vendor: split httplib to cpp/h files (#17150)

* vendor: split httplib to cpp/h files

* move defines

* include httplib if curl is not used

* add TODO

* fix build ios

* fix build visionos instead

scripts/sync_vendor.py

@@ -20,3 +20,20 @@ vendor = {
 for url, filename in vendor.items():
     print(f"downloading {url} to {filename}") # noqa: NP100
     urllib.request.urlretrieve(url, filename)
+
+    # split cpp/h files for httplib
+    # see: https://github.com/yhirose/cpp-httplib/blob/master/split.py
+    if 'httplib.h' in filename:
+        border = '// ----------------------------------------------------------------------------'
+        with open(filename, 'r') as f:
+            content = f.read()
+        header, implementation, footer = content.split(border, 2)
+        fname_cpp = filename.replace('.h', '.cpp')
+        with open(filename, 'w') as fh:
+            fh.write(header)
+            fh.write(footer)
+        with open(fname_cpp, 'w') as fc:
+            fc.write('#include "httplib.h"\n')
+            fc.write('namespace httplib {\n')
+            fc.write(implementation.replace('\ninline ', '\n'))
+            fc.write('} // namespace httplib\n')