package com.peachpasswords.sync

import org.junit.Assert.assertEquals
import org.junit.Assert.assertNull
import org.junit.Assert.assertTrue
import org.junit.Test

/**
 * The relay frames share a channel with ordinary sync frames, so the one thing
 * that must never break is telling them apart: a sync frame misread as a relay
 * frame would be forwarded to another device, and a relay frame misread as sync
 * would be handed to the vault.
 */
class RelayFramesTest {

    @Test fun `a relay request round-trips`() {
        val key = "ab".repeat(32)
        val decoded = decodeRelayMessage(RelayMessage.Request(key).encodeToBytes())
        assertEquals(RelayMessage.Request(key), decoded)
    }

    @Test fun `frames use the type discriminator the browser sync frames use`() {
        val json = String(RelayMessage.Request("00".repeat(32)).encodeToBytes(), Charsets.UTF_8)
        assertTrue(json, json.contains("\"type\":\"RELAY_REQUEST\""))
        assertTrue(json, json.contains("\"targetDeviceId\":"))
    }

    @Test fun `sync traffic is not mistaken for a relay frame`() {
        val hello = SyncMessage.Hello("v", "d", 1, 2).encodeToBytes()
        assertNull(decodeRelayMessage(hello))
    }

    @Test fun `junk and empty frames are not relay frames`() {
        assertNull(decodeRelayMessage(ByteArray(0)))
        assertNull(decodeRelayMessage(byteArrayOf(0x01, 0x02, 0x03)))
        assertNull(decodeRelayMessage("not json".toByteArray()))
    }

    @Test fun `a payload survives forwarding unchanged`() {
        val opaque = java.util.Base64.getEncoder().encodeToString(byteArrayOf(0, 1, 2, -1, -2))
        val decoded = decodeRelayMessage(RelayMessage.Payload(opaque).encodeToBytes())
        assertEquals(opaque, (decoded as RelayMessage.Payload).payload)
    }

    @Test fun `the parameterless responses decode by type alone`() {
        listOf(
            RelayMessage.Accept,
            RelayMessage.Unavailable,
            RelayMessage.Disabled,
            RelayMessage.Close,
        ).forEach { assertEquals(it, decodeRelayMessage(it.encodeToBytes())) }
    }
}