#!/bin/bash

# Path to the backup directory
backup_dir="/backup"

# Path to the volume directory
volume_dir="/var/lib/docker/volumes"

if [ ! -d "$backup_dir" ]; then
    echo "Error: /backup directory does not exist"
    exit 1
fi

if [ ! -d "$volume_dir" ]; then
    echo "Error: /var/lib/docker/volumes directory does not exist"
    exit 1
fi

calculate_required_space() {
    # Extract the size from the filename
    size=$(echo "$1" | grep -oE '[0-9]+G')

    # Remove 'G' from the size and convert it to bytes
    size_bytes=$(echo "$size" | sed 's/G//')
    if [[ $size_bytes == 0* ]]; then
      # this happens when the size is smalleer than 1 GB
      size_bytes=1
    fi

    size_bytes=$(echo "$size_bytes * 1024 * 1024 * 1024" | bc)

    # Calculate 10% of the size and add it to the required space
    ten_percent=$(echo "$size_bytes / 10" | bc)
    required_space=$(echo "$size_bytes + $ten_percent" | bc)
    #required_space=$(( size_bytes + ten_percent ))

    echo "$required_space"
}

# Read the JSON input and extract the list of keys
keys=$(cat /root/rpc/$1.yml | yaml2json - | jq '.volumes' | jq -r 'keys[]')

# Iterate over the list of keys

total_space=0
cleanup_space=0

restore_files=()
cleanup_folders=()

for key in $keys; do
    volume_name="rpc_$key"

    newest_file=$(ls -1 "$backup_dir"/"${volume_name}"-[0-9]*G.tar.zst 2>/dev/null | sort | tail -n 1)
    directory="$volume_dir/rpc_$key/_data/"
    [ -d "$directory" ] && existing_size=$(du -sb "$directory" | awk '{ total += $1 } END { print total }') || existing_size=0

    #echo "$directory: $existing_size"

    if [ -z "$newest_file" ]; then
	if [[ "$2" = "--print-size-only" && $existing_size -gt 0 ]]; then
	    # I only want to have a theoretical file size
	    status=$(./sync-status "$1")
	    if [ $? -eq 0 ]; then
		# 0 means it's synced
		required_space=$existing_size
	    fi
	    #GB=$(echo "$existing_size / 1024 / 1024 / 1024" | bc )
	    #echo "$GB"
	    #exit 0
	else
	    echo "Error: No backup found for volume '$volume_name'"
	    exit 1
	fi
    else
      restore_files+=("$newest_file")
      cleanup_folders+=("$directory")

      required_space=$(calculate_required_space "$(basename "$newest_file")")
    fi

    #echo "$volume_name: $required_space"
    total_space=$(echo "$total_space + $required_space" | bc)


    cleanup_space=$(echo "$cleanup_space + existing_size" | bc)
done

if [ "$2" = "--print-size-only" ]; then
    GB=$(echo "$total_space / 1024 / 1024 / 1024" | bc )
    echo "$GB"
    exit 0
fi

available_space=$(df --output=avail -B1 "$volume_dir" | tail -n 1)
available_space=$((available_space + cleanup_space))

if [ "$available_space" -lt "$total_space" ]; then
    echo "Error: Not enough free space in $volume_dir"
    exit 1
fi

for folder in $cleanup_folders; do
    echo "delete $folder"
    [ -d "$folder" ] && rm -rf "$folder/*"
done

for file in $restore_files; do    
    tar -I zstd -xf "$file" -C /
    echo "Backup '$file' restored"        
done

echo "node $1 restored."