"""
PlatformIO pre-build script: reads .env and injects values as -D build flags.

Handles quoting so that comma-separated WIFI_NETWORKS works as a single string.
"""

Import("env")
import os

env_file = os.path.join(env.get("PROJECT_DIR", "."), ".env")
if not os.path.exists(env_file):
    print("WARNING: .env file not found, skipping credential injection")
else:
    with open(env_file) as f:
        for line in f:
            line = line.strip()
            if not line or line.startswith("#"):
                continue
            key, _, value = line.partition("=")
            key = key.strip()
            value = value.strip().strip('"').strip("'")
            if not key or not value:
                continue
            # Escape for C string literal
            escaped = value.replace("\\", "\\\\").replace('"', '\\"')
            env.Append(CPPDEFINES=[(key, env.StringifyMacro(escaped))])
            print(f"  .env: {key} = {value[:20]}...")