#!/usr/bin/env bash
#
# Guided setup for the MonitorSpider Linux backup (linux-files-mysql.sh).
#
#   curl -fsSO https://monitorspider.com/backup-kits/setup.sh
#   sudo bash setup.sh
#
# Paste your monitor's ping URL when asked (shown on the monitor's page at
# monitorspider.com) and answer a few questions. It will:
#   - fetch the monitor's settings and propose a matching cron schedule
#   - detect MySQL/PostgreSQL and ask what to back up and where to upload it
#   - install the backup script to /usr/local/sbin/monitorspider-backup.sh
#   - write the config to /etc/monitorspider-backup.conf (chmod 600)
#   - create the cron entry (/etc/cron.d/monitorspider-backup)
#   - offer to run the first backup right away
#
# Re-running is safe: existing config values are offered as defaults.
# From https://monitorspider.com/backup-kits/ — MIT licensed, plain text: read it first.

set -euo pipefail

CONF="${MSPIDER_CONF:-/etc/monitorspider-backup.conf}"
DEST="${MSPIDER_DEST:-/usr/local/sbin/monitorspider-backup.sh}"
CRON_FILE="${MSPIDER_CRON:-/etc/cron.d/monitorspider-backup}"

if [ "${MSPIDER_SETUP_TEST:-}" != "1" ] && [ "$(id -u)" -ne 0 ]; then
	echo "Please run as root:  sudo bash setup.sh"; exit 1
fi

ask() { # $1 prompt, $2 default
	local a
	read -rp "$1${2:+ [$2]}: " a
	echo "${a:-${2:-}}"
}

echo
echo "=== MonitorSpider backup setup ==="
echo

# --- 1. monitor -------------------------------------------------------------
echo "Step 1 of 4 — your MonitorSpider monitor"
echo "In the dashboard: Monitors -> your Backup (push) monitor -> copy the ping URL."
PING_URL="${1:-}"
MON_ID=""; MON_TOKEN=""
while true; do
	[ -n "$PING_URL" ] || read -rp "Paste the ping URL: " PING_URL
	if [[ "$PING_URL" =~ id=([0-9]+).*token=([0-9a-fA-F]+) ]]; then
		MON_ID="${BASH_REMATCH[1]}"; MON_TOKEN="${BASH_REMATCH[2]}"; break
	fi
	echo "That does not look like a ping URL (expected ...backup-ping?id=<number>&token=<hex>)."
	PING_URL=""
done
BASE="${PING_URL%%/srv/*}"
MON_JSON="$(curl -fsS --max-time 20 "$BASE/srv/backup-config?id=$MON_ID&token=$MON_TOKEN")" || {
	echo "Could not fetch the monitor's settings — check the URL is complete and the monitor is enabled."; exit 1; }
MON_NAME="$(sed -n 's/.*"name":"\([^"]*\)".*/\1/p' <<<"$MON_JSON")"
MON_INTERVAL="$(sed -n 's/.*"expected_interval_hours":\([0-9.]*\).*/\1/p' <<<"$MON_JSON")"
MON_GRACE="$(sed -n 's/.*"grace_hours":\([0-9.]*\).*/\1/p' <<<"$MON_JSON")"
echo "Connected: monitor '$MON_NAME' expects a backup every ${MON_INTERVAL:-168}h (+${MON_GRACE:-6}h grace)."
echo

# --- 2. questions -> config --------------------------------------------------
echo "Step 2 of 4 — what to back up, where to send it"
# shellcheck disable=SC1090
[ -f "$CONF" ] && { echo "Found existing $CONF — its values are offered as defaults."; . "$CONF"; }

DIRS_DEFAULT="${BACKUP_DIRS[*]:-/etc /var/www}"
DIRS_RAW="$(ask 'Folders to back up (space-separated)' "$DIRS_DEFAULT")"
read -ra NEW_DIRS <<<"$DIRS_RAW"
for d in "${NEW_DIRS[@]}"; do [ -e "$d" ] || echo "  note: $d does not exist right now"; done

MYSQL_DEFAULT="no"; command -v mysqldump >/dev/null && pgrep -x mysqld >/dev/null 2>&1 && MYSQL_DEFAULT="yes"
NEW_MYSQL="$(ask 'Dump MySQL/MariaDB (all databases)? yes/no' "${MYSQL_DUMP:-$MYSQL_DEFAULT}")"
PG_DEFAULT="no"; command -v pg_dumpall >/dev/null && pgrep -x postgres >/dev/null 2>&1 && PG_DEFAULT="yes"
NEW_PG="$(ask 'Dump PostgreSQL (pg_dumpall)? yes/no' "${PGSQL_DUMP:-$PG_DEFAULT}")"

echo
echo "Where should the backups be uploaded? Two options:"
echo "  1) rclone — any cloud/SFTP/FTP remote you have configured (rclone config)"
echo "  2) curl   — a plain FTP/SFTP URL like ftp://user:pass@host/folder/"
NEW_RCLONE="${RCLONE_REMOTE:-}"; NEW_CURL="${CURL_UPLOAD_URL:-}"
if command -v rclone >/dev/null && [ -n "$(rclone listremotes 2>/dev/null)" ]; then
	echo "rclone remotes found:"; rclone listremotes | sed 's/^/    /'
	NEW_RCLONE="$(ask 'rclone destination (remote:folder), or Enter to use a curl URL instead' "$NEW_RCLONE")"
fi
if [ -z "$NEW_RCLONE" ]; then
	while [ -z "$NEW_CURL" ]; do NEW_CURL="$(ask 'Upload URL (ftp://user:pass@host/folder/ — note the trailing slash)' "$NEW_CURL")"; done
fi

