#include "mail.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "db.h"
#include "secret.h"
#include "smtp.h"
#include "util.h"

struct mail_cfg {
    char *host;
    char *port;
    char *from;
    char *reply_to;
    char *security;
    char *user;
    char *password;
    char from_name[256];
};

static void mail_cfg_free(struct mail_cfg *c)
{
    free(c->host);
    free(c->port);
    free(c->from);
    free(c->reply_to);
    free(c->security);
    free(c->user);
    free(c->password);
    memset(c, 0, sizeof *c);
}

static void set_err(char *err, size_t errlen, const char *msg)
{
    if (err && errlen)
        snprintf(err, errlen, "%s", msg);
}

static int mail_cfg_load(sqlite3 *db, int64_t org_id, struct mail_cfg *c,
                         char *err, size_t errlen)
{
    memset(c, 0, sizeof *c);
    c->host = db_setting(db, org_id, "smtp_host");
    c->port = db_setting(db, org_id, "smtp_port");
    c->from = db_setting(db, org_id, "smtp_from");
    c->reply_to = db_setting(db, org_id, "smtp_reply_to");
    c->security = db_setting(db, org_id, "smtp_security");
    c->user = db_setting(db, org_id, "smtp_user");
    c->password = db_setting(db, org_id, "smtp_password");

    if (!c->host || !*c->host || !c->from || !*c->from) {
        set_err(err, errlen, "smtp_host and smtp_from must be set");
        goto fail;
    }
    if (c->user && *c->user) {
        if (!c->password || !*c->password) {
            set_err(err, errlen,
                    "smtp_user is set but smtp_password is missing");
            goto fail;
        }
        if (!secret_available()) {
            set_err(err, errlen,
                    "smtp_password is set but BOKFD_SECRET_KEY is missing or"
                    " invalid");
            goto fail;
        }
        char *plain = NULL;
        if (secret_decrypt(c->password, &plain) != 0 || !plain) {
            free(plain);
            set_err(err, errlen,
                    "cannot decrypt smtp_password, check BOKFD_SECRET_KEY");
            goto fail;
        }
        free(c->password);
        c->password = plain;
    }

    sqlite3_stmt *st = NULL;
    int ok = 0;
    if (sqlite3_prepare_v2(db, "SELECT name FROM orgs WHERE id=?1", -1, &st,
                           NULL) == SQLITE_OK) {
        sqlite3_bind_int64(st, 1, org_id);
        if (sqlite3_step(st) == SQLITE_ROW) {
            const unsigned char *name = sqlite3_column_text(st, 0);
            snprintf(c->from_name, sizeof c->from_name, "%s",
                     name ? (const char *)name : "");
            ok = 1;
        }
    }
    sqlite3_finalize(st);
    if (!ok) {
        set_err(err, errlen, "org not found");
        goto fail;
    }
    return 0;

fail:
    mail_cfg_free(c);
    return -1;
}

static int mail_cfg_port(const char *s)
{
    if (s && *s) {
        long v = strtol(s, NULL, 10);
        if (v >= 1 && v <= 65535)
            return (int)v;
    }
    return 587;
}

int mail_config_check(sqlite3 *db, int64_t org_id, char *err, size_t errlen)
{
    struct mail_cfg c;
    if (err && errlen)
        err[0] = '\0';
    if (!db) {
        set_err(err, errlen, "no database");
        return -1;
    }
    if (mail_cfg_load(db, org_id, &c, err, errlen) != 0)
        return -1;
    mail_cfg_free(&c);
    return 0;
}

int mail_send_pdf(sqlite3 *db, int64_t org_id, const struct mail_message *m,
                  char *err, size_t errlen)
{
    if (err && errlen)
        err[0] = '\0';
    if (!m || !m->to || !*m->to) {
        set_err(err, errlen, "no recipient");
        return -2;
    }
    struct mail_cfg c;
    if (mail_cfg_load(db, org_id, &c, err, errlen) != 0)
        return -1;

    struct smtp_message sm;
    memset(&sm, 0, sizeof sm);
    sm.host = c.host;
    sm.port = mail_cfg_port(c.port);
    sm.security = c.security && *c.security ? c.security : "starttls";
    sm.user = c.user && *c.user ? c.user : "";
    sm.password = c.password ? c.password : "";
    sm.from = c.from;
    sm.from_name = c.from_name;
    sm.to = m->to;
    sm.subject = m->subject;
    sm.body = m->body;
    sm.attach_name = m->attach_name;
    sm.attach = m->attach;
    sm.attach_len = m->attach_len;

    char send_err[512];
    send_err[0] = '\0';
    int rc = smtp_send(&sm, send_err, sizeof send_err);
    mail_cfg_free(&c);
    if (rc != 0) {
        set_err(err, errlen,
                send_err[0] ? send_err : "smtp send failed");
        return -2;
    }
    return 0;
}