#!/usr/bin/env bash

# Retrieves the script's directory and cd's into it.
script_dir="$(cd "$(dirname "$0")" && pwd)"
cd ${script_dir}

# Check if the current directory is inside a Git repository.
if [ -d .git ] || git rev-parse --is-inside-work-tree > /dev/null 2>&1 ; then
    # Pull updated scripts from CoastalCommits.
    echo "Updating scripts..."
    git pull
    echo "Scripts updated!"
    echo "Server must be restarted for script updates to take effect."
else
    echo "WARNING: This directory is not a Git repository. Script updates will not be automatically fetched."
fi

# If config.sh exists, fetch variables from it
if [ -f "config.sh" ]; then
    source config.sh
    configpath="config.sh"
    echo "Loaded configuration from config.sh"
else
    # If config.sh doesn't exist, check if config.sh.example exists
    if [ -f "config.sh.example" ]; then
        # Fetch variables from config.sh.example
        echo "WARNING: config.sh file does not exist, falling back on default configuration."
        source config.sh.example
        configpath="config.sh.example"
        echo "Loaded configuration from config.sh.example"
    else
        # Handle the scenario when both files are missing
        echo "FATAL: Configuration files are missing! Cannot start the Factorio server."
        exit 1
    fi
fi

# Load the last downloaded Factorio version from config.sh, if available
if [ "$configpath" = "config.sh" ]; then
    last_downloaded_version=$(grep -oP 'last_downloaded_version=\K[^"]*' "$configpath")
    if [ $? -ne 0 ]; then
        last_download_version="None"
    fi
else
    last_downloaded_version="None"
fi

# Check if the last downloaded version matches the current version
if [ "$last_downloaded_version" != "$version" ] || [ "$version" = "stable" ] || [ "$version" = "latest" ]; then
    echo "Fetching Factorio binary..."
    wget "https://factorio.com/get-download/${version}/headless/linux64" -O factorio_headless.tar.xz
    if [ $? -ne 0 ]; then
        echo "FATAL: There is not a headless linux64 build available for the version you've selected in your ${configpath} file."
        echo "FATAL: See this website for a list of all Factorio versions: https://factorio.com/download/archive/"
        rm -f factorio_headless.tar.xz
        exit 1
    fi
    echo "Extracting Factorio binary..."
    tar -xf factorio_headless.tar.xz --strip-components=1 --overwrite
    echo "Factorio binary updated!"
    rm -f factorio_headless.tar.xz
else
    echo "Not updating Factorio binary, as the existing version matches the version stated in the configuration file."
fi

# Update the last downloaded version in the config.sh file
if [ "$configpath" = "config.sh" ]; then
    sed -i "/last_downloaded_version=.*/i # This parameter is used for auto-updating the Factorio binary." "$configpath"
    sed -i "/last_downloaded_version=.*/i # Do not change this parameter unless you know what you're doing!" "$configpath"
    sed -i "s/last_downloaded_version=.*/last_downloaded_version=\"$version\"/" "$configpath"
fi

# This checks if the ./saves/$save_name.zip save file exists or not...
if [ ! -f "./saves/${save_name}.zip" ]; then
    # ...if not, create the save file
    ./bin/x64/factorio ${extra_params_create} --create "./saves/${save_name}.zip"
fi

# This creates a byobu session that starts the server.
byobu new-session -d -s factorio "./bin/x64/factorio ${extra_params_start_server} --start-server ./saves/${save_name}.zip"

# This attaches the current terminal to the byobu session.
# Comment this out if you don't want this functionality.
byobu attach -t factorio


# Load the last downloaded Factorio version from config.sh, if available
if [ "$configpath" = "config.sh" ]; then
    last_downloaded_version=$(grep -oP 'last_downloaded_version=\K[^"]*' "$configpath")
    if [ $? -ne 0 ]; then
        last_download_version="None"
    fi
else
    last_downloaded_version="None"
fi

# Check if the last downloaded version matches the current version
if [ "$last_downloaded_version" != "$version" ] || [ "$last_downloaded_version" = "stable" ] || [ "$last_downloaded_version" = "latest" ]; then
    echo "Fetching Factorio binary..."
    wget "https://factorio.com/get-download/${version}/headless/linux64" -O factorio_headless.tar.xz
    if [ $? -ne 0 ]; then
        echo "FATAL: There is not a headless linux64 build available for the version you've selected in your ${configpath} file."
        echo "FATAL: See this website for a list of all Factorio versions: https://factorio.com/download/archive/"
        rm -f factorio_headless.tar.xz
        exit 1
    fi
    echo "Extracting Factorio binary..."
    tar -xf factorio_headless.tar.xz --strip-components=1 --overwrite
    echo "Factorio binary updated!"
    rm -f factorio_headless.tar.xz
else
    echo "Not updating Factorio binary, as the existing version matches the version stated in the configuration file."

    # Update the last downloaded version in the config.sh file
    if [ -f "$configpath" ]; then
        sed -i "s/last_downloaded_version=.*/last_downloaded_version=\"$version\"/" "$configpath"
    fi
fi