#!/usr/bin/env bash
set -euo pipefail
source ./lib.sh

MAIL_SSL_DIR="/etc/ssl/mail"
MAIL_CERT="${MAIL_SSL_DIR}/fullchain.pem"
MAIL_KEY="${MAIL_SSL_DIR}/privkey.pem"

log "Dovecot konfigurieren …"

# ──────────────────────────────────────────────────────────────────────────────
# 1) vmail-Benutzer/Gruppe & Mailspool vorbereiten (DYNAMIC UID!)
# ──────────────────────────────────────────────────────────────────────────────

# Sicherstellen, dass die Gruppe 'mail' existiert (auf Debian/Ubuntu idR vorhanden)
getent group mail >/dev/null || groupadd -g 8 mail || true

# vmail anlegen, wenn er fehlt. Bevorzugt UID 109, falls frei – sonst automatisch.
if ! getent passwd vmail >/dev/null; then
  if ! getent passwd 109 >/dev/null; then
    useradd -u 109 -g mail -d /var/mail -M -s /usr/sbin/nologin vmail
  else
    useradd -g mail -d /var/mail -M -s /usr/sbin/nologin vmail
  fi
fi

# Tatsächliche vmail-UID ermitteln (wird unten in die Dovecot-Config geschrieben)
VMAIL_UID="$(id -u vmail)"

# Mailspool-Basis
install -d -m 0770 -o vmail -g mail /var/mail/vhosts

# ──────────────────────────────────────────────────────────────────────────────
# 2) Dovecot Grundgerüst
# ──────────────────────────────────────────────────────────────────────────────

# Hauptdatei
install -d -m 0755 /etc/dovecot/conf.d
cat > /etc/dovecot/dovecot.conf <<'CONF'
!include_try /etc/dovecot/conf.d/*.conf
CONF

# Mail-Location & Namespace + UID-Grenzen
cat > /etc/dovecot/conf.d/10-mail.conf <<CONF
protocols = imap pop3 lmtp
mail_location = maildir:/var/mail/vhosts/%d/%n

namespace inbox {
  inbox = yes
}

mail_privileged_group = mail
mail_access_groups = mail
first_valid_uid = ${VMAIL_UID}
last_valid_uid  = ${VMAIL_UID}
CONF

cat > /etc/dovecot/conf.d/15-mailboxes.conf <<'CONF'
namespace inbox {
  inbox = yes

  mailbox Drafts {
    special_use = \Drafts
    auto = subscribe
  }
  mailbox Junk {
    special_use = \Junk
    auto = subscribe
  }
  mailbox Trash {
    special_use = \Trash
    auto = subscribe
  }
  mailbox Sent {
    special_use = \Sent
    auto = subscribe
  }
  mailbox Archive {
    special_use = \Archive
    auto = create
  }
}
CONF

# Auth
cat > /etc/dovecot/conf.d/10-auth.conf <<'CONF'
disable_plaintext_auth = yes
auth_mechanisms = plain login
!include_try auth-sql.conf.ext

auth_cache_size = 10M
auth_cache_ttl  = 1 hour
CONF

# SQL-Anbindung (Passwörter aus App-DB)
cat > /etc/dovecot/dovecot-sql.conf.ext <<CONF
driver = mysql
connect = host=127.0.0.1 dbname=${DB_NAME} user=${DB_USER} password=${DB_PASS}
default_pass_scheme = BLF-CRYPT
password_query = SELECT u.email AS user, u.password_hash AS password FROM mail_users u JOIN domains d ON d.id = u.domain_id WHERE u.email = '%u' AND u.is_active = 1 AND u.can_login = 1 AND u.password_hash IS NOT NULL AND d.is_active = 1 LIMIT 1;
CONF
chown root:dovecot /etc/dovecot/dovecot-sql.conf.ext
chmod 640 /etc/dovecot/dovecot-sql.conf.ext

# Auth-SQL → userdb static auf vmail:mail (Home unter /var/mail/vhosts/%d/%n)
cat > /etc/dovecot/conf.d/auth-sql.conf.ext <<'CONF'
passdb {
  driver = sql
  args = /etc/dovecot/dovecot-sql.conf.ext
}
userdb {
  driver = static
  args = uid=vmail gid=mail home=/var/mail/vhosts/%d/%n
}
CONF
chown root:dovecot /etc/dovecot/conf.d/auth-sql.conf.ext
chmod 640 /etc/dovecot/conf.d/auth-sql.conf.ext

