Fix bugs, add timehash

src/lib/util.ts

@@ -1,5 +1,6 @@
 import {hexToBytes, bytesToHex} from "@noble/hashes/utils"
 import * as nip19 from "nostr-tools/nip19"
+import {HOUR} from "@welshman/lib"
 
 export const displayList = <T>(xs: T[], conj = "and", n = 6, locale = "en-US") => {
   const stringItems = xs.map(String)
@@ -24,3 +25,36 @@ export const nsecDecode = (nsec: string) => {
 
   return bytesToHex(data)
 }
+
+export const timeHash = (seconds: number, precision = 32) => {
+  const alphabet = "0123456789bcdefghjkmnpqrstuvwxyz"
+  const uint32 = Math.min(seconds >>> 0, 0xffffffff)
+  const binary = uint32.toString(2).padStart(32, "0")
+  const chunks = Math.min(Math.floor(precision / 5), 6)
+
+  let hash = ""
+
+  for (let i = 0; i < chunks * 5; i += 5) {
+    const chunk = binary.slice(i, i + 5)
+    const index = parseInt(chunk, 2)
+
+    hash += alphabet[index]
+  }
+
+  return hash
+}
+
+export const timeHashesBetween = (a: number, b: number) => {
+  const precisions = [10, 15, 20]
+  const start = Math.min(a, b) >>> 0
+  const end = Math.min(Math.max(a, b) >>> 0, 0xffffffff)
+  const hashes = new Set<string>()
+
+  for (let seconds = start; seconds <= end; seconds += HOUR) {
+    for (const precision of precisions) {
+      hashes.add(timeHash(seconds, precision))
+    }
+  }
+
+  return Array.from(hashes).sort()
+}