import struct
from typing import Tuple
from . import tools


def read_unique_identifier(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=0)


def read_primary_variable(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=1)


def read_loop_current_and_percent(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=2)
 

def read_dynamic_variables_and_loop_current(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=3)


def write_polling_address(address: bytes, new_polling_address: int) -> bytes:
    assert 0 <= new_polling_address <= 63
    return tools.pack_command(address, command_id=6, data=new_polling_address.to_bytes(1, "big"))


def read_unique_identifier_associated_with_tag(tag: bytes, *, address: int = 0) -> bytes:
    return tools.pack_command(address, command_id=11, data=tag)


def read_message(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=12)


def read_tag_descriptor_date(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=13)


def read_primary_variable_information(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=14)


def read_output_information(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=15)


def read_final_assembly_number(address: bytes) -> bytes:
    return tools.pack_command(address, command_id=16)


def write_message(address: bytes, message: str) -> bytes:
    """Writes a 24-char message to the device (Command 17)."""
    # Per spec, message is 24 characters, packed into 18 bytes.
    packed_message = tools.pack_packed_ascii(message, expected_len=32)
    return tools.pack_command(address, command_id=17, data=packed_message)


def write_tag_descriptor_date(address: bytes, tag: str, descriptor: str, date: Tuple[int, int, int]):
    """Writes tag, descriptor, and date to the device (Command 18)."""
    # Per spec, tag is 6 chars, descriptor is 12 chars.
    packed_tag = tools.pack_packed_ascii(tag, 8)
    packed_descriptor = tools.pack_packed_ascii(descriptor, 16)
    data = packed_tag + packed_descriptor
    day, month, year = date
    data += day.to_bytes(1, "big")
    data += month.to_bytes(1, "big")
    data += year.to_bytes(1, "big")
    # print(len(data))
    return tools.pack_command(address, command_id=18, data=data)


def write_final_assembly_number(address: bytes, number: int):
    data = number.to_bytes(3, "big")
    return tools.pack_command(address, command_id=19, data=data)


def write_primary_variable_damping(address: bytes, damping_time: float) -> bytes:
    """修改主变量阻尼时间（单位s） command 34"""
    data = struct.pack(">f", damping_time)
    return tools.pack_command(address, command_id=34, data=data)


def write_primary_variable_range(address: bytes, units_code: int, upper_range: float, lower_range: float) -> bytes:
    """修改主变量量程范围 command 35"""
    data = units_code.to_bytes(1, "big")
    data += struct.pack(">ff", upper_range, lower_range)
    return tools.pack_command(address, command_id=35, data=data)


def calibrate_20ma(address: bytes) -> bytes:
    """20mA校准 command 36"""
    return tools.pack_command(address, command_id=36)


def calibrate_4ma(address: bytes) -> bytes:
    """4mA校准 command 37"""
    return tools.pack_command(address, command_id=37)


def set_fixed_current_output(address: bytes, enable: bool, current_value: float = 0.0) -> bytes:
    """设置固定电流输出/退出固定模式 command 40"""
    if enable:
        data = struct.pack(">f", current_value)
    else:
        data = struct.pack(">f", 0)
    return tools.pack_command(address, command_id=40, data=data)


def calibrate_zero_point(address: bytes) -> bytes:
    """零点校准 command 43"""
    return tools.pack_command(address, command_id=43)


def write_primary_variable_units(address: bytes, units_code: int) -> bytes:
    """修改主变量单位 command 44"""
    data = units_code.to_bytes(1, "big")
    return tools.pack_command(address, command_id=44, data=data)


def trim_loop_current_4ma(address: bytes, measured_current: float) -> bytes:
    """微调环路电流4mA command 45"""
    data = struct.pack(">f", measured_current)
    return tools.pack_command(address, command_id=45, data=data)


def trim_loop_current_20ma(address: bytes, measured_current: float) -> bytes:
    """微调环路电流20mA command 46"""
    data = struct.pack(">f", measured_current)
    return tools.pack_command(address, command_id=46, data=data)


def write_primary_variable_output_function(address: bytes, transfer_function_code: int) -> bytes:
    """修改主变量输出函数 command 47"""
    data = transfer_function_code.to_bytes(1, "big")
    return tools.pack_command(address, command_id=47, data=data)