#!/bin/bash
# =============================================================================
# ns8-backup-monitor - Installer / Uninstaller
# =============================================================================
# Usage:
#   install.sh            - install
#   install.sh --uninstall - remove everything installed by this script
#
# Requires: root, python3, git
# Tested on: AlmaLinux 8/9, Rocky Linux 8/9 (NS8 supported distros)
# =============================================================================
set -euo pipefail

# --- constants ---------------------------------------------------------------
SERVICE_NAME="ns8-backup-monitor"
INSTALL_DIR="/opt/ns8-backup-monitor"
CONFIG_DIR="/etc/ns8-backup-monitor"
CONFIG_FILE="${CONFIG_DIR}/config.yml"
SERVICE_FILE="/etc/systemd/system/${SERVICE_NAME}.service"
REPO_URL="https://repo.lelekaos.com/admin/ns8-backup-monitor.git"
PYTHON=$(command -v python3 || true)

# --- colours -----------------------------------------------------------------
RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'
BLUE='\033[0;34m'; BOLD='\033[1m'; RESET='\033[0m'

info()    { echo -e "${BLUE}[INFO]${RESET}  $*"; }
ok()      { echo -e "${GREEN}[OK]${RESET}    $*"; }
warn()    { echo -e "${YELLOW}[WARN]${RESET}  $*"; }
error()   { echo -e "${RED}[ERROR]${RESET} $*" >&2; exit 1; }

# =============================================================================
# UNINSTALL
# =============================================================================
do_uninstall() {
    echo -e "${BOLD}=== ns8-backup-monitor UNINSTALL ===${RESET}"
    warn "This will stop and remove the service, code and config."
    read -rp "Continue? [y/N] " confirm
    [[ "$confirm" =~ ^[Yy]$ ]] || { info "Aborted."; exit 0; }

    # Stop & disable service
    if systemctl is-active --quiet "$SERVICE_NAME" 2>/dev/null; then
        info "Stopping service..."
        systemctl stop "$SERVICE_NAME"
    fi
    if systemctl is-enabled --quiet "$SERVICE_NAME" 2>/dev/null; then
        info "Disabling service..."
        systemctl disable "$SERVICE_NAME"
    fi

    # Remove service file
    if [[ -f "$SERVICE_FILE" ]]; then
        info "Removing systemd unit..."
        rm -f "$SERVICE_FILE"
        systemctl daemon-reload
        ok "Systemd unit removed."
    fi

    # Remove install dir
    if [[ -d "$INSTALL_DIR" ]]; then
        info "Removing ${INSTALL_DIR}..."
        rm -rf "$INSTALL_DIR"
        ok "Install directory removed."
    fi

    # Ask about config
    if [[ -d "$CONFIG_DIR" ]]; then
        read -rp "Remove config directory ${CONFIG_DIR}? [y/N] " rmcfg
        if [[ "$rmcfg" =~ ^[Yy]$ ]]; then
            rm -rf "$CONFIG_DIR"
            ok "Config directory removed."
        else
            warn "Config kept at ${CONFIG_DIR}."
        fi
    fi

    echo -e "${GREEN}${BOLD}Uninstall complete.${RESET}"
}

# =============================================================================
# INSTALL
# =============================================================================
do_install() {
    echo -e "${BOLD}=== ns8-backup-monitor INSTALLER ===${RESET}\n"

    # --- pre-flight checks ---------------------------------------------------
    [[ $EUID -eq 0 ]] || error "Run as root (or with sudo)."
    [[ -n "$PYTHON" ]] || error "python3 not found."
    command -v git &>/dev/null || error "git not found."
    command -v ns8-sendmail &>/dev/null || \
        warn "ns8-sendmail not found in PATH - make sure this runs on an NS8 node."

