import subprocess
import sys
from unittest import mock

import pytest

import pre_commit.constants as C
from pre_commit import git
from pre_commit.commands import hook_impl
from pre_commit.envcontext import envcontext
from pre_commit.util import cmd_output
from pre_commit.util import make_executable
from testing.fixtures import git_dir
from testing.fixtures import sample_local_config
from testing.fixtures import write_config
from testing.util import cwd
from testing.util import git_commit


def test_validate_config_file_exists(tmpdir):
    cfg = tmpdir.join(C.CONFIG_FILE).ensure()
    hook_impl._validate_config(0, cfg, True)


def test_validate_config_missing(capsys):
    with pytest.raises(SystemExit) as excinfo:
        hook_impl._validate_config(123, 'DNE.yaml', False)
    ret, = excinfo.value.args
    assert ret == 1
    assert capsys.readouterr().out == (
        'No DNE.yaml file was found\n'
        '- To temporarily silence this, run '
        '`PRE_COMMIT_ALLOW_NO_CONFIG=1 git ...`\n'
        '- To permanently silence this, install pre-commit with the '
        '--allow-missing-config option\n'
        '- To uninstall pre-commit run `pre-commit uninstall`\n'
    )


def test_validate_config_skip_missing_config(capsys):
    with pytest.raises(SystemExit) as excinfo:
        hook_impl._validate_config(123, 'DNE.yaml', True)
    ret, = excinfo.value.args
    assert ret == 123
    expected = '`DNE.yaml` config file not found. Skipping `pre-commit`.\n'
    assert capsys.readouterr().out == expected


def test_validate_config_skip_via_env_variable(capsys):
    with pytest.raises(SystemExit) as excinfo:
        with envcontext((('PRE_COMMIT_ALLOW_NO_CONFIG', '1'),)):
            hook_impl._validate_config(0, 'DNE.yaml', False)
    ret, = excinfo.value.args
    assert ret == 0
    expected = '`DNE.yaml` config file not found. Skipping `pre-commit`.\n'
    assert capsys.readouterr().out == expected


def test_run_legacy_does_not_exist(tmpdir):
    retv, stdin = hook_impl._run_legacy('pre-commit', tmpdir, ())
    assert (retv, stdin) == (0, b'')


def test_run_legacy_executes_legacy_script(tmpdir, capfd):
    hook = tmpdir.join('pre-commit.legacy')
    hook.write('#!/usr/bin/env bash\necho hi "$@"\nexit 1\n')
    make_executable(hook)
    retv, stdin = hook_impl._run_legacy('pre-commit', tmpdir, ('arg1', 'arg2'))
    assert capfd.readouterr().out.strip() == 'hi arg1 arg2'
    assert (retv, stdin) == (1, b'')


def test_run_legacy_pre_push_returns_stdin(tmpdir):
    with mock.patch.object(sys.stdin.buffer, 'read', return_value=b'stdin'):
        retv, stdin = hook_impl._run_legacy('pre-push', tmpdir, ())
    assert (retv, stdin) == (0, b'stdin')


def test_run_legacy_recursive(tmpdir):
    hook = tmpdir.join('pre-commit.legacy').ensure()
    make_executable(hook)

    # simulate a call being recursive
    def call(*_, **__):
        return hook_impl._run_legacy('pre-commit', tmpdir, ())

    with mock.patch.object(subprocess, 'run', call):
        with pytest.raises(SystemExit):
            call()


@pytest.mark.parametrize(
    ('hook_type', 'args'),
    (
        ('pre-commit', []),
        ('pre-merge-commit', []),
        ('pre-push', ['branch_name', 'remote_name']),
        ('commit-msg', ['.git/COMMIT_EDITMSG']),
        ('post-commit', []),
        ('post-checkout', ['old_head', 'new_head', '1']),
        # multiple choices for commit-editmsg
        ('prepare-commit-msg', ['.git/COMMIT_EDITMSG']),
        ('prepare-commit-msg', ['.git/COMMIT_EDITMSG', 'message']),
        ('prepare-commit-msg', ['.git/COMMIT_EDITMSG', 'commit', 'deadbeef']),
    ),
)
def test_check_args_length_ok(hook_type, args):
    hook_impl._check_args_length(hook_type, args)


def test_check_args_length_error_too_many_plural():
    with pytest.raises(SystemExit) as excinfo:
        hook_impl._check_args_length('pre-commit', ['run', '--all-files'])
    msg, = excinfo.value.args
    assert msg == (
        'hook-impl for pre-commit expected 0 arguments but got 2: '
        "['run', '--all-files']"
    )


def test_check_args_length_error_too_many_singular():
    with pytest.raises(SystemExit) as excinfo:
        hook_impl._check_args_length('commit-msg', [])
    msg, = excinfo.value.args
    assert msg == 'hook-impl for commit-msg expected 1 argument but got 0: []'


def test_check_args_length_prepare_commit_msg_error():
    with pytest.raises(SystemExit) as excinfo:
        hook_impl._check_args_length('prepare-commit-msg', [])
    msg, = excinfo.value.args
    assert msg == (
        'hook-impl for prepare-commit-msg expected 1, 2, or 3 arguments '
        'but got 0: []'
    )


