# (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

import sys
import os
import shlex
import re
import codecs
import jinja2
import yaml
import optparse
import operator
from ansible import errors
from ansible import color
from ansible import __version__
import ansible.constants as C

try:
    import json
except ImportError:
    import simplejson as json

try:
    from hashlib import md5 as _md5
except ImportError:
    from md5 import md5 as _md5

###############################################################
# UTILITY FUNCTIONS FOR COMMAND LINE TOOLS
###############################################################

def err(msg):
    ''' print an error message to stderr '''

    print >> sys.stderr, msg

def exit(msg, rc=1):
    ''' quit with an error to stdout and a failure code '''

    err(msg)
    sys.exit(rc)

def jsonify(result, format=False):
    ''' format JSON output (uncompressed or uncompressed) '''

    result2 = result.copy()
    if format:
        return json.dumps(result2, sort_keys=True, indent=4)
    else:
        return json.dumps(result2, sort_keys=True)

def write_tree_file(tree, hostname, buf):
    ''' write something into treedir/hostname '''

    # TODO: might be nice to append playbook runs per host in a similar way
    # in which case, we'd want append mode.
    path = os.path.join(tree, hostname)
    fd = open(path, "w+")
    fd.write(buf)
    fd.close()

def is_failed(result):
    ''' is a given JSON result a failed result? '''

    return ((result.get('rc', 0) != 0) or (result.get('failed', False) in [ True, 'True', 'true']))

def prepare_writeable_dir(tree):
    ''' make sure a directory exists and is writeable '''

    if tree != '/':
        tree = os.path.realpath(os.path.expanduser(tree))
    if not os.path.exists(tree):
        try:
            os.makedirs(tree)
        except (IOError, OSError), e:
            exit("Could not make dir %s: %s" % (tree, e))
    if not os.access(tree, os.W_OK):
        exit("Cannot write to path %s" % tree)

def path_dwim(basedir, given):
    ''' make relative paths work like folks expect '''

    if given.startswith("/"):
        return given
    elif given.startswith("~/"):
        return os.path.expanduser(given)
    else:
        return os.path.join(basedir, given)

def json_loads(data):
    ''' parse a JSON string and return a data structure '''

    return json.loads(data)

def parse_json(data):
    ''' this version for module return data only '''

    try:
        return json.loads(data)
    except:
        # not JSON, but try "Baby JSON" which allows many of our modules to not
        # require JSON and makes writing modules in bash much simpler
        results = {}
        try:
            tokens = shlex.split(data)
        except:
            print "failed to parse json: "+ data
            raise

        for t in tokens:
            if t.find("=") == -1:
                raise errors.AnsibleError("failed to parse: %s" % data)
            (key,value) = t.split("=", 1)
            if key == 'changed' or 'failed':
                if value.lower() in [ 'true', '1' ]:
                    value = True
                elif value.lower() in [ 'false', '0' ]:
                    value = False
            if key == 'rc':
                value = int(value)
            results[key] = value
        if len(results.keys()) == 0:
            return { "failed" : True, "parsed" : False, "msg" : data }
        return results

_LISTRE = re.compile(r"(\w+)\[(\d+)\]")

def _varLookup(name, vars):
    ''' find the contents of a possibly complex variable in vars. '''

    path = name.split('.')
    space = vars
    for part in path:
        if part in space:
            space = space[part]
        elif "[" in part:
            m = _LISTRE.search(part)
            if not m:
                return
            try:
                space = space[m.group(1)][int(m.group(2))]
            except (KeyError, IndexError):
                return
        else:
            return
    return space

_KEYCRE = re.compile(r"\$(?P<complex>\{){0,1}((?(complex)[\w\.\[\]]+|\w+))(?(complex)\})")

def varLookup(varname, vars):
    ''' helper function used by varReplace '''

    m = _KEYCRE.search(varname)
    if not m:
        return None
    return _varLookup(m.group(2), vars)

def varReplace(raw, vars):
    ''' Perform variable replacement of $variables in string raw using vars dictionary '''
    # this code originally from yum

    done = [] # Completed chunks to return

    while raw:
        m = _KEYCRE.search(raw)
        if not m:
            done.append(raw)
            break

        # Determine replacement value (if unknown variable then preserve
        # original)
        varname = m.group(2)

        replacement = unicode(_varLookup(varname, vars) or m.group())

        start, end = m.span()
        done.append(raw[:start])    # Keep stuff leading up to token
        done.append(replacement)    # Append replacement value
        raw = raw[end:]             # Continue with remainder of string

    return ''.join(done)

def template(text, vars):
    ''' run a text buffer through the templating engine until it no longer changes '''

    prev_text = ''
    depth = 0
    while prev_text != text:
        depth = depth + 1
        if (depth > 20):
            raise errors.AnsibleError("template recursion depth exceeded")
        prev_text = text
        text = varReplace(unicode(text), vars)
    return text

def template_from_file(basedir, path, vars):
    ''' run a file through the templating engine '''

    environment = jinja2.Environment(loader=jinja2.FileSystemLoader(basedir), trim_blocks=False)
    data = codecs.open(path_dwim(basedir, path), encoding="utf8").read()
    t = environment.from_string(data)
    vars = vars.copy()
    res = t.render(vars)
    if data.endswith('\n') and not res.endswith('\n'):
        res = res + '\n'
    return template(res, vars)

def parse_yaml(data):
    ''' convert a yaml string to a data structure '''

    return yaml.load(data)

def parse_yaml_from_file(path):
    ''' convert a yaml file to a data structure '''

    try:
        data = file(path).read()
        return parse_yaml(data)
    except IOError:
        raise errors.AnsibleError("file not found: %s" % path)
    except yaml.YAMLError, exc:
        if hasattr(exc, 'problem_mark'):
            mark = exc.problem_mark
            if mark.line -1 >= 0:
                before_probline = data.split("\n")[mark.line-1]
            else:
                before_probline = ''
            probline = data.split("\n")[mark.line]
            arrow = " " * mark.column + "^"
            msg = """Syntax Error while loading YAML script, %s
Note: The error may actually appear before this position: line %s, column %s

