Process metadata only in metadata.cpp

Improves cache utilization as fewer things are passed via CFLAGS to
all files.  In the event that no metadata is available, let the cpp
file handle warning about default usage.

pio-scripts/set_metadata.py

@@ -1,5 +1,6 @@
 Import('env')
 import subprocess
+import json
 import re
 
 def get_github_repo():
@@ -42,7 +43,7 @@ def get_github_repo():
         
         # Check if it's a GitHub URL
         if 'github.com' not in remote_url.lower():
-            return 'unknown'
+            return None
         
         # Parse GitHub URL patterns:
         # https://github.com/owner/repo.git
@@ -63,17 +64,56 @@ def get_github_repo():
         if ssh_match:
             return ssh_match.group(1)
         
-        return 'unknown'
+        return None
         
     except FileNotFoundError:
         # Git CLI is not installed or not in PATH
-        return 'unknown'
+        return None
     except subprocess.CalledProcessError:
         # Git command failed (e.g., not a git repo, no remote, etc.)
-        return 'unknown'
+        return None
     except Exception:
         # Any other unexpected error
-        return 'unknown'
+        return None
 
-repo = get_github_repo()
-env.Append(BUILD_FLAGS=[f'-DWLED_REPO=\\"{repo}\\"'])
+PACKAGE_FILE = "package.json"
+
+def get_version():
+    with open(PACKAGE_FILE, "r") as package:
+        return json.load(package)["version"]
+    return None
+
+
+def has_def(cppdefs, name):
+    """ Returns true if a given name is set in a CPPDEFINES collection """
+    for f in cppdefs:
+        if isinstance(f, tuple):
+            f = f[0]
+    if f == name:
+        return True
+    return False
+
+
+def add_wled_metadata_flags(env, node):    
+    cdefs = env["CPPDEFINES"].copy()
+
+    if not has_def(cdefs, "WLED_REPO"):
+        repo = get_github_repo()
+        if repo:
+            cdefs.append(("WLED_REPO", f"\\\"{repo}\\\""))
+
+    if not has_def(cdefs, "WLED_VERSION"):
+        version = get_version()
+        if version:
+            cdefs.append(("WLED_VERSION", get_version()))
+
+    # This transforms the node in to a Builder; it cannot be modified again
+    return env.Object(
+        node,
+        CPPDEFINES=cdefs
+    )
+   
+env.AddBuildMiddleware(
+    add_wled_metadata_flags,
+    "*/wled_metadata.cpp"
+)

pio-scripts/set_version.py

@@ -1,8 +0,0 @@
-Import('env')
-import json
-
-PACKAGE_FILE = "package.json"
-
-with open(PACKAGE_FILE, "r") as package:
-    version = json.load(package)["version"]
-    env.Append(BUILD_FLAGS=[f"-DWLED_VERSION={version}"])