#!/bin/sh
set -eu

APP_DIR=${POBSYNC_APP_DIR:-$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)}
VENV_DIR=${POBSYNC_VENV_DIR:-/opt/pobsync/venv}
ENV_FILE=${POBSYNC_ENV_FILE:-/etc/pobsync/pobsync.env}
SERVICE_USER=${POBSYNC_SERVICE_USER:-pobsync}
SERVICE_GROUP=${POBSYNC_SERVICE_GROUP:-pobsync}
INSTALL_EXTRAS=${POBSYNC_INSTALL_EXTRAS:-}
SERVER_NAME=${POBSYNC_SERVER_NAME:-_}
WITH_NGINX=0

while [ "$#" -gt 0 ]; do
    case "$1" in
        --with-nginx)
            WITH_NGINX=1
            shift
            ;;
        --server-name)
            SERVER_NAME=$2
            shift 2
            ;;
        *)
            echo "Unknown argument: $1" >&2
            exit 2
            ;;
    esac
done

if [ "$(id -u)" -ne 0 ]; then
    echo "Run this installer as root." >&2
    exit 1
fi

if ! command -v python3 >/dev/null 2>&1; then
    echo "python3 is required." >&2
    exit 1
fi

if ! command -v rsync >/dev/null 2>&1; then
    echo "rsync is required." >&2
    exit 1
fi

if ! command -v ssh >/dev/null 2>&1; then
    echo "openssh-client is required." >&2
    exit 1
fi

if ! getent group "$SERVICE_GROUP" >/dev/null 2>&1; then
    groupadd --system "$SERVICE_GROUP"
fi

if ! id "$SERVICE_USER" >/dev/null 2>&1; then
    useradd --system --home /var/lib/pobsync --shell /usr/sbin/nologin --gid "$SERVICE_GROUP" "$SERVICE_USER"
fi

mkdir -p /etc/pobsync /var/lib/pobsync /var/log/pobsync "$(dirname "$VENV_DIR")"
chown "$SERVICE_USER:$SERVICE_GROUP" /var/lib/pobsync /var/log/pobsync
chmod 0750 /var/lib/pobsync /var/log/pobsync

python3 -m venv "$VENV_DIR"
"$VENV_DIR/bin/python" -m pip install --upgrade pip
"$VENV_DIR/bin/python" -m pip install -e "$APP_DIR$INSTALL_EXTRAS"

if [ ! -f "$ENV_FILE" ]; then
    secret=$("$VENV_DIR/bin/python" -c "import secrets; print(secrets.token_urlsafe(48))")
    cat > "$ENV_FILE" <<EOF
POBSYNC_DJANGO_DEBUG=0
POBSYNC_DJANGO_SECRET_KEY=$secret
POBSYNC_DJANGO_ALLOWED_HOSTS=localhost,127.0.0.1
POBSYNC_DJANGO_CSRF_TRUSTED_ORIGINS=

POBSYNC_HOME=/var/lib/pobsync
POBSYNC_BACKUP_ROOT=/backups
POBSYNC_SQLITE_PATH=/var/lib/pobsync/pobsync.sqlite3
POBSYNC_STATIC_ROOT=/var/lib/pobsync/static

POBSYNC_WEB_BIND=127.0.0.1:8010
POBSYNC_GUNICORN_WORKERS=2
POBSYNC_GUNICORN_TIMEOUT=120
POBSYNC_WORKER_INTERVAL=15
POBSYNC_SCHEDULER_INTERVAL=60
EOF
    chmod 0640 "$ENV_FILE"
    chown "root:$SERVICE_GROUP" "$ENV_FILE"
    echo "Created $ENV_FILE. Edit allowed hosts and backup root before exposing the service."
fi

install_unit() {
    src=$1
    dest=$2
    sed \
        -e "s|@POBSYNC_APP_DIR@|$APP_DIR|g" \
        -e "s|@POBSYNC_VENV_DIR@|$VENV_DIR|g" \
        -e "s|@POBSYNC_ENV_FILE@|$ENV_FILE|g" \
        -e "s|@POBSYNC_USER@|$SERVICE_USER|g" \
        -e "s|@POBSYNC_GROUP@|$SERVICE_GROUP|g" \
        "$src" > "$dest"
    chmod 0644 "$dest"
}

install_unit "$APP_DIR/deploy/systemd/pobsync-web.service" /etc/systemd/system/pobsync-web.service
install_unit "$APP_DIR/deploy/systemd/pobsync-worker.service" /etc/systemd/system/pobsync-worker.service
install_unit "$APP_DIR/deploy/systemd/pobsync-scheduler.service" /etc/systemd/system/pobsync-scheduler.service

systemctl daemon-reload
"$VENV_DIR/bin/python" "$APP_DIR/manage.py" migrate --noinput
"$VENV_DIR/bin/python" "$APP_DIR/manage.py" collectstatic --noinput --clear
systemctl enable --now pobsync-web.service pobsync-worker.service pobsync-scheduler.service

if [ "$WITH_NGINX" -eq 1 ]; then
    if ! command -v nginx >/dev/null 2>&1; then
        echo "nginx is not installed; skipping nginx config." >&2
    else
        sed "s|@POBSYNC_SERVER_NAME@|$SERVER_NAME|g" "$APP_DIR/deploy/nginx/pobsync.conf" > /etc/nginx/sites-available/pobsync.conf
        ln -sf /etc/nginx/sites-available/pobsync.conf /etc/nginx/sites-enabled/pobsync.conf
        nginx -t
        systemctl reload nginx
    fi
fi

systemctl --no-pager --full status pobsync-web.service pobsync-worker.service pobsync-scheduler.service || true