#!/usr/bin/env python3
import argparse
import struct
from pathlib import Path

MAGIC = b"TSLUPD1\0"
HEADER_SIZE = 32


def main():
    parser = argparse.ArgumentParser(description="Create a combined ESP32 update package.")
    parser.add_argument("--firmware", default=".pio/build/seeed_xiao_esp32c3/firmware.bin")
    parser.add_argument("--filesystem", default=".pio/build/seeed_xiao_esp32c3/littlefs.bin")
    parser.add_argument("--output", default=".pio/build/seeed_xiao_esp32c3/update.tslpkg")
    args = parser.parse_args()

    firmware_path = Path(args.firmware)
    filesystem_path = Path(args.filesystem)
    output_path = Path(args.output)

    firmware = firmware_path.read_bytes()
    filesystem = filesystem_path.read_bytes()
    output_path.parent.mkdir(parents=True, exist_ok=True)

    header = MAGIC + struct.pack("<III", HEADER_SIZE, len(filesystem), len(firmware)) + bytes(12)
    output_path.write_bytes(header + filesystem + firmware)

    print(f"Created {output_path}")
    print(f"  filesystem: {filesystem_path} ({len(filesystem)} bytes)")
    print(f"  firmware:   {firmware_path} ({len(firmware)} bytes)")
    print(f"  total:      {output_path.stat().st_size} bytes")


if __name__ == "__main__":
    main()