"""
Test lldb 'commands regex' command which allows the user to create a regular expression command.
"""

from __future__ import print_function


import os
import lldb
from lldbsuite.test.decorators import *
from lldbsuite.test.lldbtest import *
from lldbsuite.test import lldbutil


class CommandRegexTestCase(TestBase):

    mydir = TestBase.compute_mydir(__file__)

    @expectedFailureAll(
        hostoslist=["windows"],
        bugnumber="llvm.org/pr22274: need a pexpect replacement for windows")
    @no_debug_info_test
    def test_command_regex(self):
        """Test a simple scenario of 'command regex' invocation and subsequent use."""
        import pexpect
        prompt = "(lldb) "
        regex_prompt = "Enter one of more sed substitution commands in the form: 's/<regex>/<subst>/'.\r\nTerminate the substitution list with an empty line.\r\n"
        regex_prompt1 = "\r\n"

        child = pexpect.spawn('%s %s' %
                              (lldbtest_config.lldbExec, self.lldbOption))
        # Turn on logging for what the child sends back.
        if self.TraceOn():
            child.logfile_read = sys.stdout
        # So that the spawned lldb session gets shutdown durng teardown.
        self.child = child

        # Substitute 'Help!' for 'help' using the 'commands regex' mechanism.
        child.expect_exact(prompt)
        child.sendline("command regex 'Help__'")
        child.expect_exact(regex_prompt)
        child.sendline('s/^$/help/')
        child.expect_exact(regex_prompt1)
        child.sendline('')
        child.expect_exact(prompt)
        # Help!
        child.sendline('Help__')
        # If we see the familiar 'help' output, the test is done.
        child.expect('Debugger commands:')
        # Try and incorrectly remove "Help__" using "command unalias" and
        # verify we fail
        child.sendline('command unalias Help__')
        child.expect_exact(
            "error: 'Help__' is not an alias, it is a debugger command which can be removed using the 'command delete' command")
        child.expect_exact(prompt)

        # Delete the regex command using "command delete"
        child.sendline('command delete Help__')
        child.expect_exact(prompt)
        # Verify the command was removed
        child.sendline('Help__')
        child.expect_exact("error: 'Help__' is not a valid command")
        child.expect_exact(prompt)