package com.xuqm.sdk.bugcollect

object Fingerprint {
    // exceptionType = exception class name (e.g. "NullPointerException"), NOT the level string
    // Only the innermost "at" frame (throw site) is used for grouping.
    // Kotlin coroutine dispatcher frames (frame 2+) vary across runs of the same logical error,
    // which caused identical errors to create separate issues.
    fun compute(exceptionType: String, message: String, stack: String): String {
        val top1 = stack.lines().filter { it.trim().startsWith("at ") }.take(1).joinToString("|")
        val normalized = message.replace(Regex("\\b\\d{4,}\\b"), "N")
        return sha256("$exceptionType:$normalized:$top1")
    }

    private fun sha256(s: String): String =
        java.security.MessageDigest.getInstance("SHA-256")
            .digest(s.toByteArray())
            .joinToString("") { "%02x".format(it) }
}