#!/bin/bash
set -euo pipefail

echo "--- Initializing Restic Backup Script ---"

# Source environment variables if the file exists
# This script expects RESTIC_ENV_FILE to be set in the environment
# The environment file includes rclone throttling settings to prevent timeouts
# shellcheck source=/dev/null
if [ -f "$RESTIC_ENV_FILE" ]; then
	source "$RESTIC_ENV_FILE"
	echo "Environment variables loaded from $RESTIC_ENV_FILE"
else
	echo "Error: RESTIC_ENV_FILE not found. Please run setup.sh first." >&2
	exit 1
fi

# Source common functions
# shellcheck source=/dev/null
source "$(dirname "$0")/common.sh"

# --- Pre-warm rclone connection ---
pre_warm_connection "Restic Backup"

# --- Exit Trap ---
# This will call notify with the script's final exit code upon termination.
trap 'notify "Restic Backup ($(whoami)@$(hostname))" "Restic backup script finished with exit code $?" $?' EXIT

# --- Main Backup Logic ---
echo "--- Starting Restic Backup at $(date) ---"

# Perform the Restic backup
echo "Starting Restic backup to repository: $RESTIC_REPOSITORY"
restic backup \
	--repo "${RESTIC_REPOSITORY}" \
	--files-from "${CONFIG_DIR}/paths" \
	--exclude-file "${CONFIG_DIR}/excludes" \
	--password-file "${RESTIC_PASSWORD_FILE}" \
	--option rclone.timeout=20m \
	--lock-retry-after 5m \
	--lock-stale-timeout 24h \
	--tag daily || {
	echo "Error: Restic backup failed." >&2
	notify "Restic Backup ($(whoami)@$(hostname))" "Backup phase failed!" 8
	exit 1
}


# Prune old snapshots - only on specific hours to avoid conflicts
HOUR=$(date +%H)
# Only prune between 2-4 AM to reduce multi-device conflicts
if [ $HOUR -ge 2 ] && [ $HOUR -lt 4 ]; then
	# Add random delay to stagger multiple devices
	sleep $(shuf -i 0-1800 -n 1)  # 0-30 minutes random delay
	echo "Applying Restic retention policy and pruning old snapshots..."
	restic forget \
		--repo "${RESTIC_REPOSITORY}" \
		--password-file "${RESTIC_PASSWORD_FILE}" \
		--option rclone.timeout=20m \
		--lock-retry-after 5m \
		--lock-stale-timeout 24h \
		--keep-daily 7 \
		--keep-weekly 4 \
		--keep-monthly 6 \
		--keep-yearly 6 \
		--prune || {
		echo "Warning: Restic forget/prune failed (another device might be pruning)." >&2
		notify "Restic Backup ($(whoami)@$(hostname))" "Prune phase failed!" 6
		# Don't exit on prune failure - backup was successful
	}
else
	echo "Skipping prune - only running between 2-4 AM to avoid multi-device conflicts"
fi


echo "--- Restic Backup finished at $(date) ---"