#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
/* event_struct.h must be included first cause of LIST_HEAD macro used by libevent2 */
#include <event2/event.h>
#include <syslog.h>
#include <event2/event_struct.h>
#include <json-c/json.h>
#include <iwinfo.h> /* iwinfo library (package/libiwinfo */

#include "sysinfo.h"
#include "config.h"
#include "list.h" //double linked list header lib from linux kernel

static void parse_line(json_object *root_cur, char *line);


static void parse_cfg_json_object(json_object *jso, char *buf, size_t buf_len, char **p, size_t depth, bool is_delete);
static void parse_cfg_json_array(json_object *a, char *buf, size_t buf_len, char **p, size_t depth, bool is_delete);
static void parse_cfg_json_string(json_object *s, char *buf, size_t buf_len, char **p, bool is_delete);
static void parse_cfg_json_boolean(json_object *b, char *buf, size_t buf_len, char **p, bool is_delete);
static void parse_cfg_json_int(json_object *i, char *buf, size_t buf_len, char **p, bool is_delete);
static void parse_cfg_json_double(json_object *d, char *buf, size_t buf_len, char **p, bool is_delete);
static void parse_cfg_json(json_object *val, char *buf, size_t buf_len, char **p, size_t depth, bool is_delete);

/**
 * @brief check if file exists
 * 
 * @param fname 
 * @return true 
 * @return false 
 */
bool is_file_exists(const char *fname){
    FILE *file;
    if ((file = fopen(fname, "r")))
    {
        fclose(file);
        return true;
    }
    return false;
}


/**
 * Remove trailing white space characters from string
 */
size_t trim_str(char * str){
    int index, i;

    /* Set default index */
    index = -1;

    /* Find last index of non-white space character */
    i = 0;
    while(str[i] != '\0')
    {
        /* somehow char 127 'del' may appear */
        if(str[i] != ' ' && str[i] != '\t' && str[i] != '\n')
        {
            index = i;
        }

        i++;
    }

    /* Mark next character to last non-white space character as NULL */
    str[index + 1] = '\0';
    return index;
}

static void parse_cfg_json_object(json_object *jso, char *buf, size_t buf_len, char **p, size_t depth, bool is_delete) {
    lh_table *table = json_object_get_object(jso);
    for (struct lh_entry *entry = table->head; entry; entry = entry->next) {
        char subbuf[4096];
        char *subp = subbuf;
        size_t subbuf_len = buf_len;
        memcpy(subbuf, buf, buf_len);
        subp += buf_len;
        char *key = (char *) entry->k;
        if (memcmp(key, "section_type", 12)) {
            const char *pattern = depth == 0 ? "%s" : ".%s";
            subbuf_len += snprintf(subp, 4096, pattern, key);
        }

        parse_cfg_json((json_object *) entry->v, subbuf, subbuf_len, p, depth + 1, is_delete);
    }
}

/**
 * @brief parse json entry type array
 * 
 * @param a 
 * @param buf 
 * @param buf_len 
 * @param p 
 * @param depth 
 * @param is_delete 
 */
static void parse_cfg_json_array(json_object *a, char *buf, size_t buf_len, char **p, size_t depth, bool is_delete) {
    array_list *list = json_object_get_array(a);
    size_t len = list->length;


    for (size_t i = 0; i < len; i++) {
        char subbuf[4096];
        char *subp = subbuf;
        size_t subbuf_len = buf_len;
        memcpy(subbuf, buf, buf_len);
        subp += buf_len;

        subbuf_len += snprintf(subp, 512, "[%zu]", i);
        json_object *o = (json_object *) list->array[i];
        parse_cfg_json(o, subbuf, subbuf_len, p, depth + 1, is_delete);
    }
}

/**
 * @brief parse json entry type string
 * 
 * @param s 
 * @param buf 
 * @param buf_len 
 * @param p 
 * @param is_delete 
 */
static void parse_cfg_json_string(json_object *s, char *buf, size_t buf_len, char **p, bool is_delete) {
    memcpy(*p, buf, buf_len);
    *p += buf_len;
    if (!is_delete) {
        const char *string = json_object_get_string(s);
        *p += snprintf(*p, 512, "=\"%s\"\n", string);
    } else {
        **p = '\n';
        *p += 1;
    }
}

