cinny/src/app/plugins/markdown.ts
2023-10-31 08:57:59 +05:30

368 lines
11 KiB
TypeScript

export type MatchResult = RegExpMatchArray | RegExpExecArray;
export type RuleMatch = (text: string) => MatchResult | null;
export const beforeMatch = (text: string, match: RegExpMatchArray | RegExpExecArray): string =>
text.slice(0, match.index);
export const afterMatch = (text: string, match: RegExpMatchArray | RegExpExecArray): string =>
text.slice((match.index ?? 0) + match[0].length);
export const replaceMatch = <C>(
convertPart: (txt: string) => Array<string | C>,
text: string,
match: MatchResult,
content: C
): Array<string | C> => [
...convertPart(beforeMatch(text, match)),
content,
...convertPart(afterMatch(text, match)),
];
/*
*****************
* INLINE PARSER *
*****************
*/
export type InlineMDParser = (text: string) => string;
export type InlineMatchConverter = (parse: InlineMDParser, match: MatchResult) => string;
export type InlineMDRule = {
match: RuleMatch;
html: InlineMatchConverter;
};
export type InlineRuleRunner = (
parse: InlineMDParser,
text: string,
rule: InlineMDRule
) => string | undefined;
export type InlineRulesRunner = (
parse: InlineMDParser,
text: string,
rules: InlineMDRule[]
) => string | undefined;
const MIN_ANY = '(.+?)';
const URL_NEG_LB = '(?<!(https?|ftp|mailto|magnet):\\/\\/\\S*)';
const BOLD_MD_1 = '**';
const BOLD_PREFIX_1 = '\\*{2}';
const BOLD_NEG_LA_1 = '(?!\\*)';
const BOLD_REG_1 = new RegExp(
`${URL_NEG_LB}${BOLD_PREFIX_1}${MIN_ANY}${BOLD_PREFIX_1}${BOLD_NEG_LA_1}`
);
const BoldRule: InlineMDRule = {
match: (text) => text.match(BOLD_REG_1),
html: (parse, match) => {
const [, , g2] = match;
return `<strong data-md="${BOLD_MD_1}">${parse(g2)}</strong>`;
},
};
const ITALIC_MD_1 = '*';
const ITALIC_PREFIX_1 = '\\*';
const ITALIC_NEG_LA_1 = '(?!\\*)';
const ITALIC_REG_1 = new RegExp(
`${URL_NEG_LB}${ITALIC_PREFIX_1}${MIN_ANY}${ITALIC_PREFIX_1}${ITALIC_NEG_LA_1}`
);
const ItalicRule1: InlineMDRule = {
match: (text) => text.match(ITALIC_REG_1),
html: (parse, match) => {
const [, , g2] = match;
return `<i data-md="${ITALIC_MD_1}">${parse(g2)}</i>`;
},
};
const ITALIC_MD_2 = '_';
const ITALIC_PREFIX_2 = '_';
const ITALIC_NEG_LA_2 = '(?!_)';
const ITALIC_REG_2 = new RegExp(
`${URL_NEG_LB}${ITALIC_PREFIX_2}${MIN_ANY}${ITALIC_PREFIX_2}${ITALIC_NEG_LA_2}`
);
const ItalicRule2: InlineMDRule = {
match: (text) => text.match(ITALIC_REG_2),
html: (parse, match) => {
const [, , g2] = match;
return `<i data-md="${ITALIC_MD_2}">${parse(g2)}</i>`;
},
};
const UNDERLINE_MD_1 = '__';
const UNDERLINE_PREFIX_1 = '_{2}';
const UNDERLINE_NEG_LA_1 = '(?!_)';
const UNDERLINE_REG_1 = new RegExp(
`${URL_NEG_LB}${UNDERLINE_PREFIX_1}${MIN_ANY}${UNDERLINE_PREFIX_1}${UNDERLINE_NEG_LA_1}`
);
const UnderlineRule: InlineMDRule = {
match: (text) => text.match(UNDERLINE_REG_1),
html: (parse, match) => {
const [, , g2] = match;
return `<u data-md="${UNDERLINE_MD_1}">${parse(g2)}</u>`;
},
};
const STRIKE_MD_1 = '~~';
const STRIKE_PREFIX_1 = '~{2}';
const STRIKE_NEG_LA_1 = '(?!~)';
const STRIKE_REG_1 = new RegExp(
`${URL_NEG_LB}${STRIKE_PREFIX_1}${MIN_ANY}${STRIKE_PREFIX_1}${STRIKE_NEG_LA_1}`
);
const StrikeRule: InlineMDRule = {
match: (text) => text.match(STRIKE_REG_1),
html: (parse, match) => {
const [, , g2] = match;
return `<del data-md="${STRIKE_MD_1}">${parse(g2)}</del>`;
},
};
const CODE_MD_1 = '`';
const CODE_PREFIX_1 = '`';
const CODE_NEG_LA_1 = '(?!`)';
const CODE_REG_1 = new RegExp(`${URL_NEG_LB}${CODE_PREFIX_1}(.+?)${CODE_PREFIX_1}${CODE_NEG_LA_1}`);
