# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2024)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import annotations

from typing import TYPE_CHECKING, Final, cast

from streamlit.proto.Markdown_pb2 import Markdown as MarkdownProto
from streamlit.runtime.metrics_util import gather_metrics
from streamlit.string_util import clean_text
from streamlit.type_util import SupportsStr, is_sympy_expession

if TYPE_CHECKING:
    import sympy

    from streamlit.delta_generator import DeltaGenerator

MARKDOWN_HORIZONTAL_RULE_EXPRESSION: Final = "---"


class MarkdownMixin:
    @gather_metrics("markdown")
    def markdown(
        self,
        body: SupportsStr,
        unsafe_allow_html: bool = False,
        *,  # keyword-only arguments:
        help: str | None = None,
    ) -> DeltaGenerator:
        r"""Display string formatted as Markdown.

        Parameters
        ----------
        body : str
            The string to display as GitHub-flavored Markdown. Syntax
            information can be found at: https://github.github.com/gfm.

            This also supports:

            * Emoji shortcodes, such as ``:+1:``  and ``:sunglasses:``.
              For a list of all supported codes,
              see https://share.streamlit.io/streamlit/emoji-shortcodes.

            * Google Material Symbols (rounded style), using the syntax
              ``:material/icon_name:``, where "icon_name" is the name of the
              icon in snake case. For a complete list of icons, see Google's
              `Material Symbols <https://fonts.google.com/icons?icon.set=Material+Symbols&icon.style=Rounded>`_
              font library.

            * LaTeX expressions, by wrapping them in "$" or "$$" (the "$$"
              must be on their own lines). Supported LaTeX functions are listed
              at https://katex.org/docs/supported.html.

            * Colored text and background colors for text, using the syntax
              ``:color[text to be colored]`` and ``:color-background[text to be colored]``,
              respectively. ``color`` must be replaced with any of the following
              supported colors: blue, green, orange, red, violet, gray/grey, rainbow.
              For example, you can use ``:orange[your text here]`` or
              ``:blue-background[your text here]``.

        unsafe_allow_html : bool
            Whether to render HTML within ``body``. If this is ``False``
            (default), any HTML tags found in ``body`` will be escaped and
            therefore treated as raw text. If this is ``True``, any HTML
            expressions within ``body`` will be rendered.

            Adding custom HTML to your app impacts safety, styling, and
            maintainability.

            .. note::
                If you only want to insert HTML or CSS without Markdown text,
                we recommend using ``st.html`` instead.

        help : str
            An optional tooltip that gets displayed next to the Markdown.

        Examples
        --------
        >>> import streamlit as st
        >>>
        >>> st.markdown("*Streamlit* is **really** ***cool***.")
        >>> st.markdown('''
        ...     :red[Streamlit] :orange[can] :green[write] :blue[text] :violet[in]
        ...     :gray[pretty] :rainbow[colors] and :blue-background[highlight] text.''')
        >>> st.markdown("Here's a bouquet &mdash;\
        ...             :tulip::cherry_blossom::rose::hibiscus::sunflower::blossom:")
        >>>
        >>> multi = '''If you end a line with two spaces,
        ... a soft return is used for the next line.
        ...
        ... Two (or more) newline characters in a row will result in a hard return.
        ... '''
        >>> st.markdown(multi)

        .. output::
           https://doc-markdown.streamlit.app/
           height: 350px

        """
        markdown_proto = MarkdownProto()

        markdown_proto.body = clean_text(body)
        markdown_proto.allow_html = unsafe_allow_html
        markdown_proto.element_type = MarkdownProto.Type.NATIVE
        if help:
            markdown_proto.help = help

        return self.dg._enqueue("markdown", markdown_proto)

    @gather_metrics("code")
    def code(
        self,
        body: SupportsStr,
        language: str | None = "python",
    ) -> DeltaGenerator:
        """Display a code block with optional syntax highlighting.

        (This is a convenience wrapper around `st.markdown()`)

        Parameters
        ----------
        body : str
            The string to display as code.

        language : str or None
            The language that the code is written in, for syntax highlighting.
            If ``None``, the code will be unstyled. Defaults to ``"python"``.

