#!/bin/bash

# Script to check if mounted disks have up-to-date borg2 backups
# Compares the last modification date of borg_archives/borg2 on each disk
# with /home/poule/borg_archives/borg2

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

echo "Checking mounted disks for borg2 backup status..."

# Reference directory
REFERENCE_DIR="/home/poule/borg_archives/borg2"

# Check if reference directory exists
if [ ! -d "$REFERENCE_DIR" ]; then
    echo -e "${RED}Error: Reference directory $REFERENCE_DIR does not exist.${NC}"
    exit 1
fi

# Get current time
CURRENT_TIME=$(date +%s)
# Calculate time 24 hours ago
TIME_24H_AGO=$((CURRENT_TIME - 86400))

# Get only mount points in /media/$USER/
MOUNT_POINTS=$(df -h | grep "/media/$USER/" | awk '{print $6}')

# Initialize arrays for results
OUTDATED_DISKS=()
OUTDATED_TIMES=()
UP_TO_DATE_DISKS=()
NO_BORG_DISKS=()
LOW_SPACE_DISKS=()
LOW_SPACE_VALUES=()

# Function to calculate time difference in years, months, days
calculate_time_diff() {
    local timestamp=$1
    local now=$(date +%s)
    local diff=$((now - timestamp))

    # Calculate years, months, days
    local days=$((diff / 86400))
    local years=$((days / 365))
    local remaining_days=$((days % 365))
    local months=$((remaining_days / 30))
    remaining_days=$((remaining_days % 30))

    echo "${years}y ${months}m ${remaining_days}d"
}

# Check each mount point
for MOUNT in $MOUNT_POINTS; do
    BORG_DIR="$MOUNT/borg_archives/borg2"

    # Skip the reference directory itself
    if [ "$MOUNT" == "/home" ] || [ "$MOUNT" == "/" ]; then
        continue
    fi

    echo -e "${YELLOW}Checking $MOUNT...${NC}"

    # Check available disk space
    AVAILABLE_SPACE=$(df -BG "$MOUNT" | awk 'NR==2 {print $4}' | sed 's/G//')
    if [ "$AVAILABLE_SPACE" -lt 10 ]; then
        echo -e "  ${RED}! Low disk space: ${AVAILABLE_SPACE}GB available${NC}"
        LOW_SPACE_DISKS+=("$MOUNT")
        LOW_SPACE_VALUES+=("$AVAILABLE_SPACE")
    fi

    # Check if borg_archives/borg2 exists on this mount
    if [ -d "$BORG_DIR" ]; then
        # Get last modification time of the borg directory
        BORG_TIME=$(stat -c %Y "$BORG_DIR")

        # Compare times - consider up-to-date if modified within the last 24 hours
        if [ "$BORG_TIME" -ge "$TIME_24H_AGO" ]; then
            echo -e "  ${GREEN}✓ Backup is up to date${NC}"
            UP_TO_DATE_DISKS+=("$MOUNT")
        else
            echo -e "  ${RED}✗ Backup is outdated${NC}"
            OUTDATED_DISKS+=("$MOUNT")
            OUTDATED_TIMES+=("$BORG_TIME")
        fi
    else
        echo -e "  ${YELLOW}! No borg2 backup directory found${NC}"
        NO_BORG_DISKS+=("$MOUNT")
    fi
done

# Print summary
echo -e "\n${YELLOW}=== Backup Status Summary ===${NC}"

if [ ${#UP_TO_DATE_DISKS[@]} -gt 0 ]; then
    echo -e "\n${GREEN}Up-to-date disks:${NC}"
    for DISK in "${UP_TO_DATE_DISKS[@]}"; do
        echo "  - $DISK"
    done
fi

if [ ${#OUTDATED_DISKS[@]} -gt 0 ]; then
    echo -e "\n${RED}Outdated disks (need backup):${NC}"
    for i in "${!OUTDATED_DISKS[@]}"; do
        DISK="${OUTDATED_DISKS[$i]}"
        BORG_TIME="${OUTDATED_TIMES[$i]}"
        FORMATTED_DATE=$(date -d "@$BORG_TIME" "+%Y-%m-%d %H:%M:%S")
        TIME_DIFF=$(calculate_time_diff "$BORG_TIME")
        echo "  - $DISK (Last modified: $FORMATTED_DATE, Age: $TIME_DIFF)"
    done
fi

if [ ${#NO_BORG_DISKS[@]} -gt 0 ]; then
    echo -e "\n${YELLOW}Disks without borg2 backup directory:${NC}"
    for DISK in "${NO_BORG_DISKS[@]}"; do
        echo "  - $DISK"
    done
fi

if [ ${#LOW_SPACE_DISKS[@]} -gt 0 ]; then
    echo -e "\n${RED}Disks with low space (less than 10GB free):${NC}"
    for i in "${!LOW_SPACE_DISKS[@]}"; do
        DISK="${LOW_SPACE_DISKS[$i]}"
        SPACE="${LOW_SPACE_VALUES[$i]}"
        echo "  - $DISK (${SPACE}GB available)"
    done
fi

# Exit with error code if there are outdated disks
if [ ${#OUTDATED_DISKS[@]} -gt 0 ]; then
    exit 1
else
    exit 0
fi