echo
NEW_PASS="${ENCRYPT_PASSPHRASE:-}"
if [ -n "$NEW_PASS" ]; then
	echo "Keeping the existing encryption passphrase from $CONF."
else
	NEW_PASS="$(ask 'Encryption passphrase (GPG AES-256) — enter your own, or press Enter to generate one')"
	if [ -z "$NEW_PASS" ]; then
		NEW_PASS="$(tr -dc 'A-Za-z0-9' </dev/urandom | head -c 24)"
		echo
		echo "  Generated passphrase:  $NEW_PASS"
		echo "  SAVE IT IN YOUR PASSWORD MANAGER NOW — without it the backups CANNOT be"
		echo "  restored, and it must not live only on this server."
		read -rp "  Press Enter once you have saved it"
	fi
fi
NEW_PREFIX="$(ask 'Backup set name prefix' "${SET_PREFIX:-$(hostname -s)}")"
NEW_STAGING="$(ask 'Local staging folder' "${STAGING_DIR:-/var/backups/monitorspider}")"

# --- 3. install script + config + deps check ---------------------------------
echo
echo "Step 3 of 4 — install"
if [ -f "$(dirname "$0")/linux-files-mysql.sh" ]; then
	cp "$(dirname "$0")/linux-files-mysql.sh" "$DEST"
else
	echo "Downloading the backup script from $BASE/backup-kits/ ..."
	curl -fsS "$BASE/backup-kits/linux-files-mysql.sh" -o "$DEST"
fi
chmod 700 "$DEST"
echo "Installed $DEST"

{
	echo "# MonitorSpider backup configuration — written by setup.sh $(date +%F)"
	echo "# Sourced by $DEST; re-run setup.sh to change it."
	echo "PING_URL=\"$PING_URL\""
	echo "SET_PREFIX=\"$NEW_PREFIX\""
	echo "BACKUP_DIRS=(${NEW_DIRS[*]})"
	echo "STAGING_DIR=\"$NEW_STAGING\""
	echo "MYSQL_DUMP=\"$NEW_MYSQL\""
	echo "MYSQL_DEFAULTS_FILE=\"${MYSQL_DEFAULTS_FILE:-}\""
	echo "PGSQL_DUMP=\"$NEW_PG\""
	echo "ENCRYPT_PASSPHRASE=\"$NEW_PASS\""
	echo "RCLONE_REMOTE=\"$NEW_RCLONE\""
	echo "CURL_UPLOAD_URL=\"$NEW_CURL\""
	echo "KEEP_LOCAL=${KEEP_LOCAL:-2}"
	echo "REMOTE_RETENTION_DAYS=${REMOTE_RETENTION_DAYS:-28}"
} > "$CONF"
chmod 600 "$CONF"
echo "Wrote $CONF (readable by root only — it contains credentials)"

MISSING=""
for c in tar gzip curl; do command -v "$c" >/dev/null || MISSING="$MISSING $c"; done
[ -n "$NEW_PASS" ] && ! command -v gpg >/dev/null && MISSING="$MISSING gnupg"
[ "$NEW_MYSQL" = "yes" ] && ! command -v mysqldump >/dev/null && MISSING="$MISSING mysql-client"
[ -n "$MISSING" ] && { echo "MISSING tools:$MISSING — install them (apt/yum) and re-run setup."; exit 1; }
echo "All required tools present."

# --- 4. cron ------------------------------------------------------------------
echo
echo "Step 4 of 4 — schedule it"
RUN_TIME="$(ask 'Run at what time? (24h HH:MM)' '03:00')"
HH="${RUN_TIME%%:*}"; MM="${RUN_TIME##*:}"
if [ "${MON_INTERVAL%.*}" -le 24 ] 2>/dev/null; then
	echo "Your monitor expects a backup every ${MON_INTERVAL}h — scheduling DAILY at $RUN_TIME."
	CRON_SPEC="$MM $HH * * *"
else
	DOW="$(ask 'Run on which day? (Sunday..Saturday)' 'Sunday')"
	CRON_SPEC="$MM $HH * * ${DOW:0:3}"
	echo "Scheduling WEEKLY on $DOW at $RUN_TIME (monitor window: ${MON_INTERVAL}h + ${MON_GRACE}h grace)."
fi
{
	echo "# MonitorSpider backup — written by setup.sh; monitor: $MON_NAME"
	echo "$CRON_SPEC root $DEST >/dev/null 2>&1"
} > "$CRON_FILE"
chmod 644 "$CRON_FILE"
echo "Wrote $CRON_FILE"

echo
echo "Setup complete."
echo "  - Script:  $DEST"
echo "  - Config:  $CONF"
echo "  - Cron:    $CRON_FILE ($CRON_SPEC)"
echo "  - Monitor: $MON_NAME — it will alert if a backup fails or stops arriving."
echo
RUN_NOW="$(ask 'Run the first backup now? It seeds the monitor and the size graph (y/N)' 'N')"
if [[ "$RUN_NOW" =~ ^[yY] ]]; then
	bash "$DEST" && echo "First backup completed — the monitor page should be green with a size sample." \
		|| echo "First backup reported errors (see above) — the monitor received a FAIL ping, which is the system working."
fi