/**
 * @brief parse json entry type boolean
 * 
 * @param b 
 * @param buf 
 * @param buf_len 
 * @param p 
 * @param is_delete 
 * @return void* 
 */
static void parse_cfg_json_boolean(json_object *b, char *buf, size_t buf_len, char **p, bool is_delete) {
    memcpy(*p, buf, buf_len);
    *p += buf_len;
    if (!is_delete) {
        int i = json_object_get_boolean(b);
        *p += snprintf(*p, 512, "=%d\n", i);
    } else {
        **p = '\n';
        *p += 1;
    }
}
/**
 * @brief parse json entry type integer
 * 
 * @param i 
 * @param buf 
 * @param buf_len 
 * @param p 
 * @param is_delete 
 * @return char* 
 */
static void parse_cfg_json_int(json_object *i, char *buf, size_t buf_len, char **p, bool is_delete) {
    memcpy(*p, buf, buf_len);
    *p += buf_len;
    if (!is_delete) {
        int ii = json_object_get_int(i);
        *p += snprintf(*p, 512, "=%d\n", ii);
    } else {
        **p = '\n';
        *p += 1;
    }
}

/**
 * @brief parse json entry type double
 * 
 * @param d 
 * @param buf 
 * @param buf_len 
 * @param p 
 * @param is_delete 
 * @return void* 
 */
static void parse_cfg_json_double(json_object *d, char *buf, size_t buf_len, char **p, bool is_delete) {
    memcpy(*p, buf, buf_len);
    *p += buf_len;
    if (!is_delete) {
        double dd = json_object_get_double(d);
        *p += snprintf(*p, 512, "=%f\n", dd);
    } else {
        **p = '\n';
        *p += 1;
    }
}

/**
 * @brief dispatcher fucntion to parse json object
 * 
 * @param val 
 * @param buf 
 * @param buf_len 
 * @param p 
 * @param depth 
 * @param is_delete 
 */
static void parse_cfg_json(json_object *val, char *buf, size_t buf_len, char **p, size_t depth, bool is_delete) {
    json_type type = json_object_get_type(val);
    switch (type) {
        case json_type_object:
            parse_cfg_json_object(val, buf, buf_len, p, depth, is_delete);
            break;
        case json_type_array:
            parse_cfg_json_array(val, buf, buf_len, p, depth, is_delete);
            break;

        case json_type_string:
            parse_cfg_json_string(val, buf, buf_len, p, is_delete);
            break;

        case json_type_boolean:
            parse_cfg_json_boolean(val, buf, buf_len, p, is_delete);
            break;

        case json_type_int:
            parse_cfg_json_int(val, buf, buf_len, p, is_delete);
            break;

        case json_type_double:
            parse_cfg_json_double(val, buf, buf_len, p, is_delete);
            break;

        case json_type_null:
        default:
            break;
    }
}

/*
lh_table *table = json_object_get_object(root);
for (struct lh_entry *entry = table->head; entry; entry = entry->next){
    char *key = (char *)entry->k;
    char *val =  json_object_get_string((json_object *)entry->v);
    syslogwda(LOG_DEBUG,"key: %s val: %s\n", key, val);
}
 */

bool config_set_or_delete(json_object *root, bool is_delete) {
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    char *uci_command = is_delete ? "uci delete" : "uci set";

    /* parse json */
    char buf[16384]; /* commands buffer */
    char *bp = buf;
    char **p = &bp;

    if (json_object_get_type(root) != json_type_object) {
        syslogwda(LOG_ALERT,"error: data is not an object\n");
        return false;
    }

    parse_cfg_json(root, NULL, 0, p, 0, is_delete);
    syslogwda(LOG_DEBUG,"commands:\n%s\n", buf);