%s
%s
%s""" % (path, mark.line + 1, mark.column + 1, before_probline, probline, arrow)
        else:
            # No problem markers means we have to throw a generic
            # "stuff messed up" type message. Sry bud.
            msg = "Could not parse YAML. Check over %s again." % path
        raise errors.AnsibleYAMLValidationFailed(msg)

def parse_kv(args):
    ''' convert a string of key/value items to a dict '''

    options = {}
    if args is not None:
        # attempting to split a unicode here does bad things
        vargs = shlex.split(str(args), posix=True)
        for x in vargs:
            if x.find("=") != -1:
                k, v = x.split("=",1)
                options[k]=v
    return options

def md5(filename):
    ''' Return MD5 hex digest of local file, or None if file is not present. '''

    if not os.path.exists(filename):
        return None
    digest = _md5()
    blocksize = 64 * 1024
    infile = open(filename, 'rb')
    block = infile.read(blocksize)
    while block:
        digest.update(block)
        block = infile.read(blocksize)
    infile.close()
    return digest.hexdigest()

def default(value, function):
    ''' syntactic sugar around lazy evaluation of defaults '''
    if value is None:
        return function()
    return value

####################################################################
# option handling code for /usr/bin/ansible and ansible-playbook
# below this line

class SortedOptParser(optparse.OptionParser):
    '''Optparser which sorts the options by opt before outputting --help'''

    def format_help(self, formatter=None):
        self.option_list.sort(key=operator.methodcaller('get_opt_string'))
        return optparse.OptionParser.format_help(self, formatter=None)

def base_parser(constants=C, usage="", output_opts=False, runas_opts=False, async_opts=False, connect_opts=False):
    ''' create an options parser for any ansible script '''

    parser = SortedOptParser(usage, version="%prog " + __version__)
    parser.add_option('-v','--verbose', default=False, action="store_true",
        help='verbose mode')
    parser.add_option('-f','--forks', dest='forks', default=constants.DEFAULT_FORKS, type='int',
        help="specify number of parallel processes to use (default=%s)" % constants.DEFAULT_FORKS)
    parser.add_option('-i', '--inventory-file', dest='inventory',
        help="specify inventory host file (default=%s)" % constants.DEFAULT_HOST_LIST,
        default=constants.DEFAULT_HOST_LIST)
    parser.add_option('-k', '--ask-pass', default=False, dest='ask_pass', action='store_true',
        help='ask for SSH password')
    parser.add_option('--private-key', default=None, dest='private_key_file',
        help='use this file to authenticate the connection')
    parser.add_option('-K', '--ask-sudo-pass', default=False, dest='ask_sudo_pass', action='store_true',
        help='ask for sudo password')
    parser.add_option('-M', '--module-path', dest='module_path',
        help="specify path(s) to module library (default=%s)" % constants.DEFAULT_MODULE_PATH,
        default=constants.DEFAULT_MODULE_PATH)
    parser.add_option('-T', '--timeout', default=constants.DEFAULT_TIMEOUT, type='int',
        dest='timeout',
        help="override the SSH timeout in seconds (default=%s)" % constants.DEFAULT_TIMEOUT)

    if output_opts:
        parser.add_option('-o', '--one-line', dest='one_line', action='store_true',
            help='condense output')
        parser.add_option('-t', '--tree', dest='tree', default=None,
            help='log output to this directory')

    if runas_opts:
        parser.add_option("-s", "--sudo", default=False, action="store_true",
            dest='sudo', help="run operations with sudo (nopasswd)")
        parser.add_option('-U', '--sudo-user', dest='sudo_user', help='desired sudo user (default=root)',
            default=None)   # Can't default to root because we need to detect when this option was given
        parser.add_option('-u', '--user', default=constants.DEFAULT_REMOTE_USER,
            dest='remote_user',
            help='connect as this user (default=%s)' % constants.DEFAULT_REMOTE_USER)

    if connect_opts:
        parser.add_option('-c', '--connection', dest='connection',
                          choices=C.DEFAULT_TRANSPORT_OPTS,
                          default=C.DEFAULT_TRANSPORT,
                          help="connection type to use (default=%s)" % C.DEFAULT_TRANSPORT)

    if async_opts:
        parser.add_option('-P', '--poll', default=constants.DEFAULT_POLL_INTERVAL, type='int',
            dest='poll_interval',
            help="set the poll interval if using -B (default=%s)" % constants.DEFAULT_POLL_INTERVAL)
        parser.add_option('-B', '--background', dest='seconds', type='int', default=0,
            help='run asynchronously, failing after X seconds (default=N/A)')

    return parser