new: Overhaul generate-large-binary-resource.sh

Thank you, GAI!

.github/scripts/generate-large-binary-resource.sh

@@ -1,7 +1,55 @@
 #!/bin/bash -e
 
-# generate 8 MiB random data as Base64
-DATA=$(openssl rand -base64 8388608)
+generate_random_data() {
+    # Default size: 8 MiB
+    local size=${1:-8388608}
+    openssl rand -base64 "$size"
+}
 
-echo "{\"resourceType\": \"Binary\", \"data\": \"$DATA\"}" > large-binary.json
-echo "<Binary xmlns=\"http://hl7.org/fhir\"><data value=\"$DATA\"/></Binary>" > large-binary.xml
+create_data_string() {
+    local data=${1:-""}
+    local type=${2:-""}
+
+    if [[ -z "$data" ]]; then
+        echo "Error: No data provided for string creation."
+        return 1
+    fi
+
+    case "$type" in
+        json)
+            echo "{\"resourceType\": \"Binary\", \"data\": \"$data\"}"
+            ;;
+        xml)
+            echo "<Binary xmlns=\"http://hl7.org/fhir\"><data value=\"$data\"/></Binary>"
+            ;;
+        *)
+            echo "Error: Unsupported type '$type'. Use 'json' or 'xml'."
+            return 1
+            ;;
+    esac
+}
+
+write_to_file() {
+    local output=${1}
+    local filename=${2}
+
+    if [[ -z "$output" || -z "$filename" ]]; then
+        echo "Error: output or filename cannot be empty."
+        return 1
+    fi
+
+    echo "$output" > "$filename"
+}
+
+main() {
+    local data_size=8388608 # 8 MiB
+    local random_data=$(generate_random_data "$data_size")
+
+    local json_output=$(create_data_string "$random_data" "json")
+    local xml_output=$(create_data_string "$random_data" "xml")
+
+    write_to_file "$json_output" "large-binary.json"
+    write_to_file "$xml_output" "large-binary.xml"
+}
+
+main