#define _POSIX_C_SOURCE 200809L

#include "jwt.h"
#include <cjson/cJSON.h>
#include <dynstr.h>
#include <sodium.h>
#include <sqlite3.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

static int tokenkey(void *const args, const int n, char **const values,
    char **const keys)
{
    char *key;

    if (n != 1)
    {
        fprintf(stderr, "%s: expected 1 key only, got %d\n", __func__, n);
        return -1;
    }
    else if (!(key = strdup(*values)))
    {
        fprintf(stderr, "%s: strdup(3): %s\n", __func__, strerror(errno));
        return -1;
    }

    *(char **)args = key;
    return 0;
}

static int process(sqlite3 *const db, const char *const user)
{
    static const char query[] = "SELECT value FROM globals "
        "WHERE key = 'tokenkey';";
    int ret = -1, error;
    cJSON *j = NULL;
    char *s = NULL, *key = NULL, *jwt = NULL;
    unsigned char dkey[32];
    time_t t;

    if ((error = sqlite3_exec(db, query, tokenkey, &key, &s)) != SQLITE_OK)
    {
        fprintf(stderr, "%s: sqlite3_exec \"%s\": %s (%s)\n", __func__, query,
            sqlite3_errstr(error), s);
        goto end;
    }
    else if (strlen(key) != sizeof dkey * 2)
    {
        fprintf(stderr, "%s: unexpected key length: %zu\n", __func__,
            strlen(key));
        goto end;
    }
    else if (sodium_hex2bin(dkey, sizeof dkey, key, strlen(key), NULL, NULL,
        NULL))
    {
        fprintf(stderr, "%s: sodium_hex2bin failed\n", __func__);
        goto end;
    }
    else if (!(j = cJSON_CreateObject()))
    {
        fprintf(stderr, "%s: cJSON_CreateObject failed\n", __func__);
        goto end;
    }
    else if (!cJSON_AddStringToObject(j, "name", user))
    {
        fprintf(stderr, "%s: cJSON_AddStringToObject failed\n", __func__);
        goto end;
    }
    else if ((t = time(NULL)) == (time_t)-1)
    {
        fprintf(stderr, "%s: time(2): %s\n", __func__, strerror(errno));
        goto end;
    }
    else if (!cJSON_AddNumberToObject(j, "exp", t + 24 * 60 * 60))
    {
        fprintf(stderr, "%s: cJSON_AddNumberToObject failed\n", __func__);
        goto end;
    }
    else if (!(jwt = jwt_encode(j, dkey, sizeof dkey)))
    {
        fprintf(stderr, "%s: jwt_encode failed\n", __func__);
        goto end;
    }

    printf("%s %s\n", user, jwt);
    ret = 0;

end:
    free(jwt);
    free(key);
    sqlite3_free(s);
    cJSON_Delete(j);
    return ret;
}

static sqlite3 *open_db(const char *const dir)
{
    sqlite3 *ret = NULL, *db = NULL;
    struct dynstr d;
    int error;

    dynstr_init(&d);

    if (dynstr_append(&d, "%s/nanobbs.db", dir))
    {
        fprintf(stderr, "%s: dynstr_append failed\n", __func__);
        goto end;
    }
    else if ((error = sqlite3_open(d.str, &db)) != SQLITE_OK)
    {
        fprintf(stderr, "%s: sqlite3_open %s: %s\n", __func__, d.str,
            sqlite3_errstr(error));
        goto end;
    }

    ret = db;

end:
    dynstr_free(&d);
    return ret;
}

int main(int argc, char *argv[])
{
    int ret = EXIT_FAILURE, error;
    sqlite3 *db = NULL;

    if (argc < 3)
    {
        fprintf(stderr, "%s <dir> <user> [...]\n", *argv);
        goto end;
    }
    else if (!(db = open_db(argv[1])))
        goto end;

    for (int i = 2; i < argc; i++)
        if (process(db, argv[i]))
            goto end;

    ret = EXIT_SUCCESS;

end:

    if ((error = sqlite3_close(db)) != SQLITE_OK)
    {
        fprintf(stderr, "%s: sqlite3_close: %s\n", __func__,
            sqlite3_errstr(error));
        ret = EXIT_FAILURE;
    }

    return ret;
}