package io.flamenet.e2e

import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertNotEquals

/**
 * Audit H3: a substituted post-quantum identity must change the digits two
 * people read aloud. Cross-platform: these values are the same ones the iOS
 * SafetyNumberPQTests use, so a drift between the two engines fails here.
 */
class SafetyNumberPQTest {
    private val aliceIK = ByteArray(32) { 0x11 }
    private val bobIK = ByteArray(32) { 0x22 }
    private val alicePQ = ByteArray(32) { 0xA1.toByte() }
    private val bobPQ = ByteArray(32) { 0xB2.toByte() }

    @Test fun `both sides see the same number`() {
        assertEquals(
            SafetyNumber.compute(aliceIK, alicePQ, bobIK, bobPQ),
            SafetyNumber.compute(bobIK, bobPQ, aliceIK, alicePQ))
    }

    @Test fun `swapping the PQ identity changes the number`() {
        assertNotEquals(
            SafetyNumber.compute(aliceIK, alicePQ, bobIK, bobPQ),
            SafetyNumber.compute(aliceIK, alicePQ, bobIK, ByteArray(32) { 0xEE.toByte() }))
    }

    @Test fun `a classical pair keeps the classical number`() {
        assertEquals(SafetyNumber.compute(aliceIK, bobIK),
                     SafetyNumber.compute(aliceIK, null, bobIK, bobPQ))
        assertEquals(SafetyNumber.compute(aliceIK, bobIK),
                     SafetyNumber.compute(aliceIK, alicePQ, bobIK, null))
    }

    /**
     * The exact digits, from an INDEPENDENT implementation of the rule — the
     * same constant the iOS suite pins. This is what makes both platforms
     * agree with the spec rather than merely with each other; a silent drift
     * would show two people different numbers and read as an attack.
     */
    @Test fun `the number matches the independently computed value`() {
        assertEquals(
            "526042701003577849302816285461391061377406450730104222477184",
            SafetyNumber.compute(aliceIK, alicePQ, bobIK, bobPQ))
    }

    @Test fun `the PQ number differs from the classical one`() {
        assertNotEquals(SafetyNumber.compute(aliceIK, bobIK),
                        SafetyNumber.compute(aliceIK, alicePQ, bobIK, bobPQ))
    }
}