const constants = require("../constants") function tryMatch(text, against, callback) { if (against instanceof RegExp && against.global) { // if it's a global match, keep sending matches to the callback while the callback returns true let matched let ok = true while (ok && (matched = against.exec(text))) { ok = callback(matched) } against.lastIndex = 0 } else { // if it's a non-global match, just do the match. let matched = text.match(against) if (matched) callback(matched) } } function textToParts(text) { return [{type: "text", text: text}] } function replacePart(parts, index, match, replacements) { const toReplace = parts.splice(index, 1)[0] const before = toReplace.text.slice(0, match.index) const after = toReplace.text.slice(match.index + match[0].length) parts.splice(index, 0, ...textToParts(before), ...replacements, ...textToParts(after)) } function partsUsername(parts) { for (let i = 0; i < parts.length; i++) { if (parts[i].type === "text") { tryMatch(parts[i].text, new RegExp(`@(${constants.external.username_regex})`, "g"), match => { if (match.index === 0 || parts[i].text[match.index-1].match(/\s/)) { // check that there's a space before the username replacePart(parts, i, match, [ {type: "user", text: match[0], user: match[1]} ]) i += 1 // skip the newly created part return false } else { return true } }) } } return parts } function partsHashtag(parts) { for (let i = 0; i < parts.length; i++) { if (parts[i].type === "text") { tryMatch(parts[i].text, `#(${constants.external.hashtag_regex})`, match => { replacePart(parts, i, match, [ {type: "hashtag", text: match[0], hashtag: match[1]} ]) i += 1 // skip the newly created part }) } } return parts } function structure(text) { const parts = textToParts(text) partsUsername(parts) partsHashtag(parts) return parts } module.exports.structure = structure module.exports.partsUsername = partsUsername module.exports.partsHashtag = partsHashtag