    # --- interactive mail config ---------------------------------------------
    echo -e "${BOLD}Mail configuration${RESET}"
    echo -e "Email delivery uses ${BLUE}ns8-sendmail${RESET} (NS8 configured relay)."
    echo

    # mail from
    local default_from="ns8-backup-monitor@$(hostname -f 2>/dev/null || echo localhost)"
    read -rp "Sender address (From) [${default_from}]: " MAIL_FROM
    MAIL_FROM="${MAIL_FROM:-$default_from}"

    # mail to - loop until at least one address is entered
    local MAIL_TO_LIST=()
    echo "Recipient addresses (To) - enter one per line, empty line to finish:"
    while true; do
        read -rp "  Recipient: " addr
        [[ -z "$addr" ]] && break
        MAIL_TO_LIST+=("$addr")
    done
    [[ ${#MAIL_TO_LIST[@]} -gt 0 ]] || error "At least one recipient is required."

    # subject prefix
    read -rp "Subject prefix [[NS8 Backup]]: " SUBJECT_PREFIX
    SUBJECT_PREFIX="${SUBJECT_PREFIX:-[NS8 Backup]}"

    echo
    info "From:    $MAIL_FROM"
    info "To:      ${MAIL_TO_LIST[*]}"
    info "Prefix:  $SUBJECT_PREFIX"
    echo
    read -rp "Confirm and proceed with install? [Y/n] " go
    [[ "$go" =~ ^[Nn]$ ]] && { info "Aborted."; exit 0; }
    echo

    # --- clone / update source -----------------------------------------------
    if [[ -d "${INSTALL_DIR}/.git" ]]; then
        info "Updating existing clone in ${INSTALL_DIR}..."
        git -C "$INSTALL_DIR" pull --ff-only
    else
        info "Cloning into ${INSTALL_DIR}..."
        git clone "$REPO_URL" "$INSTALL_DIR"
    fi
    ok "Source ready."

    # --- config directory ----------------------------------------------------
    mkdir -p "$CONFIG_DIR"
    chmod 750 "$CONFIG_DIR"

    if [[ -f "$CONFIG_FILE" ]]; then
        warn "Config file ${CONFIG_FILE} already exists - keeping it."
        warn "Edit it manually if you need to change mail settings."
    else
        info "Writing ${CONFIG_FILE}..."

        # Build YAML 'to' list
        local to_yaml=""
        for addr in "${MAIL_TO_LIST[@]}"; do
            to_yaml+="    - \"${addr}\"\n"
        done

        cat > "$CONFIG_FILE" <<EOF
# ns8-backup-monitor configuration
# Generated by install.sh on $(date -u '+%Y-%m-%d %H:%M UTC')

# Email delivery is handled by ns8-sendmail (NS8 configured relay).
mail:
  from: "${MAIL_FROM}"
  to:
$(printf '%b' "$to_yaml")
  subject_prefix: "${SUBJECT_PREFIX}"

receiver:
  host: "127.0.0.1"
  port: 9099

correlator:
  wait_seconds: 30
  recent_window: 3600

redis:
  socket: "/var/lib/nethserver/cluster/state/redis.sock"

repo_check:
  timeout: 60
  restic_flags: ""

logging:
  level: INFO
  file: "/var/log/ns8-backup-monitor.log"
EOF
        chmod 640 "$CONFIG_FILE"
        ok "Config written."
    fi

    # --- systemd unit --------------------------------------------------------
    info "Installing systemd unit..."
    cp "${INSTALL_DIR}/deploy/ns8-backup-monitor.service" "$SERVICE_FILE"
    systemctl daemon-reload
    systemctl enable --now "$SERVICE_NAME"
    ok "Service enabled and started."

    # --- done ----------------------------------------------------------------
    echo
    echo -e "${GREEN}${BOLD}Installation complete.${RESET}"
    echo -e "  Config:  ${CONFIG_FILE}"
    echo -e "  Logs:    journalctl -u ${SERVICE_NAME} -f"
    echo -e "  Status:  systemctl status ${SERVICE_NAME}"
    echo
    echo -e "To uninstall: ${BOLD}bash ${INSTALL_DIR}/deploy/install.sh --uninstall${RESET}"
}

# =============================================================================
# ENTRYPOINT
# =============================================================================
case "${1:-}" in
    --uninstall|-u|uninstall)
        do_uninstall
        ;;
    --help|-h)
        echo "Usage: $0 [--uninstall]"
        exit 0
        ;;
    "")
        do_install
        ;;
    *)
        error "Unknown argument: $1. Use --uninstall to remove."
        ;;
esac