 0) fail("fork failed\n");
    if (pid > 0) exit(0);

    proc_forked = 1;

    if (setsid() < 0) fail("setsid failed\n");

    /* second fork */
    pid = fork();
    if (pid < 0) fail("fork2 failed\n");
    if (pid > 0) exit(0);

    null_rd = open("/dev/null", O_RDONLY);
    if (null_rd == -1) fail("open (r) /dev/null failed\n");
    null_wr = open("/dev/null", O_WRONLY);
    if (null_wr == -1) fail("open (w) /dev/null failed\n");

    rv = dup2(null_rd, STDIN_FILENO);
    if (rv == -1) fail("dup2 (stdin) failed\n");

    rv = dup2(null_wr, STDOUT_FILENO);
    if (rv == -1) fail("dup2 (stdout) failed\n");

    rv = dup2(null_wr, STDERR_FILENO);
    if (rv == -1) fail("dup2 (stderr) failed\n");

    close(null_rd);
    close(null_wr);
}

int main(int argc, char *argv[]) {
    char *endptr;
    char *log_fn;
    uid_t uid;
    gid_t gid;
    int detach;
    char *init_switch;
    ecp_tr_addr_t my_addr;
    ECPNode node;
    ECPContext ctx;
    ECPSocket sock;
    ECPConnHandler vconn_handler;
    ECPConnHandler vlink_handler;
    int _argi, _argc, fd;
    int rv;

    memset(&srv_config, 0, sizeof(srv_config));
    memset(&node, 0, sizeof(node));

    if (argc < 1) fail("Bad arguments\n");

    _argc = argc - 1;
    _argi = 1;

    log_fn = NULL;
    detach = 0;
    uid = 0;
    gid = 0;
    while (_argc && (argv[_argi][0] == '-')) {
        switch (argv[_argi][1]) {
            case 'd': {
                _argi++;
                _argc--;
                detach = 1;
                break;
            }
            case 'l': {
                _argi++;
                _argc--;
                if (_argc == 0) usage(argv[0]);
                log_fn = strdup(argv[_argi]);
                _argi++;
                _argc--;
                break;
            }

            case 'u': {
                _argi++;
                _argc--;
                if (_argc == 0) usage(argv[0]);
                uid = (uid_t)strtol(argv[_argi], &endptr, 10);
                if (endptr[0] != '\0') fail("Bad uid\n");
                _argi++;
                _argc--;
                break;
            }

            case 'g': {
                _argi++;
                _argc--;
                if (_argc == 0) usage(argv[0]);
                gid = (gid_t)strtol(argv[_argi], &endptr, 10);
                if (endptr[0] != '\0') fail("Bad gid\n");
                _argi++;
                _argc--;
                break;
            }

            default:
                usage(argv[0]);
        }
    }

    if (_argc < 4) usage(argv[0]);

    srv_config.region = (uint8_t)strtol(argv[_argi], &endptr, 16);
    if (endptr[0] != '\0') fail("Bad region\n");
    if (srv_config.region >= MAX_REGION) fail("Bad region\n");
    _argi++;
    _argc--;

    srv_config.roles = (uint8_t)strtol(argv[_argi], &endptr, 16);
    if (endptr[0] != '\0') fail("Bad roles\n");
    _argi++;
    _argc--;

    fd = open(argv[_argi], O_RDONLY);
    if (fd < 0) fail("Unable to open %s\n", argv[_argi]);

    rv = ecp_util_read_key(fd, &srv_config.key_perma.public, &srv_config.key_perma.private);
    close(fd);
    if (rv) fail("Unable to read key from %s\n", argv[_argi]);
    srv_config.key_perma.valid = 1;
    _argi++;
    _argc--;

    rv = ecp_addr_init(&my_addr, argv[_argi]);
    if (rv) fail("ecp_addr_init err:%d\n", rv);
    _argi++;
    _argc--;

    rv = acl_init();
    if (rv) fail("acl_init err:%d\n", rv);

    if (srv_config.roles & ECP_ROLE_DIR) {
        if (_argc < 2) usage(argv[0]);

        srv_config.acl_fn_dir = strdup(argv[_argi]);
        _argi++;
        _argc--;
        srv_config.acl_fn = strdup(argv[_argi]);
        _argi++;
        _argc--;

        rv = acl_load();
        if (rv) fail("acl_load err:%d\n", rv);
    }

    if (_argc == 2) {
        ecp_ecdh_public_t node_pub;

        fd = open(argv[_argi], O_RDONLY);
        if (fd < 0) fail("Unable to open %s\n", argv[_argi]);

        rv = ecp_util_read_key(fd, &node_pub, NULL);
        close(fd);
        if (rv) fail("Unable to read public key from %s\n", argv[_argi]);
        _argi++;
        _argc--;

        ecp_node_init(&node, &node_pub, NULL);

        rv = ecp_node_set_addr(&node, argv[_argi]);
        if (rv) fail("ecp_node_set_addr err:%d\n", rv);
        _argi++;
        _argc--;
    } else if (_argc) {
        usage(argv[0]);
    }

    umask(077);     /* rw for owner only */
    if (log_fn) {
        log_file = fopen(log_fn, "a");
        if (log_file == NULL) fail("Unable to open log file: %s\n", log_fn);
    }

    if (detach) daemonize();

    rv = sig_init();
    if (rv) fail("sig_init err:%d\n", rv);

    rv = sig_start_handler(&sock);
    if (rv) fail("sig_start_handler err:%d\n", rv);

    rv = ecp_init(&ctx, &vconn_handler, &vlink_handler);
    if (rv) fail("ecp_init err:%d\n", rv);

    rv = ecp_sock_create(&sock, &ctx, &srv_config.key_perma);
    if (rv) fail("ecp_sock_create err:%d\n", rv);

    rv = ecp_vconn_sock_create(&sock);
    if (rv) fail("ecp_vconn_sock_create err:%d\n", rv);

    rv = ecp_sock_open(&sock, &my_addr);
    if (rv) fail("ecp_sock_open err:%d\n", rv);
    srv_config.my_addr = my_addr;

    if (uid || gid) {
        if (gid) {
            rv = setgid(gid);
            if (rv) fail("Unable to set group id\n");
        }
        if (uid) {
            rv = setuid(uid);
            if (rv) fail("Unable to set user id\n");
        }
    }

    rv = dir_init(&sock);
    if (rv) fail("dir_init err:%d\n", rv);

    rv = vlink_init(&sock);
    if (rv) fail("vlink_init err:%d\n", rv);

    rv = ecp_start_receiver(&sock);
    if (rv) fail("ecp_start_receiver err:%d\n", rv);

    if (node.key_perma.valid) {
        rv = dir_init_ann(&sock, &node);
        if (rv) fail("dir_init_ann err:%d\n", rv);
    }

    init_switch = getenv("ECP_INITSW");
    if (init_switch) {
        int init_ann;

        init_ann = (int)strtol(init_switch, &endptr, 10);
        if (endptr[0] != '\0') fail("Bad environment");

        LOG(LOG_DEBUG, "init switch start - number of announces:%d\n", init_ann);
        dir_init_switch(&sock, init_ann);
        LOG(LOG_DEBUG, "init switch done\n");
    }

    rv = dir_start_announce(&sock);
    if (rv) fail("dir_start_announce err:%d\n", rv);

    rv = vlink_start_keyx(&sock);
    if (rv) fail("vlink_start_keyx err:%d\n", rv);

    while(1) pause();
}