            For a list of available ``language`` values, see:

            https://github.com/react-syntax-highlighter/react-syntax-highlighter/blob/master/AVAILABLE_LANGUAGES_PRISM.MD

        Example
        -------
        >>> import streamlit as st
        >>>
        >>> code = '''def hello():
        ...     print("Hello, Streamlit!")'''
        >>> st.code(code, language="python")

        """
        code_proto = MarkdownProto()
        markdown = f'```{language or ""}\n{body}\n```'
        code_proto.body = clean_text(markdown)
        code_proto.element_type = MarkdownProto.Type.CODE
        return self.dg._enqueue("markdown", code_proto)

    @gather_metrics("caption")
    def caption(
        self,
        body: SupportsStr,
        unsafe_allow_html: bool = False,
        *,  # keyword-only arguments:
        help: str | None = None,
    ) -> DeltaGenerator:
        """Display text in small font.

        This should be used for captions, asides, footnotes, sidenotes, and
        other explanatory text.

        Parameters
        ----------
        body : str
            The text to display as GitHub-flavored Markdown. Syntax
            information can be found at: https://github.github.com/gfm.

            See the ``body`` parameter of |st.markdown|_ for additional,
            supported Markdown directives.

            .. |st.markdown| replace:: ``st.markdown``
            .. _st.markdown: https://docs.streamlit.io/develop/api-reference/text/st.markdown

        unsafe_allow_html : bool
            Whether to render HTML within ``body``. If this is ``False``
            (default), any HTML tags found in ``body`` will be escaped and
            therefore treated as raw text. If this is ``True``, any HTML
            expressions within ``body`` will be rendered.

            Adding custom HTML to your app impacts safety, styling, and
            maintainability.

            .. note::
                If you only want to insert HTML or CSS without Markdown text,
                we recommend using ``st.html`` instead.

        help : str
            An optional tooltip that gets displayed next to the caption.

        Examples
        --------
        >>> import streamlit as st
        >>>
        >>> st.caption("This is a string that explains something above.")
        >>> st.caption("A caption with _italics_ :blue[colors] and emojis :sunglasses:")

        """
        caption_proto = MarkdownProto()
        caption_proto.body = clean_text(body)
        caption_proto.allow_html = unsafe_allow_html
        caption_proto.is_caption = True
        caption_proto.element_type = MarkdownProto.Type.CAPTION
        if help:
            caption_proto.help = help
        return self.dg._enqueue("markdown", caption_proto)

    @gather_metrics("latex")
    def latex(
        self,
        body: SupportsStr | sympy.Expr,
        *,  # keyword-only arguments:
        help: str | None = None,
    ) -> DeltaGenerator:
        # This docstring needs to be "raw" because of the backslashes in the
        # example below.
        r"""Display mathematical expressions formatted as LaTeX.

        Supported LaTeX functions are listed at
        https://katex.org/docs/supported.html.

        Parameters
        ----------
        body : str or SymPy expression
            The string or SymPy expression to display as LaTeX. If str, it's
            a good idea to use raw Python strings since LaTeX uses backslashes
            a lot.

        help : str
            An optional tooltip that gets displayed next to the LaTeX expression.


        Example
        -------
        >>> import streamlit as st
        >>>
        >>> st.latex(r'''
        ...     a + ar + a r^2 + a r^3 + \cdots + a r^{n-1} =
        ...     \sum_{k=0}^{n-1} ar^k =
        ...     a \left(\frac{1-r^{n}}{1-r}\right)
        ...     ''')

        """
        if is_sympy_expession(body):
            import sympy

            body = sympy.latex(body)

        latex_proto = MarkdownProto()
        latex_proto.body = "$$\n%s\n$$" % clean_text(body)
        latex_proto.element_type = MarkdownProto.Type.LATEX
        if help:
            latex_proto.help = help
        return self.dg._enqueue("markdown", latex_proto)

    @gather_metrics("divider")
    def divider(self) -> DeltaGenerator:
        """Display a horizontal rule.

        .. note::
            You can achieve the same effect with st.write("---") or
            even just "---" in your script (via magic).

        Example
        -------
        >>> import streamlit as st
        >>>
        >>> st.divider()

        """
        divider_proto = MarkdownProto()
        divider_proto.body = MARKDOWN_HORIZONTAL_RULE_EXPRESSION
        divider_proto.element_type = MarkdownProto.Type.DIVIDER
        return self.dg._enqueue("markdown", divider_proto)

    @property
    def dg(self) -> DeltaGenerator:
        """Get our DeltaGenerator."""
        return cast("DeltaGenerator", self)