const CodeRule: InlineMDRule = {
match: (text) => text.match(CODE_REG_1),
html: (parse, match) => {
const [, , g2] = match;
return `<code data-md="${CODE_MD_1}">${g2}</code>`;
},
};
const SPOILER_MD_1 = '||';
const SPOILER_PREFIX_1 = '\\|{2}';
const SPOILER_NEG_LA_1 = '(?!\\|)';
const SPOILER_REG_1 = new RegExp(
`${URL_NEG_LB}${SPOILER_PREFIX_1}${MIN_ANY}${SPOILER_PREFIX_1}${SPOILER_NEG_LA_1}`
);
const SpoilerRule: InlineMDRule = {
match: (text) => text.match(SPOILER_REG_1),
html: (parse, match) => {
const [, , g2] = match;
return `<span data-md="${SPOILER_MD_1}" data-mx-spoiler>${parse(g2)}</span>`;
},
};
const LINK_ALT = `\\[${MIN_ANY}\\]`;
const LINK_URL = `\\((https?:\\/\\/.+?)\\)`;
const LINK_REG_1 = new RegExp(`${LINK_ALT}${LINK_URL}`);
const LinkRule: InlineMDRule = {
match: (text) => text.match(LINK_REG_1),
html: (parse, match) => {
const [, g1, g2] = match;
return `<a data-md href="${g2}">${parse(g1)}</a>`;
},
};
const runInlineRule: InlineRuleRunner = (parse, text, rule) => {
const matchResult = rule.match(text);
if (matchResult) {
const content = rule.html(parse, matchResult);
return replaceMatch((txt) => [parse(txt)], text, matchResult, content).join('');
}
return undefined;
};
/**
* Runs multiple rules at the same time to better handle nested rules.
* Rules will be run in the order they appear.
*/
const runInlineRules: InlineRulesRunner = (parse, text, rules) => {
const matchResults = rules.map((rule) => rule.match(text));
let targetRule: InlineMDRule | undefined;
let targetResult: MatchResult | undefined;
for (let i = 0; i < matchResults.length; i += 1) {
const currentResult = matchResults[i];
if (currentResult && typeof currentResult.index === 'number') {
if (
!targetResult ||
(typeof targetResult?.index === 'number' && currentResult.index < targetResult.index)
) {
targetResult = currentResult;
targetRule = rules[i];
}
}
}
if (targetRule && targetResult) {
const content = targetRule.html(parse, targetResult);
return replaceMatch((txt) => [parse(txt)], text, targetResult, content).join('');
}
return undefined;
};
const LeveledRules = [
BoldRule,
ItalicRule1,
UnderlineRule,
ItalicRule2,
StrikeRule,
SpoilerRule,
LinkRule,
];
export const parseInlineMD: InlineMDParser = (text) => {
if (text === '') return text;
let result: string | undefined;
if (!result) result = runInlineRule(parseInlineMD, text, CodeRule);
if (!result) result = runInlineRules(parseInlineMD, text, LeveledRules);
return result ?? text;
};
/*
****************
* BLOCK PARSER *
****************
*/
export type BlockMDParser = (test: string, parseInline?: (txt: string) => string) => string;
export type BlockMatchConverter = (
match: MatchResult,
parseInline?: (txt: string) => string
) => string;
export type BlockMDRule = {
match: RuleMatch;
html: BlockMatchConverter;
};
export type BlockRuleRunner = (
parse: BlockMDParser,
text: string,
rule: BlockMDRule,
parseInline?: (txt: string) => string
) => string | undefined;
const HEADING_REG_1 = /^(#{1,6}) +(.+)\n?/m;
const HeadingRule: BlockMDRule = {
match: (text) => text.match(HEADING_REG_1),
html: (match, parseInline) => {
const [, g1, g2] = match;
const level = g1.length;
return `<h${level} data-md="${g1}">${parseInline ? parseInline(g2) : g2}</h${level}>`;
},
};
const CODEBLOCK_MD_1 = '```';
const CODEBLOCK_REG_1 = /^`{3}(\S*)\n((?:.*\n)+?)`{3} *(?!.)\n?/m;
const CodeBlockRule: BlockMDRule = {
match: (text) => text.match(CODEBLOCK_REG_1),
html: (match) => {
const [, g1, g2] = match;
