/* snac - A simple, minimalistic ActivityPub instance */
/* copyright (c) 2022 - 2023 grunfink / MIT license */

#include "xs.h"
#include "xs_io.h"
#include "xs_encdec.h"
#include "xs_json.h"
#include "xs_time.h"
#include "xs_openssl.h"

#include "snac.h"

#include <sys/stat.h>
#include <stdlib.h>

const char *default_srv_config = "{"
    "\"host\":                 \"\","
    "\"prefix\":               \"\","
    "\"address\":              \"127.0.0.1\","
    "\"port\":                 8001,"
    "\"layout\":               0.0,"
    "\"dbglevel\":             0,"
    "\"queue_retry_minutes\":  2,"
    "\"queue_retry_max\":      10,"
    "\"cssurls\":              [\"\"],"
    "\"max_timeline_entries\": 128,"
    "\"timeline_purge_days\":  120,"
    "\"local_purge_days\":     0"
    "}";

const char *default_css =
    "body { max-width: 48em; margin: auto; line-height: 1.5; padding: 0.8em }\n"
    "img { max-width: 100% }\n"
    ".snac-origin { font-size: 85% }\n"
    ".snac-score { float: right; font-size: 85% }\n"
    ".snac-top-user { text-align: center; padding-bottom: 2em }\n"
    ".snac-top-user-name { font-size: 200% }\n"
    ".snac-top-user-id { font-size: 150% }\n"
    ".snac-avatar { float: left; height: 2.5em; padding: 0.25em }\n"
    ".snac-author { font-size: 90% }\n"
    ".snac-pubdate { color: #a0a0a0; font-size: 90% }\n"
    ".snac-top-controls { padding-bottom: 1.5em }\n"
    ".snac-post { border-top: 1px solid #a0a0a0; }\n"
    ".snac-children { padding-left: 2em; border-left: 1px solid #a0a0a0; }\n"
    ".snac-textarea { font-family: inherit; width: 100% }\n"
    ".snac-history { border: 1px solid #606060; border-radius: 3px; margin: 2.5em 0; padding: 0 2em }\n"
    ".snac-btn-mute { float: right; margin-left: 0.5em }\n"
    ".snac-btn-unmute { float: right; margin-left: 0.5em }\n"
    ".snac-btn-follow { float: right; margin-left: 0.5em }\n"
    ".snac-btn-unfollow { float: right; margin-left: 0.5em }\n"
    ".snac-btn-hide { float: right; margin-left: 0.5em }\n"
    ".snac-btn-delete { float: right; margin-left: 0.5em }\n"
    ".snac-footer { margin-top: 2em; font-size: 75% }\n";

const char *greeting_html =
    "<!DOCTYPE html>\n"
    "<html><head>\n"
    "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\"/>\n"
    "<title>Welcome to %host%</title>\n"
    "<body style=\"margin: auto; max-width: 50em\">\n"
    "<h1>Welcome to %host%</h1>\n"
    "<p>This is a <a href=\"https://en.wikipedia.org/wiki/Fediverse\">Fediverse</a> instance\n"
    "that uses the <a href=\"https://en.wikipedia.org/wiki/ActivityPub\">ActivityPub</a> protocol.\n"
    "In other words, users at this host can communicate with people that use software like\n"
    "Mastodon, Pleroma, Friendica, etc. all around the world.</p>\n"
    "\n"
    "<p>There is no automatic sign up process for this server. If you want to be a part of\n"
    "this community, please write an email to\n"
    "\n"
    "the administrator of this instance\n"
    "\n"
    "and ask politely indicating what is your preferred user id (alphanumeric characters\n"
    "only) and the full name you want to appear as.</p>\n"
    "\n"
    "<p>The following users are already part of this community:</p>\n"
    "\n"
    "%userlist%\n"
    "\n"
    "<p>This site is powered by <abbr title=\"Social Networks Are Crap\">snac</abbr>.</p>\n"
    "</body></html>\n";

int snac_init(const char *basedir)
{
    FILE *f;

