#!/bin/bash

# hourly-backup-cleanup.sh
# Retains last N backups (default: 24), then 1 per day after that
# Usage:
#   ./hourly-backup-cleanup.sh                # local, keep 24
#   ./hourly-backup-cleanup.sh --remote       # remote, keep 24
#   ./hourly-backup-cleanup.sh --keep 36      # local, keep 36
#   ./hourly-backup-cleanup.sh --remote --keep 48

# Default values
IS_REMOTE="no"
KEEP_HOURS=24

# Parse arguments
while [[ $# -gt 0 ]]; do
    case "$1" in
        --remote)
            IS_REMOTE="yes"
            shift
            ;;
        --keep)
            KEEP_HOURS="$2"
            shift 2
            ;;
        *)
            echo "Unknown option: $1"
            echo "Usage: $0 [--remote] [--keep <hours>]"
            exit 1
            ;;
    esac
done

cleanup_backups() {
    local PATH_TYPE="$1"  # "local" or "remote"
    local BACKUP_PATH="$2"

    declare -A seen_dates
    local count=0

    if [[ "$PATH_TYPE" == "remote" ]]; then
        if [[ -z "$BKUSER" || -z "$BKSVR" || -z "$RSYNCLOCATION" ]]; then
            echo "Missing required remote variables: BKUSER, BKSVR, RSYNCLOCATION"
            exit 1
        fi
        SSH_CMD="ssh -oStrictHostKeyChecking=no -i ${HOME}/.ssh/wpo_backups ${BKUSER}@${BKSVR}"
        backups=$($SSH_CMD "ls -1 ${BACKUP_PATH} | grep '^back-' | sort")
    else
        backups=$(ls -1 "$BACKUP_PATH" | grep '^back-' | sort)
    fi

    total_backups=$(echo "$backups" | wc -l)

    while read -r backup; do
        backup_date=$(echo "$backup" | grep -oP '\d{4}-\d{2}-\d{2}')
        [ -z "$backup_date" ] && continue

        if [ $((total_backups - count)) -le "$KEEP_HOURS" ]; then
            seen_dates["$backup_date"]=1
            ((count++))
            continue
        fi

        if [[ -z ${seen_dates["$backup_date"]} ]]; then
            seen_dates["$backup_date"]=1
            ((count++))
            continue
        fi

        echo "Removing $PATH_TYPE backup: $backup"
        if [[ "$PATH_TYPE" == "remote" ]]; then
            $SSH_CMD "rm -rf ${BACKUP_PATH}/$backup"
        else
            rsync -a --delete /backup/empty/ "$BACKUP_PATH/$backup/"
            rm -rf "$BACKUP_PATH/$backup"
        fi

        ((count++))
    done <<< "$backups"
}

if [[ "$IS_REMOTE" == "yes" ]]; then
    cleanup_backups "remote" "$RSYNCLOCATION"
else
    cleanup_backups "local" "/backup"
fi