#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <pthread.h>
#include "kni_utils.h"
#include "tfe_mgr.h"

extern struct kni_field_stat_handle *g_kni_fs_handle;

struct tfe_node{
    int tfe_id;
    uint32_t ipaddr;
};

struct tfe_mgr{
    pthread_rwlock_t rwlock;
    struct tfe_node tfe_enabled_nodes[TFE_COUNT_MAX];
    int tfe_enabled_node_count;
    int tfe_alive_nodes[TFE_COUNT_MAX];
    int tfe_alive_node_count;
    int keepalive_switch;                                       
    void *logger;
};

struct thread_tfe_keepalive_accept_args{
    struct tfe_mgr* mgr;
    int sockfd;
    int keepalive_idle;
    int keepalive_intvl;
    int keepalive_cnt;
    void *logger;
};

struct thread_tfe_keepalive_recv_args{
    struct tfe_mgr* mgr;
    int client_fd;
    int tfe_id;
    void *logger;
};

enum tfe_mgr_errno{
    TFE_MGR_NOT_EXISTED = -1,
    TFE_MGR_HAS_EXISTED = -2,
    TFE_MGR_EXCEED_MAX_COUNT = -3,
};

static char* tfe_mgr_errmsg_get(enum tfe_mgr_errno _errno){
	switch(_errno){
		case TFE_MGR_NOT_EXISTED:
			return (char*)"tfe not existed";
		case TFE_MGR_HAS_EXISTED:
			return (char*)"tfe has existed";
		case TFE_MGR_EXCEED_MAX_COUNT:
			return (char*)"tfe exceed max count";
		default:
			return (char*)"unknown";
	}
}

static int tfe_mgr_alive_node_del(struct tfe_mgr *mgr, int tfe_id){
    pthread_rwlock_wrlock(&(mgr->rwlock));
    int i, ret;
    for(i = 0; i < mgr->tfe_alive_node_count; i++){
        if(mgr->tfe_alive_nodes[i] == tfe_id){
            break;
        }
    }
    if(i == mgr->tfe_alive_node_count){
        ret = TFE_MGR_NOT_EXISTED;
        goto out;
    }
    for(int j = i; j < mgr->tfe_alive_node_count - 1; j++){
        mgr->tfe_alive_nodes[j] = mgr->tfe_alive_nodes[j + 1];
    }
    mgr->tfe_alive_node_count--;
    ret = 0;
    FS_operate(g_kni_fs_handle->handle, g_kni_fs_handle->fields[KNI_FIELD_TFE_STATUS_BASE + tfe_id], 0, FS_OP_SET, 0);
    goto out;

out: 
    pthread_rwlock_unlock(&(mgr->rwlock));
    return ret;
}

static int tfe_mgr_alive_node_add(struct tfe_mgr *mgr, int tfe_id){
    pthread_rwlock_wrlock(&(mgr->rwlock));
    int ret;
    for(int i = 0; i < mgr->tfe_alive_node_count; i++){
        if(mgr->tfe_alive_nodes[i] == tfe_id){
            ret = TFE_MGR_HAS_EXISTED;
            goto out;
        }
    }
    if(mgr->tfe_alive_node_count == TFE_COUNT_MAX){
        ret = TFE_MGR_EXCEED_MAX_COUNT;
        goto out;
    }
    mgr->tfe_alive_nodes[mgr->tfe_alive_node_count] = tfe_id;
    mgr->tfe_alive_node_count++;
    ret = 0;
    FS_operate(g_kni_fs_handle->handle, g_kni_fs_handle->fields[KNI_FIELD_TFE_STATUS_BASE + tfe_id], 0, FS_OP_SET, 1);
    goto out;

out:
    pthread_rwlock_unlock(&(mgr->rwlock));
    return ret;
}

static void* thread_tfe_keepalive_recv(void *args){
    struct thread_tfe_keepalive_recv_args *_args = (struct thread_tfe_keepalive_recv_args*)args;
    struct tfe_mgr *mgr = _args->mgr;
    int client_fd = _args->client_fd;
    int tfe_id = _args->tfe_id;
    void *logger = _args->logger;
    FREE(&args);
    char buff[BUFF_SIZE_MAX];
    char *errmsg = NULL;
    int ret;
    while(true){
        ret = recv(client_fd, buff, sizeof(buff), 0);
        if(ret == 0){
            KNI_LOG_ERROR(logger, "recv fin, del tfe alive node, tfe_id is %d", tfe_id);
            break;
        }
        if(ret <= 0){
            if(errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK){
                KNI_LOG_ERROR(logger, "recv error, errno is %d, errmsg is %s, continue recv, tfe_id is %d", errno, strerror(errno), tfe_id);
                continue;
            }
            if(errno == ETIMEDOUT){
                KNI_LOG_ERROR(logger, "recv error, errno is %d, errmsg is %s, del tfe alive node, tfe_id is %d", errno, strerror(errno), tfe_id);
                break;
            }
            KNI_LOG_ERROR(logger, "recv error, errno is %d, errmsg is %s, error_out, tfe_id is %d", errno, strerror(errno), tfe_id);
            goto error_out;
        }
    }
    //recv fin: del alive node
    close(client_fd);
    ret = tfe_mgr_alive_node_del(mgr, tfe_id);
    if(ret < 0){
        errmsg = tfe_mgr_errmsg_get((enum tfe_mgr_errno)ret);
        KNI_LOG_ERROR(logger, "Failed at del tfe alive node, tfe_id is %d, errmsg is %s", tfe_id, errmsg);
    }
    else{
        KNI_LOG_ERROR(logger, "Succeed at del tfe alive node, tfe_id is %d", tfe_id);
    }
    return NULL;