# ──────────────────────────────────────────────────────────────────────────────
# 3) IMAP Optimierung (iOS/IDLE-freundlich)
# ──────────────────────────────────────────────────────────────────────────────

cat > /etc/dovecot/conf.d/20-imap.conf <<'CONF'
# IMAP-spezifische Einstellungen

imap_idle_notify_interval = 2 mins
imap_hibernate_timeout = 0

protocol imap {
  mail_max_userip_connections = 20
  imap_logout_format = in=%i out=%o deleted=%{deleted} expunged=%{expunged}
}
CONF

# ──────────────────────────────────────────────────────────────────────────────
# 4) Master Services (LMTP, AUTH, IMAP, POP3, STATS)
# ──────────────────────────────────────────────────────────────────────────────

cat > /etc/dovecot/conf.d/10-master.conf <<'CONF'
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
    mode = 0600
    user = postfix
    group = postfix
  }
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    mode = 0660
    user = postfix
    group = postfix
  }
  unix_listener auth-userdb {
    mode = 0660
    user = vmail
    group = mail
  }
  process_limit = 1
}
service imap-login {
  inet_listener imap {
    port = 143
  }
  inet_listener imaps {
    port = 993
    ssl = yes
  }
  process_limit = 128
  process_min_avail = 10
  service_count = 0
  vsz_limit = 512M
}
service pop3-login {
  inet_listener pop3 {
    port = 110
  }
  inet_listener pop3s {
    port = 995
    ssl = yes
  }
  process_limit = 50
  service_count = 0
}
CONF

# --- Dovecot: doveadm-server für App-Zugriff ---
cat >/etc/dovecot/conf.d/99-mailwolt-perms.conf <<'CONF'
service auth {
  unix_listener auth-userdb {
    mode = 0660
    user = vmail
    group = mail
  }
}

service stats {
  unix_listener stats-reader {
    mode = 0660
    user = vmail
    group = mail
  }
  unix_listener stats-writer {
    mode = 0660
    user = vmail
    group = mail
  }
}
CONF

# ──────────────────────────────────────────────────────────────────────────────
# 5) SSL-Konfiguration (ohne DH-Param-Erzeugung)
# ──────────────────────────────────────────────────────────────────────────────

DOVECOT_SSL_CONF="/etc/dovecot/conf.d/10-ssl.conf"
touch "$DOVECOT_SSL_CONF"
grep -q '^ssl\s*=' "$DOVECOT_SSL_CONF" 2>/dev/null || echo "ssl = required" >> "$DOVECOT_SSL_CONF"
if grep -q '^\s*ssl_cert\s*=' "$DOVECOT_SSL_CONF"; then
  sed -i "s|^\s*ssl_cert\s*=.*|ssl_cert = <${MAIL_CERT}|" "$DOVECOT_SSL_CONF"
else
  echo "ssl_cert = <${MAIL_CERT}" >> "$DOVECOT_SSL_CONF"
fi
if grep -q '^\s*ssl_key\s*=' "$DOVECOT_SSL_CONF"; then
  sed -i "s|^\s*ssl_key\s*=.*|ssl_key  = <${MAIL_KEY}|" "$DOVECOT_SSL_CONF"
else
  echo "ssl_key  = <${MAIL_KEY}" >> "$DOVECOT_SSL_CONF"
fi
grep -q '^ssl_min_protocol' "$DOVECOT_SSL_CONF" || echo "ssl_min_protocol = TLSv1.2" >> "$DOVECOT_SSL_CONF"
grep -q '^ssl_prefer_server_ciphers' "$DOVECOT_SSL_CONF" || echo "ssl_prefer_server_ciphers = yes" >> "$DOVECOT_SSL_CONF"

grep -q '^ssl_dh' "$DOVECOT_SSL_CONF" || echo "ssl_dh = </etc/ssl/private/dhparam.pem" >> "$DOVECOT_SSL_CONF"

# ──────────────────────────────────────────────────────────────────────────────
# 6) Verzeichnisse & Rechte prüfen
# ──────────────────────────────────────────────────────────────────────────────

mkdir -p /var/spool/postfix/private
chown root:root /var/spool/postfix
chmod 0755     /var/spool/postfix
chown postfix:postfix /var/spool/postfix/private
chmod 0755            /var/spool/postfix/private


# ──────────────────────────────────────────────────────────────────────────────
# 7) Abschluss
# ──────────────────────────────────────────────────────────────────────────────

log "Dovecot-Konfiguration abgeschlossen."