from __future__ import absolute_import

import errno

import os

import re

import socket

import stat

import subprocess

import sys

import tempfile

tempprefix = 'hg-hghave-'

checks = {

    "true": (lambda: True, "yak shaving"),

    "false": (lambda: False, "nail clipper"),

}

def check(name, desc):

    def decorator(func):

        checks[name] = (func, desc)

        return func

    return decorator

def checkfeatures(features):

    result = {

        'error': [],

        'missing': [],

        'skipped': [],

    }

    for feature in features:

        negate = feature.startswith('no-')

        if negate:

            feature = feature[3:]

        if feature not in checks:

            result['missing'].append(feature)

            continue

        check, desc = checks[feature]

        try:

            available = check()

        except Exception:

            result['error'].append('hghave check failed: %s' % feature)

            continue

        if not negate and not available:

            result['skipped'].append('missing feature: %s' % desc)

        elif negate and available:

            result['skipped'].append('system supports %s' % desc)

    return result

def require(features):

    """Require that features are available, exiting if not."""

    result = checkfeatures(features)

    for missing in result['missing']:

        sys.stderr.write('skipped: unknown feature: %s\n' % missing)

    for msg in result['skipped']:

        sys.stderr.write('skipped: %s\n' % msg)

    for msg in result['error']:

        sys.stderr.write('%s\n' % msg)

    if result['missing']:

        sys.exit(2)

    if result['skipped'] or result['error']:

        sys.exit(1)

def matchoutput(cmd, regexp, ignorestatus=False):

    """Return the match object if cmd executes successfully and its output

    is matched by the supplied regular expression.

    """

    r = re.compile(regexp)

    try:

        p = subprocess.Popen(

            cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

    except OSError as e:

        if e.errno != errno.ENOENT:

            raise

        ret = -1

    ret = p.wait()

    s = p.stdout.read()

    return (ignorestatus or not ret) and r.search(s)

@check("baz", "GNU Arch baz client")

def has_baz():

    return matchoutput('baz --version 2>&1', r'baz Bazaar version')

@check("bzr", "Canonical's Bazaar client")

def has_bzr():

    try:

        import bzrlib

        return bzrlib.__doc__ is not None

    except ImportError:

        return False

@check("bzr114", "Canonical's Bazaar client >= 1.14")

def has_bzr114():

    try:

        import bzrlib

        return (bzrlib.__doc__ is not None

                and bzrlib.version_info[:2] >= (1, 14))

    except ImportError:

        return False

@check("cvs", "cvs client/server")

def has_cvs():

    re = r'Concurrent Versions System.*?server'

    return matchoutput('cvs --version 2>&1', re) and not has_msys()

@check("cvs112", "cvs client/server >= 1.12")

def has_cvs112():

    re = r'Concurrent Versions System \(CVS\) 1.12.*?server'

    return matchoutput('cvs --version 2>&1', re) and not has_msys()

@check("darcs", "darcs client")

def has_darcs():

    return matchoutput('darcs --version', r'2\.[2-9]', True)

@check("mtn", "monotone client (>= 1.0)")

def has_mtn():

    return matchoutput('mtn --version', r'monotone', True) and not matchoutput(

        'mtn --version', r'monotone 0\.', True)

@check("eol-in-paths", "end-of-lines in paths")

def has_eol_in_paths():

    try:

        fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix, suffix='\n\r')

        os.close(fd)

        os.remove(path)

        return True

    except (IOError, OSError):

        return False

@check("execbit", "executable bit")

def has_executablebit():

    try:

        EXECFLAGS = stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH

        fh, fn = tempfile.mkstemp(dir='.', prefix=tempprefix)

        try:

            os.close(fh)

            m = os.stat(fn).st_mode & 0o777

            new_file_has_exec = m & EXECFLAGS

            os.chmod(fn, m ^ EXECFLAGS)

            exec_flags_cannot_flip = ((os.stat(fn).st_mode & 0o777) == m)

        finally:

            os.unlink(fn)

    except (IOError, OSError):

        # we don't care, the user probably won't be able to commit anyway

        return False

    return not (new_file_has_exec or exec_flags_cannot_flip)

@check("icasefs", "case insensitive file system")

def has_icasefs():

    # Stolen from mercurial.util

    fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix)

    os.close(fd)

    try:

        s1 = os.stat(path)

        d, b = os.path.split(path)

        p2 = os.path.join(d, b.upper())

        if path == p2:

            p2 = os.path.join(d, b.lower())

        try:

            s2 = os.stat(p2)

            return s2 == s1

        except OSError:

            return False

    finally:

        os.remove(path)

@check("fifo", "named pipes")

def has_fifo():

    if getattr(os, "mkfifo", None) is None:

        return False

    name = tempfile.mktemp(dir='.', prefix=tempprefix)

    try:

        os.mkfifo(name)

        os.unlink(name)

        return True

    except OSError:

        return False

@check("killdaemons", 'killdaemons.py support')

def has_killdaemons():

    return True

@check("cacheable", "cacheable filesystem")

def has_cacheable_fs():

    from mercurial import util

    fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix)

    os.close(fd)

    try:

        return util.cachestat(path).cacheable()

    finally:

        os.remove(path)

