import os
import sys
import pyvisa


address  = None
dev_list = []
devstr   = ""
inst     = None

rm = pyvisa.ResourceManager()

def terminate():
    print("")
    exit()

def help():
    print("")
    print(f"  Usage: python {sys.argv[0]}")
    print("  Command:")
    print("    list     : show device list")
    print("    addr 18  : set GPIB address to 18")
    print("    >string  : write 'string' to the GPIB address")
    print("    <string  : read response from the GPIB address")
    print("    ?string  : write string and read response from GPIB address")
    print("    string?  :  write string and read response from GPIB address")
    print("    timeout t: set timeout to t [ms]")
    print("    delay t  : set delay to t [s]")
    print("    exit|quit|bye: exit this program")
    print("    d2mate|qiita|scpi|pyvisa|2450: show web pages")
    print("    help: show this help")
    print("")

def pint(s, defval = None):
    try:
        return int(s)
    except:
        return defval


def other_command(str):
    if str == "help":
        help()
    elif str in ["exit", "quit", "bye"]:
        terminate()
    elif str == 'd2mate':
        url1 = "http://conf.msl.titech.ac.jp/D2MatE/D2MatE_programs.html"
        os.system(f"start {url1}")
    elif str == 'scpi':
        url1 = "https://rfmw.em.keysight.com/spdhelpfiles/33500/webhelp/jp/content/__I_SCPI/00%20scpi_introduction.htm"
        url2 = "https://rfmw.em.keysight.com/bihelpfiles/aps/webhelp-mobile/JP/Advanced/Content/__H_SCPI%20Programming%20Reference/20%20-%20Command_Quick_Reference.htm"
        os.system(f"start {url1}")
        os.system(f"start {url2}")
    elif str == 'qiita':
        url1 = 'https://qiita.com/go_yu_/items/2c03b7c2570628059b18'
        url2 = 'https://qiita.com/YujiMatsu/items/8e0437b33555647b0fc4'
        os.system(f"start {url1}")
        os.system(f"start {url2}")
    elif str == 'pyvisa':
        url1 = 'https://pyvisa.readthedocs.io/en/latest/'
        url2 = 'https://www.texio.co.jp/uploads/WebExpo/Study/Study_0001/Python_VISA.pdf'
        url3 = 'https://rightcode.co.jp/blog/information-technology/python-oscilloscope-remote-control-screen-capture'
        os.system(f"start {url1}")
        os.system(f"start {url2}")
        os.system(f"start {url3}")
    elif str == '2450':
        url1 = 'https://download.tek.com/manual/2450-900-02E_Aug_2019_User.pdf'
        os.system(f"start {url1}")
    else:
        return False

    return True

def list_device(is_print = True):
    global dev_list

    dev_list = rm.list_resources()

    if is_print:
        print("  Device list:", dev_list)
    return dev_list

def get_devstr(addr):
    global dev_list

    dev_list = list_device(is_print = False)
#    print("dev_list=", dev_list)
    for s in dev_list:
        aa = s.split('::')
#        print("s=", s, aa)
        if len(aa) < 2:
            continue
        
        if pint(aa[1]) == addr:
            return s

    return None

def close_device():
    global inst
    
    if inst:
        inst.close()
        inst = None
        return True
    
    return False

def open_device(devname):
    global devstr, address, inst 

    close_device()

    inst = rm.open_resource(devname)
    if inst:
        print(f"  found device [{devname}]. assigned to current instrument handle")
        devstr = devname
        aa = devname.strip().split('::')
        address = pint(aa[1])
    else:
        print(f"  Error: Can not open device [{devname}]")

    return inst

def main():
    global rm, dev_list, devstr, address, inst

    dev_list = list_device()
    if len(dev_list) > 0:
        inst = open_device(dev_list[0])

    while 1:
        print("# ", end = '')

        instr = input().strip()
        str   = instr.lower()
        aa    = str.split(' ', 1)
        cmd = aa[0]
        if len(aa) >= 2:
            argline = aa[1]
        else:
            argline = ''
#        print("cmd=", cmd, argline)

        if str == "":
            continue
        elif str == 'list':
            list_device()
        elif str[:4] == 'addr':
            if argline == '':
                print("  Error: addr command takes one integer as GPIB address")
                continue

            v = pint(argline)
            if v is None:
                print("  Error: Invalid address [{argline}]")
                continue

            address = v
            print(f"  set GPIB address to {address}")
            devstr = get_devstr(address)
            if devstr is None:
                print(f"  Error: GPIB address [{address}] is not connected")
                list_device()
            else:
                inst = open_device(devstr)
        elif str[:8] == 'timeout':
            if largline == '':
                print(f"  Error: timeout is not given. specify by ms")
                continue
            v = pint(argline)
            if v is None:
                print(f"  Error: Invalid timeout [{argline}]. specify by ms")
                continue

            inst.timeout = v
        elif str[:5] == 'delay':
            if argline == '':
                print(f"  Error: delay is not given. specify by seconds")
                continue
            v = pint(argline)
            if v is None:
                print(f"  Error: Invalid delay [{argline}]. specify by seconds")
                continue

            inst.delay = v
        elif str[0] == '>':
            query =instr[1:].strip()

            if inst is None:
                print(f"  Error: Instrument is not specified. Use addr command")
                continue

            print(f"  write [{query}] to {devstr}")
            try:
                inst.write(query)
            except:
                print(f"  Error: Illeagal query [{query}]")
        elif str[0] == '<':
            if inst is None:
                print(f"  Error: Instrument is not specified. Use addr command")
                continue

            print(f"  reading from {devstr}")
            try:
                ret = inst.read()
                print(f"  Return: [{ret.strip()}]")
            except:
                print(f"  Error: read timeout")
        elif str[0] == '?' or cmd[-1] == '?':
            if str[0] == '?':
                query = instr[1:].strip()
            else:
                query = instr.strip()

            if inst is None:
                print(f"  Error: Instrument is not specified. Use addr command")
                continue

            print(f"  write [{query}] to {devstr} and waiting query")
            try:
                ret = inst.query(query)
                print(f"  Return: [{ret.strip()}]")
            except:
                print(f"  Error: Illeagal query [{query}]")
        else:
            ret = other_command(instr)
            if not ret:
                print(f"  Warning: Ivvalid command [{instr}]")

    close_device()


if __name__ == "__main__":
    main()