error_out:
    if(client_fd > 0){
        close(client_fd);
    }
    return NULL;
}

static void* thread_tfe_keepalive_accept(void *args){
    struct thread_tfe_keepalive_accept_args *_args = (struct thread_tfe_keepalive_accept_args*)args;
    struct tfe_mgr *mgr = _args->mgr;
    int sockfd = _args->sockfd;
    int keepalive_idle = _args->keepalive_idle;
    int keepalive_intvl = _args->keepalive_intvl;
    int keepalive_cnt = _args->keepalive_cnt;
    void *logger = mgr->logger;
    FREE(&args);
    //accept
    struct sockaddr_in client_addr;
    socklen_t client_addr_len = sizeof(client_addr);
    uint32_t client_ipaddr;
    char client_ipaddr_str[INET_ADDRSTRLEN] = "";
    int flags, ret, client_fd;
    pthread_t thread_id = -1;
    int tfe_id = -1;
    char *errmsg = NULL;
    while(true){
        client_fd = accept(sockfd, (struct sockaddr *)&client_addr, &client_addr_len);
        if(client_fd < 0){
            KNI_LOG_ERROR(logger, "Failed at accept, errno is %d, errmsg is %s, tfe_id is %d", errno, strerror(errno), tfe_id);
            continue;
        }
        client_ipaddr = client_addr.sin_addr.s_addr;
        inet_ntop(AF_INET, &client_ipaddr, client_ipaddr_str, INET_ADDRSTRLEN);
        for(int i = 0; i < mgr->tfe_enabled_node_count; i++){
            if(client_ipaddr == mgr->tfe_enabled_nodes[i].ipaddr){
                tfe_id = i;
                break;
            }
        }
        if(tfe_id == -1){
            KNI_LOG_ERROR(logger, "Receive connection not from tfe, client addr is %s", client_ipaddr_str);
            close(client_fd);
            continue;
        }
        //set socketopt keepalive
        flags = 1;
        ret = setsockopt(client_fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&flags, sizeof(flags));
        if(ret < 0){
            KNI_LOG_ERROR(logger, "Failed at set socketopt SO_KEEPALIVE, errno is %d, errmsg is %s, tfe_id is %d", errno, strerror(errno), tfe_id);
            close(client_fd);
            continue;
        }
        ret = setsockopt(client_fd, SOL_TCP, TCP_KEEPIDLE, (void *)&keepalive_idle, sizeof(keepalive_idle));
        if(ret < 0){
            KNI_LOG_ERROR(logger, "Failed at set socketopt TCP_KEEPIDLE, errno is %d, errmsg is %s, tfe_id is %d", errno, strerror(errno), tfe_id);
            close(client_fd);
            continue;
        }
        ret = setsockopt(client_fd, SOL_TCP, TCP_KEEPINTVL, (void *)&keepalive_intvl, sizeof(keepalive_intvl));
        if(ret < 0){
            KNI_LOG_ERROR(logger, "Failed at set socketopt TCP_KEEPINTVL, errno is %d, errmsg is %s, tfe_id is %d", errno, strerror(errno), tfe_id);
            close(client_fd);
            continue;
        }
        ret = setsockopt(client_fd, SOL_TCP, TCP_KEEPCNT, (void *)&keepalive_cnt, sizeof(keepalive_cnt));
        if(ret < 0){
            KNI_LOG_ERROR(logger, "Failed at set socketopt TCP_KEEPCNT, errno is %d, errmsg is %s, tfe_id is %d", errno, strerror(errno), tfe_id);
            close(client_fd);
            continue;
        }
        //add alive node
        ret = tfe_mgr_alive_node_add(mgr, tfe_id);
        if(ret < 0){
            errmsg = tfe_mgr_errmsg_get((enum tfe_mgr_errno)ret);
            KNI_LOG_ERROR(logger, "Failed at add tfe alive node, tfe_id is %d, errmsg is %s", tfe_id, errmsg);
            close(client_fd);
            continue;
        }
        else{
            KNI_LOG_ERROR(logger, "Succeed at add tfe alive node, tfe_id is %d", tfe_id);
        }
        //create thread_tfe_keepalive_recv
        struct thread_tfe_keepalive_recv_args *recv_args = ALLOC(struct thread_tfe_keepalive_recv_args, 1);
        recv_args->mgr = mgr;
        recv_args->client_fd = client_fd;
        recv_args->tfe_id = tfe_id;
        recv_args->logger = logger;
        ret = pthread_create(&thread_id, NULL, thread_tfe_keepalive_recv, (void *)recv_args);
		if(unlikely(ret != 0)){
			KNI_LOG_ERROR(logger, "Failed at thread_tfe_keepalive_recv, thread_func is thread_tfe_keepalive_recv, errno is %d, errmsg is %s", errno, strerror(errno));
			FREE(&recv_args);
            close(client_fd);
            tfe_mgr_alive_node_del(mgr, tfe_id);
            continue;
		}
    }
    return NULL;
}

