Half Baked Script To Update Server Mods From Modrinth Modpack

update.sh

#!/bin/bash

# Define paths
MODS_DIR="./mods"
BACKUP_DIR="./backup"
MRPACK_URL="$1"  # Replace with your actual Modrinth .mrpack URL
TEMP_DIR="./temp"  # Temporary directory to unzip the .mrpack file

# Create the backup directory if it doesn't exist
rm -rf "$TEMP_DIR"  # Remove any existing temp directory

mkdir -p "$BACKUP_DIR"
mkdir -p "$TEMP_DIR"

# Function to backup the existing mods folder
backup_mods() {
    if [ ! -d "$MODS_DIR" ]; then
        echo "Mods directory $MODS_DIR does not exist. Nothing to backup."
        return
    fi

    # Create a timestamped backup
    TIMESTAMP=$(date +"%Y%m%d%H%M%S")
    BACKUP_PATH="$BACKUP_DIR/mods_backup_$TIMESTAMP.zip"

    # Zip the current mods folder
    echo "Backing up mods to $BACKUP_PATH..."
    zip -r "$BACKUP_PATH" "$MODS_DIR"
    if [ $? -eq 0 ]; then
        echo "Backup completed: $BACKUP_PATH"
    else
        echo "Error: Backup failed."
        exit 1
    fi
}

# Function to download a file
download_file() {
    local url=$1
    local dest=$2

    echo "Downloading $url to $dest..."
    curl -sSL "$url" -o "$dest"
    if [ $? -eq 0 ]; then
        echo "Downloaded successfully: $dest"
    else
        echo "Error: Failed to download $url"
        exit 1
    fi
}

# Function to unzip the .mrpack file
unzip_mrpack() {
    local mrpack_url=$1
    local temp_dir=$2

    echo "Downloading .mrpack file from $mrpack_url..."
    local mrpack_file="$temp_dir/modpack.mrpack"

    download_file "$mrpack_url" "$mrpack_file"

    echo "Unzipping .mrpack file..."
    unzip -q "$mrpack_file" -d "$temp_dir"
    if [ $? -eq 0 ]; then
        echo ".mrpack file unzipped successfully."
    else
        echo "Error: Failed to unzip .mrpack file."
        exit 1
    fi
}

# Function to update mods from the Modrinth JSON file
update_server_mods() {
    # Unzip the .mrpack file and extract the JSON
    unzip_mrpack "$MRPACK_URL" "$TEMP_DIR"

    # The JSON file should be inside the unzipped contents
    JSON_FILE="$TEMP_DIR/modrinth.index.json"

    if [ ! -f "$JSON_FILE" ]; then
        echo "Error: modrinth.index.json not found in the .mrpack file."
        exit 1
    fi

    # Fetch mod URLs and paths from the JSON
    echo "Parsing modrinth.index.json..."
    MOD_URLS=$(jq -r '.files[] | select(.env.server != "unsupported") | .downloads[0]' "$JSON_FILE")
    MOD_PATHS=$(jq -r '.files[] | select(.env.server != "unsupported") | .path' "$JSON_FILE")

    # Loop through each mod URL and download the corresponding mod file
    echo "Updating mods..."
    for i in $(seq 0 $(($(echo "$MOD_URLS" | wc -l) - 1))); do
        MOD_URL=$(echo "$MOD_URLS" | sed -n "$((i + 1))p")
        MOD_PATH=$(echo "$MOD_PATHS" | sed -n "$((i + 1))p")

        MOD_SAVE_PATH="$MOD_PATH"

        # Ensure the mods directory exists
        mkdir -p "$(dirname "$MOD_SAVE_PATH")"

        # Download the mod
        download_file "$MOD_URL" "$MOD_SAVE_PATH"
    done
}

# Main execution flow
echo "Starting mod update process..."

# Step 1: Backup existing mods
backup_mods

# Step 2: Update mods from Modrinth
update_server_mods

# Clean up temporary files
echo "Cleaning up temporary files..."
rm -rf "$TEMP_DIR"

echo "Mod update process completed!"