# -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function, unicode_literals
"""
Easy YAML serialisation compatible with TAP (http://testanything.org/) format.
Copyright (C) 2012 Red Hat, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
----------------------------------

Available on https://github.com/AndyA/Data--YAML

=head1 DESCRIPTION

In the spirit of L<YAML::Tiny>, L<Data::YAML::Reader> and
L<Data::YAML::Writer> provide lightweight, dependency-free YAML
handling. While C<YAML::Tiny> is designed principally for working with
configuration files C<Data::YAML> concentrates on the transparent round-
tripping of YAML serialized Perl data structures.

As an example of why this distinction matters consider that
C<YAML::Tiny> doesn't handle hashes with keys containing non-printable
characters. This is fine for configuration files but likely to cause
problems when handling arbitrary Perl data structures. C<Data::YAML>
handles exotic hash keys correctly.

The syntax accepted by C<Data::YAML> is a subset of YAML. Specifically
it is the same subset of YAML that L<Data::YAML::Writer> produces. See
L<Data::YAML> for more information.

=head2 YAML syntax

Although YAML appears to be a simple language the entire YAML
specification is huge. C<Data::YAML> implements a small subset of the
complete syntax trading completeness for compactness and simplicity.
This restricted syntax is known (to me at least) as 'YAMLish'.

These examples demonstrates the full range of supported syntax. 

All YAML documents must begin with '---' and end with a line
containing '...'.

    --- Simple scalar
    ...

Unprintable characters are represented using standard escapes in double
quoted strings.

    --- "\t\x01\x02\n"
    ...

Array and hashes are represented thusly

    ---
      - "This"
      - "is"
      - "an"
      - "array"
    ...

    ---
      This: is
      a: hash
    ...

Structures may nest arbitrarily

    ---
      -
        name: 'Hash one'
        value: 1
      -
        name: 'Hash two'
        value: 2
    ...

Undef is a tilde

    --- ~
    ...

=head2 Uses

Use C<Data::YAML> may be used any time you need to freeze and thaw Perl
data structures into a human readable format. The output from
C<Data::YAML::Writer> should be readable by any YAML parser.

C<Data::YAML> was originally written to allow machine-readable
diagnostic information to be passed from test scripts to
L<TAP::Harness>. That means that if you're writing a testing system that
needs to output TAP version 13 or later syntax you might find
C<Data::YAML> useful.

Read more about TAP and YAMLish here: L<http://testanything.org/wiki>

"""

import logging
import yaml

__version__ = "0.2"
__author__ = "Matěj Cepl <mcepl_at_redhat_dot_com>"

class _YamlishLoader(yaml.loader.SafeLoader):
    """
    Remove a datetime resolving.

    YAMLish returns unchanged string.
    """
    def __init__(self, stream):
        yaml.loader.SafeLoader.__init__(self, stream)

    @classmethod
    def remove_implicit_resolver(cls, tag):
        """
        Remove an implicit resolver from a Loader class identified by its tag. 
        """
        if not 'yaml_implicit_resolvers' in cls.__dict__:
            cls.yaml_implicit_resolvers = cls.yaml_implicit_resolvers.copy()
        for key in cls.yaml_implicit_resolvers:
            resolvers_set = cls.yaml_implicit_resolvers[key]
            for idx in range(len(resolvers_set)):
                if resolvers_set[idx][0] == tag:
                    del resolvers_set[idx]
            if len(resolvers_set) == 0:
                del cls.yaml_implicit_resolvers[key]

_YamlishLoader.remove_implicit_resolver(u'tag:yaml.org,2002:timestamp')

def load(source):
    """
    Return object loaded from a YAML document in source.

    Source is either a representation of the YAML document itself
    or any document providing an iterator (that includes file, list, and
    many others).
    """
    out = None
    logging.debug("inobj:\n%s", source)
    if isinstance(source, (str, unicode)):
        out = yaml.load(source, Loader=_YamlishLoader)
        logging.debug("out (string) = %s", out)
    elif hasattr(source, "__iter__"):
        inobj = ""
        for line in source:
            inobj += line + '\n'
        out = load(inobj)
        logging.debug("out (iter) = %s", out)
    return out

def dump(source, destination):
    """
    Store source in destination file.

    Destination is either a file object or a string with a filename.
    """
    if isinstance(destination, (str, unicode)):
        with open(destination, "w") as outf:
            dump(source, outf)
    elif getattr(destination, "file"):
        yaml.dump(source, destination, encoding="utf-8",
                  default_flow_style=False, canonical=False,
                  Dumper=yaml.SafeDumper)
    else:
        raise NameError

def dumps(source):
    """
    Return YAMLish string from given source.
    """
    return yaml.dump(source, encoding="utf-8",
                     explicit_start=True, explicit_end=True,
                     default_flow_style=False, default_style=False,
                     canonical=False, Dumper=yaml.SafeDumper)