package com.peachpasswords.sync

internal data class NoiseKKKeyPair(
    val publicKey: ByteArray,
    val secretKey: ByteArray,
)

/**
 * Standard unmodified Noise KK reconnect through the canonical Rust core.
 * Both static keys are supplied from durable local pairing state; there is no
 * NK downgrade or peer-controlled key selection.
 */
internal suspend fun noiseKKInitiator(
    ourStaticPrivateKey: ByteArray,
    ourStaticPublicKey: ByteArray,
    responderStaticPublicKey: ByteArray,
    send: suspend (ByteArray) -> Unit,
    receive: suspend () -> ByteArray,
    ephemeral: NoiseKKKeyPair? = null,
): NoiseNKSession {
    val native = RustNoiseSession(
        if (ephemeral == null) {
            RustNoiseNative.nativeCreateKkInitiator(
                ourStaticPrivateKey,
                ourStaticPublicKey,
                responderStaticPublicKey,
            )
        } else {
            RustNoiseNative.nativeCreateKkInitiatorForTest(
                ourStaticPrivateKey,
                ourStaticPublicKey,
                responderStaticPublicKey,
                ephemeral.secretKey,
            )
        },
    )
    return try {
        send(native.writeHandshake())
        native.readHandshake(receive())
        native
    } catch (error: Throwable) {
        native.close()
        throw error
    }
}

internal suspend fun noiseKKResponder(
    ourStaticPrivateKey: ByteArray,
    ourStaticPublicKey: ByteArray,
    expectedInitiatorStaticPublicKey: ByteArray,
    send: suspend (ByteArray) -> Unit,
    receive: suspend () -> ByteArray,
    ephemeral: NoiseKKKeyPair? = null,
): NoiseNKSession {
    val native = RustNoiseSession(
        if (ephemeral == null) {
            RustNoiseNative.nativeCreateKkResponder(
                ourStaticPrivateKey,
                ourStaticPublicKey,
                expectedInitiatorStaticPublicKey,
            )
        } else {
            RustNoiseNative.nativeCreateKkResponderForTest(
                ourStaticPrivateKey,
                ourStaticPublicKey,
                expectedInitiatorStaticPublicKey,
                ephemeral.secretKey,
            )
        },
    )
    return try {
        native.readHandshake(receive())
        send(native.writeHandshake())
        native
    } catch (error: Throwable) {
        native.close()
        throw error
    }
}