@check("lsprof", "python lsprof module")

def has_lsprof():

    try:

        import _lsprof

        _lsprof.Profiler # silence unused import warning

        return True

    except ImportError:

        return False

@check("gettext", "GNU Gettext (msgfmt)")

def has_gettext():

    return matchoutput('msgfmt --version', 'GNU gettext-tools')

@check("git", "git command line client")

def has_git():

    return matchoutput('git --version 2>&1', r'^git version')

@check("docutils", "Docutils text processing library")

def has_docutils():

    try:

        from docutils.core import publish_cmdline

        publish_cmdline # silence unused import

        return True

    except ImportError:

        return False

def getsvnversion():

    m = matchoutput('svn --version --quiet 2>&1', r'^(\d+)\.(\d+)')

    if not m:

        return (0, 0)

    return (int(m.group(1)), int(m.group(2)))

@check("svn15", "subversion client and admin tools >= 1.5")

def has_svn15():

    return getsvnversion() >= (1, 5)

@check("svn13", "subversion client and admin tools >= 1.3")

def has_svn13():

    return getsvnversion() >= (1, 3)

@check("svn", "subversion client and admin tools")

def has_svn():

    return matchoutput('svn --version 2>&1', r'^svn, version') and \

        matchoutput('svnadmin --version 2>&1', r'^svnadmin, version')

@check("svn-bindings", "subversion python bindings")

def has_svn_bindings():

    try:

        import svn.core

        version = svn.core.SVN_VER_MAJOR, svn.core.SVN_VER_MINOR

        if version < (1, 4):

            return False

        return True

    except ImportError:

        return False

@check("p4", "Perforce server and client")

def has_p4():

    return (matchoutput('p4 -V', r'Rev\. P4/') and

            matchoutput('p4d -V', r'Rev\. P4D/'))

@check("symlink", "symbolic links")

def has_symlink():

    if getattr(os, "symlink", None) is None:

        return False

    name = tempfile.mktemp(dir='.', prefix=tempprefix)

    try:

        os.symlink(".", name)

        os.unlink(name)

        return True

    except (OSError, AttributeError):

        return False

@check("hardlink", "hardlinks")

def has_hardlink():

    from mercurial import util

    fh, fn = tempfile.mkstemp(dir='.', prefix=tempprefix)

    os.close(fh)

    name = tempfile.mktemp(dir='.', prefix=tempprefix)

    try:

        util.oslink(fn, name)

        os.unlink(name)

        return True

    except OSError:

        return False

    finally:

        os.unlink(fn)

@check("tla", "GNU Arch tla client")

def has_tla():

    return matchoutput('tla --version 2>&1', r'The GNU Arch Revision')

@check("gpg", "gpg client")

def has_gpg():

    return matchoutput('gpg --version 2>&1', r'GnuPG')

@check("unix-permissions", "unix-style permissions")

def has_unix_permissions():

    d = tempfile.mkdtemp(dir='.', prefix=tempprefix)

    try:

        fname = os.path.join(d, 'foo')

        for umask in (0o77, 0o07, 0o22):

            os.umask(umask)

            f = open(fname, 'w')

            f.close()

            mode = os.stat(fname).st_mode

            os.unlink(fname)

            if mode & 0o777 != ~umask & 0o666:

                return False

        return True

    finally:

        os.rmdir(d)

@check("unix-socket", "AF_UNIX socket family")

def has_unix_socket():

    return getattr(socket, 'AF_UNIX', None) is not None

@check("root", "root permissions")

def has_root():

    return getattr(os, 'geteuid', None) and os.geteuid() == 0

@check("pyflakes", "Pyflakes python linter")

def has_pyflakes():

    return matchoutput("sh -c \"echo 'import re' 2>&1 | pyflakes\"",

                       r"<stdin>:1: 're' imported but unused",

                       True)

@check("pygments", "Pygments source highlighting library")

def has_pygments():

    try:

        import pygments

        pygments.highlight # silence unused import warning

        return True

    except ImportError:

        return False

@check("outer-repo", "outer repo")

def has_outer_repo():

    # failing for other reasons than 'no repo' imply that there is a repo

    return not matchoutput('hg root 2>&1',

                           r'abort: no repository found', True)

def has_ssl():

    try:

        import ssl

        return True

    except ImportError:

        return False

@check("sslcontext", "python >= 2.7.9 ssl")

def has_sslcontext():

    try:

        import ssl

        ssl.SSLContext

        return True

    except (ImportError, AttributeError):

        return False

@check("defaultcacerts", "can verify SSL certs by system's CA certs store")

def has_defaultcacerts():

    from mercurial import sslutil

    return sslutil._defaultcacerts() != '!'

@check("windows", "Windows")

def has_windows():

    return os.name == 'nt'

@check("system-sh", "system() uses sh")

def has_system_sh():

    return os.name != 'nt'

@check("serve", "platform and python can manage 'hg serve -d'")

def has_serve():

    return os.name != 'nt' # gross approximation