Return a script of an initializer for *attrs* and a dict of globals.

    The globals are expected by the generated script.

    If *frozen* is True, we cannot set the attributes directly so we use
    a cached ``object.__setattr__``.

def _attrs_to_init_script(
    attrs, frozen, slots, post_init, cache_hash, base_attr_map, is_exc
):
    """
    Return a script of an initializer for *attrs* and a dict of globals.

    The globals are expected by the generated script.

    If *frozen* is True, we cannot set the attributes directly so we use
    a cached ``object.__setattr__``.
    """
    lines = []
    any_slot_ancestors = any(
        _is_slot_attr(a.name, base_attr_map) for a in attrs
    )
    if frozen is True:
        if slots is True:
            lines.append(
                # Circumvent the __setattr__ descriptor to save one lookup per
                # assignment.
                # Note _setattr will be used again below if cache_hash is True
                "_setattr = _cached_setattr.__get__(self, self.__class__)"
            )

            def fmt_setter(attr_name, value_var):
                return "_setattr('%(attr_name)s', %(value_var)s)" % {
                    "attr_name": attr_name,
                    "value_var": value_var,
                }

            def fmt_setter_with_converter(attr_name, value_var):
                conv_name = _init_converter_pat.format(attr_name)
                return "_setattr('%(attr_name)s', %(conv)s(%(value_var)s))" % {
                    "attr_name": attr_name,
                    "value_var": value_var,
                    "conv": conv_name,
                }

        else:
            # Dict frozen classes assign directly to __dict__.
            # But only if the attribute doesn't come from an ancestor slot
            # class.
            # Note _inst_dict will be used again below if cache_hash is True
            lines.append("_inst_dict = self.__dict__")
            if any_slot_ancestors:
                lines.append(
                    # Circumvent the __setattr__ descriptor to save one lookup
                    # per assignment.
                    "_setattr = _cached_setattr.__get__(self, self.__class__)"
                )

            def fmt_setter(attr_name, value_var):
                if _is_slot_attr(attr_name, base_attr_map):
                    res = "_setattr('%(attr_name)s', %(value_var)s)" % {
                        "attr_name": attr_name,
                        "value_var": value_var,
                    }
                else:
                    res = "_inst_dict['%(attr_name)s'] = %(value_var)s" % {
                        "attr_name": attr_name,
                        "value_var": value_var,
                    }
                return res

            def fmt_setter_with_converter(attr_name, value_var):
                conv_name = _init_converter_pat.format(attr_name)
                if _is_slot_attr(attr_name, base_attr_map):
                    tmpl = "_setattr('%(attr_name)s', %(c)s(%(value_var)s))"
                else:
                    tmpl = "_inst_dict['%(attr_name)s'] = %(c)s(%(value_var)s)"
                return tmpl % {
                    "attr_name": attr_name,
                    "value_var": value_var,
                    "c": conv_name,
                }

    else:
        # Not frozen.
        def fmt_setter(attr_name, value):
            return "self.%(attr_name)s = %(value)s" % {
                "attr_name": attr_name,
                "value": value,
            }

        def fmt_setter_with_converter(attr_name, value_var):
            conv_name = _init_converter_pat.format(attr_name)
            return "self.%(attr_name)s = %(conv)s(%(value_var)s)" % {
                "attr_name": attr_name,
                "value_var": value_var,
                "conv": conv_name,
            }

    args = []
    kw_only_args = []
    attrs_to_validate = []

    # This is a dictionary of names to validator and converter callables.
    # Injecting this into __init__ globals lets us avoid lookups.
    names_for_globals = {}
    annotations = {"return": None}

