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import pytest
import tempfile
import socket
import pexpect
import os

from tests.common.custom_cluster_test_suite import CustomClusterTestSuite
from tests.common.impala_service import ImpaladService
from tests.common.test_vector import ImpalaTestVector
from tests.common.test_dimensions import create_client_protocol_dimension
from tests.shell.util import ImpalaShell, get_shell_cmd, get_impalad_port
# Follow tests/shell/test_shell_interactive.py naming.
from shell.impala_shell import ImpalaShell as ImpalaShellClass
from tests.verifiers.metric_verifier import MetricVerifier

NUM_QUERIES = 'impala-server.num-queries'

class TestShellInteractiveReconnect(CustomClusterTestSuite):
  """ Check if interactive shell is using the current DB after reconnecting """
  @classmethod
  def get_workload(cls):
    return 'functional-query'

  @pytest.mark.execute_serially
  def test_manual_reconnect(self):
    # Iterate over test vector within test function to avoid restarting cluster.
    for vector in\
        [ImpalaTestVector([value]) for value in create_client_protocol_dimension()]:
      p = ImpalaShell(vector)
      p.send_cmd("USE functional")
      # Connect without arguments works because the custom cluster will have the default
      # HS2 and Beeswax ports.
      p.send_cmd("CONNECT")
      p.send_cmd("SHOW TABLES")

      result = p.get_result()
      assert "alltypesaggmultifilesnopart" in result.stdout, result.stdout

  @pytest.mark.execute_serially
  def test_auto_reconnect(self):
    impalad = ImpaladService(socket.getfqdn())

    # Iterate over test vector within test function to avoid restarting cluster.
    for vector in\
        [ImpalaTestVector([value]) for value in create_client_protocol_dimension()]:
      p = ImpalaShell(vector)
      # ImpalaShell startup may issue query to get server info - get num queries after
      # starting shell.
      start_num_queries = impalad.get_metric_value(NUM_QUERIES)
      p.send_cmd("USE functional")

      # wait for the USE command to finish
      impalad.wait_for_metric_value(NUM_QUERIES, start_num_queries + 1)
      assert impalad.wait_for_num_in_flight_queries(0)

      self._start_impala_cluster([])

      p.send_cmd("SHOW TABLES")
      result = p.get_result()
      assert "alltypesaggmultifilesnopart" in result.stdout, result.stdout

  @pytest.mark.execute_serially
  def test_auto_reconnect_after_impalad_died(self):
    """Test reconnect after restarting the remote impalad without using connect;"""
    # Use pexpect instead of ImpalaShell() since after using get_result() in ImpalaShell()
    # to check Disconnect, send_cmd() will no longer have any effect so we can not check
    # reconnect.
    impalad = ImpaladService(socket.getfqdn())

    # Iterate over test vector within test function to avoid restarting cluster.
    for vector in\
        [ImpalaTestVector([value]) for value in create_client_protocol_dimension()]:
      cmd = get_shell_cmd(vector)
      proc = pexpect.spawn(cmd[0], cmd[1:])
      proc.expect("{0}] default>".format(get_impalad_port(vector)))
      # ImpalaShell startup may issue query to get server info - get num queries after
      # starting shell.
      start_num_queries = impalad.get_metric_value(NUM_QUERIES)
      proc.sendline("use tpch;")

      # wait for the USE command to finish
      impalad.wait_for_metric_value(NUM_QUERIES, start_num_queries + 1)
      assert impalad.wait_for_num_in_flight_queries(0)

      # Disconnect
      self.cluster.impalads[0].kill()
      proc.sendline("show tables;")
      # Search from [1:] since the square brackets "[]" are special characters in regex
      proc.expect(ImpalaShellClass.DISCONNECTED_PROMPT[1:])
      # Restarting Impalad
      self.cluster.impalads[0].start()
      # Check reconnect
      proc.sendline("show tables;")
      proc.expect("nation")
      proc.expect("{0}] tpch>".format(get_impalad_port(vector)))
      proc.sendeof()
      proc.wait()

      # Ensure no sessions or queries are left dangling.
      verifier = MetricVerifier(self.impalad_test_service)
      verifier.verify_metrics_are_zero()