const classNameAtt = g1 ? ` class="language-${g1}"` : '';
return `<pre data-md="${CODEBLOCK_MD_1}"><code${classNameAtt}>${g2}</code></pre>`;
},
};
const BLOCKQUOTE_MD_1 = '>';
const QUOTE_LINE_PREFIX = /^> */;
const BLOCKQUOTE_TRAILING_NEWLINE = /\n$/;
const BLOCKQUOTE_REG_1 = /(^>.*\n?)+/m;
const BlockQuoteRule: BlockMDRule = {
match: (text) => text.match(BLOCKQUOTE_REG_1),
html: (match, parseInline) => {
const [blockquoteText] = match;
const lines = blockquoteText
.replace(BLOCKQUOTE_TRAILING_NEWLINE, '')
.split('\n')
.map((lineText) => {
const line = lineText.replace(QUOTE_LINE_PREFIX, '');
if (parseInline) return `${parseInline(line)}<br/>`;
return `${line}<br/>`;
})
.join('');
return `<blockquote data-md="${BLOCKQUOTE_MD_1}">${lines}</blockquote>`;
},
};
const ORDERED_LIST_MD_1 = '-';
const O_LIST_ITEM_PREFIX = /^(-|[\da-zA-Z]\.) */;
const O_LIST_START = /^([\d])\./;
const O_LIST_TYPE = /^([aAiI])\./;
const O_LIST_TRAILING_NEWLINE = /\n$/;
const ORDERED_LIST_REG_1 = /(^(?:-|[\da-zA-Z]\.) +.+\n?)+/m;
const OrderedListRule: BlockMDRule = {
match: (text) => text.match(ORDERED_LIST_REG_1),
html: (match, parseInline) => {
const [listText] = match;
const [, listStart] = listText.match(O_LIST_START) ?? [];
const [, listType] = listText.match(O_LIST_TYPE) ?? [];
const lines = listText
.replace(O_LIST_TRAILING_NEWLINE, '')
.split('\n')
.map((lineText) => {
const line = lineText.replace(O_LIST_ITEM_PREFIX, '');
const txt = parseInline ? parseInline(line) : line;
return `<li><p>${txt}</p></li>`;
})
.join('');
const dataMdAtt = `data-md="${listType || listStart || ORDERED_LIST_MD_1}"`;
const startAtt = listStart ? ` start="${listStart}"` : '';
const typeAtt = listType ? ` type="${listType}"` : '';
return `<ol ${dataMdAtt}${startAtt}${typeAtt}>${lines}</ol>`;
},
};
const UNORDERED_LIST_MD_1 = '*';
const U_LIST_ITEM_PREFIX = /^\* */;
const U_LIST_TRAILING_NEWLINE = /\n$/;
const UNORDERED_LIST_REG_1 = /(^\* +.+\n?)+/m;
const UnorderedListRule: BlockMDRule = {
match: (text) => text.match(UNORDERED_LIST_REG_1),
html: (match, parseInline) => {
const [listText] = match;
const lines = listText
.replace(U_LIST_TRAILING_NEWLINE, '')
.split('\n')
.map((lineText) => {
const line = lineText.replace(U_LIST_ITEM_PREFIX, '');
const txt = parseInline ? parseInline(line) : line;
return `<li><p>${txt}</p></li>`;
})
.join('');
return `<ul data-md="${UNORDERED_LIST_MD_1}">${lines}</ul>`;
},
};
const runBlockRule: BlockRuleRunner = (parse, text, rule, parseInline) => {
const matchResult = rule.match(text);
if (matchResult) {
const content = rule.html(matchResult, parseInline);
return replaceMatch((txt) => [parse(txt, parseInline)], text, matchResult, content).join('');
}
return undefined;
};
export const parseBlockMD: BlockMDParser = (text, parseInline) => {
if (text === '') return text;
let result: string | undefined;
if (!result) result = runBlockRule(parseBlockMD, text, CodeBlockRule, parseInline);
if (!result) result = runBlockRule(parseBlockMD, text, BlockQuoteRule, parseInline);
if (!result) result = runBlockRule(parseBlockMD, text, OrderedListRule, parseInline);
if (!result) result = runBlockRule(parseBlockMD, text, UnorderedListRule, parseInline);
if (!result) result = runBlockRule(parseBlockMD, text, HeadingRule, parseInline);
// replace \n with <br/> because want to preserve empty lines
if (!result) {
if (parseInline) {
result = text
.split('\n')
.map((lineText) => parseInline(lineText))
.join('<br/>');
} else {
result = text.replace(/\n/g, '<br/>');
}
}
return result ?? text;
};