#!/usr/bin/env python3

# TODO might be better to use PyEpics or Caproto or something

import os
import pathlib
import sys
import time

from queue import Queue, Empty
from subprocess import Popen, PIPE, run
from threading import Thread


os.environ['EPICS_BASE'] = '/usr/local/epics/base-7.0.7'
os.environ['EPICS_HOST_ARCH'] = 'linux-x86_64'
os.environ['PARENT_PATH'] = str(pathlib.Path(__file__).parent.resolve())


def queue_output(pipe, queue):
    while True:
        line = pipe.readline()

        if not line:
            break

        queue.put(line.decode('ascii').rstrip())
    pipe.close()

def get_piped_output(proc):
    stdqueue = Queue()
    stdthread = Thread(target=queue_output, args=(proc.stdout, stdqueue))
    stdthread.daemon = True
    stdthread.start()

    errqueue = Queue()
    errthread = Thread(target=queue_output, args=(proc.stderr, errqueue))
    errthread.daemon = True
    errthread.start()

    return stdqueue, errqueue

def getState(prefix, name):
    result = run(['caget', f'{prefix}:{name}:STATUS'], stdout=PIPE)
    state = result.stdout.decode('ascii').rstrip().split()[1] 
    print(f'Currently in state {state}')
    return state

def getCount(prefix, name, ch):
    result = run(['caget', f'{prefix}:{name}:M{ch}'], stdout=PIPE)
    count = int(result.stdout.decode('ascii').rstrip().split()[1])
    print(f'M{ch} == {count}')
    return count

def presetTime(prefix, name, time):
    print(f'Starting count for {time} seconds')
    run(['caput', f'{prefix}:{name}:PRESET-TIME', f'{time}'])

def presetCount(prefix, name, count):
    print(f'Starting count until channel 1 reaches {count}')
    run(['caput', f'{prefix}:{name}:PRESET-COUNT', f'{count}'])

def testCanCount(prefix, name):
    # Check in Idle State
    assert getState(prefix, name) == 'Idle', 'Not in valid state'
    
    # Start Time Based Count and Check that Status Changes
    assert getCount(prefix, name, 1) == 0, "Erroneous nonzero starting count value"
    presetTime(prefix, name, 5)
    time.sleep(1)
    assert getState(prefix, name) == 'Counting', 'Didn\'t start counting'
    time.sleep(5)
    assert getState(prefix, name) == 'Idle', 'Didn\'t finish counting'
    assert getCount(prefix, name, 1) > 0, 'No events were counted'

    # Start Monitor Based Count and Check that Status Changes
    presetAmount = 100
    presetCount(prefix, name, presetAmount)
    time.sleep(1)
    assert getState(prefix, name) == 'Counting', 'Didn\'t start counting'
    assert getCount(prefix, name, 1) < presetAmount
    while getState(prefix, name) != 'Idle':
        time.sleep(1)
    assert getCount(prefix, name, 1) == presetAmount, 'Counted events not equal to preset'
    assert getCount(prefix, name, 2) > 0

def test(prefix, name):

    # TODO pass prefix and name to script
    proc = Popen([f'{os.environ["PARENT_PATH"]}/st.cmd'], stdout=PIPE, stderr=PIPE, shell=False)

    try:
        stdqueue, errqueue = get_piped_output(proc)

        while True:
            line = stdqueue.get()
            print(line)

            if 'iocRun: All initialization complete' in line:
                break # IOC is now running

        testCanCount(prefix, name)

        print("Success")
        proc.kill()
        proc.wait()
        return True

    except Exception as e:
        print(f"Failure: {e}", file=sys.stderr)
        proc.kill()
        proc.wait()
        return False


if __name__ == '__main__':

    print("Starting Test")

    # Test V2
    if test('SQ:TEST', 'CB_TEST'):
        exit(0)
    else:
        exit(1)