# -----------------------------------------------------------------------------
#  Copyright (C) Jupyter Development Team
#
#  Distributed under the terms of the BSD License.  The full license is in
#  the file COPYING, distributed as part of this software.
# -----------------------------------------------------------------------------


def default_formats():
    """
    Return the currently-implemented formats.

    These are not classes, but maybe should be: would they survive pickling?

    - exporter:
        an Exporter subclass.
        if not defined, and key is in nbconvert.export.exporter_map, it will be added
        automatically
    - nbconvert_template:
        the name of the nbconvert template to add to config.ExporterClass
    - test:
        a function(notebook_object, notebook_json)
        conditionally offer a format based on content if truthy. see
        `RenderingHandler.filter_exporters`
    - postprocess:
        a function(html, resources)
        perform any modifications to html and resources after nbconvert
    - content_Type:
        a string specifying the Content-Type of the response from this format.
        Defaults to  text/html; charset=UTF-8
    """

    def test_slides(nb, json):
        """Determines if at least one cell has a non-blank or "-" as its
        metadata.slideshow.slide_type value.

        Parameters
        ----------
        nb: nbformat.notebooknode.NotebookNode
            Top of the parsed notebook object model
        json: str
            JSON source of the notebook, unused

        Returns
        -------
        bool
        """
        for cell in nb.cells:
            if (
                "metadata" in cell
                and "slideshow" in cell.metadata
                and cell.metadata.slideshow.get("slide_type", "-") != "-"
            ):
                return True
        return False

    return {
        "html": {"nbconvert_template": "basic", "label": "Notebook", "icon": "book"},
        "slides": {
            "nbconvert_template": "slides_reveal",
            "label": "Slides",
            "icon": "gift",
            "test": test_slides,
        },
        "script": {
            "label": "Code",
            "icon": "code",
            "content_type": "text/plain; charset=UTF-8",
        },
    }