build: Clean up updating build params by adding functions

Author: redmushie

scripts/embed_env_vars.py

@@ -1,13 +1,17 @@
 from utils import pioenv, sysenv, dotenv
 
-Import('env')  # type: ignore
-pio = pioenv.PioEnv(env)  # type: ignore
-
 # This file is invoked by PlatformIO during build.
 # See 'extra_scripts' in 'platformio.ini'.
 
+#######################################################
+#           DETERMINING THE ENVIRONMENT               #
+#######################################################
+
+# Import the PlatformIO env and initialize our PioEnv wrapper.
+Import('env')  # type: ignore
+pio = pioenv.PioEnv(env)  # type: ignore
+
 # Get PIO variables.
-build_flags = pio.get_string_array('BUILD_FLAGS', [])
 project_dir = pio.get_string('PROJECT_DIR')
 
 # By default, the build is run in DEVELOP mode.
@@ -25,52 +29,70 @@
 pio_build_type = 'release' if is_release_build else 'debug'
 dotenv_type = 'production' if is_release_build else 'development'
 
+# Read the correct .env file.
 dot = dotenv.DotEnv(project_dir, dotenv_type)
 
-# Defines that will be passed to the compiler.
-cpp_defines: dict[str, str | int | bool] = {}
+#######################################################
+#             UPDATING BUILD PARAMETERS               #
+#######################################################
 
-# Gets the build flags from the PIO ini file, removes the -D prefix, splits on the first '=', and then converts to a dictionary.
-# (Intent: Remove everything from buildflags, then add everything as cppdefines, and readd the non-key-value build flags.)
-leftover_flags = []
-for flag in build_flags:
-    if flag.startswith('-D'):
-        flag = flag[2::]
-        if '=' in flag:
-            (k, v) = flag.split('=', 1)
 
-            cpp_defines[k] = v
+# Parse PIO build flags.
+#   All CPP Defines, i.e. flags starting with "-D", are parsed for key/value and stored in a dictionary (first value).
+#   All other build flags are returned in a list (second value)
+def parse_pio_build_flags(raw_flags: list[str]) -> tuple[dict[str, str | int | bool], list[str]]:
+    flag_dict = {}
+    leftover_flags = []
+    for flag in raw_flags:
+        if flag.startswith('-D'):
+            flag = flag[2::]
+            if '=' in flag:
+                (k, v) = flag.split('=', 1)
+                flag_dict[k] = v
+            else:
+                flag_dict[flag] = True
         else:
-            cpp_defines[flag] = True
-    else:
-        leftover_flags.append(flag)
+            leftover_flags.append(flag)
+    return (flag_dict, [])
 
-# Gets all the environment variables prefixed with 'OPENSHOCK_'.
+
+# Serialize CPP Defines.
+#   Strings are escaped to be a correct CPP macro.
+#   Booleans are turned into integers, True => 1 and False => 0.
+#   Integers are kept as-is.
+def serialize_cpp_defines(raw_defines: dict[str, str | int | bool]) -> dict[str, str | int]:
+    result_defines = {}
+    for k, v in raw_defines.items():
+        try:
+            v = int(v)
+        except ValueError:
+            pass
+        if isinstance(v, str):
+            result_defines[k] = env.StringifyMacro(v)
+        else:
+            result_defines[k] = v
+    return result_defines
+
+
+# Fetch the current build flags and group them into (CPP Defines, Other Flags).
+raw_build_flags = pio.get_string_array('BUILD_FLAGS', [])
+(cpp_defines, remaining_build_flags) = parse_pio_build_flags(raw_build_flags)
+
+# Gets all the environment variables prefixed with 'OPENSHOCK_' and add them as CPP Defines.
 openshock_vars = dot.get_all_prefixed('OPENSHOCK_')
 cpp_defines.update(openshock_vars)
 
 # Gets the log level from environment variables.
+# TODO: Delete get_loglevel and use... something more generic.
 log_level_int = dot.get_loglevel('LOG_LEVEL')
 if log_level_int is None:
     raise ValueError('LOG_LEVEL must be set in environment variables.')
 cpp_defines['CORE_DEBUG_LEVEL'] = log_level_int
 
-# Convert all the string values to macros.
-for k, v in cpp_defines.items():
-    try:
-        v = int(v)
-    except ValueError:
-        pass
-
-    if isinstance(v, str):
-        cpp_defines[k] = env.StringifyMacro(v)
-    else:
-        cpp_defines[k] = v
-
 print('Build type: ' + pio_build_type)
 print('Build defines: ' + str(cpp_defines))
 
 # Set PIO variables.
 env['BUILD_TYPE'] = pio_build_type
-env['BUILD_FLAGS'] = leftover_flags
-env.Append(CPPDEFINES=[(k, v) for k, v in cpp_defines.items()])
+env['BUILD_FLAGS'] = remaining_build_flags
+env.Append(CPPDEFINES=list(cpp_defines.items()))