More conversion to a modular system.

.includes/functions.sh

@@ -22,6 +22,67 @@ check_requirements() {
     return 0
 }
 
+download() {
+   local source=($@)
+   for i in "${source[@]}" ; do
+       local dest="${i##*/}"
+       dest="${dest//%20/ }"
+       dest="${dest#*\?filename=}"
+       dest="${dest%\?*}"
+       # Remove the destination file if it is empty.
+       [[ -s "${cache}/${dest}" ]] || rm -f "${cache}/${dest}" 2> /dev/null
+       if [[ "${redownload}" == "true" ]] && [[ -e "${cache}/${dest}" ]]; then
+           rm -v "${cache}/${dest}"
+       fi
+       # Skip if the item is in cache.
+       [[ -e "${cache}/${dest}" ]] && continue
+       { if ! curl -L4 -C - --retry 10 --output "${cache}/${dest}" "${i}" ; then
+           echo "Could not download \"$i\"..."
+           exit 1
+       fi; } | dialog --backtitle "Audio Game Manager" \
+           --progressbox "Downloading \"$dest\" from \"$i\"" -1 -1
+       local downloadError=1
+       case "${dest##*.}" in
+           "pk3"|"zip")
+               unzip -tq "${cache}/${dest}"  | dialog --backtitle "Audio Game Manager" \
+                   --progressbox "Validating ${dest##*.} file" -1 -1 --stdout
+                   downloadError=$?
+           ;;
+           "7z")
+               7z t "${cache}/${dest}" | dialog --backtitle "Audio Game Manager" \
+                   --progressbox "Validating 7z file" -1 -1 --stdout
+                   downloadError=$?
+           ;;
+           "exe")
+               # Check if it's a valid Windows executable by looking at the MZ header
+               hexdump -n 2 -v -e '/1 "%02X"' "${cache}/${dest}" | grep -q "4D5A"
+                   downloadError=$?
+           ;;
+           "wad")
+               if [[ "$(file -b --mime-type "${cache}/${dest}")" != "application/octet-stream" ]]; then
+                   downloadError=0
+               fi
+           ;;
+           *)
+               # Add HTML check for other file types
+               if file -b "${cache}/${dest}" | grep -q "HTML document" ; then
+                   echo "File not found: \"$i\" (HTML document probably 404)"
+                   downloadError=1
+               else
+                   downloadError=0
+               fi
+           ;;
+       esac
+       if [[ $downloadError -ne 0 ]]; then
+           rm -fv "${cache}/${dest}"
+                   dialog --backtitle "Audio Game Manager" \
+                       --infobox "Error downloading \"${dest}\". Installation cannot continue." -1 -1 --stdout
+                   alert
+                   exit 1
+       fi
+   done
+}
+
 # Function to open urls across OS.
 open_url() {
     if [[ "$(uname)" == "Darwin" ]]; then