    for a in attrs:
        if a.validator:
            attrs_to_validate.append(a)
        attr_name = a.name
        arg_name = a.name.lstrip("_")
        has_factory = isinstance(a.default, Factory)
        if has_factory and a.default.takes_self:
            maybe_self = "self"
        else:
            maybe_self = ""
        if a.init is False:
            if has_factory:
                init_factory_name = _init_factory_pat.format(a.name)
                if a.converter is not None:
                    lines.append(
                        fmt_setter_with_converter(
                            attr_name,
                            init_factory_name + "({0})".format(maybe_self),
                        )
                    )
                    conv_name = _init_converter_pat.format(a.name)
                    names_for_globals[conv_name] = a.converter
                else:
                    lines.append(
                        fmt_setter(
                            attr_name,
                            init_factory_name + "({0})".format(maybe_self),
                        )
                    )
                names_for_globals[init_factory_name] = a.default.factory
            else:
                if a.converter is not None:
                    lines.append(
                        fmt_setter_with_converter(
                            attr_name,
                            "attr_dict['{attr_name}'].default".format(
                                attr_name=attr_name
                            ),
                        )
                    )
                    conv_name = _init_converter_pat.format(a.name)
                    names_for_globals[conv_name] = a.converter
                else:
                    lines.append(
                        fmt_setter(
                            attr_name,
                            "attr_dict['{attr_name}'].default".format(
                                attr_name=attr_name
                            ),
                        )
                    )
        elif a.default is not NOTHING and not has_factory:
            arg = "{arg_name}=attr_dict['{attr_name}'].default".format(
                arg_name=arg_name, attr_name=attr_name
            )
            if a.kw_only:
                kw_only_args.append(arg)
            else:
                args.append(arg)
            if a.converter is not None:
                lines.append(fmt_setter_with_converter(attr_name, arg_name))
                names_for_globals[
                    _init_converter_pat.format(a.name)
                ] = a.converter
            else:
                lines.append(fmt_setter(attr_name, arg_name))
        elif has_factory:
            arg = "{arg_name}=NOTHING".format(arg_name=arg_name)
            if a.kw_only:
                kw_only_args.append(arg)
            else:
                args.append(arg)
            lines.append(
                "if {arg_name} is not NOTHING:".format(arg_name=arg_name)
            )
            init_factory_name = _init_factory_pat.format(a.name)
            if a.converter is not None:
                lines.append(
                    "    " + fmt_setter_with_converter(attr_name, arg_name)
                )
                lines.append("else:")
                lines.append(
                    "    "
                    + fmt_setter_with_converter(
                        attr_name,
                        init_factory_name + "({0})".format(maybe_self),
                    )
                )
                names_for_globals[
                    _init_converter_pat.format(a.name)
                ] = a.converter
            else:
                lines.append("    " + fmt_setter(attr_name, arg_name))
                lines.append("else:")
                lines.append(
                    "    "
                    + fmt_setter(
                        attr_name,
                        init_factory_name + "({0})".format(maybe_self),
                    )
                )
            names_for_globals[init_factory_name] = a.default.factory
        else:
            if a.kw_only:
                kw_only_args.append(arg_name)
            else:
                args.append(arg_name)
            if a.converter is not None:
                lines.append(fmt_setter_with_converter(attr_name, arg_name))
                names_for_globals[
                    _init_converter_pat.format(a.name)
                ] = a.converter
            else:
                lines.append(fmt_setter(attr_name, arg_name))

        if a.init is True and a.converter is None and a.type is not None:
            annotations[arg_name] = a.type

    if attrs_to_validate:  # we can skip this if there are no validators.
        names_for_globals["_config"] = _config
        lines.append("if _config._run_validators is True:")
        for a in attrs_to_validate:
            val_name = "__attr_validator_{}".format(a.name)
            attr_name = "__attr_{}".format(a.name)
            lines.append(
                "    {}(self, {}, self.{})".format(val_name, attr_name, a.name)
            )
            names_for_globals[val_name] = a.validator
            names_for_globals[attr_name] = a
    if post_init:
        lines.append("self.__attrs_post_init__()")

    # because this is set only after __attrs_post_init is called, a crash
    # will result if post-init tries to access the hash code.  This seemed
    # preferable to setting this beforehand, in which case alteration to
    # field values during post-init combined with post-init accessing the
    # hash code would result in silent bugs.
    if cache_hash:
        if frozen:
            if slots:
                # if frozen and slots, then _setattr defined above
                init_hash_cache = "_setattr('%s', %s)"
            else:
                # if frozen and not slots, then _inst_dict defined above
                init_hash_cache = "_inst_dict['%s'] = %s"
        else:
            init_hash_cache = "self.%s = %s"
        lines.append(init_hash_cache % (_hash_cache_field, "None"))

    # For exceptions we rely on BaseException.__init__ for proper
    # initialization.
    if is_exc:
        vals = ",".join("self." + a.name for a in attrs if a.init)

        lines.append("BaseException.__init__(self, %s)" % (vals,))

    args = ", ".join(args)
    if kw_only_args:
        if PY2:
            raise PythonTooOldError(
                "Keyword-only arguments only work on Python 3 and later."
            )

        args += "{leading_comma}*, {kw_only_args}".format(
            leading_comma=", " if args else "",
            kw_only_args=", ".join(kw_only_args),
        )
    return (
        """\
def __init__(self, {args}):
    {lines}
""".format(
            args=args, lines="\n    ".join(lines) if lines else "pass"
        ),
        names_for_globals,
        annotations,
    )