#!/bin/bash
#
# Minecraft Server Backup Script
# Deployed by Ansible - {{ ansible_date_time.iso8601 if ansible_date_time is defined else 'managed' }}
#
# Creates rolling backups of the Minecraft world and data directories.
# Prunes old backups based on retention count.
#

set -euo pipefail

# Configuration
DATA_DIR="{{ paths.data_dir }}"
BACKUP_DIR="{{ paths.backup_dir }}"
RETENTION_COUNT="{{ backup.retention_count | default(10) }}"
COMPRESS="{{ backup.compress | default('true') }}"
SERVER_NAME="{{ minecraft.server_name }}"

# Timestamp for this backup
TIMESTAMP="$(date +%Y%m%d_%H%M%S)"

# Log function
log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
}

# Safety checks
if [ ! -d "$DATA_DIR" ]; then
    log "ERROR: Data directory $DATA_DIR does not exist"
    exit 1
fi

if [ ! -d "$BACKUP_DIR" ]; then
    log "Creating backup directory: $BACKUP_DIR"
    mkdir -p "$BACKUP_DIR"
fi

# Create backup using tar
BACKUP_FILE="${BACKUP_DIR}/${SERVER_NAME}_${TIMESTAMP}"

log "Starting backup of $DATA_DIR..."

# Use atomic save if RCON is enabled
USE_RCON="{{ minecraft.rcon_enabled | default('false') }}"
if [ "$USE_RCON" = "true" ]; then
    log "Using RCON for world save..."
    # Send save-all command via rcon-cli or telnet
    # This is a best-effort operation - fall back to tar if it fails
    if command -v rcon-cli >/dev/null 2>&1; then
        rcon-cli -a localhost -p {{ minecraft.rcon_port }} -P {{ minecraft.rcon_password }} save-all || true
        sleep 5
    elif command -v mcrcon >/dev/null 2>&1; then
        mcrcon -H localhost -P {{ minecraft.rcon_port }} -p {{ minecraft.rcon_password }} "save-all" || true
        sleep 5
    else
        log "RCON client not found, skipping save-all command (backup may be inconsistent)"
    fi
fi

# Deterministic backup using tar
if [ "$COMPRESS" = "true" ]; then
    BACKUP_FILE="${BACKUP_FILE}.tar.gz"
    log "Creating compressed backup: $BACKUP_FILE"
    tar --warning=no-file-changed -czf "$BACKUP_FILE" \
        --exclude="$DATA_DIR/logs/*.gz" \
        -C "$(dirname $DATA_DIR)" "$(basename $DATA_DIR)"
else
    BACKUP_FILE="${BACKUP_FILE}.tar"
    log "Creating uncompressed backup: $BACKUP_FILE"
    tar --warning=no-file-changed -cf "$BACKUP_FILE" \
        --exclude="$DATA_DIR/logs/*.gz" \
        -C "$(dirname $DATA_DIR)" "$(basename $DATA_DIR)"
fi

log "Backup created successfully: $BACKUP_FILE"

# Prune old backups, retaining the most recent N
log "Pruning old backups (keeping $RETENTION_COUNT)..."

# Count backups (whether .tar or .tar.gz)
BACKUP_COUNT=$(ls "${BACKUP_DIR}/"${SERVER_NAME}_*.tar* 2>/dev/null | wc -l)
OVERFLOW=$((BACKUP_COUNT - RETENTION_COUNT))

if [ "$OVERFLOW" -gt 0 ]; then
    # Remove oldest backups
    ls -t "${BACKUP_DIR}/"${SERVER_NAME}_*.tar* 2>/dev/null | tail -n "$OVERFLOW" | while read -r old_backup; do
        log "Removing old backup: $old_backup"
        rm -f "$old_backup"
    done
else
    log "Backup count ($BACKUP_COUNT) is within retention limit ($RETENTION_COUNT)"
fi

log "Backup completed at $(date '+%Y-%m-%d %H:%M:%S')"
log "Current backups:"
ls -lh "${BACKUP_DIR}/" 2>/dev/null || true