#!/usr/bin/env python

"""Test the running system for features availability. Exit with zero

if all features are there, non-zero otherwise. If a feature name is

prefixed with "no-", the absence of feature is tested.

"""

import optparse

import os

import re

import sys

import tempfile

tempprefix = 'hg-hghave-'

def matchoutput(cmd, regexp):

    """Return True if cmd executes successfully and its output

    is matched by the supplied regular expression.

    """

    r = re.compile(regexp)

    fh = os.popen(cmd)

    s = fh.read()

    ret = fh.close()

    return ret is None and r.search(s)

def has_symlink():

    return hasattr(os, "symlink")

def has_fifo():

    return hasattr(os, "mkfifo")

def has_executablebit():

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

    os.close(fd)

    try:

        s = os.lstat(path).st_mode

        os.chmod(path, s | 0100)

        return (os.lstat(path).st_mode & 0100 != 0)

    finally:

        os.remove(path)

def has_eol_in_paths():

    try:

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

        os.close(fd)

        os.remove(path)

        return True

    except:

        return False

def has_hotshot():

    try:

        # hotshot.stats tests hotshot and many problematic dependencies

        # like profile.

        import hotshot.stats

        return True

    except ImportError:

        return False

def has_lsprof():

    try:

        import _lsprof

        return True

    except ImportError:

        return False

def has_git():

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

checks = {

    "eol-in-paths": (has_eol_in_paths, "end-of-lines in paths"),

    "execbit": (has_executablebit, "executable bit"),

    "git": (has_git, "git command line client"),

    "fifo": (has_fifo, "named pipes"),

    "hotshot": (has_hotshot, "python hotshot module"),

    "lsprof": (has_lsprof, "python lsprof module"),

    "symlink": (has_symlink, "symbolic links"),

}

def list_features():

    for name, feature in checks.iteritems():

        desc = feature[1]

        print name + ':', desc

parser = optparse.OptionParser("%prog [options] [features]")

parser.add_option("--list-features", action="store_true",

                  help="list available features")

parser.add_option("-q", "--quiet", action="store_true",

                  help="check features silently")

if __name__ == '__main__':

    options, args = parser.parse_args()

    if options.list_features:

        list_features()

        sys.exit(0)

    quiet = options.quiet

    failures = 0

    def error(msg):

        global failures

        if not quiet:

            sys.stderr.write(msg + '\n')

        failures += 1

    for feature in args:

        negate = feature.startswith('no-')

        if negate:

            feature = feature[3:]

        if feature not in checks:

            error('hghave: unknown feature: ' + feature)

            continue

        check, desc = checks[feature]

        if not negate and not check():

            error('hghave: missing feature: ' + desc)

        elif negate and check():

            error('hghave: system supports %s' % desc)

    if failures != 0:

        sys.exit(1)