def test_run_ns_pre_commit():
    ns = hook_impl._run_ns('pre-commit', True, (), b'')
    assert ns is not None
    assert ns.hook_stage == 'commit'
    assert ns.color is True


def test_run_ns_commit_msg():
    ns = hook_impl._run_ns('commit-msg', False, ('.git/COMMIT_MSG',), b'')
    assert ns is not None
    assert ns.hook_stage == 'commit-msg'
    assert ns.color is False
    assert ns.commit_msg_filename == '.git/COMMIT_MSG'


def test_run_ns_post_commit():
    ns = hook_impl._run_ns('post-commit', True, (), b'')
    assert ns is not None
    assert ns.hook_stage == 'post-commit'
    assert ns.color is True


def test_run_ns_post_checkout():
    ns = hook_impl._run_ns('post-checkout', True, ('a', 'b', 'c'), b'')
    assert ns is not None
    assert ns.hook_stage == 'post-checkout'
    assert ns.color is True
    assert ns.from_ref == 'a'
    assert ns.to_ref == 'b'
    assert ns.checkout_type == 'c'


@pytest.fixture
def push_example(tempdir_factory):
    src = git_dir(tempdir_factory)
    git_commit(cwd=src)
    src_head = git.head_rev(src)

    clone = tempdir_factory.get()
    cmd_output('git', 'clone', src, clone)
    git_commit(cwd=clone)
    clone_head = git.head_rev(clone)
    return (src, src_head, clone, clone_head)


def test_run_ns_pre_push_updating_branch(push_example):
    src, src_head, clone, clone_head = push_example

    with cwd(clone):
        args = ('origin', src)
        stdin = f'HEAD {clone_head} refs/heads/b {src_head}\n'.encode()
        ns = hook_impl._run_ns('pre-push', False, args, stdin)

    assert ns is not None
    assert ns.hook_stage == 'push'
    assert ns.color is False
    assert ns.remote_name == 'origin'
    assert ns.remote_url == src
    assert ns.from_ref == src_head
    assert ns.to_ref == clone_head
    assert ns.all_files is False


def test_run_ns_pre_push_new_branch(push_example):
    src, src_head, clone, clone_head = push_example

    with cwd(clone):
        args = ('origin', src)
        stdin = f'HEAD {clone_head} refs/heads/b {hook_impl.Z40}\n'.encode()
        ns = hook_impl._run_ns('pre-push', False, args, stdin)

    assert ns is not None
    assert ns.from_ref == src_head
    assert ns.to_ref == clone_head


def test_run_ns_pre_push_new_branch_existing_rev(push_example):
    src, src_head, clone, _ = push_example

    with cwd(clone):
        args = ('origin', src)
        stdin = f'HEAD {src_head} refs/heads/b2 {hook_impl.Z40}\n'.encode()
        ns = hook_impl._run_ns('pre-push', False, args, stdin)

    assert ns is None


def test_pushing_orphan_branch(push_example):
    src, src_head, clone, _ = push_example

    cmd_output('git', 'checkout', '--orphan', 'b2', cwd=clone)
    git_commit(cwd=clone, msg='something else to get unique hash')
    clone_rev = git.head_rev(clone)

    with cwd(clone):
        args = ('origin', src)
        stdin = f'HEAD {clone_rev} refs/heads/b2 {hook_impl.Z40}\n'.encode()
        ns = hook_impl._run_ns('pre-push', False, args, stdin)

    assert ns is not None
    assert ns.all_files is True


def test_run_ns_pre_push_deleting_branch(push_example):
    src, src_head, clone, _ = push_example

    with cwd(clone):
        args = ('origin', src)
        stdin = f'(delete) {hook_impl.Z40} refs/heads/b {src_head}'.encode()
        ns = hook_impl._run_ns('pre-push', False, args, stdin)

    assert ns is None


def test_hook_impl_main_noop_pre_push(cap_out, store, push_example):
    src, src_head, clone, _ = push_example

    stdin = f'(delete) {hook_impl.Z40} refs/heads/b {src_head}'.encode()
    with mock.patch.object(sys.stdin.buffer, 'read', return_value=stdin):
        with cwd(clone):
            write_config('.', sample_local_config())
            ret = hook_impl.hook_impl(
                store,
                config=C.CONFIG_FILE,
                color=False,
                hook_type='pre-push',
                hook_dir='.git/hooks',
                skip_on_missing_config=False,
                args=('origin', src),
            )
    assert ret == 0
    assert cap_out.get() == ''


def test_hook_impl_main_runs_hooks(cap_out, tempdir_factory, store):
    with cwd(git_dir(tempdir_factory)):
        write_config('.', sample_local_config())
        ret = hook_impl.hook_impl(
            store,
            config=C.CONFIG_FILE,
            color=False,
            hook_type='pre-commit',
            hook_dir='.git/hooks',
            skip_on_missing_config=False,
            args=(),
        )
    assert ret == 0
    expected = '''\
Block if "DO NOT COMMIT" is found....................(no files to check)Skipped
'''
    assert cap_out.get() == expected
