#!/bin/bash

# ZTNet Docker Compose Backup Script
# This script stops containers, backs up volumes and configs, then restarts

set -e  # Exit on error

# Configuration
BACKUP_DIR="./backup"
COMPOSE_FILE="docker-compose.yml"
MAX_BACKUPS=5
TIMESTAMP=$(date +"%Y%m%d_%H%M%S")
BACKUP_NAME="ztnet_backup_${TIMESTAMP}"
BACKUP_PATH="${BACKUP_DIR}/${BACKUP_NAME}"

# Colors for output
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
RED='\033[0;31m'
NC='\033[0m' # No Color

# Function to print colored messages
log_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

log_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}

log_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# Check if docker-compose file exists
if [ ! -f "$COMPOSE_FILE" ]; then
    log_error "docker-compose.yml not found in current directory!"
    exit 1
fi

# Create backup directory if it doesn't exist
mkdir -p "$BACKUP_DIR"

log_info "Starting backup process..."
log_info "Backup will be saved to: ${BACKUP_PATH}"

# Step 1: Stop containers
log_info "Stopping Docker containers..."
docker compose down

# Step 2: Create backup directory for this backup
mkdir -p "$BACKUP_PATH"

# Step 3: Backup PostgreSQL data volume
log_info "Backing up PostgreSQL data..."
docker run --rm \
    -v ztnet_postgres-data:/data \
    -v "$(pwd)/${BACKUP_PATH}:/backup" \
    alpine tar czf /backup/postgres-data.tar.gz -C /data .

# Step 4: Backup ZeroTier volume
log_info "Backing up ZeroTier data..."
docker run --rm \
    -v ztnet_zerotier:/data \
    -v "$(pwd)/${BACKUP_PATH}:/backup" \
    alpine tar czf /backup/zerotier.tar.gz -C /data .

# Step 5: Backup docker-compose.yml
log_info "Backing up docker-compose.yml..."
cp "$COMPOSE_FILE" "${BACKUP_PATH}/docker-compose.yml"

# Step 6: Create backup metadata
cat > "${BACKUP_PATH}/backup_info.txt" << EOF
Backup Information
==================
Date: $(date)
Timestamp: ${TIMESTAMP}
Hostname: $(hostname)
Docker Version: $(docker --version)
Docker Compose Version: $(docker compose version)

Backed up volumes:
- postgres-data
- zerotier

Backed up files:
- docker-compose.yml
EOF

log_info "Backup completed successfully!"

# Step 7: Cleanup old backups (keep only last 5)
log_info "Cleaning up old backups (keeping last ${MAX_BACKUPS})..."
cd "$BACKUP_DIR"
ls -t | grep "ztnet_backup_" | tail -n +$((MAX_BACKUPS + 1)) | xargs -r rm -rf
cd - > /dev/null

REMAINING_BACKUPS=$(ls -1 "$BACKUP_DIR" | grep "ztnet_backup_" | wc -l)
log_info "Current number of backups: ${REMAINING_BACKUPS}"

# Step 8: Restart containers
log_info "Starting Docker containers..."
docker compose up -d

# Step 9: Wait for services to be ready
log_info "Waiting for services to start..."
sleep 5

# Check if containers are running
log_info "Checking container status..."
docker compose ps

log_info "=========================================="
log_info "Backup process completed successfully!"
log_info "Backup location: ${BACKUP_PATH}"
log_info "Backup size: $(du -sh "${BACKUP_PATH}" | cut -f1)"
log_info "=========================================="