"""Join raw text tokens with the rest of the text

This is set as a separate rule to provide an opportunity for plugins
to run text replacements after text join, but before escape join.

For example, `\\:)` shouldn't be replaced with an emoji.
"""

from __future__ import annotations

from ..token import Token
from .state_core import StateCore


def text_join(state: StateCore) -> None:
    """Join raw text for escape sequences (`text_special`) tokens with the rest of the text"""

    for inline_token in state.tokens[:]:
        if inline_token.type != "inline":
            continue

        # convert text_special to text and join all adjacent text nodes
        new_tokens: list[Token] = []
        children = inline_token.children or []
        i = 0
        while i < len(children):
            child_token = children[i]
            if child_token.type == "text_special":
                child_token.type = "text"
            if (
                child_token.type == "text"
                and new_tokens
                and new_tokens[-1].type == "text"
            ):
                # Collapse a run of adjacent text nodes in a single join, instead
                # of pairwise `a + b` concatenation. The pairwise form is O(L*k)
                # in the size of the run because each step rebuilds the growing
                # prefix; "".join is O(L).
                parts = [new_tokens[-1].content, child_token.content]
                i += 1
                while i < len(children):
                    next_token = children[i]
                    if next_token.type == "text_special":
                        next_token.type = "text"
                    if next_token.type != "text":
                        break
                    parts.append(next_token.content)
                    i += 1
                new_tokens[-1].content = "".join(parts)
            else:
                new_tokens.append(child_token)
                i += 1
        inline_token.children = new_tokens