Android Kotlin Helpers

GravatarHelpers.kt

// requires StringHelpers

enum class GravatarDefault(val str: String) {
    ERROR_404 ("404"),
    MYSTERY ("mm"),
    IDENTICON ("identicon"),
    MONSTER ("monsterid"),
    WAVATAR ("wavatar"),
    RETRO ("retro"),
    BLANK ("blank"),
}

fun gravatarUrl(email: String,
                size: Int = 80,
                default: GravatarDefault = GravatarDefault.MYSTERY,
                secure: Boolean = false): String {
                
    val hash = email.trim().toLowerCase().md5()
    val protocol = if (secure) "https" else "http"
    return "$protocol://www.gravatar.com/avatar/$hash?s=$size&d=${default.str}"
}

StringHelpers.kt

@Throws(Exception::class)
fun String.md5(): String {
    val md = MessageDigest.getInstance("MD5")
    md.update(this.toByteArray())

    val byteData = md.digest()
    val hexString = StringBuffer()
    for (i in byteData.indices) {
        val hex = Integer.toHexString(255 and byteData[i].toInt())
        if (hex.length == 1) hexString.append('0')
        hexString.append(hex)
    }

    return hexString.toString()
}