    /* exec */
    FILE *fp;
    char command[256];
    char outbuf[256];
    char *line = strtok(buf, "\n");
    do {
        snprintf(command, 256, "%s %s", uci_command, line);
        syslogwda(LOG_WARNING,"cmd exec: %s\n", command);

        fp = popen(command, "r");
        if (fp == NULL) {
            syslogwda(LOG_ALERT,"error: Unable to open process %s\n", command);
            return false;
        }

        /* print cmd outbuf */
        while (fgets(outbuf, 256, fp) != NULL) {
            syslogwda(LOG_DEBUG,"%s\n", outbuf);
        }

        /* status code */
        int ret = WEXITSTATUS(pclose(fp));
        if (ret != 0) syslogwda(LOG_WARNING,"status code: %d %s\n", ret, strerror(ret));


    } while ((line = strtok(NULL, "\n")));


    /* commit and reload */
    snprintf(buf, 512, "uci commit\nreload_config\n");
    line = strtok(buf, "\n");
    do {
        snprintf(command, 256, "%s", line);
        syslogwda(LOG_WARNING,"cmd exec: %s\n", command);

        fp = popen(command, "r");
        if (fp == NULL) {
            syslogwda(LOG_ALERT,"error: %s Unable to open process %s\n", strerror(errno), command);
            return false;
        }

        /* print cmd outbuf */
        while (fgets(outbuf, 256, fp) != NULL) {
            syslogwda(LOG_DEBUG,"%s\n", outbuf);
        }

        /* status code */
        int ret = WEXITSTATUS(pclose(fp));
        if(ret != 0) syslogwda(LOG_DEBUG,"status code: %d %s\n", ret, strerror(ret));

    } while ((line = strtok(NULL, "\n")));


    return true;

}

size_t read_file(const char *filepath, char *buf, size_t buf_len){
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    FILE *fp = fopen(filepath,"r");
    if(fp == NULL){
        syslogwda(LOG_ALERT,"error: Unable to open file %s\n", filepath);
        return 0;
    }
    size_t read = fread(buf, 1, buf_len, fp);
    buf[read] = '\0'; //set terminator
    fclose(fp);
    return read;
}

/**
 * @brief exec given command with shell
 * 
 * @param command 
 * @param buf 
 * @param buf_len 
 * @return int 
 */
int exec(const char *command, char *buf, size_t buf_len){
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    FILE *fp;
    syslogwda(LOG_NOTICE,"exec: %s\n", command);

    fp = popen(command, "r");
    if (fp == NULL) {
        syslogwda(LOG_ERR,"error: %s Unable to open process %s\n", strerror(errno), command);
        return errno;
    }
    
    if(buf == NULL || buf_len == 0) {
        buf_len = 8192;
        char tmp_buf[buf_len];
        buf = (char *)&tmp_buf;
    }

    size_t p = fread(buf, 1, buf_len, fp); //fread will return number of 1 byte entries readed
    /* check bounds */
    if(p > buf_len){
        syslogwda(LOG_ERR, "INFO: exec stdout > buf_len %zu\n", buf_len);
        buf[buf_len - 1] = '\0';
    } else {
        buf[p] = '\0'; //set terminator
    }
    
    /* status code */
    int ret = WEXITSTATUS(pclose(fp));
    if(ret != 0) syslogwda(LOG_NOTICE, "status code: %d %s\n", ret, strerror(ret));
    return ret;
}

/**
 * @brief exec given command with format like printf, fprintf etc
 * 
 * @param buf 
 * @param buflen 
 * @param fmt 
 * @param ... 
 * @return int 
 */
int execf(char *buf, size_t buflen, const char *fmt, ...){
    size_t cmdlen = 2048;
    char cmd[cmdlen];
    va_list arg;

    va_start (arg, fmt);
    cmdlen -= vsnprintf(cmd, cmdlen, fmt, arg);
    va_end (arg);

    return exec(cmd, buf, buflen);
}

int exec2(char *outbuf, size_t *outbufsize, char *errbuf, size_t *errbufsize, char *argv[]) {
  int fdout[2];     /* pipe fd array for the stdout */
  int fderr[2];     /* pipe fd array for the stderr */
  pid_t pid;        /* process id */
  int status;       /* place to store child process status */

  if (pipe(fdout)==-1)  /* first pipe for the stdout */
    perror("pipe out");    /* exit with error if something wrong */

