#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>

#include <ecp/core.h>
#include <ecp/cr.h>
#include <ecp/ht.h>
#include <ecp/dir/dir.h>

#include <util.h>

#include "server.h"
#include "acl.h"

static SRVConfig *srv_config;

static ecp_ht_table_t *acl_keys = NULL;
static ecp_ht_table_t *acl_keys_dir = NULL;
static pthread_mutex_t acl_li_mutex;
static pthread_rwlock_t acl_ht_rwlock;
static ACLItem *acl_head = NULL;
static ACLItem *acl_head_dir = NULL;
static int acl_mark = 0;

ACLItem *acl_create_item(void) {
    ACLItem *ret = NULL;

    ret = malloc(sizeof(ACLItem));
    if (ret == NULL) return ret;
    memset(&ret->key, 0, sizeof(ret->key));
    ret->key_cnt = 0;
    ret->next = NULL;

    return ret;
}

void acl_destroy_item(ACLItem *item) {
    free(item);
}

void acl_destroy_list(ACLItem *head) {
    ACLItem *acl_next;

    while (head) {
        acl_next = head->next;
        acl_destroy_item(head);
        head = acl_next;
    }
}

static int _add_key(ecp_ecdh_public_t *public, uint8_t roles) {
    int rv;

    if ((acl_keys == NULL) || (acl_keys_dir == NULL)) return ECP_ERR;

    if ((srv_config->roles & ECP_ROLE_DIR) || (srv_config->roles & roles & ECP_ROLE_VCONN)) {
        /* directory server accepts all connections
           vconn server accepts connections only from other vconn servers */
        rv = ecp_ht_insert_uniq(acl_keys, public, &acl_mark);
        if (rv && (rv != ECP_ERR_DUP)) return rv;
    }
    if (srv_config->roles & roles & ECP_ROLE_DIR) {
        rv = ecp_ht_insert_uniq(acl_keys_dir, public, &acl_mark);
        if (rv && (rv != ECP_ERR_DUP)) return rv;
    }

    return ECP_OK;
}

static int _read_file(int fd, ACLItem *head) {
    ecp_ecdh_public_t public;
    int rv;

    if (head == NULL) return ECP_ERR_ALLOC;

    while (head->next) {
        head = head->next;
    }

    while(ecp_util_read_key(fd, &public, NULL) == ECP_OK) {
        if (head->key_cnt == ACL_MAX_KEY) {
            head->next = acl_create_item();
            if (head->next == NULL) return ECP_ERR_ALLOC;
            head = head->next;
        }
        memcpy(&head->key[head->key_cnt], &public, sizeof(head->key[head->key_cnt]));
        head->key_cnt++;
    }

    return ECP_OK;
}

static int _li2ht(ACLItem *head, int is_dir) {
    int i;
    int rv;

    while (head) {
        for (i=0; i<head->key_cnt; i++) {
            rv = _add_key(&head->key[i], is_dir ? ECP_ROLE_DIR : 0);
            if (rv) return rv;
        }
        head = head->next;
    }

    return ECP_OK;
}

int acl_add_key(ECPDirItem *dir_item) {
    int rv;

    pthread_rwlock_wrlock(&acl_ht_rwlock);
    rv = _add_key(&dir_item->node.key_perma.public, dir_item->roles);
    pthread_rwlock_unlock(&acl_ht_rwlock);

    return rv;
}

int acl_inlist(ecp_ecdh_public_t *public) {
    void *item = NULL;

    pthread_rwlock_rdlock(&acl_ht_rwlock);
    if (acl_keys) item = ecp_ht_search(acl_keys, public);
    pthread_rwlock_unlock(&acl_ht_rwlock);

    return (item != NULL);
}

unsigned int acl_count(void) {
    unsigned int r = 0;

    pthread_rwlock_rdlock(&acl_ht_rwlock);
    if (acl_keys) r = ecp_ht_count(acl_keys);
    pthread_rwlock_unlock(&acl_ht_rwlock);

    return r;
}

int acl_dir_inlist(ecp_ecdh_public_t *public) {
    void *item = NULL;

    pthread_rwlock_rdlock(&acl_ht_rwlock);
    if (acl_keys_dir) item = ecp_ht_search(acl_keys_dir, public);
    pthread_rwlock_unlock(&acl_ht_rwlock);

    return (item != NULL);
}

unsigned int acl_dir_count(void) {
    unsigned int r = 0;

    pthread_rwlock_rdlock(&acl_ht_rwlock);
    if (acl_keys) r = ecp_ht_count(acl_keys_dir);
    pthread_rwlock_unlock(&acl_ht_rwlock);

