Import('env')
import os
import shutil
import gzip

platform = env.PioPlatform()
board = env.BoardConfig()
mcu = board.get("build.mcu", "esp32")
# gzip only for ESP8266
if env["PIOPLATFORM"] != "espressif32":

    OUTPUT_DIR = "build_output{}".format(os.path.sep)

    def bin_gzip(source, target, env):
        variant = str(target[0]).split(os.path.sep)[2]

        # create string with location and file names based on variant
        bin_file = "{}firmware{}{}.bin".format(OUTPUT_DIR, os.path.sep, variant)
        gzip_file = "{}firmware{}{}.bin.gz".format(OUTPUT_DIR, os.path.sep, variant)

        # check if new target files exist and remove if necessary
        if os.path.isfile(gzip_file): os.remove(gzip_file)

        # write gzip firmware file
        with open(bin_file,"rb") as fp:
            with gzip.open(gzip_file, "wb", compresslevel = 9) as f:
                shutil.copyfileobj(fp, f)

        ORG_FIRMWARE_SIZE = os.stat(bin_file).st_size
        GZ_FIRMWARE_SIZE = os.stat(gzip_file).st_size

        print("Compression reduced firmware size by {:.0f}% (was {} bytes, now {} bytes)".format((GZ_FIRMWARE_SIZE / ORG_FIRMWARE_SIZE) * 100, ORG_FIRMWARE_SIZE, GZ_FIRMWARE_SIZE))

    env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", [bin_gzip])