import unittest
import os
import sys
import subprocess
import socket
import time

from testzcc import ZccBaseTestCase

# Store testdir for safe switch back to directory:
testdir = os.path.dirname(os.path.abspath(__file__))

def runQemu(kernel, machine='lm3s811evb'):
    """ Runs qemu on a given kernel file on some machine """
    args = ['qemu-system-arm', '-M', machine, '-m', '16M',
        '-nographic', '-kernel', kernel, '-monitor',
        'unix:qemucontrol.sock,server',
        '-serial', 'unix:qemuserial.sock,server']
    p = subprocess.Popen(args, stdout=subprocess.DEVNULL,
        stderr=subprocess.DEVNULL)

    # Give process some time to boot:
    time.sleep(0.5)

    # Connect to the control socket:
    qemu_control = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    qemu_control.connect('qemucontrol.sock')

    time.sleep(0.5)

    # Now connect to the serial output:
    qemu_serial = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    qemu_serial.connect('qemuserial.sock')

    time.sleep(0.5)

    qemu_serial.settimeout(0.2)

    # Receive all data:
    data = bytearray()
    for i in range(40):
        try:
            data += qemu_serial.recv(1)
        except socket.timeout as e:
            break
    data = data.decode('ascii')
    # print(data)

    # Send quit command:
    qemu_control.send("quit\n".encode('ascii'))
    p.wait(timeout=3)
    qemu_control.close()
    qemu_serial.close()

    # Check that output was correct:
    return data


class EmulationTestCase(ZccBaseTestCase):
    """ Tests the compiler driver """
    def setUp(self):
        if 'TESTEMU' not in os.environ:
            self.skipTest('Not running emulation tests')

    def testM3Bare(self):
        """ Build bare m3 binary and emulate it """
        recipe = os.path.join(testdir, 'm3_bare', 'recipe.yaml')
        self.buildRecipe(recipe)
        data = runQemu('m3_bare/bare.bin')
        self.assertEqual('Hello worle', data)

    def testA9Bare(self):
        """ Build vexpress cortex-A9 binary and emulate it """
        recipe = os.path.join(testdir, '..', 'examples', 'qemu_a9_hello', 'recipe.yaml')
        self.buildRecipe(recipe)
        data = runQemu('../examples/qemu_a9_hello/hello.bin', machine='vexpress-a9')
        self.assertEqual('Hello worle', data)

    def testKernelVexpressA9(self):
        """ Build vexpress cortex-A9 binary and emulate it """
        recipe = os.path.join(testdir, '..', 'kernel', 'arm.yaml')
        self.buildRecipe(recipe)
        data = runQemu('../kernel/kernel_arm.bin', machine='vexpress-a9')
        self.assertEqual('Welcome to lcfos!', data[:17])


if __name__ == '__main__':
    unittest.main()