from __future__ import annotations

from h8536.bench_connect_lcd import format_frame, frame_checksum, frame_checksum_ok, parse_frame


FRAME_LENGTH = 6

HEARTBEAT_FRAME = bytes.fromhex("0000000080DA")

# Command 0, selector 0, value 0x8080. This seeds E000/E800 selector zero.
ACTIVE_SEED_COMMAND0 = bytes.fromhex("00000080805A")

# The older bench cadence sequence. It is still useful as an optional wake-up
# strategy because the real panel proved timing-sensitive around these frames.
CONNECT_CADENCE_SEQUENCE = (
    bytes.fromhex("04000040001E"),
    bytes.fromhex("0400008000DE"),
    bytes.fromhex("040000C0009E"),
)

# Command 5, selector 0x0040, value ignored. ROM trace shows this is the safest
# neutral report-consume candidate.
NEUTRAL_ACK_FRAME = bytes.fromhex("05004000001F")


def build_frame(command: int, selector: int, value: int) -> bytes:
    """Build a six-byte host frame for simple page-0/page-1 selectors.

    This helper covers the selector encodings we currently use in fake-CCU
    probes. Keep more exotic mapping in one place when we learn it.
    """

    if not 0 <= command <= 0xFF:
        raise ValueError("command byte out of range")
    if not 0 <= selector <= 0x01FF:
        raise ValueError("selector out of supported range 0x000-0x1FF")
    if not 0 <= value <= 0xFFFF:
        raise ValueError("value out of range")

    if selector <= 0x007F:
        byte1 = 0x00
        byte2 = selector
    elif selector <= 0x017F:
        byte1 = 0x01
        byte2 = selector - 0x0080
    else:
        byte1 = 0x02
        byte2 = selector - 0x0180

    frame = bytes(
        [
            command & 0xFF,
            byte1 & 0xFF,
            byte2 & 0xFF,
            (value >> 8) & 0xFF,
            value & 0xFF,
        ]
    )
    return frame + bytes([frame_checksum(frame)])