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/*
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 * text-highlighting.ts
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 *
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 * Copyright (C) 2020-2022 Posit Software, PBC
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 */
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import { join } from "../deno_ral/path.ts";
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import { kDefaultHighlightStyle } from "../command/render/constants.ts";
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import { kHighlightStyle, kSyntaxHighlighting } from "../config/constants.ts";
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import { FormatPandoc } from "../config/types.ts";
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import { existsSync } from "../deno_ral/fs.ts";
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import { resourcePath } from "../core/resources.ts";
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import { normalizePath } from "../core/path.ts";
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import { warnOnce } from "../core/log.ts";
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export interface ThemeDescriptor {
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  json: Record<string, unknown>;
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  isAdaptive: boolean;
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}
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const kDarkSuffix = "dark";
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const kLightSuffix = "light";
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// Resolve highlight theme from syntax-highlighting (new) or highlight-style (deprecated)
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export function getHighlightTheme(
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  pandoc: FormatPandoc,
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): string | Record<string, string> {
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  return pandoc[kSyntaxHighlighting] ||
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    pandoc[kHighlightStyle] ||
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    kDefaultHighlightStyle;
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}
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export function textHighlightThemePath(
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  inputDir: string,
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  theme: string | Record<string, string>,
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  style?: "dark" | "light",
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) {
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  let resolvedTheme: string;
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  if (typeof theme === "object") {
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    if (style && theme[style]) {
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      resolvedTheme = theme[style] as string;
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    } else {
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      resolvedTheme = theme[Object.keys(theme)[0]] as string;
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    }
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  } else {
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    resolvedTheme = theme as string;
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  }
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  // First try the style specific version of the theme, otherwise
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  // fall back to the plain name
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  const names = [
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    `${resolvedTheme}-${style === "dark" ? kDarkSuffix : kLightSuffix}`,
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    resolvedTheme,
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  ];
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  const themePath = names.map((name) => {
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    return resourcePath(join("pandoc", "highlight-styles", `${name}.theme`));
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  }).find((path) => existsSync(path));
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  if (themePath) {
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    // first see if this matches a built in name
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    return themePath;
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  } else {
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    // see if this is a path to a user theme
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    const userThemePath = join(inputDir, resolvedTheme);
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    if (existsSync(userThemePath)) {
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      return normalizePath(userThemePath);
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    }
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  }
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  // Could find a path
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  return undefined;
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}
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export function readHighlightingTheme(
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  inputDir: string,
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  pandoc: FormatPandoc,
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  style: "dark" | "light" | "default",
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): ThemeDescriptor | undefined {
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  const theme = getHighlightTheme(pandoc);
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  const themeRaw = readTheme(inputDir, theme, style);
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  if (themeRaw) {
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    return {
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      json: JSON.parse(themeRaw),
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      isAdaptive: isAdaptiveTheme(theme),
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    };
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  }
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  return undefined;
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}
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export function hasAdaptiveTheme(pandoc: FormatPandoc) {
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  return isAdaptiveTheme(getHighlightTheme(pandoc));
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}
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export function hasTextHighlighting(pandoc: FormatPandoc): boolean {
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  return getHighlightTheme(pandoc) !== "none";
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}
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export function isAdaptiveTheme(theme: string | Record<string, string>) {
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  if (typeof theme === "string") {
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    return [
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      "a11y",
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      "arrow",
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      "atom-one",
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      "ayu",
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      "breeze",
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      "github",
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      "gruvbox",
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      "monochrome",
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    ].includes(
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      theme,
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    );
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  } else {
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    const keys = Object.keys(theme);
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    return keys.includes("dark") && keys.includes("light");
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  }
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}
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// Reads the contents of a theme file, falling back if the style specific version isn't available
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export function readTheme(
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  inputDir: string,
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  theme: string | Record<string, string>,
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  style: "light" | "dark" | "default",
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) {
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  const themeFile = textHighlightThemePath(
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    inputDir,
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    theme,
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    style === "default" ? undefined : style,
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  );
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  if (!themeFile) {
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    return undefined;
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  }
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  if (!existsSync(themeFile)) {
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    warnOnce(`The text highlighting theme ${themeFile} does not exist.`);
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    return undefined;
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  }
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  if (Deno.statSync(themeFile).isDirectory) {
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    throw new Error(
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      `The text highlighting theme ${themeFile} is a directory. Please provide a valid theme name or path to a .theme file.`,
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    );
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  }
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  return Deno.readTextFileSync(themeFile);
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}
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// From  https://github.com/jgm/skylighting/blob/a1d02a0db6260c73aaf04aae2e6e18b569caacdc/skylighting-core/src/Skylighting/Format/HTML.hs#L117-L147
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export const kAbbrevs: Record<string, string> = {
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  "Keyword": "kw",
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  "DataType": "dt",
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  "DecVal": "dv",
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  "BaseN": "bn",
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  "Float": "fl",
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  "Char": "ch",
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  "String": "st",
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  "Comment": "co",
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  "Other": "ot",
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  "Alert": "al",
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  "Function": "fu",
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  "RegionMarker": "re",
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  "Error": "er",
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  "Constant": "cn",
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  "SpecialChar": "sc",
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  "VerbatimString": "vs",
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  "SpecialString": "ss",
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  "Import": "im",
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  "Documentation": "do",
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  "Annotation": "an",
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  "CommentVar": "cv",
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  "Variable": "va",
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  "ControlFlow": "cf",
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  "Operator": "op",
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  "BuiltIn": "bu",
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  "Extension": "ex",
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  "Preprocessor": "pp",
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  "Attribute": "at",
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  "Information": "in",
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  "Warning": "wa",
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  "Normal": "",
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};
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