/**

* Generates a UUID v4 string safe for all contexts.

*

* `crypto.randomUUID()` requires a secure context (HTTPS or localhost) in

* browsers. Self-hosted deployments served over plain HTTP will throw

* `TypeError: crypto.randomUUID is not a function`. This utility falls back

* to `crypto.getRandomValues()`, which does not require a secure context.

*/

export function generateId(): string {

if (typeof crypto !== 'undefined' && typeof crypto.randomUUID === 'function') {

return crypto.randomUUID()

}

const bytes = new Uint8Array(16)

crypto.getRandomValues(bytes)

bytes[6] = (bytes[6] & 0x0f) | 0x40

bytes[8] = (bytes[8] & 0x3f) | 0x80

const hex = Array.from(bytes, (b) => b.toString(16).padStart(2, '0')).join('')

return `${hex.slice(0, 8)}-${hex.slice(8, 12)}-${hex.slice(12, 16)}-${hex.slice(16, 20)}-${hex.slice(20)}`

}

const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i

/**

* Validates whether a string is a well-formed UUID (any version).

*/

export function isValidUuid(value: string): boolean {

return UUID_RE.test(value)

}

const URL_SAFE_ALPHABET = 'useandom-26T198340PX75pxJACKVERYMINDBUSHWOLF_GQZbfghjklqvwyzrict'

/**

* Generates a short, URL-safe random ID.

*

* Replaces `nanoid` — uses `crypto.getRandomValues()` which works in all

* contexts including non-secure (HTTP) browsers.

*

* @param size - Length of the generated ID (default: 21)

* @param alphabet - Optional custom alphabet (replaces nanoid's `customAlphabet`).

* Length must be in [2, 256].

* @returns A random string drawn from the alphabet

*/

export function generateShortId(size = 21, alphabet: string = URL_SAFE_ALPHABET): string {

const alphabetLength = alphabet.length

if (alphabetLength < 2 || alphabetLength > 256) {

throw new Error('generateShortId alphabet length must be between 2 and 256')

}

const mask = (2 << (31 - Math.clz32((alphabetLength - 1) | 1))) - 1

const step = Math.ceil((1.6 * mask * size) / alphabetLength)

let id = ''

while (id.length < size) {

const bytes = new Uint8Array(step)

crypto.getRandomValues(bytes)

for (let i = 0; i < step && id.length < size; i++) {

const index = bytes[i] & mask

if (index < alphabetLength) {

id += alphabet[index]

}

}

}

return id

}