  if (pipe(fderr)==-1)  /* second pipe for the stderr */
    perror("pipe err");    
    /*
    *   On success, the PID of the child process is returned in the
    *   parent, and 0 is returned in the child.  On failure, -1 is
    *   returned in the parent, no child process is created, and errno is
    *   set to indicate the error.
    */
  if ((pid = fork()) == -1) /* fork current process and store pid */
    perror("fork error");

  if(pid == 0) { /* if pid == 0 than this is a child process */

    dup2 (fdout[1], STDOUT_FILENO); /* send stdout to the pipe fdout */
    dup2 (fderr[1], STDERR_FILENO); /* send stderr to the pipe fderr */
    
    /* close both sides of the pipe in the child */
    close(fdout[0]);
    close(fdout[1]);

    /* close both sides of the pipe in the child */
    close(fderr[0]);
    close(fderr[1]);


    /* execvp is called in the child ps 
     * argv[0] is a ptr to the first arg
     * &argv[0] is a ptr to a ptr to the first arg
     */
    execvp(argv[0], &argv[0]); 
    
    /* this part is never reached if execvp success */
    return errno;

  } else { /* parent */    
    while(wait(&status) > 0){} /* wait for the child processes to finish */
    
    /* close write ends of the pipes */
    close(fdout[1]);
    close(fderr[1]);
    
    /* if child process finished with errorprint error 
     * and return error code from parent process
     */
    if (WIFEXITED(status) && WEXITSTATUS(status)){
      printf("%s\n", strerror(WEXITSTATUS(status)));
      return WEXITSTATUS(status);
    }

    *outbufsize = read(fdout[0], outbuf, *outbufsize);
    outbuf[*outbufsize] = '\0';
    //printf("OUT: \"%.*s\"\n", (int)*outbufsize, outbuf);

    *errbufsize = read(fderr[0], errbuf, *errbufsize);
    errbuf[*errbufsize] = '\0';
    //printf("ERR: \"%.*s\"\n", (int)*errbufsize, errbuf);

    /* close read ends of the pipes */
    close(fdout[0]);
    close(fderr[0]);
  }

  return 0;
}

json_object *config_get_raw() {
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    size_t bufsize = 32768;
    char *buf = malloc(bufsize);
    exec("uci show", buf, bufsize);
    json_object *json_array = json_object_new_array();
    char *tok = strtok(buf, "\n");
    size_t idx = 0;
    do {
        syslogwda(LOG_INFO,"uci cmd: %s\n", tok);
        json_object *json_string = json_object_new_string(tok);
        json_object_array_put_idx(json_array, idx, json_string);
        idx++;
    } while ((tok = strtok(NULL, "\n")));
    free(buf);
    return json_array;
}

void config_wireless_iface(bool remove){
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    char buf[16384];
    exec("uci show wireless | grep '=wifi-iface'", buf, 16384);
    char *tok = strtok(buf, "\n");
    if(tok == NULL) return;

    size_t idx = 0;
    do {
        char *last = strchr(tok,'=');
        if(last == NULL){
            syslogwda(LOG_INFO,"%zu found: '%s' wifi-iface not found! skip.\n", idx, tok);
            continue;
        }

        size_t len = last - tok;
        char wifi_iface[len + 1]; /* + 1 for terminator byte '\0' */
        memcpy(wifi_iface, tok, len);
        wifi_iface[len] = '\0'; /* terminate string */
        syslogwda(LOG_INFO,"%zu found '%s' len: %zu wifi-iface: '%s'\n", idx, tok, len, wifi_iface);
        if(remove) {
            char command[256];
            snprintf(command, 256, "uci delete %s", wifi_iface);
            exec(command, NULL, 0);
        }
        idx++;
    } while ((tok = strtok(NULL, "\n")));

    return;
}

void config_network_clear(){
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    char buf[16384];
    exec("uci show network | grep -E '=[device|interface]' | grep -Ev 'dev\\d{1,2}=|loopback'", buf, 16384);
    char *tok = strtok(buf, "\n");
    if(tok == NULL) return;