    return r;
}

int acl_reset_ht(void) {
    int rv = ECP_OK;

    pthread_rwlock_wrlock(&acl_ht_rwlock);
    if (acl_keys) ecp_ht_destroy(acl_keys);
    if (acl_keys_dir) ecp_ht_destroy(acl_keys_dir);
    acl_keys = ecp_ht_create_keys();
    acl_keys_dir = ecp_ht_create_keys();
    if ((acl_keys == NULL) || (acl_keys_dir == NULL)) rv = ECP_ERR_ALLOC;
    pthread_rwlock_unlock(&acl_ht_rwlock);

    return rv;
}

int acl_load_ht(void) {
    int rv = ECP_OK;
    int _rv;

    pthread_mutex_lock(&acl_li_mutex);
    pthread_rwlock_wrlock(&acl_ht_rwlock);

    _rv = _li2ht(acl_head, 0);
    if (_rv) rv = ECP_ERR;
    _rv = _li2ht(acl_head_dir, 1);
    if (_rv) rv = ECP_ERR;

    pthread_rwlock_unlock(&acl_ht_rwlock);
    pthread_mutex_unlock(&acl_li_mutex);

    return rv;
}

int acl_load(void) {
    ACLItem *acl_new = NULL;
    ACLItem *acl_dir_new = NULL;
    int fd = -1;
    int fd_dir = -1;
    int rv = ECP_OK;
    int _rv;

    if ((srv_config->acl_fn == NULL) && (srv_config->acl_fn_dir == NULL)) return ECP_OK;

    if (srv_config->acl_fn) {
        fd = open(srv_config->acl_fn, O_RDONLY);
        if (fd < 0) {
            LOG(LOG_ERR, "acl_load: unable to open: %s\n", srv_config->acl_fn);
            return ECP_ERR;
        }
    }

    if (srv_config->acl_fn_dir) {
        fd_dir = open(srv_config->acl_fn_dir, O_RDONLY);
        if (fd_dir < 0) {
            LOG(LOG_ERR, "acl_load: unable to open: %s\n", srv_config->acl_fn_dir);
            close(fd);
            return ECP_ERR;
        }
    }

    pthread_mutex_lock(&acl_li_mutex);
    if (fd >= 0) {
        acl_new = acl_create_item();
        rv = _read_file(fd, acl_new);
        if (rv) {
            LOG(LOG_ERR, "acl_load: read from file: %s err:%d\n", srv_config->acl_fn, rv);
            acl_destroy_list(acl_new);
            goto load_fin;
        }
    }

    if (fd_dir >= 0) {
        acl_dir_new = acl_create_item();
        rv = _read_file(fd_dir, acl_dir_new);
        if (rv) {
            LOG(LOG_ERR, "acl_load: read from file: %s err:%d\n", srv_config->acl_fn_dir, rv);
            acl_destroy_list(acl_dir_new);
            acl_destroy_list(acl_new);
            goto load_fin;
        }
    }
    if (acl_new) {
        acl_destroy_list(acl_head);
        acl_head = acl_new;
    }
    if (acl_dir_new) {
        acl_destroy_list(acl_head_dir);
        acl_head_dir = acl_dir_new;
    }

    pthread_rwlock_wrlock(&acl_ht_rwlock);
    if (acl_new) {
        _rv = _li2ht(acl_new, 0);
        if (_rv) rv = ECP_ERR;
    }
    if (acl_dir_new) {
        _rv = _li2ht(acl_dir_new, 1);
        if (_rv) rv = ECP_ERR;
    }

    pthread_rwlock_unlock(&acl_ht_rwlock);

load_fin:
    pthread_mutex_unlock(&acl_li_mutex);

    close(fd_dir);
    close(fd);

    return rv;
}

int acl_init(void) {
    int rv;

    srv_config = srv_get_config();

    rv = pthread_mutex_init(&acl_li_mutex, NULL);
    if (rv) return ECP_ERR;

    rv = pthread_rwlock_init(&acl_ht_rwlock, NULL);
    if (rv) {
        pthread_mutex_destroy(&acl_li_mutex);
        return ECP_ERR;
    }

    acl_keys = ecp_ht_create_keys();
    acl_keys_dir = ecp_ht_create_keys();
    if ((acl_keys == NULL) || (acl_keys_dir == NULL)) {
        pthread_rwlock_destroy(&acl_ht_rwlock);
        pthread_mutex_destroy(&acl_li_mutex);
        if (acl_keys_dir) ecp_ht_destroy(acl_keys_dir);
        if (acl_keys) ecp_ht_destroy(acl_keys);
        return ECP_ERR_ALLOC;
    }

    return ECP_OK;
}