import serial
import struct
import random
import threading
import time
import sys
from pathlib import Path
from datetime import datetime
import pyvisa
import vxi11

# Initial state
toggle_state = 0

#ser = serial.Serial(port='/dev/ttyACM0', baudrate=115200)

VISA_ADDRESS = "TCPIP::192.168.45.3::INSTR" 

rm = pyvisa.ResourceManager()

SPD = rm.open_resource(
    VISA_ADDRESS,
    write_termination='\n',
    read_termination='\n'
)

class DS1202ZE(vxi11.Instrument):
    def __init__(self, host, *args, **kwargs):
        super(DS1202ZE, self).__init__(host, *args, **kwargs)
    def get_identification(self):
        return self.ask("*IDN?")
    def get_vavg_channel1(self):
        return self.ask(":MEAS:ITEM? VAVG, CHAN1\n")
    def get_vavg_channel2(self):
        return self.ask(":MEAS:ITEM? VAVG, CHAN2\n")

class Tee(object):
    def __init__(self, filename):
        self.terminal = sys.stdout
        self.log = open(filename, "w") # Use "a" to append

    def write(self, message):
        self.terminal.write(message)
        self.log.write(message)

    def flush(self):
        # This flush method is needed for python 3 compatibility.
        self.terminal.flush()
        self.log.flush()

def pack_integers_to_bytes(*integers: int) -> bytes:
    # Setup Header (Sync bytes)
    sync_bytes = [0x41, 0x52]
    
    # Process Data
    # Mask each input to 8-bit to prevent packing errors
    data_bytes = [i & 0xFF for i in integers]

    # Get length
    data_length = [len(data_bytes) & 0xFF]
    
    # Calculate Checksum
    # Summing all data bytes, then applying bitwise NOT
    total_sum = sum(data_bytes)
    rx_checksum = ~total_sum
    
    rx_checksum_h = (rx_checksum >> 8) & 0xFF
    rx_checksum_l = rx_checksum & 0xFF
    checksum_bytes = [rx_checksum_h, rx_checksum_l]

    # Combine all components
    full_packet = sync_bytes + data_length + data_bytes + checksum_bytes
    
    # Dynamically create format string
    # '!' = Network order, 'B' = unsigned char
    # We need as many 'B's as there are elements in full_packet
    format_string = f"!{len(full_packet)}B"
    
    return struct.pack(format_string, *full_packet)

def set_voltage():
    global SPD

    voltage = random.randint(9, 30)
    voltage_f = float(voltage)
    
    SPD.write('CH1:VOLT ' + str(voltage_f))  # Send power supply source voltage

    print(f"[{time.strftime('%H:%M:%S')}] VOLTAGE SET TO: " + str(voltage) + "V")

    # Schedule the NEXT random trigger
    # random.uniform(60, 360) provides the random delay in seconds
    delay = random.uniform(60, 360)
    
    # Create and start a new timer thread
    timer = threading.Timer(delay, set_voltage)
    timer.start()

def trigger_serial_command():
    global toggle_state
    global ser
    global min_delay_input_f
    global max_delay_input_f

    toggle_state = 1 - toggle_state

    if toggle_state == 0:
        state = 0

        print(f"[{time.strftime('%H:%M:%S')}] SWITCH SET TO: OFF")

    else:
        state = 1
        
        print(f"[{time.strftime('%H:%M:%S')}] SWITCH SET TO: ON")
    
    # Serial logic
    print(f"[{time.strftime('%H:%M:%S')}] SENDING SERIAL COMMAND...")

    command = 115 # 0x73 's' ASCII

    data = (command, state)
    byte_data = pack_integers_to_bytes(*data)
    #ser.write(serial.to_bytes(byte_data)) 
    
    # Schedule the NEXT random trigger
    # random.uniform(0.1, 100.0) provides the random delay in seconds
    delay = random.uniform(min_delay_input_f, max_delay_input_f)
    print(f"[{time.strftime('%H:%M:%S')}] NEXT COMMAND IN {delay:.2f} SECONDS...")

    # Create and start a new timer thread
    timer = threading.Timer(delay, trigger_serial_command)
    timer.start()

# Run main
if __name__ == '__main__':
    now = datetime.now()

    # Format as string: YYYY-MM-DD HH:MM:SS
    timestamp_str = now.strftime("%Y_%m_%d_%H_%M_%S")
    build_path = "~/Python/Automotive-Power-Simulator-App/LOGS/" + timestamp_str + ".txt"
    log_file = Path(build_path).expanduser()
    sys.stdout = Tee(log_file)
    print(f"[{time.strftime('%H:%M:%S')}] LOGGING TO: " + str(log_file))

    SPD.write('CH1:VOLT ' + str(24.0))  # Send power supply source voltage
    SPD.write('CH1:CURR ' + str(1.5))   # Send power supply current limit

    # Enable power supply output source
    SPD.write('OUTP CH1,ON')    # Enable supply output

    # Get time constants
    print (f"[{time.strftime('%H:%M:%S')}] PLEASE ENTER A MINIMUM DELAY VALUE...")

    min_delay_input = input()
    min_delay_input_f = float(min_delay_input)

    print(f"[{time.strftime('%H:%M:%S')}] MINIMUM TIME DELAY: " + str(min_delay_input_f))

    # Get time constants
    print (f"[{time.strftime('%H:%M:%S')}] PLEASE ENTER A MAXIMUM DELAY VALUE...")

    max_delay_input = input()
    max_delay_input_f = float(max_delay_input)

    print(f"[{time.strftime('%H:%M:%S')}] MAXIMUM TIME DELAY: " + str(max_delay_input_f))
    
    # Start the very first trigger
    trigger_serial_command()
    set_voltage()

    try:        
        while (1):
            time.sleep(1)

    except KeyboardInterrupt:
        state = 0
        command = 115 # 0x73 's' ASCII
        
        data = (command, state)
        byte_data = pack_integers_to_bytes(*data)
        #ser.write(serial.to_bytes(byte_data)) 

        #ser.close()

        SPD.write('CH1:VOLT ' + str(0.0))  # Send power supply source voltage
        SPD.write('CH1:CURR ' + str(0.0))  # Send power supply current limit

        # Disable power supply output source
        SPD.write('OUTP CH1,OFF')
        SPD.close()