    size_t idx = 0;
    do {
        char *last = strchr(tok,'=');
        if(last == NULL){
            syslogwda(LOG_DEBUG,"%zu found: '%s' network interface not found! skip.\n", idx, tok);
            continue;
        }

        size_t len = last - tok;
        char net_iface[len + 1]; /* + 1 for terminator byte '\0' */
        memcpy(net_iface, tok, len);
        net_iface[len] = '\0'; /* terminate string */
        syslogwda(LOG_DEBUG,"%zu found '%s' len: %zu network iface: '%s'\n", idx, tok, len, net_iface);
        
        char command[256];
        snprintf(command, 256, "uci delete %s", net_iface);
        exec(command, NULL, 0);
    
        idx++;
    } while ((tok = strtok(NULL, "\n")));

    return;
}


json_object *config_get() {
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    FILE *fp;

    char string[1024]; /* stdout string len */
    fp = popen("uci show", "r");
    if (fp == NULL) return false;


    /* json init */
    json_object *root = json_object_new_object();
    while (fgets(string, 1024, fp) != NULL) {
        parse_line(root, string);
    }

    pclose(fp);
    return root;
}

static void parse_line(json_object *root_cur, char *line) {
    char *start = NULL, *end = NULL, *pos = NULL, *val = NULL, *tok = NULL, *tok_prev = NULL, *tok_last = NULL;
    json_object *root_parent = NULL, *child = NULL;
    bool is_section_type; //this flag for special parse uci section_type e.g.: wireless.2g=wifi-iface
    is_section_type = false;

    /* value delimiter */
    char delim = '=';
    pos = strchr(line, delim);
    if (pos == NULL) {
        syslogwda(LOG_DEBUG,"warning: delimiter '%c' not found in the line: %s\n", delim, line);
        return;
    }

    *pos = '\0';  /* set terminator inplace delimiter */
    val = pos + 1;

    /* remove trailing \n */
    size_t len = strlen(val);
    end = val + len - 1; // last char pos
    if (*end == '\n') *end = '\0';
    end--; // replace \n with line terminator

    /* remove quotes if exists */
    if (*val == '"' || *val == '\'') {
        val++; //shift forward to remove opening quote
        if (*end == '"' || *end == '\'') *end = '\0';
        end--; // shift backward to remove closing quote
    } else{
        is_section_type = true;
    }


    /*last token detection */
    tok_last = strrchr(line, '.');
    if (tok_last) {
        tok_last += 1;
    } else {
        tok_last = line;
    };

    /* split line by dots */
    tok = strtok(line, ".");

    do {
        size_t idx = 0;
        bool is_array = false;
        json_object *container;
        //syslogwda(LOG_DEBUG,"\ttok: %s \n", tok);


        /* if array is present in token */
        if ((start = strchr(tok, '['))) {
            *start = '\0'; /* set terminator char */
            //syslogwda(LOG_DEBUG,"\ttok clean: %s\n", tok);

            if ((end = strchr(start + 1, ']'))) {
                is_array = true;
                *end = '\0'; /* set terminator char */
                idx = atoi(start + 1); /* array index */
                //syslogwda(LOG_DEBUG,"\t\tarray idx: %d\n", idx);
            }
        }

        /* if last token */
        if (tok == tok_last) {
            child = json_object_new_string(val);
            /* 2 scenarios */
            if (!is_array) {
                if (json_object_get_type(root_cur) != json_type_object){
                    json_object_object_del(root_parent, tok_prev);
                    root_cur = json_object_new_object();
                    json_object_object_add(root_parent, tok_prev, root_cur);
                }
                //special parse section_type
                if(is_section_type){
                    json_object *jso = json_object_new_object();
                    json_object_object_add(root_cur, tok, jso);
                    root_cur = jso;
                    json_object_object_add(root_cur, "section_type", child);
                }else {
                    json_object_object_add(root_cur, tok, child);
                }
            } else if (is_array) {
                //special parse section_type
                if(is_section_type){
                    json_object *jso = json_object_new_object();
                    json_object_object_add(jso, "section_type", child);
                    child = jso;
                }

                json_object_object_get_ex(root_cur, tok, &container);
                //remove if not an array
                if(json_object_get_type(container) != json_type_array){
                    json_object_object_del(root_cur, tok); //delete container
                    container = json_object_new_array();
                    json_object_object_add(root_cur, tok, container);
                }



                json_object_array_put_idx(container, idx, child);
            }

            continue;
        }



        /* get tok container */
        json_object_object_get_ex(root_cur, tok, &container);

