import pytest
from mock import Mock

from pip._internal.cli.status_codes import ERROR, SUCCESS
from pip._internal.commands import commands_dict, create_command
from pip._internal.exceptions import CommandError


def test_run_method_should_return_success_when_finds_command_name():
    """
    Test HelpCommand.run for existing command
    """
    options_mock = Mock()
    args = ('freeze',)
    help_cmd = create_command('help')
    status = help_cmd.run(options_mock, args)
    assert status == SUCCESS


def test_run_method_should_return_success_when_command_name_not_specified():
    """
    Test HelpCommand.run when there are no args
    """
    options_mock = Mock()
    args = ()
    help_cmd = create_command('help')
    status = help_cmd.run(options_mock, args)
    assert status == SUCCESS


def test_run_method_should_raise_command_error_when_command_does_not_exist():
    """
    Test HelpCommand.run for non-existing command
    """
    options_mock = Mock()
    args = ('mycommand',)
    help_cmd = create_command('help')

    with pytest.raises(CommandError):
        help_cmd.run(options_mock, args)


def test_help_command_should_exit_status_ok_when_command_exists(script):
    """
    Test `help` command for existing command
    """
    result = script.pip('help', 'freeze')
    assert result.returncode == SUCCESS


def test_help_command_should_exit_status_ok_when_no_cmd_is_specified(script):
    """
    Test `help` command for no command
    """
    result = script.pip('help')
    assert result.returncode == SUCCESS


def test_help_command_should_exit_status_error_when_cmd_does_not_exist(script):
    """
    Test `help` command for non-existing command
    """
    result = script.pip('help', 'mycommand', expect_error=True)
    assert result.returncode == ERROR


def test_help_commands_equally_functional(in_memory_pip):
    """
    Test if `pip help` and 'pip --help' behave the same way.
    """
    results = list(map(in_memory_pip.pip, ('help', '--help')))
    results.append(in_memory_pip.pip())

    out = map(lambda x: x.stdout, results)
    ret = map(lambda x: x.returncode, results)

    msg = '"pip --help" != "pip help" != "pip"'
    assert len(set(out)) == 1, 'output of: ' + msg
    assert sum(ret) == 0, 'exit codes of: ' + msg
    assert all(len(o) > 0 for o in out)

    for name in commands_dict:
        assert (
            in_memory_pip.pip('help', name).stdout ==
            in_memory_pip.pip(name, '--help').stdout != ""
        )