VERSION="2.1.0"

  $PROGRAM [OPTIONS] check-updates [MOD_DIRECTORY_PATH]

check-updates [MOD_DIRECTORY_PATH]

  Arguments:

    MOD_DIRECTORY_PATH (path to base directory)

  Checks for available dependency updates (listed in the info

  file). Only dependencies with explicitly listed version are

  processed.

#

# Checks dependencies for available updates.

#

# Arguments:

#

#   $1 (base_dir)

#     Base (top-level) directory with the mod files.

#

# Outputs:

#

#   List of available dependency updates.

#

# Returns:

#

#   0 on success, 1 otherwise.

#

function command_check_updates() {

    local base_dir="$1"

    local info_file dependency mod_name local_version latest_version mod_info_url mod_info

    local outdated_dependency

    local outdated_dependencies=()

    info_file=$(get_info_file "$base_dir") || return 1

    # Process dependencies. Only take into account specifcations that include version.

    while read -r dependency; do

        # Extracts mod name and version from dependency specification.

        mod_name=$(echo "$dependency" | grep -E -o '.*(<|<=|=|>=|>)' | sed -E 's/[[:blank:]]*(<|<=|=|>=|>)//;s/^[[:blank:]]*([!?~]|\([?]\))[[:blank:]]*//')

        local_version=$(echo "$dependency" | grep -E -o "[[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+$")

        [[ $mod_name == "base" ]] && continue

        # Fetch the information from public API. Encode the URL

        # because some mods have whitespaces in name.

        mod_info_url="https://mods.factorio.com/api/mods/${mod_name// /%20}"

        if ! mod_info=$(curl --silent --show-error "$mod_info_url"); then

            error "Failed to fetch mod information: $mod_name"

            error "Request URL: $mod_info_url"

            return 1

        fi

        latest_version=$(echo "$mod_info" | jq -r '.releases[].version' | sort --version-sort | tail -n1)

        if ! [[ $latest_version =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then

            error "Failed to extract latest mod version: $mod_name"

            return 1

        fi

        # Sort by version, and use the check mode (returns 0 if lines are already sorted).

        if ! echo -e "$latest_version\n$local_version" | sort --version-sort --check=silent; then

            outdated_dependency=$(printf "%-48s %8s -> %8s" "$mod_name" "$local_version" "$latest_version")

            outdated_dependencies+=("$outdated_dependency")

        fi

    done < <(jq -r ".dependencies[]" "$info_file" | grep -E "(<|<=|=|>=|>)" | sed -e 's/^[[:blank:]]*//;s/[[:blank:]]*$//')

    if (( ${#outdated_dependencies[@]} == 0 )); then

        success "All listed dependencies are up-to-date."

    else

        echo -e "Dependencies with available updates:\n"

        for outdated_dependency in "${outdated_dependencies[@]}"; do

            echo "  $outdated_dependency"

        done

        echo

        warning "Some of the listed dependencies are outdated."

    fi

    return 0

}

elif [[ $COMMAND == check-updates ]]; then

    MOD_DIRECTORY_PATH="${1:-.}"

    shift

    # Ensure that passed-in base directory is the repository root.

    if [[ ! -d $MOD_DIRECTORY_PATH/.git ]]; then

        error "Passed-in path does not point to base directory of the mod (must contain the .git sub-directory)."

        exit "$ERROR_ARGUMENTS"

    fi

    if ! command_check_updates "$MOD_DIRECTORY_PATH"; then

        exit "$ERROR_GENERAL"

    fi