"""PlatformIO upload hook for env:versapad_usb.

The board's actual bootloader (bootloader/, UF2/mass-storage) does not speak
SAM-BA, so upload_protocol=sam-ba (the board.json default, inherited from an
Arduino-Zero-style template) does not work here. This converts the built
.bin to .uf2 and copies it onto the VERSABOOT mass-storage volume instead --
Windows only for now, matching the rest of this project's dev environment.
"""
import ctypes
import os
import string
import sys

Import("env")

sys.path.insert(0, env.subst("$PROJECT_DIR"))
import uf2conv

VOLUME_LABEL = "VERSABOOT"
DRIVE_UNKNOWN = 0
DRIVE_NO_ROOT_DIR = 1


def find_versaboot_drive(label=VOLUME_LABEL):
    for letter in string.ascii_uppercase:
        root = f"{letter}:\\"
        drive_type = ctypes.windll.kernel32.GetDriveTypeW(root)
        if drive_type in (DRIVE_UNKNOWN, DRIVE_NO_ROOT_DIR):
            continue
        vol_name_buf = ctypes.create_unicode_buffer(261)
        fs_name_buf = ctypes.create_unicode_buffer(261)
        ok = ctypes.windll.kernel32.GetVolumeInformationW(
            ctypes.c_wchar_p(root),
            vol_name_buf,
            ctypes.sizeof(vol_name_buf),
            None,
            None,
            None,
            fs_name_buf,
            ctypes.sizeof(fs_name_buf),
        )
        if ok and vol_name_buf.value == label:
            return root
    return None


def upload_via_uf2(source, target, env):
    build_dir = env.subst("$BUILD_DIR")
    bin_path = os.path.join(build_dir, "firmware.bin")
    uf2_path = os.path.join(build_dir, "firmware.uf2")

    if not os.path.isfile(bin_path):
        print(f"error: {bin_path} not found (expected as a normal build product)")
        env.Exit(1)

    num_blocks = uf2conv.convert(bin_path, uf2_path, base_addr=0x2000, family_id=uf2conv.SAMD21_FAMILY_ID)
    print(f"Wrote {uf2_path}: {num_blocks} blocks")

    drive = find_versaboot_drive()
    if drive is None:
        print(f"error: no drive labeled '{VOLUME_LABEL}' found.")
        print("Hold the bottom-right Cherry MX key while plugging in USB to enter the bootloader.")
        env.Exit(1)

    dest = os.path.join(drive, "firmware.uf2")
    print(f"Copying {uf2_path} -> {dest}")
    with open(uf2_path, "rb") as src, open(dest, "wb") as dst:
        dst.write(src.read())
    print("Upload triggers a reset into the app on the device side; no further action needed.")


env.Replace(UPLOADCMD=upload_via_uf2)