# (c) 2012-2014, 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 os
import pwd
import random
import traceback
import tempfile
import base64

import ansible.constants as C
from ansible import utils
from ansible import errors
from ansible import module_common
from ansible.runner.return_data import ReturnData

class ActionModule(object):

    def __init__(self, runner):
        self.runner = runner

    def run(self, conn, tmp, module_name, module_args, inject, complex_args=None, **kwargs):
        ''' handler for fetch operations '''

        if self.runner.noop_on_check(inject):
            return ReturnData(conn=conn, comm_ok=True, result=dict(skipped=True, msg='check mode not (yet) supported for this module'))

        # load up options
        options = {}
        if complex_args:
            options.update(complex_args)
        options.update(utils.parse_kv(module_args))
        source = options.get('src', None)
        dest = options.get('dest', None)
        flat = options.get('flat', False)
        flat = utils.boolean(flat)
        fail_on_missing = options.get('fail_on_missing', False)
        fail_on_missing = utils.boolean(fail_on_missing)
        validate_md5 = options.get('validate_md5', True)
        validate_md5 = utils.boolean(validate_md5)
        if source is None or dest is None:
            results = dict(failed=True, msg="src and dest are required")
            return ReturnData(conn=conn, result=results)

        source = conn.shell.join_path(source)

        # calculate md5 sum for the remote file
        remote_md5 = self.runner._remote_md5(conn, tmp, source)

        # use slurp if sudo and permissions are lacking
        remote_data = None
        if remote_md5 in ('1', '2') or self.runner.sudo:
            slurpres = self.runner._execute_module(conn, tmp, 'slurp', 'src=%s' % source, inject=inject)
            if slurpres.is_successful():
                if slurpres.result['encoding'] == 'base64':
                    remote_data = base64.b64decode(slurpres.result['content'])
                if remote_data is not None:
                    remote_md5 = utils.md5s(remote_data)
                # the source path may have been expanded on the
                # target system, so we compare it here and use the
                # expanded version if it's different
                remote_source = slurpres.result.get('source')
                if remote_source and remote_source != source:
                    source = remote_source

        # calculate the destination name
        if os.path.sep not in conn.shell.join_path('a', ''):
            source_local = source.replace('\\', '/')
        else:
            source_local = source

        dest = os.path.expanduser(dest)
        if flat:
            if dest.endswith("/"):
                # if the path ends with "/", we'll use the source filename as the
                # destination filename
                base = os.path.basename(source_local)
                dest = os.path.join(dest, base)
            if not dest.startswith("/"):
                # if dest does not start with "/", we'll assume a relative path
                dest = utils.path_dwim(self.runner.basedir, dest)
        else:
            # files are saved in dest dir, with a subdir for each host, then the filename
            dest = "%s/%s/%s" % (utils.path_dwim(self.runner.basedir, dest), conn.host, source_local)

        dest = dest.replace("//","/")

        # these don't fail because you may want to transfer a log file that possibly MAY exist
        # but keep going to fetch other log files
        if remote_md5 == '0':
            result = dict(msg="unable to calculate the md5 sum of the remote file", file=source, changed=False)
            return ReturnData(conn=conn, result=result)
        if remote_md5 == '1':
            if fail_on_missing:
                result = dict(failed=True, msg="the remote file does not exist", file=source)
            else:
                result = dict(msg="the remote file does not exist, not transferring, ignored", file=source, changed=False)
            return ReturnData(conn=conn, result=result)
        if remote_md5 == '2':
            result = dict(msg="no read permission on remote file, not transferring, ignored", file=source, changed=False)
            return ReturnData(conn=conn, result=result)

        # calculate md5 sum for the local file
        local_md5 = utils.md5(dest)

        if remote_md5 != local_md5:
            # create the containing directories, if needed
            if not os.path.isdir(os.path.dirname(dest)):
                os.makedirs(os.path.dirname(dest))

            # fetch the file and check for changes
            if remote_data is None:
                conn.fetch_file(source, dest)
            else:
                f = open(dest, 'w')
                f.write(remote_data)
                f.close()
            new_md5 = utils.md5(dest)
            if validate_md5 and new_md5 != remote_md5:
                result = dict(failed=True, md5sum=new_md5, msg="md5 mismatch", file=source, dest=dest, remote_md5sum=remote_md5)
                return ReturnData(conn=conn, result=result)
            result = dict(changed=True, md5sum=new_md5, dest=dest, remote_md5sum=remote_md5)
            return ReturnData(conn=conn, result=result)
        else:
            result = dict(changed=False, md5sum=local_md5, file=source, dest=dest)
            return ReturnData(conn=conn, result=result)