    if (basedir == NULL) {
        printf("Base directory:\n");
        srv_basedir = xs_strip_i(xs_readline(stdin));
    }
    else
        srv_basedir = xs_str_new(basedir);

    if (srv_basedir == NULL || *srv_basedir == '\0')
        return 1;

    if (xs_endswith(srv_basedir, "/"))
        srv_basedir = xs_crop_i(srv_basedir, 0, -1);

    if (mtime(srv_basedir) != 0.0) {
        printf("ERROR: directory '%s' must not exist\n", srv_basedir);
        return 1;
    }

    srv_config = xs_json_loads(default_srv_config);

    xs *layout = xs_number_new(disk_layout);
    srv_config = xs_dict_set(srv_config, "layout", layout);

    printf("Network address [%s]:\n", xs_dict_get(srv_config, "address"));
    {
        xs *i = xs_strip_i(xs_readline(stdin));
        if (*i)
            srv_config = xs_dict_set(srv_config, "address", i);
    }

    printf("Network port [%d]:\n", (int)xs_number_get(xs_dict_get(srv_config, "port")));
    {
        xs *i = xs_strip_i(xs_readline(stdin));
        if (*i) {
            xs *n = xs_number_new(atoi(i));
            srv_config = xs_dict_set(srv_config, "port", n);
        }
    }

    printf("Host name:\n");
    {
        xs *i = xs_strip_i(xs_readline(stdin));
        if (*i == '\0')
            return 1;

        srv_config = xs_dict_set(srv_config, "host", i);
    }

    printf("URL prefix:\n");
    {
        xs *i = xs_strip_i(xs_readline(stdin));

        if (*i) {
            if (xs_endswith(i, "/"))
                i = xs_crop_i(i, 0, -1);

            srv_config = xs_dict_set(srv_config, "prefix", i);
        }
    }

    if (mkdirx(srv_basedir) == -1) {
        printf("ERROR: cannot create directory '%s'\n", srv_basedir);
        return 1;
    }

    xs *udir = xs_fmt("%s/user", srv_basedir);
    mkdirx(udir);

    xs *odir = xs_fmt("%s/object", srv_basedir);
    mkdirx(odir);

    xs *qdir = xs_fmt("%s/queue", srv_basedir);
    mkdirx(qdir);

    xs *ibdir = xs_fmt("%s/inbox", srv_basedir);
    mkdirx(ibdir);

    xs *gfn = xs_fmt("%s/greeting.html", srv_basedir);
    if ((f = fopen(gfn, "w")) == NULL) {
        printf("ERROR: cannot create '%s'\n", gfn);
        return 1;
    }

    fwrite(greeting_html, strlen(greeting_html), 1, f);
    fclose(f);

    xs *sfn = xs_fmt("%s/style.css", srv_basedir);
    if ((f = fopen(sfn, "w")) == NULL) {
        printf("ERROR: cannot create '%s'\n", sfn);
        return 1;
    }

    fwrite(default_css, strlen(default_css), 1, f);
    fclose(f);

    xs *cfn = xs_fmt("%s/server.json", srv_basedir);
    if ((f = fopen(cfn, "w")) == NULL) {
        printf("ERROR: cannot create '%s'\n", cfn);
        return 1;
    }

    xs *j = xs_json_dumps_pp(srv_config, 4);
    fwrite(j, strlen(j), 1, f);
    fclose(f);

    printf("Done.\n");
    return 0;
}


void new_password(const char *uid, d_char **clear_pwd, d_char **hashed_pwd)
/* creates a random password */
{
    int rndbuf[3];

    srandom(time(NULL) ^ getpid());
    rndbuf[0] = random() & 0xffffffff;
    rndbuf[1] = random() & 0xffffffff;
    rndbuf[2] = random() & 0xffffffff;

