Files
modstagram-back/utils/usernameSuggestions.js
payacom 3f416a7a60 full
2026-08-31 20:45:41 +03:30

70 lines
2.1 KiB
JavaScript

const {
validateUsername,
USERNAME_MIN_LENGTH,
USERNAME_MAX_LENGTH,
} = require('./usernameValidation')
const escapeRegex = (value) => value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
const isUsernameTaken = async (UserModel, userName, excludeUserId) => {
const existing = await UserModel.findOne({
user_name: { $regex: new RegExp(`^${escapeRegex(userName)}$`, 'i') }
})
if (!existing) return false
if (excludeUserId && existing._id.toString() === excludeUserId) return false
return true
}
const padBase = (base) => {
let value = base.replace(/[^a-zA-Z0-9._-]/g, '')
if (!/^[a-zA-Z0-9]/.test(value)) value = `u${value}`
while (value.length < USERNAME_MIN_LENGTH - 2) {
value = `${value}0`
}
return value.slice(0, Math.max(USERNAME_MIN_LENGTH - 2, 1))
}
const buildCandidates = (base, attempt) => {
const random2 = () => String(Math.floor(Math.random() * 90 + 10))
const random3 = () => String(Math.floor(Math.random() * 900 + 100))
const stem = padBase(base)
const builders = [
() => `${stem}${random2()}`,
() => `${stem}_${random2()}`,
() => `${stem}.${random2()}`,
() => `${stem}-${random2()}`,
() => `${stem}${random3()}`,
() => `${stem.slice(0, Math.max(USERNAME_MIN_LENGTH - 3, 1))}${random3()}`,
]
return builders[attempt % builders.length]()
}
const trimToMax = (value) =>
value.length > USERNAME_MAX_LENGTH ? value.slice(0, USERNAME_MAX_LENGTH) : value
const generateUsernameSuggestions = async (UserModel, baseUserName, excludeUserId) => {
const base = trimToMax(baseUserName.trim().toLowerCase())
const suggestions = []
let attempt = 0
while (suggestions.length < 3 && attempt < 40) {
const candidate = trimToMax(buildCandidates(base, attempt))
attempt += 1
if (validateUsername(candidate)) continue
if (suggestions.includes(candidate)) continue
if (await isUsernameTaken(UserModel, candidate, excludeUserId)) continue
suggestions.push(candidate)
}
return suggestions
}
module.exports = {
generateUsernameSuggestions,
}