messages implemented

resources/js/utils/emojiFlood.js

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+/**
+ * emojiFlood.js
+ *
+ * Utilities for detecting and collapsing emoji flood content on the client.
+ *
+ * These mirror the PHP-side logic in LegacySmileyMapper::collapseFlood() and
+ * ContentSanitizer::validate() so that the UI can apply the same rules without
+ * a round-trip to the server.
+ */
+
+// ── Constants ─────────────────────────────────────────────────────────────────
+
+/** Absolute emoji count above which text is considered a flood for display. */
+export const FLOOD_COUNT_THRESHOLD = 20
+
+/** Ratio of emoji / total chars above which text is a density flood. */
+export const FLOOD_DENSITY_THRESHOLD = 0.40
+
+/** Maximum consecutive identical emoji kept before the rest are collapsed. */
+export const COLLAPSE_MAX_RUN = 5
+
+// ── Emoji detection ───────────────────────────────────────────────────────────
+
+/**
+ * Regex that matches a single emoji "unit":
+ *   • Codepoints U+1F000–U+1FFFF (most modern emoji)
+ *   • Codepoints U+2600–U+27BF  (misc symbols, dingbats)
+ *   • Optionally followed by U+FE0F variation selector
+ *
+ * Note: ZWJ sequences and flags are not fully modelled here, but those
+ * multi-codepoint emoji are extremely unlikely in legacy flood spam.
+ */
+const EMOJI_UNIT_RE = /[\u{1F000}-\u{1FFFF}\u{2600}-\u{27BF}]\uFE0F?/gu
+
+/**
+ * Count emoji in a string.
+ * @param {string} text
+ * @returns {number}
+ */
+export function countEmoji(text) {
+  if (!text) return 0
+  return (text.match(EMOJI_UNIT_RE) || []).length
+}
+
+// ── Flood detection ───────────────────────────────────────────────────────────
+
+/**
+ * Returns true when the text qualifies as an emoji flood.
+ *
+ * Two independent flood signals:
+ *  1. Absolute count > FLOOD_COUNT_THRESHOLD emoji  (e.g. 21 beer mugs)
+ *  2. Density > FLOOD_DENSITY_THRESHOLD  (e.g. "🍺🍺🍺🍺" — 80% emoji, 0 text)
+ *     Only applied when count > 5 to avoid false-positives on short strings.
+ *
+ * @param {string}  text
+ * @param {object}  [opts]
+ * @param {number}  [opts.maxCount=FLOOD_COUNT_THRESHOLD]
+ * @param {number}  [opts.maxDensity=FLOOD_DENSITY_THRESHOLD]
+ * @returns {boolean}
+ */
+export function isFlood(text, { maxCount = FLOOD_COUNT_THRESHOLD, maxDensity = FLOOD_DENSITY_THRESHOLD } = {}) {
+  if (!text) return false
+  const count = countEmoji(text)
+  if (count > maxCount) return true
+  if (count > 5 && text.length > 0 && count / text.length > maxDensity) return true
+  return false
+}
+
+// ── Flood collapsing ──────────────────────────────────────────────────────────
+
+/**
+ * Collapse consecutive runs of the same emoji that exceed `maxRun` repetitions.
+ *
+ * Behaviour mirrors LegacySmileyMapper::collapseFlood() on the PHP side:
+ *   "🍺 🍺 🍺 🍺 🍺 🍺 🍺 🍺"  (8×) → "🍺 🍺 🍺 🍺 🍺 ×8"
+ *
+ * Algorithm:
+ *  1. Scan the string for all emoji "units" (codepoint + optional variation selector).
+ *  2. Group consecutive matches of the SAME emoji where the gap between each
+ *     pair is pure horizontal whitespace (space / tab / no gap at all).
+ *  3. Runs longer than `maxRun` are replaced with `maxRun` copies + " ×N".
+ *
+ * @param {string} text
+ * @param {number} [maxRun=COLLAPSE_MAX_RUN]
+ * @returns {string}
+ */
+export function collapseEmojiRuns(text, maxRun = COLLAPSE_MAX_RUN) {
+  if (!text) return text
+
+  // Step 1 – locate every emoji unit in the string.
+  const unitRe = /[\u{1F000}-\u{1FFFF}\u{2600}-\u{27BF}]\uFE0F?/gu
+  const hits   = []
+  let m
+  while ((m = unitRe.exec(text)) !== null) {
+    hits.push({ index: m.index, val: m[0], end: m.index + m[0].length })
+  }
+  if (hits.length === 0) return text
+
+  // Step 2 – group hits into "same-emoji runs separated only by whitespace".
+  const runs = []
+  let i = 0
+  while (i < hits.length) {
+    let j = i
+    while (
+      j + 1 < hits.length &&
+      hits[j + 1].val === hits[i].val &&
+      /^[ \t]*$/.test(text.slice(hits[j].end, hits[j + 1].index))
+    ) {
+      j++
+    }
+    runs.push({ from: i, to: j, emoji: hits[i].val })
+    i = j + 1
+  }
+
+  // Step 3 – rebuild the string, collapsing long runs.
+  if (!runs.some((r) => r.to - r.from + 1 > maxRun)) return text
+
+  let result = ''
+  let pos    = 0
+  for (const run of runs) {
+    const count     = run.to - run.from + 1
+    const spanStart = hits[run.from].index
+    const spanEnd   = hits[run.to].end
+
+    result += text.slice(pos, spanStart)
+
+    if (count > maxRun) {
+      result += Array(maxRun).fill(run.emoji).join(' ') + ' ×' + count
+    } else {
+      result += text.slice(spanStart, spanEnd)
+    }
+
+    pos = spanEnd
+  }
+  result += text.slice(pos)
+
+  return result
+}