"""Utilities for handling multimodal content in OpenAI-style messages."""

import copy

import re

from typing import Any

DEFAULT_MULTIMODAL_REGEX = (

    r"(?s)<MSWEA_MULTIMODAL_CONTENT><CONTENT_TYPE>(.+?)</CONTENT_TYPE>(.+?)</MSWEA_MULTIMODAL_CONTENT>"

)

def _expand_content_string(*, content: str, pattern: str) -> list[dict]:

    """Expand a content string, replacing multimodal tags with structured content."""

    matches = list(re.finditer(pattern, content))

    if not matches:

        return [{"type": "text", "text": content}]

    result = []

    last_end = 0

    for match in matches:

        text_before = content[last_end : match.start()]

        if text_before:

            result.append({"type": "text", "text": text_before})

        content_type = match.group(1).strip()

        extracted = match.group(2).strip()

        if content_type == "image_url":

            result.append({"type": "image_url", "image_url": {"url": extracted}})

        last_end = match.end()

    text_after = content[last_end:]

    if text_after:

        result.append({"type": "text", "text": text_after})

    return result

def expand_multimodal_content(content: Any, *, pattern: str) -> Any:

    """Recursively expand multimodal content in messages.

    Note: Returns copy of content, original content is not modified.

    """

    if not pattern:

        return content

    content = copy.deepcopy(content)

    if isinstance(content, str):

        return _expand_content_string(content=content, pattern=pattern)

    if isinstance(content, list):

        return [expand_multimodal_content(item, pattern=pattern) for item in content]

    if isinstance(content, dict):

        if "content" not in content:

            return content

        content["content"] = expand_multimodal_content(content["content"], pattern=pattern)

        return content

    return str(content)