#!/bin/bash

# Configuration
SOURCE_DIR="XML"
BACKUP_DIR="backup"
CONTAINER_NAME="agentdvr"
TIMESTAMP=$(date +"%Y%m%d_%H%M%S")

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

# Function to print 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 source directory exists
if [ ! -d "$SOURCE_DIR" ]; then
    log_error "Source directory '$SOURCE_DIR' does not exist!"
    exit 1
fi

# Get the image ID of the agentdvr container
log_info "Detecting Docker image ID for container: $CONTAINER_NAME"
IMAGE_ID=$(docker inspect --format='{{.Image}}' "$CONTAINER_NAME" 2>/dev/null | cut -d':' -f2 | cut -c1-12)

if [ -z "$IMAGE_ID" ]; then
    log_error "Failed to get image ID for container '$CONTAINER_NAME'"
    log_error "Make sure Docker is running and the container exists"
    exit 1
fi

log_info "Current image ID: $IMAGE_ID"

# Set backup filename with image ID
BACKUP_FILE="${BACKUP_DIR}/agent_backup-${IMAGE_ID}-${TIMESTAMP}.tar.gz"

# Create backup directory if it doesn't exist
if [ ! -d "$BACKUP_DIR" ]; then
    log_info "Creating backup directory: $BACKUP_DIR"
    mkdir -p "$BACKUP_DIR"
fi

# Find files to backup
FILES=$(find "$SOURCE_DIR" -type f \( -name "*.json" -o -name "*.db3" \))
FILE_COUNT=$(echo "$FILES" | grep -c .)

if [ -z "$FILES" ] || [ "$FILE_COUNT" -eq 0 ]; then
    log_warn "No *.json or *.db3 files found in $SOURCE_DIR"
    exit 0
fi

log_info "Found $FILE_COUNT files to backup"

# Create the backup
log_info "Creating backup: $BACKUP_FILE"
if tar -czf "$BACKUP_FILE" -C "$SOURCE_DIR" $(cd "$SOURCE_DIR" && find . -type f \( -name "*.json" -o -name "*.db3" \)) 2>/dev/null; then
    log_info "Backup created successfully: $BACKUP_FILE"
    BACKUP_SIZE=$(du -h "$BACKUP_FILE" | cut -f1)
    log_info "Backup size: $BACKUP_SIZE"
else
    log_error "Failed to create backup!"
    exit 1
fi

# Cleanup old backups
log_info "Cleaning up old backups..."

# Get list of all backup files sorted by modification time (newest first)
BACKUPS=$(ls -t "$BACKUP_DIR"/agent_backup-*.tar.gz 2>/dev/null)

if [ -z "$BACKUPS" ]; then
    log_info "No backups to clean up"
    exit 0
fi

# Convert to array
BACKUP_ARRAY=($BACKUPS)
TOTAL_BACKUPS=${#BACKUP_ARRAY[@]}

log_info "Total backups found: $TOTAL_BACKUPS"

# Keep track of backups to preserve
declare -a KEEP_BACKUPS

# Step 3: Find the newest backup with a different image ID
DIFFERENT_IMAGE_BACKUP=""
for backup in "${BACKUP_ARRAY[@]}"; do
    # Extract image ID from filename (format: agent_backup-IMAGE_ID-YYYYMMDD_HHMMSS.tar.gz)
    BACKUP_IMAGE_ID=$(basename "$backup" | sed -n 's/agent_backup-\([^-]*\)-.*/\1/p')
    if [ "$BACKUP_IMAGE_ID" != "$IMAGE_ID" ]; then
        DIFFERENT_IMAGE_BACKUP="$backup"
        log_info "Found backup from different image version: $(basename $backup) (Image: $BACKUP_IMAGE_ID)"
        break
    fi
done

# Step 3a: If no different image version, find the oldest backup of current version
OLDEST_BACKUP=""
if [ -z "$DIFFERENT_IMAGE_BACKUP" ]; then
    log_info "No different image version found, looking for oldest backup..."
    # Iterate in reverse (oldest first)
    for ((i=${#BACKUP_ARRAY[@]}-1; i>=0; i--)); do
        backup="${BACKUP_ARRAY[$i]}"
        BACKUP_IMAGE_ID=$(basename "$backup" | sed -n 's/agent_backup-\([^-]*\)-.*/\1/p')
        if [ "$BACKUP_IMAGE_ID" = "$IMAGE_ID" ]; then
            OLDEST_BACKUP="$backup"
            log_info "Found oldest backup: $(basename $backup)"
            break
        fi
    done
fi

# Step 4: Keep up to 4 newest backups
KEEP_RECENT=4
log_info "Keeping 4 newest backups"

COUNT=0
for backup in "${BACKUP_ARRAY[@]}"; do
    if [ $COUNT -lt $KEEP_RECENT ]; then
        KEEP_BACKUPS+=("$backup")
        COUNT=$((COUNT + 1))
    fi
done

# Add the special backup (different image or oldest) if found and not already in list
SPECIAL_BACKUP=""
if [ -n "$DIFFERENT_IMAGE_BACKUP" ]; then
    SPECIAL_BACKUP="$DIFFERENT_IMAGE_BACKUP"
    log_info "Preserving newest backup from different image version"
elif [ -n "$OLDEST_BACKUP" ]; then
    SPECIAL_BACKUP="$OLDEST_BACKUP"
    log_info "Preserving oldest backup from current image version"
fi

if [ -n "$SPECIAL_BACKUP" ]; then
    ALREADY_KEPT=false
    for keep in "${KEEP_BACKUPS[@]}"; do
        if [ "$keep" = "$SPECIAL_BACKUP" ]; then
            ALREADY_KEPT=true
            break
        fi
    done
    if [ "$ALREADY_KEPT" = false ]; then
        KEEP_BACKUPS+=("$SPECIAL_BACKUP")
    fi
fi

# Step 5: Delete backups that are not in the keep list
for backup in "${BACKUP_ARRAY[@]}"; do
    SHOULD_KEEP=false
    for keep in "${KEEP_BACKUPS[@]}"; do
        if [ "$backup" = "$keep" ]; then
            SHOULD_KEEP=true
            break
        fi
    done
    
    if [ "$SHOULD_KEEP" = false ]; then
        log_info "Deleting old backup: $(basename $backup)"
        rm -f "$backup"
    fi
done

# Summary
REMAINING=$(ls "$BACKUP_DIR"/agent_backup-*.tar.gz 2>/dev/null | wc -l)
log_info "Backup complete! Remaining backups: $REMAINING"
log_info "Current image ID: $IMAGE_ID"

exit 0