void tfe_mgr_destroy(struct tfe_mgr* mgr){
    if(mgr != NULL){
        pthread_rwlock_destroy(&(mgr->rwlock));
        FREE(&mgr);
    }
}

static int get_binded_sockfd(uint32_t listen_ip, uint16_t listen_port, void *logger){
    //create socket
    struct sockaddr_in server_addr;
    int ret;
    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
    int flag;
	if(sockfd < 0){
		KNI_LOG_ERROR(logger, "Failed at create tcp socket, errno is %d, errmsg is %s", errno, strerror(errno));
		goto error_out;
	}
    flag = 1;
    ret = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (void *)&flag, sizeof(flag)); 
    if(ret < 0){
        KNI_LOG_ERROR(logger, "Failed at set socketopt SO_REUSEADDR, errno is %d, errmsg is %s", errno, strerror(errno));
    }
    //bind
    memset(&server_addr, 0, sizeof(server_addr)); 
	server_addr.sin_family = AF_INET; // IPv4 
    server_addr.sin_addr.s_addr = listen_ip; 
    server_addr.sin_port = htons(listen_port);
	ret = bind(sockfd, (const struct sockaddr *)&server_addr, sizeof(server_addr));
	if(ret < 0){
		KNI_LOG_ERROR(logger, "Failed at bind tcp socket, port is %d, errno is %d, errmsg is %s", 
                    listen_port, errno, strerror(errno));
		goto error_out;
	}
    //listen
    ret = listen(sockfd, 5);
    if(ret < 0){
        KNI_LOG_ERROR(logger, "Failed at listen tcp socket, errno is %d, errmsg is %s, listen_port is %d", 
                    errno, strerror(errno), listen_port);
        goto error_out;
    }
    return sockfd;