        //save for next cycles root_cur and tok
        root_parent = root_cur;
        tok_prev = tok;

        /* 4 scenarios */
        if (!is_array && container) {
            root_cur = container;
        } else if (!is_array && !container) {
            child = json_object_new_object();
            json_object_object_add(root_cur, tok, child);
            root_cur = child;
        } else if (is_array && container) {
            if(json_object_get_type(container) != json_type_array){
                json_object_object_del(root_cur, tok); //delete container
                container = json_object_new_array();
                json_object_object_add(root_cur, tok, container);
                child = NULL;
            } else {
                child = json_object_array_get_idx(container, idx);
            }

            if (!child) {
                child = json_object_new_object();
                json_object_array_put_idx(container, idx, child);
            }
            root_cur = child;
        } else if (is_array && !container) {
            child = json_object_new_object();
            container = json_object_new_array();
            json_object_array_put_idx(container, idx, child);
            json_object_object_add(root_cur, tok, container);
            root_cur = child;
        }


    } while ((tok = strtok(NULL, ".")));

}

int wireless_del_station(const char *dev, const char *mac) {
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    syslogwda(LOG_WARNING,"delete sta dev: %s mac: %s\n", dev, mac);
    //if dev and mac passed
    if(dev && mac){
        return ubus_hostpad_del_station(dev, mac);
    }

    //if dev passed and mac is not
    size_t entry_size = sizeof(struct iwinfo_assoclist_entry);
    const struct iwinfo_ops *iw;
    int len = 0;
    char buf[IWINFO_BUFSIZE];
    if(dev && !mac) {
        iw = iwinfo_backend(dev);
        iw->assoclist(dev, buf, &len);
        for (int i = 0; i < len; i += entry_size) {
            struct iwinfo_assoclist_entry *e;
            e = (struct iwinfo_assoclist_entry *) &buf[i];
            int ret = ubus_hostpad_del_station(dev, format_mac((uint8_t *)e->mac));
            if(ret != 0) return ret;
        }
        return 0;
    }

    //if dev is not passed
    /* get wlan devs */
    size_t devs_size = 50;
    net_dev netdev[devs_size];
    net_devs devs = {.cnt = -1, .dev = (net_dev *)&netdev};     
    get_wifi_dev(&devs, devs_size);

    for (int i = 0; i < devs.cnt; i++) {
        char *ifname = devs.dev[i].name;

        /* get assoc. users list */
        iw = iwinfo_backend(ifname);
        iw->assoclist(ifname, buf, &len);

        for (int i = 0; i < len; i += entry_size) {
            struct iwinfo_assoclist_entry *e;
            e = (struct iwinfo_assoclist_entry *) &buf[i];
            int ret = ubus_hostpad_del_station(ifname, format_mac((uint8_t *)e->mac));
            if(ret != 0) return ret;
        }
    }
    return 0;
}

int ubus_hostpad_del_station(const char *dev, const char *mac) {
    syslogwda(LOG_INFO,"%s() %s:%d\n", __func__, __FILE__, __LINE__);
    syslogwda(LOG_WARNING,"delete sta dev: %s mac: %s\n", dev, mac);
    if(!dev || !mac) return -1;
    char command[256];
    snprintf(command, 256, "ubus call hostapd.%s "
                           "del_client "
                           "\"{'addr':'%s', 'reason':5, 'deauth':true, 'ban_time':0}\"",
             dev, mac);
    FILE *fp = popen(command, "r");
    /* status code */
    int ret = WEXITSTATUS(pclose(fp));
    if(ret != 0) syslogwda(LOG_WARNING,"status code: %d %s\n", ret, strerror(ret));
    return ret;
}