    *clear_pwd  = xs_base64_enc((char *)rndbuf, sizeof(rndbuf));
    *hashed_pwd = hash_password(uid, *clear_pwd, NULL);
}


int adduser(const char *uid)
/* creates a new user */
{
    snac snac;
    xs *config = xs_dict_new();
    xs *date = xs_str_utctime(0, "%Y-%m-%dT%H:%M:%SZ");
    xs *pwd = NULL;
    xs *pwd_f = NULL;
    xs *key = NULL;
    FILE *f;

    if (uid == NULL) {
        printf("User id:\n");
        uid = xs_strip_i(xs_readline(stdin));
    }

    if (!validate_uid(uid)) {
        printf("ERROR: only alphanumeric characters and _ are allowed in user ids.\n");
        return 1;
    }

    if (user_open(&snac, uid)) {
        printf("ERROR: user '%s' already exists\n", uid);
        return 1;
    }

    new_password(uid, &pwd, &pwd_f);

    config = xs_dict_append(config, "uid",       uid);
    config = xs_dict_append(config, "name",      uid);
    config = xs_dict_append(config, "avatar",    "");
    config = xs_dict_append(config, "bio",       "");
    config = xs_dict_append(config, "cw",        "");
    config = xs_dict_append(config, "published", date);
    config = xs_dict_append(config, "passwd",    pwd_f);

    xs *basedir = xs_fmt("%s/user/%s", srv_basedir, uid);

    if (mkdirx(basedir) == -1) {
        printf("ERROR: cannot create directory '%s'\n", basedir);
        return 0;
    }

    const char *dirs[] = {
        "followers", "following", "muted", "hidden",
        "public", "private", "queue", "history",
        "static", NULL };
    int n;

    for (n = 0; dirs[n]; n++) {
        xs *d = xs_fmt("%s/%s", basedir, dirs[n]);
        mkdirx(d);
    }

    xs *scssfn = xs_fmt("%s/style.css", srv_basedir);
    xs *ucssfn = xs_fmt("%s/static/style.css", basedir);

    if ((f = fopen(scssfn, "r")) != NULL) {
        FILE *i;

        if ((i = fopen(ucssfn, "w")) == NULL) {
            printf("ERROR: cannot create file '%s'\n", ucssfn);
            return 1;
        }
        else {
            xs *c = xs_readall(f);
            fwrite(c, strlen(c), 1, i);

            fclose(i);
        }

        fclose(f);
    }

    xs *cfn = xs_fmt("%s/user.json", basedir);

    if ((f = fopen(cfn, "w")) == NULL) {
        printf("ERROR: cannot create '%s'\n", cfn);
        return 1;
    }
    else {
        xs *j = xs_json_dumps_pp(config, 4);
        fwrite(j, strlen(j), 1, f);
        fclose(f);
    }

    printf("\nCreating RSA key...\n");
    key = xs_rsa_genkey(4096);
    printf("Done.\n");

    xs *kfn = xs_fmt("%s/key.json", basedir);

    if ((f = fopen(kfn, "w")) == NULL) {
        printf("ERROR: cannot create '%s'\n", kfn);
        return 1;
    }
    else {
        xs *j = xs_json_dumps_pp(key, 4);
        fwrite(j, strlen(j), 1, f);
        fclose(f);
    }

    printf("\nUser password is %s\n", pwd);

    printf("\nGo to %s/%s and continue configuring your user there.\n", srv_baseurl, uid);

    return 0;
}


int resetpwd(snac *snac)
/* creates a new password for the user */
{
    xs *clear_pwd  = NULL;
    xs *hashed_pwd = NULL;
    xs *fn         = xs_fmt("%s/user.json", snac->basedir);
    FILE *f;
    int ret = 0;

    new_password(snac->uid, &clear_pwd, &hashed_pwd);

    snac->config = xs_dict_set(snac->config, "passwd", hashed_pwd);

    if ((f = fopen(fn, "w")) != NULL) {
        xs *j = xs_json_dumps_pp(snac->config, 4);
        fwrite(j, strlen(j), 1, f);
        fclose(f);

        printf("New password for user %s is %s\n", snac->uid, clear_pwd);
    }
    else {
        printf("ERROR: cannot write to %s\n", fn);
        ret = 1;
    }

    return ret;
}