error_out:
    if(sockfd > 0){
        close(sockfd);
    }
    return -1;
}

struct tfe_mgr* tfe_mgr_init(int tfe_node_count, const char* profile, void *logger){
    struct tfe_mgr* mgr = ALLOC(struct tfe_mgr, 1);
    mgr->logger = logger;
    int ret;
    //load keepalive conf
    char section[KNI_SYMBOL_MAX] = "tfe_mgr";
    MESA_load_profile_int_def(profile, section, "keepalive_switch", &(mgr->keepalive_switch), 0);
    KNI_LOG_ERROR(logger, "MESA_prof_load, [%s]:\n keepalive_switch: %d", section, mgr->keepalive_switch);
    if(mgr->keepalive_switch == 0){
        return mgr;
    }
    int keepalive_idle, keepalive_cnt, keepalive_intvl;
    char keepalive_listen_eth[KNI_SYMBOL_MAX] = "";
    uint32_t keepalive_listen_ip;
    int keepalive_listen_port;
    uint32_t tfe_node_ipaddr;
    char tfe_ipaddr_str[INET_ADDRSTRLEN];
    pthread_t thread_id = -1;
    int sockfd;
    int tfe_node_enabled;
    int j;
    struct thread_tfe_keepalive_accept_args *args = NULL;
    MESA_load_profile_int_def(profile, section, "keepalive_idle", &keepalive_idle, 2);
    MESA_load_profile_int_def(profile, section, "keepalive_intvl", &keepalive_intvl, 1);
    MESA_load_profile_int_def(profile, section, "keepalive_cnt", &keepalive_cnt, 3);
    ret = MESA_load_profile_string_nodef(profile, section, "keepalive_listen_eth", keepalive_listen_eth, sizeof(keepalive_listen_eth));
	if(ret < 0){
		KNI_LOG_ERROR(logger, "MESA_prof_load: keepalive_listen_eth not set, profile is %s, section is %s", profile, section);
		goto error_out;
	}
    ret = MESA_load_profile_int_nodef(profile, section, "keepalive_listen_port", &keepalive_listen_port);
    if(ret < 0){
        KNI_LOG_ERROR(logger, "MESA_prof_load: keepalive_listen_port not set, profile is %s, section is %s", profile, section);
        goto error_out;
    }
    KNI_LOG_ERROR(logger, "MESA_prof_load, [%s]:\n keepalive_idle: %d\n keepalive_intvl: %d\n keepalive_cnt: %d\n keepalive_listen_eth: %s\n keepalive_listen_port: %d",
					section, keepalive_idle, keepalive_intvl, keepalive_cnt, keepalive_listen_eth, keepalive_listen_port);
    ret = kni_ipv4_addr_get_by_eth(keepalive_listen_eth, &keepalive_listen_ip);
    if(ret < 0){
        KNI_LOG_ERROR(logger, "Failed at get bind ipv4 addr, eth is %s", keepalive_listen_eth);
        goto error_out;
    }
    //load tfe_ipaddr
    j = 0;
    for(int i = 0; i < tfe_node_count; i++){
        snprintf(section, sizeof(section), "tfe%d", i);
        MESA_load_profile_int_def(profile, section, "enabled", &tfe_node_enabled, 1);
        if(tfe_node_enabled != 1){
            continue;
        }
        ret = MESA_load_profile_string_nodef(profile, section, "ip_addr", tfe_ipaddr_str, sizeof(tfe_ipaddr_str));
		if(ret < 0){
			KNI_LOG_ERROR(logger, "MESA_prof_load: ip_addr not set, profile is %s, section is %s", profile, section);
			goto error_out;
		}
        KNI_LOG_ERROR(logger, "MESA_prof_load, [%s]:\n ip_addr: %s", section, tfe_ipaddr_str);
        ret = inet_pton(AF_INET, tfe_ipaddr_str, &tfe_node_ipaddr);
        if(ret != 1){
            KNI_LOG_ERROR(logger, "Failed at inet_pton, ret is %d, errno is %d, errmsg is %s, tfe_id is %d, ip_addr is %s",
                                    ret, errno, strerror(errno), i, tfe_ipaddr_str);
            goto error_out;
        }
        mgr->tfe_enabled_nodes[j].tfe_id = i;
        mgr->tfe_enabled_nodes[j].ipaddr = tfe_node_ipaddr;
        j++;
    } 
    mgr->tfe_enabled_node_count = j;
    //init rw_lock
    ret = pthread_rwlock_init(&(mgr->rwlock), NULL);
    if(ret < 0){
        KNI_LOG_ERROR(logger, "Failed at pthread_rwlock_init, errno is %d, errmsg is %s", errno, strerror(errno));
        goto error_out;
    }
    //bind and listen
    sockfd = get_binded_sockfd(keepalive_listen_ip, keepalive_listen_port, logger);
    if(sockfd < 0){
        KNI_LOG_ERROR(logger, "Failed at get binded sockfd");
        goto error_out;
    }
    //create tfe_keepalive_accept thread
    args = ALLOC(struct thread_tfe_keepalive_accept_args, 1);
    args->mgr = mgr;
    args->keepalive_idle = keepalive_idle;
    args->sockfd = sockfd;
    args->keepalive_intvl = keepalive_intvl;
    args->keepalive_cnt = keepalive_cnt;
    args->logger = logger;
    ret = pthread_create(&thread_id, NULL, thread_tfe_keepalive_accept, (void *)args);
    if(unlikely(ret != 0)){
        KNI_LOG_ERROR(logger, "Failed at pthread_create, thread_func is thread_tfe_keepalive_accept, errno is %d, errmsg is %s", errno, strerror(errno));
        FREE(&args);
        goto error_out;
    }
    return mgr;

error_out:
    tfe_mgr_destroy(mgr);
    return NULL;
}

int tfe_mgr_alive_node_get(struct tfe_mgr *mgr, int thread_seq){
    int tfe_id = -1;
     if(mgr->keepalive_switch == 0){
         if(mgr->tfe_enabled_node_count > 0){
            int i = thread_seq % mgr->tfe_enabled_node_count;
            tfe_id = mgr->tfe_enabled_nodes[i].tfe_id;
         }
         return tfe_id;
     }
     pthread_rwlock_rdlock(&(mgr->rwlock));
     if(mgr->tfe_alive_node_count > 0){
        int i = thread_seq % mgr->tfe_alive_node_count;
        tfe_id = mgr->tfe_alive_nodes[i];
     }
     pthread_rwlock_unlock(&(mgr->rwlock));
     return tfe_id;
}